FDA hands accelerated nod to Seagen, Genmab's solo ADC in cervical cancer, but combo studies look even more promising
Biopharma’s resident antibody-drug conjugate expert Seagen has scored a clutch of oncology approvals in recent years, finding gold in what are known as “third-gen” ADCs. Now, another of their partnered conjugates is ready for prime time.
The FDA on Monday handed an accelerated approval to Seagen and Genmab’s Tivdak (tisotumab vedotin-tftv, or “TV”) in second-line patients with recurrent or metastatic cervical cancer who previously progressed after chemotherapy rather than PD-(L)1 systemic therapy, the companies said in a release.
Tivdak is an ADC that links a tissue factor-directed antibody with a payload of monomethyl auristatin E (MMAE). It’s the third ADC approved for Seagen, which has emerged as an ADC specialist in recent years.
The agency based its review on data from the Phase II innovaTV 204 study in 101 patients, with Tivdak posting a 24% response rate, as assessed by an independent review committee, with a median duration of response of 8.3 months. In keeping with the FDA’s accelerated approval program, Seagen and Genmab will run a confirmatory trial to determine the drug’s clinical outcomes.
The drug will come with a boxed warning for ocular toxicity, which includes a risk of changes in the corneal epithelium and conjunctiva resulting in changes in vision, including severe vision loss, and corneal ulceration, according to the drug’s label.
Tivdak’s wholesale acquisition cost is $5,885 per 40mg single dose vial, with patients’ individual costs determined by body weight and duration of therapy, a spokesperson said by email. The companies estimate an average WAC per patient per month of $34,000, before discounts or rebates.
TV will compete with Merck’s Keytruda in second-line cervical cancer, but that competition may quickly turn into collaboration with new combo data showing stronger response rates. The FDA also granted Keytruda an accelerated approval in 2018, based on data showing a 14% response rate — pretty abysmal results but a sign of promise in a big unmet clinical need.
Seagen and Genmab this weekend released data from the Phase Ib/II innovaTV 205 study, showing some strong results for TV in combination with the chemotherapy carboplatin or Keytruda across multiple lines of therapy for recurrent or metastatic patients.
A combination of TV and Keytruda in second- or third-line cervical cancer patients posted a 38% response rate in 34 patients, with two complete responses and 11 partial responses reported. Meanwhile, the TV-carbo combo posted a response rate of 55%, including four complete responses and 14 partial responses, in first-line recurrent or metastatic cervical cancer patients. At a median follow-up of 7.9 months, the combo’s duration of response was 8.3 months with a median progression-free survival of 9.5 months.
Also this weekend, Merck uncorked full data from the KEYNOTE-826 study showing a combination of Keytruda and chemotherapy with or without Roche’s Avastin cut the risk of death by 33% over chemo with or without Avastin (p=<0.001) in first-line advanced cervical cancer patients. The Keytruda arm posted a median OS of 24.4 months compared with 16.5 months for the chemo arm, Merck said.
Social: Clay Siegall, Seagen CEO (Life Science Washington via YouTube)