Dr Stilgenbauer on the Safety Data and the Next Steps for BGB-16673 in CLL

“The AE profile that was seen with [BGB-16673] was deemed favorable. Therefore, this drug is now being developed [in] phase 2 and 3 trials aiming at licensing.”

Stephan Stilgenbauer, MD, a professor of medicine and the medical director of the Division of CLL, Internal Medicine III at Ulm University, discussed safety data with the novel BTK degrader BGB-16673 in patients with chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma from the phase 1/2 CaDAnCe-101 trial (NCT05006716) presented at the 2026 EHA Congress.

Stilgenbauer started by emphasizing the importance of evaluating adverse effects (AE) and the safety of treatments in early drug development. He added that the safety and AE profile of BGB-16673 was closely monitored throughout CaDAnCe-101. Stilgenbauer then highlighted the safety data from the study, noting that most patients in the trial who received BGB-16673 experienced AEs. However, this was expected, Stilgenbauer said, explaining that many patients in the trial were heavily pretreated and already had AEs like cytopenias and infections at the start of the trial.

The most common AEs that occurred at high grades among patients who received the BTK degrader were neutropenia and infections, he stated. Regarding neutropenia, Stilgenbauer pointed out that this AE at high grades is still manageable for patients. In terms of high-grade infections, Stilgenbauer stressed that these AEs are also expected, considering these patients were heavily pretreated and immunodeficient. Stilgenbauer summed up the safety data for BGB-16673 as favorable, enabling further development of the BTK degrader in phase 2 and 3 trials.

Stilgenbauer concluded by shedding light on the trials that are underway further investigating BGB-16673 in CLL, pointing to multiple phase 2 and randomized phase 3 trials. Upcoming trials with the BTK degrader are covering an assortment of areas, such as combination strategies, efficacy in comparison with other established CLL regimens, and potentially moving BGB-16673 to the first-line setting, he concluded.