According to updated results from the INAVO120 trial, inavolisib plus palbociclib and fulvestrant sustained clinical benefit beyond disease progression among patients with PIK3A-mutated, hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative, locally advanced or metastatic breast cancer.  

These data will be presented by Dejan Juric, MD, Massachusetts General Hospital Cancer Center, Boston, Massachusetts, at the 2024 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago, Illinois. 

Prior results demonstrated that inavolisib plus palbociclib and fulvestrant improved progression-free survival with manageable safety and tolerability compared to placebo plus palbociclib and fulvestrant. Here, additional efficacy end points including time from randomization to end of next-line treatment and time from randomization to first chemotherapy are outlined alongside key adverse events and patient-reported outcomes.  

At a median follow-up of 21.3 months, time from randomization to end of next-line treatment was 24 months in the inavolisib arm and 15.1 months in the placebo arm. Time from randomization to first chemotherapy was not evaluable in the inavolisib arm and 15 months in the placebo arm. Key grade ≤3 adverse events included HG, diarrhea, rash, and stomatitis. Adverse events were managed with supportive care and inavolisib dose interruptions/reductions and resolved. Adverse events that led to treatment discontinuation included HG (n = 1) and stomatitis (n = 1). According to patient-reported outcomes measures, patients in the inavolisib arm experienced a longer duration of time without pain severity and were better able to maintain day-to-day functioning. In both treatment arms, patients reported levels of selected symptomatic adverse events from PRO-CTCAE and identified overall treatment bother as moderate or less. 

As study authors noted, inavolisib plus palbociclib and fulvestrant “sustained benefit beyond disease progression, delaying chemotherapy administration, with manageable safety and tolerability that was reflected in PROs…supporting it as a new standard of care.”

Source: 

Juric D, Kalinsky K, Turner NC, et al. First-line inavolisib/placebo + palbociclib + fulvestrant (Inavo/Pbo+Palbo+Fulv) in patients (pts) with PIK3CA-mutated, hormone receptor-positive, HER2‑negative locally advanced/metastatic breast cancer who relapsed during/within 12 months (mo) of adjuvant endocrine therapy completion: INAVO120 phase III randomized trial additional analyses. Presented at the ASCO Annual Meeting. May 31 – June 4, 2024; Chicago, IL. Abstract #1003