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

ABSTRACT 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.