Roche’s freshly approved PI3K inhibitor Itovebi can help extend the lives of certain patients with breast cancer when used in combination with two established medicines, new survival data from the drug’s pivotal phase 3 trial show.
In the INAVO120 study, Itovebi—used in combination with Pfizer’s Ibrance and AstraZeneca’s Faslodex—delivered a statistically significant and clinically meaningful overall survival benefit compared with Ibrance and Faslodex alone, Roche reported Tuesday. The trial enrolled a total of 325 patients with PIK3CA-mutated, HR-positive, HER2-negative breast cancer.
“These findings underscore our ambition to improve survival rates for people with breast cancer,” Roche’s chief medical officer Levi Garraway, M.D., Ph.D., said in a company release. “The Itovebi-based regimen has the potential to become the new standard of care for these patients.”
The results add to Itovebi’s known benefits. Previously, in the trial's primary analysis, Itovebi delivered a 57% improvement in progression-free survival. Patients in the treatment arm of the INAVO120 trial lived a median 15 months without their disease worsening versus 7.3 months for those in the Ibrance and Faslodex arm.
Roche said it plans to present full results from the overall survival analysis at an upcoming medical meeting.
Besides INAVO120, the company is also studying Itovebi across various combinations in PIK3CA-mutated, locally advanced or metastatic breast cancer patients through three additional phase 3 studies.
One such study pits Roche’s offering against Novartis’ rival PI3K inhibitor Piqray in the second-line setting in patients with advanced or metastatic breast cancer following CDK4/6-endocrine combination therapy.
Piqray and AstraZeneca’s AKT inhibitor Truqap represent the biggest competitors to Itovebi, but Roche is confident in the drug’s best-in-class potential, head of oncology and hematology global product development, Charlie Fuchs, M.D., said in an October interview with Fierce Pharma.
Waiting in the wings could be Eli Lilly, which just entered the arena with its $2.5 billion buyout of Scorpion Therapeutics and the biotech's PI3K pipeline. That deal includes STX-478, which last year showed promise in an early-stage trial.
Nonetheless, Roche’s pharma chief Teresa Graham put Itovebi’s peak sales potential at 2 billion Swiss francs ($2.3 billion) during an April investor call, citing the estimate that PIK3CA mutations account for about 40% of HR-positive breast cancers.
The drug is a part of a bigger breast cancer push from Roche that includes giredestrant, an oral HR-positive, HER-negative candidate with key phase 3 readouts expected this year.