There is currently no standard option for these patients. The mainstay of therapy in this setting is monotherapy with chemotherapy, but the benefit-risk profiles are poor, and overall response rates (ORRs) are less than 15%.
In the clinical trial that led to the accelerated approval, tisotumab vedotin-tftv yielded an ORR of 24%, which an expert not connected with the trial said was “impressive.”
“Tivdak’s approval as a monotherapy in the U.S. is an important milestone for women with recurrent or metastatic cervical cancer with disease progression on or after chemotherapy, as they are in need of a new treatment option and we look forward to making it available to them,” Jan van de Winkel, PhD, chief executive officer of Genmab, said in a statement.
Tisotumab vedotin is an antibody–drug conjugate: A human monoclonal antibody directed against tissue factor, which is highly expressed on many solid tumors, is attached to the microtubule-disrupting agent monomethyl auristatin E.
Details of clinical trial data
The accelerated approval was based on the results of the innovaTV 204, an open-label, multicenter, single-arm clinical trial, which was published online on April 9 in The Lancet Oncology, as reported at the time.
The trial included 101 women with recurrent or metastatic squamous cell, adenocarcinoma, or adenosquamous cervical cancer whose disease had progressed with or after doublet chemotherapy with bevacizumab (if eligible by local standards) and who had received two or fewer previous systemic regimens for recurrent or metastatic disease.
All patients received tisotumab vendotin intravenously at a dose of 2.0 mg/kg (up to a maximum of 200 mg) once every 3 weeks until disease progression or unacceptable toxicity.
The confirmed ORR was 24% and included seven (7%) complete responses and 17 (17%) partial responses.
The disease control rate was 72%, and the median duration of response was 8.3 months. The median progression-free survival was 4.2 months; the 6-month progression-free survival rate was 30%.
Median overall survival (OS) was 12.1 months. OS rates were 79% at 6 months and 51% at 12 months.
Overall, the safety profile with tisotumab vedotin was manageable, the trialists reported. The most common treatment-related adverse events were alopecia (38%), epistaxis (30%), nausea (27%), conjunctivitis (26%), fatigue (26%), and dry eye (23%). Adverse events of grade 3 or higher were reported by 28% of patients and included neutropenia (3%), fatigue (2%), ulcerative keratitis (2%), and peripheral neuropathies (2%). One patient died as a result of septic shock that was considered by the investigators to be related to therapy.
The new product labeling includes a boxed warning for ocular toxicity. It notes that tisotumab vedotin “caused changes in the corneal epithelium and conjunctiva resulting in changes in vision, including severe vision loss, and corneal ulceration.” It recommends that clinicians conduct an ophthalmic exam at baseline, prior to each dose, and as clinically indicated and that patients adhere to premedication and required eye care before, during, and after infusion.
Confirmatory trial underway
Continued approval may be contingent upon verification and description of clinical benefit in confirmatory trials.
The confirmatory trial for tisotumab vedotin is already underway: The global phase 3 innovaTV 301 trial began in January 2021. It will compare tisotumab vendotin to chemotherapy (topotecan, vinorelbine, gemcitabine, irinotecan, or pemetrexed) for patients with recurrent or metastatic cervical cancer who have received one or two prior lines of systemic therapy.
A version of this article first appeared on Medscape.com.