Dr Sun on Tisotumab Vedotin in Recurrent or Metastatic HNSCC

Lova L. Sun, MD, MSCE, assistant professor of medicine (hematology-oncology), Department of Medicine, the Hospital of the University of Pennsylvania, discusses data from part C of the phase 2 innovaTV 207 trial (NCT03485209), which evaluated the efficacy and safety of tisotumab vedotin-tftv (Tivdak) in patients with recurrent or metastatic head and neck squamous cell carcinoma (HNSCC) who received prior treatment with platinum-based chemotherapy and/or an immune checkpoint inhibitor.

Tisotumab vedotin was administered intravenously at 1.7 mg/kg once every two weeks in the HNSCC cohort. Findings presented at the 2024 ASCO Annual Meeting showed that among all patients treated in cohort C (n = 40), the confirmed objective response rate (ORR) was 32.5% (95% CI, 18.6%-49.1%), with a median duration of response (DOR) of 5.6 months (95% CI, 3.0–not reached [NR]). One patient (2.5%) experienced a complete response (CR), and the partial response (PR) rate was 30.0%. The rates of stable disease (SD) and progressive disease (PD) were 32.5% and 25.0%, respectively, and the disease control rate (DCR) was 42.5% (95% CI, 27.0%-59.1%). Notably, among these 25 patients being treated in the second- or third-line settings, 40% experienced a reduction in target lesion diameters of at least 30%.

Among a subgroup of 25 patients who were being treated in the second or third line (n = 25), the confirmed ORR was 40.0% (95% CI, 21.1%-61.3%) with a median DOR of 5.6 months (95% CI, 3.0-NR). The respective CR, PR, SD, and PD rates in this subgroup were 0%, 40.0%, 24.0%, and 28.0%. The DCR was 52.0% (95% CI, 31.3%-72.2%).

Responses were observed in patients irrespective of prior taxane exposure, Sun says, adding that deeper responses were more common in taxane-naive patients, which was expected given the MMAE payload mechanism of tisotumab vedotin.

The innovaTV 207 trial is ongoing, and it continues to enroll patients with recurrent or metastatic HNSCC being treated in the first-line setting (part F) and the second- or third-line settings (part E).