Endocyte Pursuing Phase 3 Trial of 177Lu-PSMA-617 in Metastatic PC

Endocyte Pursuing Phase 3 Trial of 177Lu-PSMA-617 in Metastatic PC

Endocyte announced it will move PSMA-617 quickly into Phase 3 development in prostate cancer after it licensed the compound from German ABX. The trial, for which the company has yet to seek approval, likely will launch by early 2018.

Although the compound, which is coupled to a radioactive molecule called 177Lu to fight cancer, has yet to enter late-stage clinical testing, it already has been given to hundreds of patients in earlier trials and compassionate use studies because of its potential to treat prostate cancer metastases.

“This transaction is transformational to Endocyte, accelerating our path to commercialization,” Mike Sherman, president and CEO of Endocyte, said in a press release, in which he spoke of the potential of 177Lu-PSMA-617 to treat both bone and soft tissue tumors found in patients with metastatic castration-resistant prostate cancer.

PSMA-617 originally was developed at the German Cancer Research Center and the Heidelberg University Hospital. ABX held the exclusive license to bring the treatment, which targets prostate-specific membrane antigen (PSMA), through early clinical development.

Endocyte said the company will focus its efforts on the upcoming Phase 3 trial with a goal of completing it by 2020.

“With the exception of a very targeted effort to generate proof-of-concept data for our CAR T-cell program, we will focus our resources on the development of 177Lu-PSMA-617. We will explore out-licensing opportunities for all other development programs,” said Sherman.

“Despite advances in the last decade that slow the progression of prostate cancer, once metastasized it is nearly always lethal, leading to 300,000 worldwide deaths annually. 177Lu-PSMA-617 has demonstrated the most compelling activity of any drug currently in development for these post-chemotherapy patients,” added Alison Armour, MD, Endocyte’s chief medical officer.

The strength of the treatment is that PSMA is mostly found on cancerous cells, meaning that the radioactive molecule selectively kills cancer cells. About 20 published studies show that 177Lu-PSMA-617 consistently lowered PSA (prostate-specific antigen) levels in 40% to 60% of patients and forced tumors to shrink in up to half of treated patients.

The latest data, presented at the European Society for Medical Oncology (ESMO) Congress, showed that 177Lu-PSMA-617 treatment of 30 patients with metastatic castration-resistant cancer triggered a response in 71 percent of patients, with PSA reductions of more than 50 percent seen in more than half of the group.

These patients survived for a median of 12.7 months, and reported improved quality of life scores and reduction in pain.

“The data generated thus far have created significant enthusiasm for 177Lu-PSMA-617. PSMA is a promising target in prostate cancer and radioligand therapy may be the best application for this target,” said Michael Morris, MD, associate professor, Genitourinary Oncology, Memorial Sloan Kettering Cancer Center.

“Particularly where disease has become resistant to current therapies, there is a tremendous need for new approaches and I look forward to working with Endocyte to investigate this innovative, first-in-class therapy for prostate cancer patients.”