Sesen Bio reached an agreement with the FDA a week ago on the product labeling of its new bladder cancer drug, which is one of the final steps in bringing the new drug to the market. Packaged product labels are usually clear signs of upcoming regulatory approvals. But on Monday, Sesen CEO Tom Cannell said that the biotechnology may require a new clinical trial.
From Cannell, until I received a letter from the FDA Refuse The drug Vicineum last Friday, there was no indication that there was a problem with the submission. At the July 13 meeting, the agency did not point out any deficiencies in the clinical trial data, nor did it require confirmatory clinical trials or require an advisory committee composed of independent experts to provide opinions. Cannell said on Monday’s conference call that the company had expected the drug to become a global best-seller, but the rejection was “a surprising turn of events.”
According to Sesen, the FDA letter provided recommendations for additional clinical and statistical data analysis. Providing this information may require another clinical trial. The company added that regulators have raised chemistry, manufacturing and control issues.
Sesen develops targeted protein fusion therapy. These drugs are made by genetically fusing a targeting antibody with another protein that is toxic to tumors. The resulting single molecule is quickly absorbed by the targeted cancer cells. These therapies are intended to replace antibody-drug conjugates (ADCs), where cytotoxic payloads are chemically linked to targeted antibodies. Although ADC has received regulatory approval, Sesen said its fusion protein can provide efficacy and safety advantages.
Vicineum is Sesen’s main drug candidate for the treatment of non-muscle invasive bladder cancer that does not respond to early BCG (BCG) therapy. Immunotherapy Often used to treat early bladder cancer. The company tested Vicineum, which was injected directly into tumors, in an open-label study that recruited 133 patients. The main goal of Phase 3 clinical trials is to measure the complete response rate to treatment.
As of the May 2019 deadline, 82 patients in the study can be evaluated. At the three-month mark, the complete response rate was 39%; at six months, 26%; at nine months, 20%; one year later, 17%. Although the FDA agreed to the complete response endpoint, Cannell said that the agency’s guidance prior to the clinical trial opened the door to another study.
“In the February 2018 guidance, the FDA pointed out that single-arm clinical trials with complete remission rate and duration of remission as the primary endpoints can provide the main evidence supporting the effectiveness of marketing applications,” Kannell told financial analysts . “However, in this guidance, the FDA also made it clear that additional tests may be required.”
Cannell said that Sesen needs to clarify what the FDA needs to see from this clinical trial, such as whether the main goal should measure the complete response to treatment and the duration of the response. The company needs to know if 90 to 100 patients are enough, or if the institution needs a larger sample size. It is also unclear whether the FDA wants a study that lasts longer than 12 months.
Sesen is seeking to clarify the FDA’s manufacturing issues. Cannell said that the Vicineum used for clinical trials comes from the company’s Winnipeg plant, which does not have commercial-scale production capabilities. Sesen has reached an agreement with Fujifilm Diosynth Biotechnologies, Baxter Oncology and Qilu Pharmaceutical for the production of Vicineum. Cannell stated that Sesen must be able to prove that the drugs produced by the company’s business partners are nearly identical to those tested in clinical trials.
Sesen was previously known as Eleven Biotherapeutics, a biotechnology company focused on developing protein drugs for the treatment of eye diseases.The company shifted its focus to cancer in 2016 get Viventia Bio is headquartered in Canada.The transaction occurred after 11 companies reported that its drug isunakinra failed two phase 3 studies, the first of which was Dry eye Then in Conjunctivitis. 11 Changed its name to Sesen in 2018.
The FDA’s Vicineum rejection may amount to a delay of at least two years for the drug. Cannell said that if Sesen needs another 12 months of trials, recruiting patients and conducting research means that new applications for biologics licenses may be ready in 2023. After resubmission, the FDA’s response timeline is six months.
As of the end of the second quarter of this year, Sesen reported a cash position of $151.1 million. Cannell stated that the company believes that the funds are sufficient to support the resubmission of Vicineum applications.
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