Relay Therapeutics has received the US Food and Drug Administration (FDA) breakthrough therapy designation (BTD) for zovegalisib (RLY-2608), along with fulvestrant, for human epidermal growth factor receptor 2-negative (HR+/HER2-) advanced breast cancer treatment.
The designation covers adults with phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA)-mutant, hormone receptor positive, HR+/HER2- locally advanced or metastatic breast cancer following recurrence or progression after treatment with cyclin-dependent kinase 4/6 (CDK4/6) inhibitors.
BTD is designed by the FDA to accelerate the development and review of products intended for serious conditions when preliminary clinical evidence indicates potential substantial improvement over existing therapies.
This status includes the benefits of a fast track designation, in addition to enhanced FDA guidance on development plans and increased interaction with senior agency officials.
It is supported by data from the Phase I/II ReDiscover trial, which assessed the tolerability, safety, pharmacodynamics, pharmacokinetics, and preliminary antitumour activity of zovegalisib with fulvestrant, as well as in combination with fulvestrant and CDK inhibitors.
The application featured clinical data across all PIK3CA mutation types for two dosing regimens: 400mg BID fed (n=57) and 600mg BID fasted (n=52).
Relay Therapeutics R&D president Don Bergstrom said: “Approximately 40% of patients with HR+/HER2- advanced breast cancer harbour PIK3CA mutations, and most experience disease recurrence or progression following treatment with CDK4/6 inhibitors, leaving limited therapeutic options.
“This breakthrough therapy designation underscores the FDA’s recognition of the potential of zovegalisib in combination with fulvestrant to meaningfully improve outcomes for these patients, reinforcing the impact of the encouraging clinical evidence we have demonstrated to date.
“We look forward to continuing to collaborate closely with the FDA as we work to advance this programme as efficiently as possible for patients.”
