Endocyte Updates Phase III Trial Design, Sells $175 Million in Stock
Published: Sep 11, 2018 By Alex Keown
Shares of Indiana-based Endocyte have slipped more than 3 percent this morning after the company announced the U.S. Food and Drug Administration accepted radiographic progression-free survival as an alternative primary endpoint in its Phase III VISION trial.
The rPFS endpoint will be in addition to overall survival, the company said Monday. The two primary endpoints will be part of the trial makeup that will support a potential New Drug Application. The Phase III VISION trial will examine the company’s Lu-PSMA-617 program for the treatment of metastatic castration-resistant prostate cancer (mCRPC).
Mike Sherman, president and chief executive officer of Endocyte, said the company was pleased with the FDA’s approval of the plan.
“This change provides an opportunity to obtain a full approval sooner than we previously anticipated and highlights the Agency’s commitment to addressing the urgent need for a new mechanism of action to treat mCRPC,” Sherman said in a statement. “Under the updated protocol, we now expect the analysis of rPFS for potential full approval to occur before the end of 2019. We also retained the final, fully powered OS analysis, which is expected to occur near the end of 2020. This provides two potential paths for approval and preserves a robust OS analysis to support a potential label.”
Earlier this year Endocyte revealed updated Phase II data that showed patients dosed with Lu-PSMA-617 saw high rates of PSA response, even those patients who had been heavily pretreated. Data showed that of the 50 patients who received Lu-PSMA-617, 62 percent saw a greater than 50 percent reduction in their PSA levels. Additionally, 44 percent of patients had a PSA reduction of 80 percent or greater, the company said.
In the first cohort of 30 patients, Endocyte said Lu-PSMA-617 helped patients achieve a median overall survival of 13.5 months. In May the company said median overall survival in the total 50 patients was not yet meaningful due to the cutoff.
Endocyte said the updated trial design will now include a single assessment of rPFS. Initially, the company thought to have two interim assessments previously planned at 50 percent and 70 percent of overall survival events. The new assessment is expected to occur at the same time the first interim OS assessment would have occurred under the prior trial design. Endocyte said if Lu-PSMA-617 meets the primary endpoint in the rPFS assessment and there are no unexpected safety issues, the company intends to seek regulatory approval in the United States.
As the company revamps its Phase III trial, Endocyte also announced Monday that it was selling $175 million worth of stock in an underwritten registered public offering. Additionally, Endocyte said it expected to grant the underwriters a 30-day option to purchase up to an additional $26.25 million of its common stock on the same terms and conditions.
The proceeds from the sale will be used to fund the Phase III VISION trial and plan for the potential commercial launch of Lu-PSMA-617. Part of the funding will also be used for working capital and general corporate purposes, Endocyte said in its announcement. Jefferies LLC, Wells Fargo Securities, LLC and RBC Capital Markets, LLC are acting as joint book-running managers for the proposed offering.