FDA Fast Tracks BGB-16673 for CLL, SLL

The Food and Drug Administration (FDA) will fast track, BGB-16673 for the treatment of adults with relapsed or refractory chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL) that has previously been treated with two or more prior therapies, according to BeiGene, the manufacturer of the novel drug.

The goal of the FDA’s fast track designation is to speed up the development and review of drugs that treat serious diseases or conditions with an unmet need, according to the agency. The goal of the designation is to more quickly get these medications to the patients who need them.

This fast track — which is specifically for patients who have been treated with a Bruton tyrosine kinase (BTK) and BCL2 inhibitor — is based on findings from a phase 1/2 trial that were presented at the European Hematology Association Congress in June. The trial is investigating different doses of BGB-16673. Data from the ongoing trial showed that BGB-16673 is tolerable and has “promising efficacy” in heavily pretreated patients with relapsed or refractory CLL or SLL.

“When disease progression for patients on BTK inhibitors occurs, there is a need for BTK-targeting agents with a different mode of action given the centrality of this pathway in CLL/SLL. BTK-protein degradation with our BTK CDAC (BGB-16673) may address this unmet need,” Dr. Mehrdad Mobasher, chief medical officer of Hematology at Beigene said in a company-issued press release.

Study findings showed that in patients with responses that were able to be evaluated, the overall response rate (percentage of patients whose disease shrunk or disappeared) was 72%. The group given the 200-milligram dosage of BGB-16673 had the highest response rate, at 88%. This included two complete responses, meaning that for two patients, all signs of cancer disappeared.

Data also showed that the median time to the first response was 2.8 months, and only one dose-limiting toxicity (side effect that warranted a smaller dose of the drug) was observed.

BGB-16673 is an oral drug (taken by mouth). It is a BTK degrader, which is a type of drug that works by eliminating the BTK protein, which is found on some types of cancer cells. By doing so, the drug blocks a certain type of cell signaling that is needed for the growth and survival of cancer cells, according to research published by the National Institutes of Health.

READ MORE: BTK Inhibitors Offer a Revolutionary Treatment of Relapsed CLL/SLL

Now researchers are enrolling patients in a phase 2 cohort of the study. According to the trial’s listing on ClinicalTrials.gov, the estimated study completion date is in March 2028.

“BGB-16673 is the most advanced BTK degrader in the clinic and is well-suited to become an important therapy for patients progressing after BTKi who have limited options,” Mobasher said.

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