Ideaya outlines regulatory path for rare eye cancer drug following positive mid-stage results

Ideaya Biosciences has revealed plans for a Phase 3 trial of its eye cancer drug darovasertib, following promising interim results from a mid-stage study. In the Phase 2 trial, which included 49 patients with neoadjuvant uveal melanoma, nearly half (49%) experienced a tumor reduction of 30% or more. Furthermore, 59% of patients saw a tumor reduction of 20% or more. The company also reported a 61% rate of eye preservation in patients who had undergone enucleation surgery, as per a press release issued on Monday.

The safety profile of darovasertib was described by Ideaya as “manageable.” The most frequently observed side effects included diarrhea, nausea, vomiting, and fatigue. Approximately 11% of patients reported adverse events of grade 3 or higher, and the trial witnessed a 3% discontinuation rate.

Encouraged by these findings and subsequent discussions with the FDA, Ideaya is moving forward with a 400-patient Phase 3 trial for neoadjuvant uveal melanoma. Ideaya’s Chief Medical Officer, Darrin Beaupre, highlighted that the successful FDA Type C meeting has outlined a potential registrational pathway for darovasertib in treating neoadjuvant uveal melanoma. The proposed primary clinical endpoints for this Phase 3 trial include eye preservation and time to vision loss, with event-free survival (EFS) in the treatment arms as a secondary endpoint.

The announcement of the Phase 2 data and the outcomes of the FDA meeting were highly anticipated, with Jefferies analysts noting that these developments could significantly reduce the risks associated with the drug's progression towards a potential market opportunity valued at $1.3 billion. Darovasertib, a protein kinase C inhibitor, was licensed by Ideaya from Novartis.

Ideaya also mentioned that discussions with the FDA are “ongoing” to potentially include the overall response rate as a surrogate and composite endpoint, which could expedite the approval process. Based on the discussions with the FDA, there is a possibility for a broad label in neoadjuvant uveal melanoma for patients at low, intermediate, and high risk of metastatic disease.

Last year, Ideaya reported positive Phase 2 data for darovasertib in combination with crizotinib for metastatic uveal melanoma, further showcasing the potential of darovasertib in treating different stages of this rare eye cancer.