Endocyte Inc. said the U.S. Food and Drug Administration has accepted a new endpoint goal for an ongoing phase 3 study of the company's prostate cancer drug, which should speed up the regulatory approval process.

The U.S. drug regulator determined that radiographic progression free survival, or rPFS, is an appropriate efficacy endpoint for a phase 3 clinical trial evaluating Lu-PSMA-617, Endocyte said in a Sept. 10 press release. The drug candidate treats patients with prostate cancer whose disease has spread to other parts of the body and whose hormone therapy is no longer controlling the disease. The rPFS goal will be an alternative primary goal to overall survival, either of which is sufficient for full approval.

"This change provides an opportunity to obtain a full approval sooner than we previously anticipated," Endocyte President and CEO Mike Sherman said. "Under the updated protocol, we now expect the analysis of rPFS for potential full approval to occur before the end of 2019."

According to the updated design of the study, which has been dubbed Vision, the FDA will consider for approval rPFS instead of two previously planned overall survival events. If the drug meets the main goal in the rPFS assessment, no unexpected safety issues arise, and it shows no detriment in overall survival relative to the control treatment, Endocyte plans to submit a new drug application to seek full approval in the U.S.

Regardless of the outcome of the rPFS assessment, the company will continue to follow patients in the study to assess final overall survival. Other aspects of the 750-patient trial remain unchanged.

The acceptance of rPFS as a main goal for full approval in Europe will be determined in upcoming regulatory interactions, the West Lafayette, Ind.-based biopharmaceutical company said.

Endocyte's stock was up 8.9% to $18.47 as of 2 p.m. ET, according to data from S&P Global Market Intelligence.