Seattle Genetics/Astellas win priority US review for armed antibody aimed at bladder cancer
Seattle Genetics has secured a speedy review of its second armed antibody, courtesy of the FDA.
The company’s ‘breakthrough’ Astellas-partnered drug — enfortumab vedotin — has procured priority review from the US regulator, after data showed it helped patients with a stubborn type of bladder cancer.
The drug-induced a 44% objective response rate (ORR) in 128 patients whose disease had progressed despite treatment with both platinum-containing chemotherapy and a checkpoint inhibitor in the one-arm EV-201 study. About 12% of the patients experienced a complete response, Seattle Genetics disclosed at ASCO this June.
A marketing application for the drug has already been submitted — and a late-stage trial designed to confirm the drug’s safety and efficacy in this patient population is ongoing.
The FDA is expected to make its decision on the drug by March 15, the company said on Monday. In a note published in July, Stifel analysts estimated that enfortumab vedotin will generate North America sales of about $367 million in 2024.
The partners are testing the drug in combination with Merck’s $MRK Keytruda and with chemotherapy, and as part of a triplet combo. The idea is to also push for approval in the frontline setting and generate blockbuster sales, Seattle Genetics’ chief Clay Siegall told Endpoints News at ASCO.
ADCs are a class of therapeutics in which a cancer-killing toxin is attached to a specific antibody using a biodegradable linker. Designed to minimize the effects of the chemotherapy on healthy cells while maximizing tumor cell death, the technology is sometimes likened to a trojan horse as it is engineered to go unnoticed, delivering chemotherapies to cells expressing the antigen target. Seattle Genetics $SGEN already has one ADC on the market, Adcetris, and a slate of others in development.
Enfortumab vedotin (EV) targets Nectin-4, a cell adhesion molecule seen in a range of solid tumors.
Urothelial cancer is the most common type of bladder cancer. About 80,470 new cases of bladder cancer are expected to be diagnosed this year, and it is anticipated that 17,670 bladder cancer deaths will occur in 2019, according to American Cancer Society estimates. Data suggest most patients do not respond to checkpoint inhibitors after a platinum-containing therapy has failed as an initial treatment for advanced disease, and there are no other approved options for patients once these two lines of treatment have been exhausted.
Social image: Clay Siegall, Life Science Washington via YouTube