Repare Therapeutics (RPTX) experienced a significant stock drop after releasing Phase 1 trial results for its combination drug, lunresertib and camonsertib, aimed at treating endometrial and platinum-resistant ovarian cancers. The study revealed mixed efficacy and safety outcomes, leading to a more than 38% plunge in the company's shares on Wednesday.
The Phase 1 clinical trial data indicated an overall response rate (ORR) of 25.9% in patients with endometrial cancer and 37.5% in those with platinum-resistant ovarian cancer. However, the trial also raised safety concerns, as 26.9% of participants experienced Grade 3 adverse events, notably anemia. These findings highlight the challenges in developing effective treatments for difficult-to-treat malignancies, particularly in the competitive oncology landscape.
Despite the market's unfavorable reaction to the Phase 1 data, Repare Therapeutics remains committed to advancing its experimental treatments. The company announced its intention to initiate a Phase 3 registrational study focusing on endometrial cancer in the second half of 2025. This decision underscores the company's confidence in the potential of its therapeutic approach, despite the observed safety issues and mixed efficacy results.
Earlier this year, Roche terminated a collaboration agreement with Repare and returned worldwide rights for camonsertib after paying a $40 million milestone fee. This event, coupled with the recent Phase 1 results, places Repare's clinical development program under increased scrutiny from industry observers. The company has yet to address specific investor concerns arising from the Phase 1 outcomes, leaving stakeholders to closely monitor Repare's strategic moves forward.
Repare's precision oncology platform, which leverages synthetic lethality to identify novel therapeutic targets, has previously garnered significant interest. However, the recent trial results represent a challenging period for the company as it navigates the complexities of drug development and regulatory approval in the oncology space.
