Astellas, Seagen Cancer Drug Becomes First and Only Approved ADC For Advanced Urothelial Cancer in Japan

Japan’s Astellas Pharma and U.S.-based Seagen has won a nod from Japan’s Ministry of Health, Labour and Welfare (MHLW). Their co-developed drug, Padcev (enfortumab vedotin), was approved on September 27, becoming the first and only antibody-drug conjugate (ADC) to be approved for patients with advanced urothelial cancer in Japan.

What is Padcev?

Padcev is a Nectin-4 targeting antibody. It can bind to the protein that’s highly expressed in bladder cancer cells, which blocks cell division and activates programmed cell death (apoptosis). It got its first USFDA approval in July 2021 to treat adult patients with locally advanced or metastatic urothelial cancer. In Japan, the drug is approved to treat patients with radically unresectable urothelial carcinoma that has progressed after chemotherapy.

Approval Based on Phase 3 Trial  

MHLW’s approval came after a global Phase 3 clinical trial (EV-301). The trial recruited 608 patients with locally advanced or metastatic urothelial cancer who were previously treated with a PD-1/L1 inhibitor and platinum-based therapies. 301 of them took enfortumab vedotin while the other 307 received chemotherapy such as docetaxel, paclitaxel or vinflunine. 

The results showed a boost in patients’ survival within a median time of 3.9-month. The median overall survival of those in the enfortumab vedotin group is 12.9 months while the control group was 9 months. In addition, the enfortumab vedotin group also performed better in the category of progression-free survival with 5.55 months compared to 3.71 months in the other group.

Astellas and Seagen’s partnership started in 2007 and expanded in 2009. In 2013, the pair added an new ADC into the collaboration, a SLITRK6-targeting ADC called ASG15ME. SLITRK6 is also known to be highly expressed in bladder and lung cancer. In 2016, Astellas released data of ASG15ME’s Phase 1 trials in Metastatic Urothelial Cancer at ASCO.

Author

Tyler Chen

"Never go to a doctor whose office plants have died."- Erma Bombeck