Investors had been “holding out hope” that there remained a regulatory path forward for RP1, but results of Replimune’s Type A meeting with the FDA do not appear to support this, according to BMO Capital Markets.
Replimune does not yet see a clear path forward for its investigational cancer therapy RP1—even after wrapping up a post-rejection meeting with the FDA.
In a brief press announcement on Thursday, the Massachusetts-based biotech said that RP1’s path forward under the accelerated approval pathway “has not been determined.” Replimune met with the FDA on Sept. 16 for a Type A meeting to discuss the regulator’s complete response letter in July for RP1.
Replimune closed Thursday’s trading session at $3.46, down nearly 40% from its ending price of $5.71 the previous day.
Thursday’s news gives BMO Capital Markets “further pause and concern for the long-term viability of the RP1 program,” analysts wrote in a note to investors. Some shareholders had been “holding out hope,” they continued, for the possibility of restructuring the RP1 program or using the data already available to build toward future approval. “These hopes do not appear to be supported today,” BMO said.
“The lack of reassurance at a time when investors need it most paints a bleak picture of the company’s future,” the analysts added.
RP1, also named vusolimogene oderparepvec, uses an engineered HSV virus that targets cancer cells and replicates inside them, in turn making them more vulnerable to an immune response. Replimune backed its application with data from the Phase III IGNYTE trial, which demonstrated a 32.9% confirmed objective response rate, including a 15% complete response rate.
The FDA’s rejection of RP1 in July came as a surprise to those who were following the drug, with BMO analysts at the time suggesting that new leadership at the FDA might have new expectations for data submitted to it. "[Center for Biologics Evaluation and Research head Vinay] Prasad has previously been critical of the approvability of uncontrolled data, and today we see that opinion underscored,” the analysts wrote.
Indeed, the FDA’s complete response letter argued that IGNYTE was not an “adequate and well-controlled clinical investigation.” In a statement following the rejection, Replimune CEO Suhil Patel said he was “surprised” and “disappointed,” particularly given that the agency had not raised the issues enumerated in the rejection letter at prior meetings. “We had also aligned on the design of the confirmatory study,” Patel said at the time.
The researchers behind IGNYTE, alongside other experts in the field, bristled at the rejection. Last month, a group of 22 scientists penned an open letter to the FDA, urging the agency to “re-review” RP1’s application.
Among other contentions, the researchers argued in their letter that the heterogeneity of IGNYTE’s population, which the FDA had flagged as a methodological weakness, more accurately reflects RP1’s real-world patient population. “Multiple treatment pathways in both the adjuvant and advanced disease setting [funnel] to the point of IGNYTE eligibility,” they wrote.
