Study Finds Inavolisib Combination Treatment Improved PFS in Patients With Breast Cancer

Positive results from the phase 3 study INAVO120 demonstrate that inavolisib in combination with palbociclib and fulvestrant could be a potential first-line treatment option for people with PIK3CA-mutated, hormone receptor (HR)-positive, HER2-negative, endocrine-resistant, locally advanced or metastatic breast cancer. The study met its primary endpoint of progression-free survival (PFS), and compared to palbociclib and fulvestrant alone, inavolisib demonstrated a statistically significant and clinically meaningful improvement.

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Inavolisib is an investigational, oral targeted treatment that has the potential to provide well-tolerated, durable disease control and improved outcomes of people with HR-positive, PIK3CA-mutated breast cancer. Further, inavolisib can help minimize the overall toxicity of treatment, differentiating itself from other PI3K inhibitors due to its high in vitro potency.

"These pivotal study results for this inavolisib combination could represent a transformative medical advance for people with PIK3CA-mutated HR-positive breast cancer," said Levi Garraway, MD, PhD, chief medical officer and head of global product development at Roche, in a press release.

The randomized, double-blind, placebo-controlled phase 3 study, INAVO120, evaluated the efficacy and safety of inavolisib in combination with palbociclib and fulvestrant compared to placebo plus palbociclib and fulvestrant in people with PIK3CA-mutated, HR-positive, HER2-negative, locally advanced or metastatic breast cancer whose disease progressed during treatment or within 12 months of completing adjuvant endocrine therapy. In addition, the enrolled patients did not receive prior systemic therapy for metastatic disease.

The study evaluated 325 patients who were randomly assigned to either the investigational or control treatment arm. The primary endpoint was PFS, and secondary endpoints included overall survival (OS), objective response rate, and clinical benefit rate. Despite the positive trend observed in the study, OS data were immature, requiring follow-up in future trials.

Currently, inavolisib is being investigated in 3 phase 3 clinical studies in people with PIK3CA-mutated metastatic breast cancer. Similar to INAVO120, these trials will evaluate treatment options of inavolisib combined with other therapies.

"We look forward to expanding our portfolio of breast cancer medicines into the HR-positive space and bringing this potentially best-in-class new treatment option to patients as quickly as possible," said Garraway in the press release.

Reference

Roche. Roche announces positive Phase III results for inavolisib combination in people with advanced hormone receptor-positive, HER2-negative breast cancer with a PIK3CA mutation. News release. December 5, 2023. Accessed December 5, 2023. Email.