Subcutaneous Dual-Target Antibody Enters Head and Neck Cancer, FDA Accepts Priority Review

Once recurrent or metastatic head and neck squamous cell carcinoma continues to worsen after platinum-containing chemotherapy and immunotherapy, subsequent options are often limited. The U.S. Food and Drug Administration (FDA) has granted Priority Review to the supplemental biologics license application for subcutaneous amivantamab, bringing a bispecific antibody that simultaneously targets EGFR and MET one step closer to clinical use in this patient population.

The application applies to adults whose disease progressed after treatment with platinum-containing chemotherapy and a PD-1 or PD-L1 inhibitor. Amivantamab can bind both the epidermal growth factor receptor EGFR and the hepatocyte growth factor receptor MET. In addition to disrupting tumor growth signals, it is designed to trigger immune-mediated antitumor activity. These two signaling pathways are frequently found in head and neck squamous cell carcinoma and may be involved in disease progression and the development of drug resistance.

The regulatory application is based primarily on data from Cohort 1 of the Phase 1b/2 OrigAMI-4 trial. This open-label study enrolled 102 patients who had received an immune checkpoint inhibitor and platinum-containing chemotherapy. Independent central review showed that subcutaneous amivantamab monotherapy had an overall response rate of 42%, with 15% of all participants achieving a complete response—equivalent to more than one-third of all responding patients.

Efficacy was not reflected only in temporary tumor shrinkage. The published analysis showed that 56% of responding patients maintained their response for at least six months; median progression-free survival was 6.8 months, and median overall survival was 12.5 months. These figures provide a preliminary signal in a difficult-to-treat population, but the study had no randomized control group, making it impossible to directly determine how much survival benefit the new therapy may add compared with current later-line treatments.

The trial population also had important boundaries: patients with HPV-positive oropharyngeal cancer and those who had previously received anti-EGFR therapy were not included. Therefore, even if the FDA ultimately grants approval, whether the evidence can be extended to these common clinical populations will still need to be answered by other studies. OrigAMI-4 is also evaluating amivantamab in combination with pembrolizumab, paclitaxel, or pembrolizumab plus carboplatin; the relevant results may further define its place in treatment.

Regarding safety, the study summary stated that no new safety signals were identified, and 8% of patients discontinued treatment because of treatment-related adverse events. However, the size and follow-up duration of an early-stage study remain insufficient to rule out less common or long-term toxicities. The subcutaneous formulation may simplify administration, but the actual treatment burden, injection-related reactions, and differences in risk compared with other therapies still require more complete data.

FDA Priority Review typically shortens the review period to approximately six months, indicating that the regulator believes the application may offer a meaningful improvement for a serious disease; it does not mean that efficacy has been confirmed or that the product has obtained an indication for head and neck cancer. The subcutaneous formulation of amivantamab is currently used in certain EGFR-mutated non-small cell lung cancer settings; its use in head and neck cancer remains investigational, and whether it can ultimately change later-line treatment will depend on the FDA's assessment of its benefits, risks, and the completeness of the early-stage single-arm evidence.