Shares of Sesen Bio (SESN) – Get Report plummeted by over 70% Friday after the Food and Drug Administration determined that it could not approve a biologics license application for the biotech company’s bladder cancer drug Vicineum.
Sesen Bio stock fell about 18% to $1.74 in after hours trading. The stock had risen to $5.95 by midday on Friday before the FDA’s announcement.
“We are deeply disappointed by this unexpected result, and it is an unfortunate day for patients suffering from BCG-unresponsive NMIBC (non-muscle invasive bladder cancer),” Sesen Bio CEO Dr. Thomas Cannell said in a statement. “We remain dedicated to our mission to save and improve the lives of patients by bringing new treatment options to patients, and we intend to work closely with the FDA to understand next steps.”
Sesen Bio on Friday received a complete response letter from the FDA regarding its biologics license application, the statement said. The FDA said it could not approve the application in its present form and provided recommendations specific to additional clinical/statistical data and analyses in addition to chemistry, manufacturing and controls issues pertaining to a recent preapproval inspection and product quality.
The biotech company said it plans to request a Type A meeting as soon as possible with the FDA to discuss the next steps that are needed before the application may be approved, the statement said.
Viniceum, a locally administered fusion protein, is Sesen Bio’s lead product candidate being developed for treatment of BCG-unresponsive non-muscle invasive bladder cancer. The company is currently in the follow-up stage of a Phase 3 registration trial in the U.S. for the drug.
BCG refers to Bacillus Calmette-Guerin and is the most common intravesical immunotherapy for treating early-stage bladder cancer.
In February, the FDA accepted the company’s biologics license application file for Viniceum and granted application priority review with a target Prescription Drug User Fee Act date of Aug. 18.
The American Cancer Society estimates there will be about 83,730 new cases of bladder cancer in 2021, with 17,200 deaths. Bladder cancer is the fourth most common cancer in men, but it’s less common in women, the society said.
Vicineum’s activity in BCG-unresponsive NMIBC is also being explored at the US National Cancer Institute in combination with AstraZeneca’s (AZN) – Get Report immune checkpoint inhibitor durvalumab, the company said in an earlier statement.
On Monday, Sesen Bio posted a wider-than-expected second-quarter loss and missed revenue expectations.