Alpelisib in PIK3CA-mutated BC patients after CDK4/6 inhibition: efficacy and toxicity

The trial presented by Dr Rik van Severen van University Hospitals Leuven investigates the efficacy and safety of alpelisib in patients with hormone receptor-positive, HER2-negative metastatic breast cancer. PIK3CA mutations were evaluated in metastatic tumour sites in thirty-eight patients to assess the PFS, CBR, and safety profile associated with the combination of alpelisib and antihormonal therapy. Both post- and premenopausal women were eligible for inclusion, irrespective of tumour specifications, and minimal exclusions were implemented.

The observed CBR stood at 26.3%, and while an increased incidence of adverse effects was noted, 8% of patients discontinued treatment due to toxicity. The primary reason for treatment discontinuation in 85% of cases was disease progression. These outcomes align with findings from analogous trials, underscoring common side effects such as hyperglycemia, nausea, and diarrhoea.

In summary, the combination of alpelisib with antihormonal treatment emerges as a promising next-generation therapeutic approach for patients with PIK3CA-mutated breast cancer, characterized by a manageable albeit noteworthy toxicity profile.

Reference:

Van Severen R, Efficacy and safety of alpelisib in PIK3CA-mutated, hormone-receptor positive advanced breast cancer after a CDK4/6 inhibitor: an open-label, multi-centre, prospective, single arm clinical trial. SABCS 2023, #PO5-01-14