TROV: TrovaGene Analysis and Research Report
2018-05-21 - by Asif , Contributing Analyst - 870 views
TrovaGene is a clinical-stage, precision medicine oncology therapeutics company. The company's primary focus is to develop oncology therapeutics for improved cancer care and to optimize drug development by leveraging its proprietary Precision Cancer Monitoring® (“PCM”) technology in tumor genomics.
The company's lead drug candidate, PCM-075, is a Polo-like Kinase 1 (“PLK1”) selective adenosine triphosphate (“ATP”) competitive inhibitor. PCM-075 has shown preclinical antitumor activity as a single agent and synergy in combination with more than ten different chemotherapeutics and targeted therapies, such as Zytiga® (abiraterone acetate), Beleodaq® (belinostat), Quizartinib (AC220), a development stage FLT3 inhibitor, and Velcade® (bortezomib) in Acute Myeloid Leukemia (“AML”), metastatic Castration-Resistant Prostate Cancer (“mCRPC”) and other hematologic and solid tumor cancers.
On March 15, 2017, the company announced the licensing of PCM-075, a PLK1 inhibitor, from Nerviano Medical Sciences S.r.l. (“Nerviano”). PCM-075 was developed to have high selectivity to PLK1, to be administered orally, and to have a relatively short drug half-life of approximately 24 hours compared to other pan Polo-like inhibitors. PCM-075 has successfully completed a safety study in patients with advanced metastatic solid tumors. PCM-075 has two active Investigational New Drugs (“IND”) and two clinical studies. The first study is TROV-052 (ClinicalTrials.gov Identifier NCT03303339), a Phase 1b/2 open-label clinical trial in patients with Acute Myeloid Leukemia (“AML”) in combination with standard-of-care. The second study is TROV-053 UNITE (ClinicalTrials.gov Identifier: NCT03414034), a Phase 2 open-label clinical trial in patients with mCRPC in combination with abiraterone acetate (Zytiga®) and prednisone.
The company's broad intellectual property and proprietary technology enables it to measure circulating tumor DNA (“ctDNA”) in urine and blood to identify and quantify clinically actionable markers for predicting response to cancer therapies. The company offer its PCM technology at its Clinical Laboratory Improvement Amendments (“CLIA”) - certified/College of American Pathologists (“CAP”) - accredited laboratory and plan to continue to vertically integrate its PCM technology with the development of precision cancer therapeutics. The company believe TrovaGene has an opportunity to utilize precision diagnostics to improve treatment outcomes for cancer patients using its proprietary technology to detect clinically actionable mutations and monitor patient response to therapy.
PCM-075 is the first PLK1 selective adenosine triphosphate (“ATP”) competitive inhibitor administered orally to enter clinical trials with apparent antitumor activity in different preclinical models. Polo-like kinase family consists of 5 members (PLK1-PLK5) and they are involved in multiple functions in cell division, including the regulation of centrosome maturation, checkpoint recovery, spindle assembly, cytokinesis, apoptosis and many others. PLK1 plays a crucial role in the regulation of mitotic checkpoints. The overexpression of PLK1 can lead to immature cell division with aneuploidy, a hallmark of cancer. PLK1 is over-expressed in a wide variety of hematologic and solid tumor malignancies including acute myeloid leukemia, prostate, lung, breast, and adrenocortical carcinoma. In addition, several studies have shown that this over-expression correlates with poor prognosis.
PCM-075 was developed to have high selectivity to PLK1 (at low nanomolar IC50 levels), oral bioavailability, and a relatively short drug half-life of approximately 24 hours compared to the pan PLK inhibitor, Volasertib (also known as BI 6727). Volasertib is a PLKi inhibitor with nanomolar IC50 level activity for PLK1, PLK2 and PLK3 and was developed by Boehringer Ingelheim. Volasertib has a half-life of 135 hours with phase 2 clinical overall response rate (“ORR”: complete remission or complete remission with incomplete blood count recovery) data in AML patients receiving Volasertib and low dose cytarabine (“LDAC”) twice the ORR vs LDAC alone. However, Volasertib was discontinued after it failed in a phase 3 trial in AML patients where it showed an unfavorable overall survival trend, possibly because of its dosing protocol. The company believe the more selective nature of PCM-075 to PLK1 as well as its 24-hour half-life and oral bioavailability may make it feasible to improve on the dosing protocol issues associated with Volasertib. The company also believe that PCM-075’s reversibility to on-target hematological toxicities may prove useful in addressing clinical therapeutic needs across a variety of cancers.
PCM-075 has been tested in vivo in different xenograft and transgenic models at times suggesting tumor growth inhibition or tumor regression when used in combination with other therapies. PCM-075 has been tested for antiproliferative activity on a panel of 148 tumor cell lines and appeared highly active with an IC50 (a measure concentration for 50% target inhibition) below 100 nM in 75 cell lines and IC50 values below 1 uM in 133 out of 148 cell lines. PCM-075 also appears active in cells expressing multi-drug resistant (“MDR”) transporter proteins and the company believe PCM-075’s apparent ability to overcome the MDR transporter resistance mechanism in cancer cells could prove useful in broader drug combination applications.
In preclinical studies, PCM-075 has demonstrated synergy when used in combination with more than ten different chemotherapeutics, including cisplatin, cytarabine, doxorubicin, gemcitabine and paclitaxel, as well as targeted therapies, such as abiraterone acetate, HDAC inhibitors, FLT3 inhibitors, and bortezomib. These therapeutics are used clinically for the treatment of many hematologic and solid tumor cancers, including Acute Myeloid Leukemia (“AML”), Non-Hodgkin Lymphoma (“NHL”), metastatic Castration-Resistant Prostate Cancer (“mCRPC”), Adrenocortical Carcinoma (“ACC”), and Triple Negative Breast Cancer (“TNBC”).
On August 16, 2017, the company announced results of preclinical research indicating potential synergy (interaction of discrete drugs such that the total effect is greater than the sum of the individual effects) of PCM-075 with an investigational FLT3 Inhibitor, Quizartinib by Daiichi Sankyo, in FLT3 mutant xenograft mouse models. This synergy assessment study was conducted for it by a third-party contract research group. Approximately one third of AML patients harbor FLT3-mutated blood cancer cells. The U.S. Food and Drug Administration (“FDA”) recently approved Rydapt® (midostaurin) by Novartis for the treatment of newly diagnosed adult patients with AML that are FLT3 mutation-positive in combination with cytarabine and daunorubicin induction and cytarabine consolidation chemotherapy. There are two additional FLT3 inhibitors in ongoing phase 3 trials, including Quizartinib. The company believe that a combination of PCM-075 with a FLT3 inhibitor for AML patients with a FLT3 mutation could extend treatment response and possibly slow or reduce resistance to FLT3 activity.
On August 21, 2017, the company announced results of preclinical research indicating potential synergy of PCM-075 with a histone deacetylase (“HDAC”) inhibitor in NHL cell lines. This synergy assessment study was conducted by Dr. Steven Grant, Associate Director for Translational Research and co-Leader, Developmental Therapeutics Program, Massey Cancer Center. Patients with relapsed or refractory NHL, such as cutaneous T cell lymphoma and peripheral T cell lymphoma, may be prescribed approved HDAC inhibitors and the company believe this continues to be an area of unmet medical need. Dr. Grant’s data appeared to indicate that the combination of PCM-075 with Beleodaq® (belinostat), an HDAC inhibitor indicated for the treatment of patients with relapsed or refractory peripheral T-cell lymphoma, reduced cancer cells by up to 80% in two different forms of NHL (aggressive double-hit B-cell lymphoma and mantle cell lymphoma) cell lines.
On October 18, 2017, the company announced results of preclinical research indicating potential synergy of PCM-075 with abiraterone acetate in C4-2 prostate cancer cells. This synergy assessment study was conducted by Dr. Michael Yaffe M.D., Ph.D. FACS, David H. Koch Professor of Biology and Biological Engineering at MIT. The results appeared to indicate that the combination of PCM-075 with Zytiga® (abiraterone) decreased cell viability in mCRPC tumor cells and the apparent synergy observed was greater than the expected effect of combining the two drugs. Zytiga is indicated for use in combination with prednisone for the treatment of patients with mCRPC who have received prior chemotherapy containing docetaxel. The company believe there is an unmet medical need to improve on the resistance to hormone therapy and extend the benefit of response to abiraterone for mCRPC patients.
PCM-075 Phase 1 Safety Study in Solid Tumors
A Phase 1 safety study of PCM-075 was completed in patients with advanced metastatic solid tumor cancers with data published in July, 2017, in the peer-reviewed journal Investigational New Drugs. Dr. Glen Weiss, Medical Oncologist at Goodyear, AZ and affiliated with Cancer Treatment Centers of America at Western Regional Medical Center, was the principal investigator and first author of the publication, entitled “Phase 1 Dose-Escalation Study of NMS-1286937, an Orally Available Polo-like Kinase 1 Inhibitor, in Patients with Advanced or Metastatic Solid Tumors.” This study evaluated first-cycle dose limiting toxicities and related maximum tolerated dose with data indicating a manageable safety profile for PCM-075 (formerly known as NMS-1286937) for the treatment of advanced or metastatic solid tumors, with transient adverse events that were likely related to the drug’s mechanism of action. The authors believe that data from preclinical work, coupled with the results of the Phase 1 trial, suggest that PCM-075 could become a new therapeutic option for the treatment of solid tumor and hematologic cancers.
In this trial, PCM-075 was administered orally, once daily for five consecutive days, every three weeks, to evaluate first cycle dose-limiting toxicities and related maximum tolerated dose in adult subjects with advanced/metastatic solid tumors. The study was also intended to evaluate PCM-075’s pharmacokinetic profile in plasma, its anti-tumor activity, and its ability to modulate intracellular targets in biopsied tissue. The study identified thrombocytopenia and neutropenia as the primary toxicities, which is consistent with the expected mechanism of action of PCM-075 and results from preclinical studies. These hematologic toxicities were reversible, with recovery usually occurring within 3 weeks. No GI disorders, mucositis, or alopecia was observed, confirming that bone marrow cells are the most sensitive to PCM-075 inhibition with the applied dosing schedule.
TrovaGene is utilizing the existing IND application to develop PCM-075 in solid tumors as part of its clinical development expansion plans, with its initial focus in mCRPC.
PCM-075 Phase 2 Study in metastatic Castration-Resistant Prostate Cancer
On December 14, 2017, the company announced the submission of its Phase 2 protocol of PCM-075 in combination with abiraterone acetate (Zytiga® - Johnson & Johnson) for the treatment of mCRPC, to the FDA and its active solid tumor IND. In this multi-center, open-label, Phase 2 trial, PCM-075 in combination with the standard dose of abiraterone and prednisone, all administered orally, will be evaluated for safety and efficacy. The primary efficacy endpoint is the proportion of patients achieving disease control after 12 weeks of study treatment, as defined by lack of Prostate Specific Antigen (“PSA”) progression in patients who are showing signs of early progressive disease (rise in PSA but minimally symptomatic or asymptomatic) while currently receiving androgen deprivation therapy (“ADT”), abiraterone and prednisone.
On January 24, 2018, the company announced plans for its Phase 2 clinical trial evaluating the combination of PCM-075 and abiraterone acetate (Zytiga®) in patients with mCRPC. The company plan to have up to 3 clinical sites for the Phase 2 study, with Beth Israel Deaconess Medical Center in Boston Massachusetts as the principal site. Dr. David Einstein at the Genitourinary Oncology Program at Beth Israel Deaconess Medical Center and Harvard Medical School is the principal investigator for the Phase 2 mCRPC trial.
PCM-075 Phase 1b/2 Study in Acute Myeloid Leukemia
In June, 2017, the company announced the submission of its IND application and its Phase 1b/2 protocol of PCM-075 in combination with standard-of-care chemotherapy for the treatment of AML to the FDA. In July, 2017, the company received notification from the FDA that its Phase 1b/2 clinical trial of PCM-075 in patients with AML “may proceed”. On October 9, 2017, the company announced that the FDA granted Orphan Drug Designation to PCM-075 for the treatment of AML. The company initiated its Phase 1b/2 AML trial in November, 2017.
The Phase 1b/2 is an open-label trial to evaluate the safety and anti-leukemic activity of PCM-075 in combination with standard-of-care chemotherapy in patients with AML. Phase 1b is a dose escalation trial to evaluate the safety, tolerability, dose and scheduling of PCM-075, and to determine a recommended clinical treatment dose for the Phase 2 continuation trial.
Pharmacokinetics of PCM-075 and correlative biomarker activity will be assessed prior to the initiation of Phase 2. The Phase 2 continuation trial is open-label with administration of the recommended PCM-075 clinical dose in combination with standard-of-care chemotherapy to further evaluate safety and assess preliminary efficacy. Doses of PCM-075 will be administered orally each day for five consecutive days in a 28-day cycle in both Phase 1b and Phase 2.
The company announced in February 2018 that the first patient has completed the first cycle of dosing with PCM-075 in combination with low-dose cytarabine in its Phase 1b/2 multicenter trial of patients with AML. Further the company announced that two clinical trial sites are currently screening and enrolling patients and five additional sites are planned to be activated by the end of the first quarter of 2018. The company plan to have up to 10 clinical sites activated for the Phase 1b/2 trial. This trial is being led by Hematologist Jorge Cortes, M.D., Deputy Department Chair, Department of Leukemia, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center.
Optimizing Drug Development with Correlative Biomarker Analysis using Circulating Tumor DNA
TrovaGene has significant experience and expertise with biomarkers and technology in cancer, including AML. TrovaGene is one of the patent holders of NPM1 for diagnosis and monitoring of patients. NPM1-mutated AML is a genetic marker in leukemia and accounts for approximately one-third of all AML patients. The company plan to use its PCM technology to profile other dominant AML markers, such as FLT3, DNMT3A, NRAS, and KIT, as well as to measure PLK1 enzymatic activity to potentially identify patients most likely to respond to PCM-075 and to measure patient therapy response.
Technological advancements in the molecular characterization of cancers have enabled researchers to identify an increasing number of key molecular drivers of cancer progression. These discoveries have led to multiple novel anticancer therapeutics, and clinical benefit in selected patient populations. As a precision medicine biotechnology company developing targeted therapies to treat hematologic and solid tumor cancers, its objective is to optimize drug development by using its proprietary precision medicine technology as part of its approach to genomic profiling of tumors.
The company's CLIA-certified/CAP-accredited laboratory in San Diego, California, enables it to use its technology platform to optimize drug development and patient care. In the clinical development of its lead drug candidate, PCM-075, correlative biomarker analysis will be used to help inform decisions in the evaluation of dose-response and optimal regimen for desired pharmacologic effect and safety. Additionally, some biomarkers can be used as a surrogate endpoint for efficacy and/or toxicity, as well as predicting patients’ response by identifying certain patient populations that are more likely to respond to the drug therapy.
Targeting cell-free nucleic acid markers allows for the development of genetic tests that use noninvasive and easy-to-obtain urine samples, as well as blood samples, rather than other more traditional and more invasive, expensive and/or often unreliable methods, such as radiographic imaging and tissue biopsy. Using its proprietary technology, the company developed NextCollect, a first of its kind high-volume urine specimen collection and DNA preservation kit. Formulated DNA preservative solution is integrated into the NextCollect reservoir cap, and dispensed when secured the NextCollect cup. When added to the urine specimen, NextCollect preserves DNA for up to 2 weeks at room temperature NextCollect™ is designed to collect a higher volume of urine specimen, containing more DNA available for testing methods. NextCollect™ urine extracted DNA can be used for a range of applications across oncology, urology, virology and infectious disease. NextCollect™ is manufactured for Research Use Only and the company began making it available in December 2017, for purchase by academic institutions, cancer centers and research laboratories for their clinical research purposes.
Operating Segment and Geographic Information
The company operate in one business segment, using one measurement of profitability to manage its business. The company do not assess the performance of its geographic regions on measures of revenue or comprehensive income or expense. In addition, all of its principal operations, assets and decision-making functions are located in the U.S. The company do not produce reports for, or measure the performance of, its geographic regions on any asset-based metrics. Therefore, geographic information is not presented for revenues or long-lived assets.
TrovaGene is a clinical-stage biotechnology company with its primary focus on the development of its lead drug candidate, PCM-075, a PLK1 inhibitor that may treat multiple hematologic and solid tumor cancers.
There have been several drug candidates in this class of targeted oncology therapeutics to enter clinical trials; however, PCM-075 is the lead candidate and is differentiated from other ATP competitive inhibitors in that:
- its inhibition of PLK1 is highly-selective and the half maximal inhibitory concentration (IC50) for PLK2 and PLK3 is over 5,000-fold of that for PLK1;
- it has a relatively short half-life of approximately 24 hours;
- it is available in an oral gelcap formulation.
The unacceptable toxicity of prior PLK inhibitors, such as volasertib from Boehringer Ingelheim, may be due to non-selective inhibition of PLK2 and PLK3 and a much longer half-life (approximately 135 hours) that could result in drug accumulation, which ultimately may have led to unsatisfactory clinical outcomes.
The company believe the efficacy of PLK1 inhibition in AML has already been shown in the proof-of-concept trial of volasertib. Therefore, PCM-075’s highly-selective activity, oral dosing and short half-life could enable favorable efficacy and safety with potential survival benefits in AML patients with relapsed/refractory disease or newly-diagnosed disease and ineligible for intensive induction therapy.
The company recently initiated a Phase 1b/2 clinical trial of PCM-075 in combination with standard-of-care chemotherapy in AML patients to evaluate the safety/tolerability, determine the maximum tolerated dose (“MTD”), and assess preliminary efficacy. This study is on file at ClinicalTrials.gov with the Identifier NCT03303339. The company also announced a Phase 2 open-label clinical trial in adult patients with mCRPC in combination with abiraterone acetate (Zytiga®) and prednisone. The mCRPC Phase 2 trial is on file at ClinicalTrials.gov with the Identifier NCT03414034. As such, TrovaGene has two active IND applications in place with the FDA, one with the hematologic division and one with the solid tumor division. This enables it to quickly activate to conduct clinical trials of its lead drug candidate, PCM-075, in both hematologic and solid tumor cancers.
Drug Development and Monitoring of Therapeutic Outcomes
Cell-free DNA diagnostic technology has significant potential as a simple, quick, noninvasive way of monitoring clinical responses to drugs in clinical development and evaluating patient-specific responses to already approved and marketed therapies. Specific target applications include, but are not limited to, optimizing drug development to identify patients most likely to respond to targeted therapeutics.
One of the largest costs associated with development of a new therapy is the phases and size of human clinical studies required to identify the cohort of responders, and the resulting statistical power required. By measuring specific genetic markers, it may be possible to pre-identify, and subsequently screen, for the most likely responders to the therapy, and to limit patient recruitment to this subset. This strategy could significantly reduce the cost to develop a drug and improve development time lines. The company believe that there is significant research potential for its molecular diagnostic technology to be incorporated into these clinical trial protocols, and ultimately into post-approval patient identification protocol.
Infectious Diseases — HPV
The rationale for screening for HPV is that high-risk subtypes cause virtually all cases of cervical cancer. TrovaGene has developed a urine-based HPV test capable of screening for known high-risk HPV types that are associated with the development of cervical cancer. Cervical cancer is the third most commonly diagnosed cancer, and the fourth leading cause of cancer deaths in females, worldwide. Deaths due to cervical cancer are a significant global problem, especially in developing countries where screening practices are inadequate.
Other areas beyond HPV detection and monitoring include those infectious diseases caused by viruses, bacteria, fungi, and parasites. Cell-free nucleic acid assays that detect molecular targets in organisms can provide a quick, accurate, simple, and cost effective method for screening and monitoring disease. Specific areas of interest include testing for molecular targets from organisms that cause Lyme disease, John Cunningham Virus, valley fever, and various fungal infections. These organisms all tend to be difficult to identify with current technology, making differential diagnosis especially challenging, thus delaying the start of potentially curative anti-infective treatment.
The company's investment in the research and development of new nucleic acid preservatives or methods, which improve the stability of urine as a cell-free nucleic acid specimen led to the development of a new urine collection and DNA preservation cup (“NextCollect™”). It is its expectation that the company will continue to provide the NextCollect™ as a stand-alone kit for research use to academic researchers and institutions that they can purchase and utilize in their own laboratories.
TrovaGene is a precision medicine biotechnology company developing oncology therapeutics for improved cancer care, optimizing drug development by leveraging its proprietary PCM technology in tumor genomics. The company's broad intellectual property and proprietary technology enables it to measure ctDNA in urine and blood to identify and quantify clinically actionable markers for predicting response to cancer therapies. The company offer its PCM technology at its CLIA-certified/CAP-accredited laboratory and plan to continue to vertically integrate its PCM technology with the development of precision cancer therapeutics.
The company believe TrovaGene has an opportunity to utilize precision diagnostics to improve treatment outcomes for cancer patients using its proprietary technology to detect clinically actionable mutations and monitor patient response to therapy. The licensing of global development and commercialization rights to PCM-075 allows it to execute its strategy to vertically integrate its PCM technology with precision cancer therapeutics, by developing drugs where its deep understanding of tumor genomics may allow for effective targeting of appropriate cancer patients.
Research and Development
TrovaGene has historically made substantial investments in research and development. The company's research and development efforts prioritize discovering, developing and testing its clinical and preclinical candidates and platform technologies. The company's research and development team is composed of researchers and scientists (PhD’s), laboratory associate scientists, and experts in drug development and tumor genomics.
Research and development expenses for the years ended December 31, 2017 and 2016 were approximately $7.9 million and $15.0 million, respectively.
The company consider the protection of its proprietary technologies and products, as well as its ability to maintain patent protection intended to cover the composition of matter of its product candidates, their methods of use, and other related technology and inventions, to be a critical element in the success of its business. As of December 31, 2017, its wholly-owned and licensed intellectual property included over 120 issued patents and over 50 pending patent applications in the U.S. and abroad. The pending applications include multiple international applications filed under the Patent Cooperation Treaty (“PCT applications”) that may be used as the basis for multiple additional patent applications.
The company plan to protect its intellectual property position by, among other things, licensing or filing its own U.S. and foreign patent applications related to its proprietary technology, and any inventions or improvements that are important to the development and implementation of its business. The company also may seek patent protection, if available, with respect to biomarkers and diagnostic methods that may be used to determine optimal patient populations for use of its product candidates.
The company's license agreement related to PCM-075 grants it exclusive, worldwide licenses under a portfolio of patents covering three broad areas: (1) Directed to PCM-075, related compounds and processes for making compounds; pharmaceutical compositions and methods of treating diseases characterized by dysregulated protein kinase activity; (2) Directed to salts and pharmaceutical compositions of PCM-075; methods of treating mammals in need of PLK inhibition; and (3) Directed to synergistic combinations of PCM-075 and one or more of a broad range of antineoplastic agents, and pharmaceutical compositions of those combinations. Members of this patent group expire between 2026 and 2029.
On October 11, 2017, the company entered into a Patent Option Agreement with Massachusetts Institute of Technology (“MIT”) for the exclusive rights to negotiate a royalty-bearing, limited-term exclusivity license to practice world-wide patent rights to US Patent 9,566,280, subject to the rights of MIT (research, testing, and educational purposes), Ortho McNeil Pharmaceuticals-Janssen Pharmaceuticals and its Affiliates (internal research and pre-clinical drug development purposes including some laboratory research) and the federal government (government-funded inventions claimed in any patent rights and to exercise march in rights). This patent is generally directed to combination therapies including an antiandrogen or androgen antagonist and polo-like kinase inhibitor for the treatment of cancer. The Patent Option Agreement expires one-year from the effective date and includes other requirements to maintain the option period.
Another group of patents and patent applications are directed to various methods relating to detecting nucleic acid sequences in urine and nucleic acid modifications and alterations in urine; detecting and monitoring cancer through urine-based testing, nucleic acid screening, and monitoring in cases of transplantation and infectious diseases, detecting specific gene mutations and indicators of disease (including NPM1 mutations). Applications are also pending to protect proprietary methods of collecting, extracting, detecting and enriching small concentrations of short nucleic acid sequences, and detecting and monitoring mutations in diseases, such as cancer, over time. Members of this patent group expire between 2018 and 2034.
Wherever possible, the company seek to protect its inventions by filing U.S. patents as well as foreign counterpart applications in select other countries. Because patent applications in the U.S. are maintained in secrecy for at least eighteen months after the applications are filed, and since publication of discoveries in the scientific or patent literature often lags behind actual discoveries, the company cannot be certain that the company were the first to make the inventions covered by each of its issued or pending patent applications, or that the company were the first to file for protection of inventions set forth in such patent applications. The company's planned or potential products may be covered by third-party patents or other intellectual property rights, in which case continued development and marketing of its products would require a license. Required licenses may not be available to it on commercially acceptable terms, if at all. If the company do not obtain these licenses, the company could encounter delays in product introductions while the company attempt to design around the patents, or the company could find that the development, manufacture or sale of products requiring such licenses are not possible.
In addition to patent protection, the company also rely on know-how, trade secrets and the careful monitoring of proprietary information, all of which can be difficult to protect. The company seek to protect some of its proprietary technology and processes by entering into confidentiality agreements with its employees, consultants, and contractors. These agreements may be breached, the company may not have adequate remedies for any breach and its trade secrets may otherwise become known or be independently discovered by competitors. To the extent that its employees or its consultants or contractors use intellectual property owned by others in their work for it, disputes may also arise as to the rights in related or resulting know-how and inventions.
Manufacturing and Distribution
TrovaGene has a supplier agreement with NerPharMa, S.r.l., a pharmaceutical manufacturing company and a subsidiary of Nerviano, to manufacture drug product for PCM-075. The agreement covers the clinical and commercial supply of PCM-075, and includes both Active Pharmaceutical Ingredients (“API”) and Good Manufacturing Process (“GMP”) production of capsules.
In 2018, the company will continue offering laboratory testing services of LDTs from its CLIA-certified/CAP-accredited laboratory. The company's primary customers for these LDT’s are pharmaceutical companies and third party laboratories. In addition, the company plan to offer its NextCollect™ urine collection and DNA preservation cup for research use by academic institutions, cancer centers and research laboratories.
The company operate in a highly regulated industry that is subject to significant federal, state, local and foreign regulation. The company's present and future business has been, and will continue to be, subject to a variety of laws including, the Federal Food, Drug, and Cosmetic Act, or FDC Act, and the Public Health Service Act, among others.
The FDC Act and other federal and state statutes and regulations govern the testing, manufacture, safety, effectiveness, labeling, storage, record keeping, approval, advertising and promotion of its products. As a result of these laws and regulations, product development and product approval processes are very expensive and time-consuming.
FDA Approval Process
In the United States, pharmaceutical products, including biologics, are subject to extensive regulation by the FDA. The FDC Act and other federal and state statutes and regulations, govern, among other things, the research, development, testing, manufacture, storage, recordkeeping, approval, labeling, promotion and marketing, distribution, post-approval monitoring and reporting, sampling, and import and export of pharmaceutical products. Failure to comply with applicable U.S. requirements may subject a company to a variety of administrative or judicial sanctions, such as FDA refusal to approve pending new drug applications, or NDAs, or biologic license applications, or BLAs, warning letters, product recalls, product seizures, total or partial suspension of production or distribution, injunctions, fines, civil penalties, and criminal prosecution.
Pharmaceutical product development in the United States typically involves preclinical laboratory and animal tests, the submission to the FDA of an IND, which must become effective before clinical testing may commence, and adequate and well-controlled clinical trials to establish the safety and effectiveness of the drug or biologic for each indication for which FDA approval is sought. Satisfaction of FDA pre-market approval requirements typically takes many years and the actual time required may vary substantially based upon the type, complexity and novelty of the product or disease.
Preclinical tests include laboratory evaluation as well as animal trials to assess the characteristics and potential pharmacology and toxicity of the product. The conduct of the preclinical tests must comply with federal regulations and requirements including good laboratory practices. The results of preclinical testing are submitted to the FDA as part of an IND along with other information, including information about product chemistry, manufacturing and controls, and a proposed clinical trial protocol. Long term preclinical tests, such as animal tests of reproductive toxicity and carcinogenicity, may continue after the IND is submitted.
A 30-day waiting period after the submission of each IND is required prior to the commencement of clinical testing in humans. If the FDA has not objected to the IND within this 30-day period, the clinical trial proposed in the IND may begin.
Clinical trials involve the administration of the investigational drug to healthy volunteers or patients under the supervision of a qualified investigator. Clinical trials must be conducted in compliance with federal regulations and good clinical practices, or GCP, as well as under protocols detailing the objectives of the trial, the parameters to be used in monitoring safety and the effectiveness criteria to be evaluated. Each protocol involving testing on U.S. patients and subsequent protocol amendments must be submitted to the FDA as part of the IND.
The FDA may order the temporary or permanent discontinuation of a clinical trial at any time or impose other sanctions if it believes that the clinical trial is not being conducted in accordance with FDA requirements or presents an unacceptable risk to the clinical trial patients. The clinical trial protocol and informed consent information for patients in clinical trials must also be submitted to an institutional review board, or IRB, for approval. An IRB may also require the clinical trial at the site to be halted, either temporarily or permanently, for failure to comply with the IRB’s requirements, or may impose other conditions.
Clinical trials to support NDAs or BLAs, which are applications for marketing approval, are typically conducted in three sequential Phases, but the Phases may overlap. In Phase 1, the initial introduction of the investigational drug candidate into healthy human subjects or patients, the investigational drug is tested to assess metabolism, pharmacokinetics, pharmacological actions, side effects associated with increasing doses and, if possible, early evidence on effectiveness. Phase 2 usually involves trials in a limited patient population, to determine the effectiveness of the investigational drug for a particular indication or indications, dosage tolerance and optimum dosage, and identify common adverse effects and safety risks. In the case of product candidates for severe or life-threatening diseases such as pneumonia, the initial human testing is often conducted in patients rather than in healthy volunteers.
If an investigational drug demonstrates evidence of effectiveness and an acceptable safety profile in Phase 2 evaluations, Phase 3 clinical trials are undertaken to obtain additional information about clinical efficacy and safety in a larger number of patients, typically at geographically dispersed clinical trial sites, to permit the FDA to evaluate the overall benefit-risk relationship of the investigational drug and to provide adequate information for its labeling.
After completion of the required clinical testing, an NDA or, in the case of a biologic, a BLA, is prepared and submitted to the FDA. FDA approval of the marketing application is required before marketing of the product may begin in the United States. The marketing application must include the results of all preclinical, clinical and other testing and a compilation of data relating to the product’s pharmacology, chemistry, manufacture, and controls.
The FDA has 60 days from its receipt of an NDA or BLA to determine whether the application will be accepted for filing based on the agency’s threshold determination that it is sufficiently complete to permit substantive review. Once the submission is accepted for filing, the FDA begins an in-depth review. The FDA has agreed to certain performance goals in the review of marketing applications. Most such applications for non-priority drug products are reviewed within ten months. The review process may be extended by the FDA for three additional months to consider new information submitted during the review or clarification regarding information already provided in the submission. The FDA may also refer applications for novel drug products or drug products that present difficult questions of safety or efficacy to an advisory committee, typically a panel that includes clinicians and other experts, for review, evaluation and a recommendation as to whether the application should be approved. The FDA is not bound by the recommendation of an advisory committee, but it generally follows such recommendations. Before approving a marketing application, the FDA will typically inspect one or more clinical sites to assure compliance with GCP.
Additionally, the FDA will inspect the facility or the facilities at which the drug product is manufactured. The FDA will not approve the NDA or, in the case of a biologic, the BLA unless compliance with cGMPs is satisfactory and the marketing application contains data that provide substantial evidence that the product is safe and effective in the indication studied. Manufacturers of biologics also must comply with FDA’s general biological product standards.
After the FDA evaluates the NDA or BLA and the manufacturing facilities, it issues an approval letter or a complete response letter. A complete response letter outlines the deficiencies in the submission and may require substantial additional testing or information in order for the FDA to reconsider the application. If and when those deficiencies have been addressed in a resubmission of the marketing application, the FDA will re-initiate review. If the FDA is satisfied that the deficiencies have been addressed, the agency will issue an approval letter. The FDA has committed to reviewing such resubmissions in two or six months depending on the type of information included. It is not unusual for the FDA to issue a complete response letter because it believes that the drug product is not safe enough or effective enough or because it does not believe that the data submitted are reliable or conclusive.
An approval letter authorizes commercial marketing of the drug product with specific prescribing information for specific indications. As a condition of approval of the marketing application, the FDA may require substantial post-approval testing and surveillance to monitor the drug product’s safety or efficacy and may impose other conditions, including labeling restrictions, which can materially affect the product’s potential market and profitability. Once granted, product approvals may be withdrawn if compliance with regulatory standards is not maintained or problems are identified following initial marketing.
Other Regulatory Requirements
Once a NDA or BLA is approved, a product will be subject to certain post-approval requirements. For instance, the FDA closely regulates the post-approval marketing and promotion of therapeutic products, including standards and regulations for direct-to-consumer advertising, off-label promotion, industry-sponsored scientific and educational activities and promotional activities involving the internet.
Biologics may be marketed only for the approved indications and in accordance with the provisions of the approved labeling. Changes to some of the conditions established in an approved application, including changes in indications, labeling, or manufacturing processes or facilities, require submission and FDA approval of a new BLA or BLA supplement, before the change can be implemented. A BLA supplement for a new indication typically requires clinical data similar to that in the original application, and the FDA uses the same procedures and actions in reviewing BLA supplements as it does in reviewing BLAs. The company cannot be certain that the FDA or any other regulatory agency will grant approval for its product candidates for any other indications or any other product candidate for any indication on a timely basis, if at all.
Adverse event reporting and submission of periodic reports is required following FDA approval of a BLA. The FDA also may require post-marketing testing, known as Phase 4 testing, risk evaluation and mitigation strategies, and surveillance to monitor the effects of an approved product or place conditions on an approval that could restrict the distribution or use of the product. In addition, quality control as well as product manufacturing, packaging, and labeling procedures must continue to conform to cGMPs after approval. Manufacturers and certain of their subcontractors are required to register their establishments with the FDA and certain state agencies, and are subject to periodic unannounced inspections by the FDA during which the agency inspects manufacturing facilities to assess compliance with cGMPs. Accordingly, manufacturers must continue to expend time, money and effort in the areas of production and quality control to maintain compliance with cGMPs. Regulatory authorities may withdraw product approvals or request product recalls if a company fails to comply with regulatory standards, if it encounters problems following initial marketing, or if previously unrecognized problems are subsequently discovered. U.S. Foreign Corrupt Practices Act
The U.S. Foreign Corrupt Practices Act, to which TrovaGene is subject, prohibits corporations and individuals from engaging in certain activities to obtain or retain business or to influence a person working in an official capacity. It is illegal to pay, offer to pay or authorize the payment of anything of value to any foreign government official, government staff member, political party or political candidate in an attempt to obtain or retain business or to otherwise influence a person working in an official capacity.
Federal and State Fraud and Abuse Laws
Healthcare providers, physicians and third-party payors play a primary role in the recommendation and prescription of drug and biologic product candidates which obtain marketing approval. In addition to FDA restrictions on marketing of pharmaceutical products, pharmaceutical manufacturers are exposed, directly, or indirectly, through customers, to broadly applicable fraud and abuse and other healthcare laws and regulations that may affect the business or financial arrangements and relationships through which a pharmaceutical manufacturer can market, sell and distribute drug and biologic products. These laws include, but are not limited to:
The federal Anti-Kickback Statute which prohibits, any person or entity from, among other things, knowingly and willfully offering, paying, soliciting, or receiving any remuneration, directly or indirectly, overtly or covertly, in cash or in-kind, to induce or reward either the referring of an individual for, or the purchasing, leasing, ordering, or arranging for the purchase, lease, or order of any healthcare item or service reimbursable, in whole or in part, under Medicare, Medicaid, or any other federally financed healthcare program. The term “remuneration” has been broadly interpreted to include anything of value. This statute has been interpreted to apply to arrangements between pharmaceutical manufacturers on one hand and prescribers, purchasers, and formulary managers on the other hand. Although there are a number of statutory exemptions and regulatory safe harbors protecting certain common activities from prosecution, the exemptions and safe harbors are drawn narrowly, and practices that involve remuneration intended to induce prescribing, purchases, or recommendations may be subject to scrutiny if they do not qualify for an exemption or safe harbor..
The federal false claims and civil monetary penalty laws, including the Federal False Claims Act, which imposes significant penalties and can be enforced by private citizens through civil qui tam actions, prohibits any person or entity from, among other things, knowingly presenting, or causing to be presented, a false, fictitious or fraudulent claim for payment to the federal government, or knowingly making, using or causing to be made, a false statement or record material to a false or fraudulent claim to avoid, decrease or conceal an obligation to pay money to the federal government. In addition, a claim including items or services resulting from a violation of the federal Anti-Kickback Statute constitutes a false or fraudulent claim for purposes of the False Claims Act. As a result of a modification made by the Fraud Enforcement and Recovery Act of 2009, a claim includes "any request or demand" for money or property presented to the U.S. government. In addition, manufacturers can be held liable under the False Claims Act even when they do not submit claims directly to government payors if they are deemed to "cause" the submission of false or fraudulent claims. Criminal prosecution is also possible for making or presenting a false, fictitious or fraudulent claim to the federal government. Recently, several pharmaceutical and other healthcare companies have been prosecuted under these laws for allegedly providing free product to customers with the expectation that the customers would bill federal programs for the product. Other companies have been prosecuted for causing false claims to be submitted because of the company’s marketing of the product for unapproved, and thus non-reimbursable, uses.
The federal Health Insurance Portability and Accountability Act of 1996, or HIPAA, which, among other things, imposes criminal liability for executing or attempting to execute a scheme to defraud any healthcare benefit program, including private third-party payors, knowingly and willfully embezzling or stealing from a healthcare benefit program, willfully obstructing a criminal investigation of a healthcare offense, and creates federal criminal laws that prohibit knowingly and willfully falsifying, concealing or covering up a material fact or making any materially false, fictitious or fraudulent statements or representations, or making or using any false writing or document knowing the same to contain any materially false, fictitious or fraudulent statement or entry in connection with the delivery of, or payment for, benefits, items or services.
HIPAA, as amended by the Health Information Technology and Clinical Health Act of 2009, or HITECH, and its implementing regulations, which impose certain requirements relating to the privacy, security, transmission and breach reporting of individually identifiable health information upon entities subject to the law, such as health plans, healthcare clearinghouses and healthcare providers and their respective business associates that perform services for them that involve individually identifiable health information. HITECH also created new tiers of civil monetary penalties, amended HIPAA to make civil and criminal penalties directly applicable to business associates, and gave state attorneys general new authority to file civil actions for damages or injunctions in U.S. federal courts to enforce the federal HIPAA laws and seek attorneys' fees and costs associated with pursuing federal civil actions.
The federal physician payment transparency requirements, sometimes referred to as the “Physician Payments Sunshine Act,” and its implementing regulations, which require certain manufacturers of drugs, devices, biologics and medical supplies for which payment is available under Medicare, Medicaid or the Children’s Health Insurance Program (with certain exceptions) to report annually to the United States Department of Health and Human Services, or HHS, information related to payments or other transfers of value made to physicians (defined to include doctors, dentists, optometrists, podiatrists and chiropractors) and teaching hospitals, as well as ownership and investment interests held by physicians and their immediate family members.
State and foreign law equivalents of each of the above federal laws, such as anti-kickback and false claims laws, that may impose similar or more prohibitive restrictions, and may apply to items or services reimbursed by non-governmental third-party payors, including private insurers.
State and foreign laws that require pharmaceutical companies to implement compliance programs, comply with the pharmaceutical industry’s voluntary compliance guidelines and the relevant compliance guidance promulgated by the federal government, or to track and report gifts, compensation and other remuneration provided to physicians and other healthcare providers, and other federal, state and foreign laws that govern the privacy and security of health information or personally identifiable information in certain circumstances, including state health information privacy and data breach notification laws which govern the collection, use, disclosure, and protection of health-related and other personal information, many of which differ from each other in significant ways and often are not pre-empted by HIPAA, thus requiring additional compliance efforts.
Because of the breadth of these laws and the narrowness of the safe harbors, it is possible that some business activities can be subject to challenge under one or more of such laws. The scope and enforcement of each of these laws is uncertain and subject to rapid change in the current environment of healthcare reform, especially in light of the lack of applicable precedent and regulations. Federal and state enforcement bodies have recently increased their scrutiny of interactions between healthcare companies and healthcare providers, which has led to a number of investigations, prosecutions, convictions and settlements in the healthcare industry.
Ensuring that business arrangements with third parties comply with applicable healthcare laws and regulations is costly and time consuming. If business operations are found to be in violation of any of the laws described above or any other applicable governmental regulations a pharmaceutical manufacturer may be subject to penalties, including civil, criminal and administrative penalties, damages, fines, disgorgement, individual imprisonment, exclusion from governmental funded healthcare programs, such as Medicare and Medicaid, contractual damages, reputational harm, diminished profits and future earnings, additional reporting obligations and oversight if subject to a corporate integrity agreement or other agreement to resolve allegations of non-compliance with these laws, and curtailment or restructuring of operations, any of which could adversely affect a pharmaceutical manufacturer’s ability to operate its business and the results of its operations.
Healthcare Reform in the United States
In the United States, there have been, and continue to be, a number of legislative and regulatory changes and proposed changes to the healthcare system that could affect the future results of pharmaceutical manufactures’ operations. In particular, there have been and continue to be a number of initiatives at the federal and state levels that seek to reduce healthcare costs. Most recently, the Patient Protection and Affordable Care Act, or PPACA, was enacted in March 2010, which includes measures to significantly change the way healthcare is financed by both governmental and private insurers. Among the provisions of the PPACA of greatest importance to the pharmaceutical and biotechnology industry are the following:
- an annual, nondeductible fee on any entity that manufactures or imports certain branded prescription drugs and biologic agents, apportioned among these entities according to their market share in certain government healthcare programs;
- implementation of the federal physician payment transparency requirements, sometimes referred to as the “Physician Payments Sunshine Act”;
- a licensure framework for follow-on biologic products;
- a new Patient-Centered Outcomes Research Institute to oversee, identify priorities in, and conduct comparative clinical effectiveness research, along with funding for such research;
- establishment of a Center for Medicare Innovation at the Centers for Medicare & Medicaid Services to test innovative payment and service delivery models to lower Medicare and Medicaid spending, potentially including prescription drug spending;
- an increase in the statutory minimum rebates a manufacturer must pay under the Medicaid Drug Rebate Program, to 23.1% and 13% of the average manufacturer price for most branded and generic drugs, respectively and capped the total rebate amount for innovator drugs at 100% of the Average Manufacturer Price, or AMP;
- a new methodology by which rebates owed by manufacturers under the Medicaid Drug Rebate Program are calculated for certain drugs and biologics, including its product candidates, that are inhaled, infused, instilled, implanted or injected;
- extension of manufacturers’ Medicaid rebate liability to covered drugs dispensed to individuals who are enrolled in Medicaid managed care organizations;
- expansion of eligibility criteria for Medicaid programs by, among other things, allowing states to offer Medicaid coverage to additional individuals and by adding new mandatory eligibility categories for individuals with income at or below 133% of the federal poverty level, thereby potentially increasing manufacturers’ Medicaid rebate liability;
- a new Medicare Part D coverage gap discount program, in which manufacturers must agree to offer 50% point-of-sale discounts off negotiated prices of applicable brand drugs to eligible beneficiaries during their coverage gap period, as a condition for the manufacturer’s outpatient drugs to be covered under Medicare Part D; and
- expansion of the entities eligible for discounts under the Public Health program.
Some of the provisions of the PPACA have yet to be implemented, and there have been legal and political challenges to certain aspects of the PPACA. Since January 2017, President Trump has signed two executive orders and other directives designed to delay, circumvent, or loosen certain requirements mandated by the PPACA. Concurrently, Congress has considered legislation that would repeal or repeal and replace all or part of the PPACA. While Congress has not passed repeal legislation, the Tax Cuts and Jobs Act of 2017 includes a provision repealing, effective January 1, 2019, the tax-based shared responsibility payment imposed by the PPACA on certain individuals who fail to maintain qualifying health coverage for all or part of a year that is commonly referred to as the “individual mandate”. Congress may consider other legislation to repeal or replace elements of the PPACA.
Many of the details regarding the implementation of the PPACA are yet to be determined, and at this time, the full effect that the PPACA would have on a pharmaceutical manufacturer remains unclear. In particular, there is uncertainty surrounding the applicability of the biosimilars provisions under the PPACA. The FDA has issued several guidance documents, but no implementing regulations, on biosimilars. A number of biosimilar applications have been approved over the past few years. The regulations that are ultimately promulgated and their implementation are likely to have considerable impact on the way pharmaceutical manufacturers conduct their business and may require changes to current strategies. A biosimilar is a biological product that is highly similar to an approved drug notwithstanding minor differences in clinically inactive components, and for which there are no clinically meaningful differences between the biological product and the approved drug in terms of the safety, purity, and potency of the product.
Individual states have become increasingly aggressive in passing legislation and implementing regulations designed to control pharmaceutical and biological product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain product access, and marketing cost disclosure and transparency measures, and to encourage importation from other countries and bulk purchasing. Legally mandated price controls on payment amounts by third-party payors or other restrictions could harm a pharmaceutical manufacturer’s business, results of operations, financial condition and prospects. In addition, regional healthcare authorities and individual hospitals are increasingly using bidding procedures to determine what pharmaceutical products and which suppliers will be included in their prescription drug and other healthcare programs. This could reduce ultimate demand for certain products or put pressure product pricing, which could negatively affect a pharmaceutical manufacturer’s business, results of operations, financial condition and prospects.
In addition, given recent federal and state government initiatives directed at lowering the total cost of healthcare, Congress and state legislatures will likely continue to focus on healthcare reform, the cost of prescription drugs and biologics and the reform of the Medicare and Medicaid programs. While no one cannot predict the full outcome of any such legislation, it may result in decreased reimbursement for drugs and biologics, which may further exacerbate industry-wide pressure to reduce prescription drug prices. This could harm a pharmaceutical manufacturer’s ability to generate revenue. Increases in importation or re-importation of pharmaceutical products from foreign countries into the United States could put competitive pressure on a pharmaceutical manufacturer’s ability to profitably price products, which, in turn, could adversely affect business, results of operations, financial condition and prospects. A pharmaceutical manufacturer might elect not to seek approval for or market products in foreign jurisdictions in order to minimize the risk of re-importation, which could also reduce the revenue generated from product sales. It is also possible that other legislative proposals having similar effects will be adopted.
Furthermore, regulatory authorities’ assessment of the data and results required to demonstrate safety and efficacy can change over time and can be affected by many factors, such as the emergence of new information, including on other products, changing policies and agency funding, staffing and leadership. No one can be sure whether future changes to the regulatory environment will be favorable or unfavorable to business prospects. For example, average review times at the FDA for marketing approval applications can be affected by a variety of factors, including budget and funding levels and statutory, regulatory and policy changes.
Regulation in the European Union
Biologics are also subject to extensive regulation outside of the United States. In the European Union, for example, there is a centralized approval procedure that authorizes marketing of a product in all countries of the European Union, which includes most major countries in Europe. If this procedure is not used, approval in one country of the European Union can be used to obtain approval in another country of the European Union under two simplified application processes, the mutual recognition procedure or the decentralized procedure, both of which rely on the principle of mutual recognition. After receiving regulatory approval through any of the European registration procedures, pricing and reimbursement approvals are also required in most countries.
TrovaGene is also subject to numerous federal, state and local laws relating to such matters as safe working conditions, manufacturing practices, environmental protection, fire hazard control, and disposal of hazardous or potentially hazardous substances and biological materials. The company may incur significant costs to comply with such laws and regulations now or in the future.
Some drugs benefit from additional government incentives. Orphan drugs receive special consideration from the FDA in order to encourage pharmaceutical companies to develop treatments for rare diseases. Incentives for the development of orphan drugs include quicker approval time and potential financial assistance, including waiver of Prescription Drug User Fee Act (“PDUFA”). Companies are often permitted to charge substantial prices for orphan drugs, making them more profitable than they would be without government intervention. As a result, the development of orphan drugs continues to grow at a faster rate than the development of traditional pharmaceuticals. The FDA granted Orphan Drug Designation (“ODD”) to PCM-075 in the treatment of AML in October, 2017.
PCM-075 is not the first PLK inhibitor that has entered clinical development; however, it currently is the only oral PLK inhibitor in active clinical development and delivers highly-selective PLK1 inhibition, which suggests that it could demonstrate survival benefits in elderly AML patients without the adverse events that have prohibited the advancement of other PLK1 inhibitors. PCM-075 has completed a Phase 1 trial in advanced metastatic solid tumor cancers and a Phase 1b/2 trial in AML was initiated in November 2017. Additionally, a Phase 2 trial in mCRPC is filed with FDA and TrovaGene is working towards the activation up to three sites including Beth Israel Deaconess Medical Center.
The most prominent PLK inhibitor tested in late-stage clinical development, thus far, is volasertib, developed by Boehringer Ingelheim. In a randomized Phase 2 trial of volasertib plus low-dose cytarabine (“LDAC”) in 87 AML patients not eligible for induction therapy, patients received LDAC 20mg twice-daily subcutaneously on days 1-10 or LDAC plus volasertib 350 mg IV on days 1 + 15 every four weeks. The response rate (complete remission and complete remission with incomplete blood count recovery) was higher for LDAC + volasertib vs LDAC (31.0% vs 13.3%; p=0.052). Median event-free survival was significantly prolonged by LDAC + volasertib compared with LDAC (5.6 vs 2.3 months). The encouraging results led to the Phase 3 POLO-AML-2 study in early 2013, which enrolled 666 elderly patients (65 years or older) with newly diagnosed AML, who were not eligible for intensive induction therapy. However; in June, 2016, Boehringer Ingelheim reported that LDAC + volasertib did not meet the primary endpoint of objective response; although better than LDAC, alone, the difference was not statistically significant. The data also showed an unfavorable overall survival trend for the experimental arm, with the safety profile of the LDAC + volasertib dosing regimen considered as the main reason for the trend. The fact that volasertib demonstrated survival benefits in the Phase 2 trial provided proof-of-concept for PLK inhibition as a mechanism of action for an AML therapy; however, its unacceptable safety profile may have resulted from the fact that volasertib’s inhibition of PLK1 is not highly selective and it also inhibits PLK2 and PLK3. By contrast, PCM-075 is able to deliver much more selective inhibition of PLK1 than volasertib. PCM-075 also has a half-life of 24 hours vs volasertib’s 135 hours.
GSK461364, developed by GSK, appears to have less sensitivity to PLK2 and PLK3 than volasertib, although it is not as specific to PLK1 as PCM-075. GSK461364 was investigated in a Phase 1 study in patients with advanced solid tumor cancers. The best response was prolonged stable disease of more than 16 weeks that occurred in 15% of patients. However, GSK461364 had off target adverse events including grade 4 pulmonary emboli. Venous thrombotic emboli (VTE) and myelosuppression were the most common grade 3-4 drug-related events; and VTE occurred in 20% of patients, which demanded co-administration of anticoagulants. There are no further clinical updates for GSK461364 after the Phase 1 study.
Other PLK inhibitors that have been evaluated include rogosertib - Oncova, a non-targeted broad-spectrum multi-kinase inhibitor (RAF, PI3K, PLK), evaluated for pancreatic cancer and Myelodysplastic Syndrome (“MDS”), which failed a Phase 3 trial in MDS. Currently, Oncova is testing an IV formualtion of rogosertib in high-risk MDS patients. CY140 - Cyclacel, a PLK1, 2, 3 inhibitor, is currently in preclinical studies for the treatment of esophageal cancer.