Progenics Pharmaceuticals Announces Initiation of a Phase 1 Clinical Trial of its PSMA-Targeted Therapeutic Candidate 1095 For the Treatment of Metastatic Prostate Cancer

Progenics Pharmaceuticals, Inc. (Nasdaq:PGNX), an oncology company developing innovative medicines and other products for targeting and treating cancer, today announced that enrollment of an investigator initiated Phase 1 clinical trial with 131-I-MIP-1095 (1095) has begun at MSK.  1095 is one of Progenics’ PSMA-targeted small molecule radiopharmaceutical candidates being developed for the treatment of metastatic prostate cancer.
1095 is designed to bind to the extracellular domain of prostate specific membrane antigen (PSMA), a protein that is expressed in greater than 95% of prostate cancer cells, and upon binding, internalized by the prostate cancer cells where its iodine-131 beta particles kill the tumor cells.  When administered under a compassionate use setting, 1095 was well tolerated and demonstrated markedly reduced PSA levels and bone pain in a group of heavily-pretreated advanced prostate cancer patients (N=28) following a single cycle of treatment.¹“MIP 1095 holds the promise of optimizing tumor-specific delivery of radiation, with the added potential benefit of rapid clearance of the molecule and its radioactive payload that can minimize radiation exposure to normal tissues,” said Michael J. Morris, MD of Memorial Sloan Kettering Cancer Center, and lead investigator of the study. “The totality of the preclinical and compassionate use data provides strong support for 1095 in metastatic castration-resistant prostate cancer, and I look forward to further evaluating this drug in the clinical setting.”This Phase 1 open-label dose-escalation study will enroll approximately 40 patients with mCRPC who have demonstrated tumor avidity to 1095.  The primary objectives of this study include determination of maximum tolerated dose, safety and tolerability, biodistribution, and efficacy.  Findings from this trial will guide the decision of an optimal dose for a Phase 2 trial.“The initiation of this trial reflects our commitment to advancing PSMA-targeted candidates that have the potential to transform how prostate cancer is detected, managed and treated,” said Mark Baker, CEO of Progenics.  “The insights we gain from this trial will help guide the design of the future clinical development program of 1095.”
About 1095
Progenics’ small molecule therapeutic candidate 1095 is designed to bind to the extracellular domain of prostate specific membrane antigen (PSMA), a protein that is expressed in >95% of prostate cancer cells, and upon binding, to be internalized by the prostate cancer cells, where its iodine-131 beta particles kill the malignant cell. The ability to specifically deliver radiation to prostate cancer cells anywhere in the body allows a commonly used therapy (radiation) to be used with precision to attack systemic disease. Preclinical data has shown high tumor uptake and a favorable tumor to kidney discrimination yielding a lethal radiation dose to the tumor while minimizing normal tissue dose. In human prostate cancer mouse models, the compound, administered in single or multiple dose schedules, significantly reduced tumor burden for a prolonged period of time and enhanced survival with no significant signs of toxicity.  When used in a compassionate use setting, 1095 markedly reduced PSA levels and bone pain in a group of 22 heavily-pretreated advanced prostate cancer patients.About ProgenicsProgenics Pharmaceuticals, Inc. develops innovative medicines and other technologies to help physicians and patients target and treat cancer. The Company’s pipeline includes: 1) therapeutic agents designed to precisely target cancer (AZEDRA^® and 1095), 2) PSMA-targeted imaging agents for prostate cancer (1404 and PyL^TM) intended to enable clinicians and patients to accurately visualize and assist with the management of their disease, and 3) imaging analysis tools and solutions for medical decision support (EXINI BSI). Progenics’ first commercial product, RELISTOR^® (methylnaltrexone bromide) for opioid-induced constipation, is partnered with Valeant Pharmaceuticals International, Inc.This press release may contain projections and other “forward-looking statements” regarding future events. Statements contained in this communication that refer to Progenics’ estimated or anticipated future results or other non-historical facts are forward-looking statements that reflect Progenics’ current perspective of existing trends and information as of the date of this communication. Forward looking statements generally will be accompanied by words such as “anticipate,” “believe,” “plan,” “could,” “should,” “estimate,” “expect,” “forecast,” “outlook,” “guidance,” “intend,” “may,” “might,” “will,” “possible,” “potential,” “predict,” “project,” or other similar words, phrases or expressions. Such statements are predictions only, and are subject to risks and uncertainties that could cause actual events or results to differ materially. These risks and uncertainties include, among others, the cost, timing and unpredictability of results of clinical trials and other development activities and collaborations, such as our collaboration with Valeant on the RELISTOR oral formulation and the Phase 3 clinical program for 1404; our ability to successfully integrate EXINI Diagnostics AB and to develop and commercialize its products; the unpredictability of the duration and results of regulatory review of New Drug Applications and Investigational NDAs; market acceptance for approved products; the effectiveness of the efforts of our partners to market and sell products on which we collaborate and the royalty revenue generated thereby; generic and other competition; the possible impairment of, inability to obtain and costs of obtaining intellectual property rights; possible product safety or efficacy concerns, general business, financial and accounting matters, litigation and other risks. More information concerning Progenics and such risks and uncertainties is available on its website, and in its press releases and reports it files with the U.S. Securities and Exchange Commission. Progenics is providing the information in this press release as of its date and, except as expressly required by law, Progenics disclaims any intent or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or circumstances or otherwise.Additional information concerning Progenics and its business may be available in press releases or other public announcements and public filings made after this release. For more information, please visit www.progenics.com. Please follow us on LinkedIn®. Information on or accessed through our website or social media sites is not included in the company’s SEC filings.¹ Zechmann et al. Eur J Nucl Med Mol Imaging, 2014(PGNX-F)
Contact: Melissa Downs
Investor Relations
(646) 975-2533
mdowns@progenics.com