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Abstract Everolimus is widely used in patients with advanced ER‐positive, HER2‐negative breast cancer. We looked at alterations in the PIK3CA/AKT/mTOR pathway in a multicenter cohort as potential biomarkers of efficacy. Patients with advanced ER‐positive, HER2‐negative breast cancer treated with everolimus and endocrine therapy between 2012 and 2014 in two cancer centers were included. Targeted sequencing examined mutations in PIK3CA, ESR1, and AKT1 genes. An immunochemical analysis was conducted to evaluate expression of PTEN, INPP4B, STK11, p4EBP1, and pS6. We analyzed 71 patients (44 primary tumors; 27 metastatic tissues). Median age was 63 years [58–69]. All patients had heavily pretreated advanced disease. A mutation in the PIK3CA pathway was observed in 32 samples (PIK3CA exons 10 and 21 and AKT1 exon 4 in 15.5%, 24.0%, and 5.6% of samples), and in ESR1 in 5 samples (7.0%), respectively. Most samples showed cytoplasmic expression of the PIK3CA pathway proteins. Progression‐free survival was longer in patients with a pS6 or p4EBP1 histoscore ≥ median value (6.6 versus 3.7 months, p = 0.037), and in patients with a PTEN histoscore ≤ median value (7.1 versus 5.3 months, p = 0.02). Overall survival was longer in patients with pS6 ≥ 3rd quartile (27.6 versus 19.3 months, p = 0.038) and in patients with any mutation in the PIK3CA/AKT/mTOR pathway (27.6 versus 19.3 months, p = 0.011). The prognosis of patients treated with everolimus for advanced ER‐positive, HER2‐negative breast cancer appears primarily driven by molecular features associated with the activation of the PIK3CA/AKT/mTOR pathway.

Although combined PD-1/CTLA-4 inhibition showed limited efficacy in single-arm, phase II trials in metastatic uveal melanoma (mUM), such combination appears frequently used in mUM patients. We here report our experience with nivolumab/ipilimumab in mUM. A retrospective cohort of 47 mUM patients, 24 men and 23 women, received nivolumab/ipilimumab between October 2019 and December 2021, mostly first line (94%). Two regimens were used: nivolumab 1 mg/kg + ipilimumab 3 mg/kg (nivo1ipi3, 49% of patients) and nivolumab 3 mg/kg + ipilimumab 1 mg/kg (nivo3ipi1, 51% of patients). Median follow-up was 37 and 88 weeks in nivo3ipi1 and nivo1ipi3 cohorts, respectively. We observed partial response in two patients (4%) and stable disease in 14 patients (30%), with no significant difference between the two regimens. Median progression-free survival was 13.6 weeks and 11.9 weeks in the nivo1ipi3 and nivo3ipi1 cohorts, respectively (p = 0.49). Severe adverse events (grade 3 or 4) were observed in seven patients (15%) among which five treated with nivo1ipi3 (22%) and two treated with nivo3ipi1 (8%). These data suggest that nivolumab/ipilimumab combination does not improve clinical outcomes compared to other therapies but is more toxic. In the absence of controlled clinical trials, we would not recommend this combination as a standard treatment in all mUM patients but rather as an option. Patients for whom the benefit–risk ratio could justify the combination need to be defined.