The VICTORIA-1 trial showed an unprecedented benefit for the gedatolisib triplet, with a hazard ratio of 0.24 in PIK3CA wild-type patients. The dramatic improvement suggests that PAM pathway activation is a dominant resistance mechanism even without a PIK3CA mutation, opening a new treatment avenue.

Next-generation mutant-specific PI3K inhibitors could lead to complex biomarker requirements. A future drug label might require a PIK3CA mutation for eligibility but simultaneously exclude patients who also have downstream PTEN or AKT alterations, which can confer resistance.

Retrospective analysis of the BOLERO-2 trial revealed that the mTOR inhibitor everolimus benefits patients irrespective of their PI3K mutation status. This challenges the assumption that pathway-targeted therapies are only effective when a specific mutation is present, suggesting broader mechanisms of action.

Data from older studies suggests that PI3K inhibitors and mTOR inhibitors (like everolimus) have distinct mechanisms and may not be cross-resistant. This allows clinicians to confidently sequence these agents, for example using everolimus after progression on a PI3K or AKT inhibitor, providing more lines of targeted therapy.

The VICTORIA-1 trial found that gedatolisib, a pan-PI3K/mTOR inhibitor, significantly improves progression-free survival in patients with PIK3CA *wild-type* tumors after CDK4/6 inhibitor progression. This is a crucial finding for a patient group lacking clear targeted options and broadens the utility of targeting the PI3K pathway beyond just mutated tumors.

The Victoria 1 study showed that adding a CDK4/6 inhibitor (triplet therapy) improved outcomes only in patients with PIK3CA wild-type tumors. In PIK3CA-mutant tumors, the doublet therapy was equally effective. This surprising finding highlights that distinct resistance mechanisms are at play and that mutation status is critical for selecting optimal combination regimens.

Despite the presence of PIK3CA mutations in some triple-negative breast cancer (TNBC) tumors, Phase III trials with AKT inhibitors have been negative. Currently, there is insufficient evidence to support using PI3K/AKT pathway inhibitors for TNBC in clinical practice.

While its IV administration is a hurdle, the pan-PI3K/mTOR inhibitor gedotolisib is clinically compelling because of its distinct safety profile. It causes significantly less hyperglycemia and diarrhea compared to oral PI3K inhibitors like alpelisib, making it an attractive option for patients where those specific toxicities are a major concern.

Cellcuity's drug is effective in breast cancer patients without PIK3CA mutations (wild type). This challenges the dominant precision medicine model that requires a specific genetic marker, showing that a pathway's aberrant activity can be a sufficient therapeutic target on its own.