U.S. FDA declines to approve Sesen Bio's bladder cancer treatment, shares plunge

Signage is seen outside of the Food and Drug Administration (FDA) headquarters in White Oak, Maryland, U.S., August 29, 2020. REUTERS/Andrew Kelly

Aug 13 (Reuters) - The U.S. drug regulator has declined to approve Sesen Bio Inc's (SESN.O) lead therapy candidate for a type of bladder cancer, the company said on Friday, sending its shares down more than 80%.

The U.S. Food and Drug Administration notified the drug developer that it cannot approve the marketing application for the drug, Vicineum, in its present form.

The agency has provided recommendations specific to additional clinical data and analyses in addition to issues pertaining to a recent pre-approval inspection and product quality, the company added.

Sesen Bio said it plans to request a meeting with the FDA to discuss the next steps in the regulatory pathway for the drug's approval.

Vicineum, administered via an injection, is a targeted fusion protein that targets and binds to epithelial cell adhesion molecule, a type of antigen found on the surface of tumor cells.

The therapy is being developed for immunotherapy unresponsive non-muscle invasive bladder cancer, a type of cancer found in the tissue that lines the inner surface of the bladder

Vicineum received FDA's 'fast track' designation in 2018 and was under the agency's priority review. The company also sought the European Medicines Agency's approval for the drug earlier this year.

In March, the company received approval to begin clinical trial of the drug in China.

Sesen has partnered with Qilu Pharmaceutical, Hikma Pharmaceuticals and Eczacibasi Pharmaceuticals Marketing (EIP), respectively, for commercialization of Vicineum in Greater China, the Middle East and North Africa and Turkey.

Sesen Bio shares slumped 82% to $0.86 in the late afternoon on the Nasdaq.

Reporting by Mrinalika Roy in Bengaluru; Editing by Shailesh Kuber

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