Roche has shared positive top-line overall survival results from a late-stage study of its oral PI3K inhibitor Itovebi (inavolisib) in a subset of advanced breast cancer patients.
The phase INAVO120 trial has been evaluating the drug in combination with Pfizer’s CDK4/6 inhibitor Ibrance (palbociclib) and AstraZeneca’s hormone therapy Faslodex (fulvestrant) in patient with PIK3CA-mutated, hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative, endocrine-resistant, locally advanced or metastatic breast cancer.
Approximately 56,800 new breast cancer cases are diagnosed in the UK every year, and HR-positive disease is the most prevalent subtype.
The PI3K signalling pathway is commonly dysregulated in HR-positive breast cancer, often due to activating PIK3CA mutations, which are considered to be a potential mechanism of resistance to standard-of-care hormone therapy in combination with CDK4/6 inhibitors.
Results from INAVO120 previously reported by Roche showed that the Itovebi-based regimen reduced the risk of disease worsening or death by 57% compared with Ibrance and Faslodex alone in the first-line setting.
The company has now announced that the trial met its secondary endpoint, with the triplet therapy demonstrating a statistically significant and clinically meaningful overall benefit versus Ibrance and Faslodex alone.
Levi Garraway, Roche’s chief medical officer and head of global product development, said: “The INAVO120 overall survival results show that the Itovebi-based regimen not only delayed disease progression, but also helped people with advanced HR-positive, PIK3CA-mutated breast cancer live longer.
“These findings underscore our ambition to improve survival rates for people with breast cancer. The Itovebi-based regimen has the potential to become the new standard of care for these patients.”
The announcement comes just three months after the US Food and Drug Administration approved the Itovebi regimen based on results from INAVO120. Data from the trial is being reviewed by other global health authorities, including the European Medicines Agency.
Garraway said at the time of the October authorisation: “Despite the high prevalence of PIK3CA mutations in this setting, treatment options have thus far remained limited, which makes [this] approval all the more significant.”
Itovebi is also currently being evaluated in various combinations across three additional late-stage studies in PIK3CA-mutated locally advanced or metastatic breast cancer.