Lesions in Radiated/Non-Radiated Fields Achieve Similar Responses with Tisotumab Vedotin in Cervical Cancer

Over half of patients with cervical cancer who received prior radiation achieved disease control, with approximately one-third achieving an objective response, from treatment with tisotumab vedotin-tftv (Tivdak), according to results from a retrospective, single-institution review shared in a poster at the 2026 Society of Gynecologic Oncology Annual Meeting on Women’s Cancer (SGO).

Among 14 patients with evaluable lesions in both radiated and non-radiated fields at the time of tisotumab vedotin treatment initiation, the best response achieved was partial response (PR) in 42.9%, stable disease in 21.4%, and progressive disease in 35.7% among radiated fields, compared with complete responses (CRs) in 7.1%, PRs in 28.6%, stable disease in 35.7%, and progressive disease in 28.6% among non-radiated fields (P = .7092). The objective response rate (ORR) was 42.9% in radiated fields vs 35.7% in non-radiated fields (P >.9999), and the clinical benefit rate (CBR) was 64.3% vs 71.4%, respectively (P >.9999).

Among all evaluable lesions in radiated or non-radiated fields at the time of tisotumab vedotin initiation, the best response achieved in 19 lesions in radiated fields was a PR in 47.4%, stable disease in 15.8%, and progressive disease in 36.8%, compared with a CR in 5.9%, PR in 29.4%, stable disease in 29.4%, and progressive disease in 35.3% among 17 lesions in non-radiated fields (P = .4910). The ORR was 47.4% in radiated fields vs 35.3% in non-radiated fields (P = .5160), and the CBR was 63.2% vs 64.7%, respectively (P >.9999).

Furthermore, the median overall survival was 11.0 months, and the median progression-free survival was 2.8 months.

Among all 29 patients who received tisotumab vedotin in the overall cohort, the outcome of treatment was dose reduction and dose delay in 48.3% each, with treatment being discontinued due to progression (72.4%), patient preference (6.9%), hospice/death (10.3%), and ongoing reasons (10.3%). The best response was CR in 0%, PR in 34.5%, stable disease in 17.2%, and progressive disease in 48.3%. The ORR was 34.5%, and the CBR was 51.7%.

“Lesions within previously radiated fields demonstrated comparable clinical responses to lesions in non-radiated fields, raising the hypothesis that the mechanism of antibody-drug conjugates may overcome the diminished effectiveness of systemic therapies historically observed in radiated fields,” wrote lead study author Reed O’Connor, MD, PhD, a gynecology-oncology fellow at The James Comprehensive Cancer Center of The Ohio State University, and coauthors.

The review included patients with recurrent cervical cancer who received treatment with tisotumab vedotin from October 2021 to July 2025, with the primary objective to evaluate clinical outcomes in this patient population, while also assessing response for lesions in the radiated field.

ORR was defined as provider-assessed CR or PR, and CBR was defined as provider-assessed CR, PR, or stable disease. Kaplan Meier analyses were used to determine PFS and OS, and Fisher’s exact test was used to compare proportional variables.

The mean age of patients was 49.6 years (SD, 11.0), and the median body mass index was 24.2 kg/m² (IQR, 22.4-31.9). Patients were White (86.2%), non-Hispanic (89.7%), never smokers (41.4%), and had hypertension (31.0%), diabetes (17.2%), chronic kidney disease (3.4%), and coronary artery disease, myocardial infection, or cerebrovascular accident (10.3%).

Disease histology was most commonly squamous cell (58.6%), followed by adenocarcinoma (34.5%) and other types (6.9%); tumor HPV status was dependent (31.0%), independent (10.3%), and unknown (55.2%); and initial disease stage was most commonly IV (48.3%) and III (37.9%).

Initial treatment included chemoradiotherapy (37.9%), surgery plus chemoradiotherapy (17.2%), and chemotherapy (17.2%), and prior treatment was immunotherapy (93.1%), bevacizumab (Avastin; 79.3%), and radiation (75.9%).

“Despite these promising response rates, outcomes were poor with most patients dying within 1 year of [tisotumab vedotin] initiation, underscoring the poor prognosis in this disease setting,” concluded O’Connor and coauthors.

References

O’Connor RM, Chalif J, Abdeen CS, et al. Does prior radiation affect response? Assessment of tisotumab vedotin activity in recurrent cervical cancer. Presented at the 2026 SGO Annual Meeting on Women’s Cancer; April 10-13, 2026; San Juan, PR. Poster 1210.