The primary end point was OS assessed sequentially for noninferiority and superiority. Secondary end points included progression-free survival (PFS), objective response rate (ORR), duration of response (DOR), safety, and quality of life (QOL).
Baseline characteristics were well balanced between the 2 study arms. In the overall study population ( n = 422), the median age was 49.5 years (interquartile range, 42-58), 79.6% of patients were younger than 60, and 85.5% were male. The primary tumor site was the oral cavity in 76.3% of patients, and 25.6% had M1 disease. Approximately 50% had received prior treatment, and 87.2% had any history of tobacco exposure.
The trial was conducted at Tata Memorial Centre in Mumbai, India, where access to standard immune checkpoint inhibitors remains severely limited, with fewer than 3% of eligible patients in India able to receive checkpoint inhibitor–based therapy due to cost and infrastructure barriers, per investigators’ background data cited in the presentation.
Key Findings From the Phase 3 Trial of TMC-I in Platinum-Sensitive HNSCC
- TMC-I reduced the risk of death by 43% vs paclitaxel-carboplatin (HR, 0.57; 95% CI, 0.44–0.73; P < .0001); median OS 10.32 vs 6.21 months
- ORR more than doubled with TMC-I (53.4% vs 24.1%; OR, 3.64; 95% CI, 2.23-5.94; P < .001)
- Median DOR extended from 3.6 to 11.0 months with TMC-I (HR, 0.32; 95% CI, 0.19-0.53; P < .001)
What Were the Additional Efficacy Findings?
TMC-I improved outcomes across all prespecified secondary efficacy end points. The median PFS was 5.5 months with TMC-I vs 2.7 months with paclitaxel/carboplatin (HR, 0.47; 95% CI, 0.37-0.58; P < .001), representing a 53% reduction in the risk of progression or death. The 1-year PFS rate was 26.1% with TMC-I compared with 4.7% with paclitaxel/carboplatin.
The ORR was 53.4% with TMC-I (n = 178) vs 24.1% with paclitaxel/carboplatin (n = 174; odds ratio [OR], 3.64; 95% CI, 2.23–5.94; P < .001). Disease control was achieved in 74.7% of patients receiving TMC-I vs 44.3% receiving paclitaxel/carboplatin (OR, 3.78; 95% CI, 2.23–6.41; P < .001). Among responders, the median DOR was 11.0 months with TMC-I vs 3.6 months with paclitaxel/carboplatin (HR, 0.32; 95% CI, 0.19–0.53; P < .001); the 1-year DOR rate was 44.5% vs 11.6%, respectively.
What did the safety analysis show?
All patients in both arms experienced at least one treatment-related adverse effect (TRAEs) of any grade. Grade 3 or higher TRAEs occurred in 37.1% of patients receiving TMC-I (n = 202) vs 47.5% of those receiving paclitaxel/carboplatin (n = 198). Checkpoint inhibitor-related AEs were infrequent with the ultra-low-dose nivolumab approach: any-grade checkpoint inhibitor–related AEs occurred in 3.5% of TMC-I–treated patients, and grade 3 or higher related AEs in 1.5% (3 of 199).
QOL assessments showed no meaningful difference between arms at any timepoint, with global health status, role functioning, and social functioning maintained throughout treatment. Minor between-arm differences in pain medication use (P = .009) and nutritional supplement use (P = .007) were observed without impact on overall QOL scores.
Investigators noted that the annual cost of TMC-I is approximately $2,700, compared with approximately $12,000 for standard chemo-immunotherapy regimens and approximately $30,000 for cetuximab-based therapy. This is a disparity the authors identified as central to the regimen’s potential scalability in low- and middle-income countries where HNSCC burden is disproportionately high.
Looking for other updates in HNSCC?
Interest in novel first-line regimens for recurrent/metastatic HNSCC has continued ahead of the 2026 ASCO Annual Meeting. A recent analysis published this month showed an ORR benefit for INBRX-106 plus pembrolizumab vs pembrolizumab alone in this population, adding to the growing body of data exploring immunotherapy-based combinations in HNSCC.2
References
- Shah MJ, Noronha V, Menon NS, et al. Ultra-low-dose immunotherapy plus oral metronomic chemotherapy versus paclitaxel-carboplatin in platinum-sensitive recurrent or metastatic head and neck squamous cell carcinoma: a randomized phase III trial. J Clin Oncol. 2026;44(suppl 17):LBA6007. doi:10.1200/JCO.2026.44.17_suppl.LBA6007
- INBRX-106 Plus Pembrolizumab Yields Efficacy Benefit vs Pembrolizumab Alone in First-Line HNSCC. OncLive. Published May 11, 2026. Accessed May 31, 2026. https://www.onclive.com/view/inbrx-106-plus-pembrolizumab-yields-efficacy-benefit-vs-pembrolizumab-alone-in-first-line-hnscc