Progenics Pharmaceuticals, an oncology company focussed on the development of innovative approaches to targeting and treating prostate cancer, announced the completion of enrollment in the chemotherapy naïve cohort in its phase II trial of PSMA ADC.

This cohort of 36 chemotherapy naïve prostate cancer patients, all of whom progressed on hormonal therapies, was added to the Phase II trial following positive response to PSMA ADC in patients in the chemotherapy experienced setting.

"We look forward to seeing the response to PSMA ADC in the chemo naive patients, as this compound may be of benefit to men earlier in their treatment cycle," said Daniel Petrylak, managing director, Professor of Medical Oncology at Yale Cancer Center, Clinical Research Programme Leader for the Prostate and Urologic Cancers Programme at Smilow Cancer Hospital at Yale-New Haven, and lead investigator on the Phase II trial.

Prostate Specific Membrane Antigen (PSMA), a protein that is a validated biomarker of prostate cancer, is expressed on the surface of prostate cancer cells as well as on blood vessels supplying other solid tumours. PSMA ADC comprises a fully human monoclonal antibody selectively targeting PSMA linked to a chemotherapeutic drug. Using technology licensed from Seattle Genetics, the PSMA antibody is linked to monomethyl auristatin E, a compound that inhibits cell proliferation by disrupting the cellular "backbone" (i.e. microtubules) required for replication.

The resultant antibody-drug conjugate attaches to the PSMA protein on the surface of prostate cancer cells and is designed to internalise into the cancer cell, release active anti-cancer drug, and destroy the malignant cell. Unlike traditional chemotherapy, PSMA ADC is designed to deliver the drug selectively to prostate cancer cells by targeting PSMA.