Activity of Low Dose Nivolumab in Patients With Advanced Squamous Cell Carcinomas and Other Cancers

Immune checkpoint inhibitors such as anti-PD-1 antibodies are essential in cancer therapy. Emerging data suggest that lower doses may be effective and more economical, though further evidence is needed. We conducted a retrospective study at Centre Léon Bérard to assess the efficacy and safety of low-dose nivolumab (20 mg every 3 weeks) in patients with advanced cancer, mainly squamous cell carcinomas (SCC). Between 2023 and 2024, 53 patients were treated, with a median age of 74 years; 39.6% were over 80. Most were male (64%) and had ECOG ≥ 2 (69.9%). Primary tumor sites included cutaneous SCC (34%), head and neck SCC (32%), and soft tissue sarcoma (15%). After a median follow-up of 8.3 months, median overall survival was 7.5 months. The objective response rate (ORR) was 20.8%, driven by the SCC subgroup; no responses were observed in non-SCC histologies, in patients with prior ICI exposure, or beyond the second line of treatment. Among IO-naïve SCC patients treated in first or second line (n = 22), ORR was 50%. Toxicity was manageable: 18.7% experienced immune-related adverse events, with only 3.7% grade 3. Low-dose nivolumab demonstrates encouraging efficacy and tolerability in a frail population, supporting its potential role in resource-limited settings. Prospective trials are warranted to confirm these findings in broader populations.