IDEAYA Biosciences (IDYA) Plunge 14.47% to 2025 Low as Clinical Updates Spark Jitters

Shares of IDEAYA Biosciences (IDYA) fell to their lowest level since August 2025 on Monday, with the stock tumbling 14.47% intraday. The sharp decline followed the release of clinical updates for two investigational therapies, IDE397 and darovasertib, which, while highlighting promising efficacy and safety profiles, failed to offset broader market skepticism or capital allocation concerns.

The Phase 1/2 trial data for IDE397 in combination with Gilead’s Trodelvy showed a 33% overall response rate (ORR) at the first dose level and 57% at the second, with disease control rates of 100% and 71%, respectively. These results, presented in a heavily pretreated patient population, underscore the potential of the therapy to address unmet needs in MTAP-deletion cancers. However, the lack of median progression-free survival data and ongoing dose selection timelines may have tempered investor enthusiasm.

Separately, interim Phase 2 results for darovasertib in neoadjuvant uveal melanoma revealed 76% tumor shrinkage and 48% reduction in radiation doses to critical eye structures, alongside vision improvements in 65% of patients. While these findings position the drug as a disruptive therapy in a niche market, the Phase 3 OptimUM-10 trial, initiated in Q2 2025, remains a key milestone that investors will scrutinize for long-term validation.

Strategic collaborations, such as the partnership with Gilead for Trodelvy supply, and a diversified pipeline targeting synthetic lethality and ADC platforms, align with industry trends. However, the company’s reliance on external capital for ongoing trials and the competitive landscape in precision oncology present ongoing risks. Upcoming data presentations at medical conferences and the 10-Year R&D Day on September 9, 2025, will be critical in shaping investor sentiment, though near-term volatility is likely as the market digests the balance between clinical progress and financial constraints.