Inavolisib (GDC-0077)

Agent Description

Inavolisib is an isoform-selective inhibitor of the Class I PI3Kα. It is a potent, selective inhibitor of the Class I PI3Kα isoform (p110α), with >300-fold less potent biochemical inhibition of the Class I PI3K β, γ, and δ isoforms and increased potency in tumor cells bearing PIK3CA mutations over cells without PIK3CA mutations.

Mechanism of Action

Inavolisib exerts its activity by binding to the ATP binding site of p110α. Inhibiting the phosphorylation of PIP2 to PIP3 decreases downstream activation of AKT and ribosomal protein S6, resulting in decreased cellular proliferation, metabolism, and angiogenesis.

Classification

Class I PI3Kα

Molecular Targets

Class I PI3Kα isoform (p110α)

Monograph

Inavolisib is under investigation in patients with PIK3CA mutated metastatic solid tumors as single agent and in combination with other agents. Single-agent toxicities were those expected of PI3K pathway inhibitors but were considered manageable; hyperglycemia was the dose-limiting toxicity at the maximum administered dose of 12 mg QD in the single-agent arm. Recent safety and tolerability data from patients on study ≥1 year (n=61) demonstrated a consistent safety profile of inavolisib with no new safety signals after long-term treatment, and some patients have remained on study after 2 years. The clinical benefit rates among the study arms have ranged from 45-79%.

Studies of Interest

Trials combining inavolisib with mechanistically rational agents in various solid tumors and trials evaluating the safety and preliminary efficacy of inavolisib in combination with other anti-cancer agents.

Information collaborator would like included in investigator proposals

Sponsor-investigator must indicate appropriate facilities/personnel, experience treating patients in desired research population and that they have an adequate sample size they can enroll into study, and a proven track record for conducting and publishing research. Formulary LOI proposal needs to describe if they have ongoing studies at their institution that would compete with the research population of interest during the expected patient accrual window.