Sesen Bio Stock (SESN): Why The Price Substantially Fell Today

By Amit Chowdhry ● Dec 9, 2021
  • The stock price of Sesen Bio Inc (NASDAQ: SESN) fell by 17.58% today. This is why it happened.

The stock price of Sesen Bio Inc (NASDAQ: SESN) – a late-stage clinical company developing targeted fusion protein therapeutics for the treatment of patients with cancer – fell by 17.58% today. Investors responded negatively to Sesen Bio announcing its anticipated regulatory path forward for Vicineum for the treatment of BCG-unresponsive non-muscle invasive bladder cancer (NMIBC) following its Clinical Type A meeting with the US Food and Drug Administration (FDA), which occurred on December 8, 2021 (Clinical Type A Meeting). The FDA rejected Vicineum in August as Sesen Bio was accused of committing violations in the clinical testing of Vicineum and investors were likely hoping for a better outcome in terms of an update from the company. 

Following the productive Clinical Type A Meeting, the company believes it has greater clarity regarding the requirements for resubmission of the BLA and the trial design, which may include these elements:

— A randomized clinical trial assessing the safety and efficacy of Vicineum compared to investigators’ choice of intravesical chemotherapy;

— Trial may include both patients who have received adequate BCG1 and patients who have received less-than-adequate BCG;

— Company encouraged to submit the final VISTA trial results with the resubmission; and

— Anticipated randomized trial design is aligned with guidance the Company has received from the European Medicines Agency, which may help to coordinate the regulatory paths forward for Vicineum in the US and the European Union (EXIT-OLD).

— The company expects to hold a Type C meeting with the FDA in early 2022 to discuss the protocol for the additional clinical trial.


“We are pleased to have greater clarity on the regulatory path forward to resubmit the BLA and ultimately bring Vicineum to market if approved. Our team looks forward to working productively with regulators as we continue to focus on our mission of saving and improving the lives of patients.”

— Dr. Thomas Cannell, president and chief executive officer of Sesen Bio

Disclaimer: This content is intended for informational purposes. Before making any investment, you should do your own analysis.