Imugene has reported one additional complete response in mantle cell lymphoma and one partial response in chronic lymphocytic leukemia in the BTK inhibitor combination cohort of its ongoing Phase 1b trial of azercabtagene zapreleucel (azer-cel).
The October 5, 2026 announcement adds results from four patients assessed at Day 28, bringing the combination cohort to seven evaluable patients. All patients enrolled in this cohort had previously received and progressed on BTK inhibitor therapy.
The study is investigating whether combining the experimental, donor-derived CD19-targeted CAR T-cell therapy with a Bruton tyrosine kinase inhibitor can enhance antitumor activity in this previously treated population.
New Responses in Mantle Cell Lymphoma and CLL
Among the four newly evaluable patients, one patient with mantle cell lymphoma achieved a complete response, while one with chronic lymphocytic leukemia achieved a partial response.
The other two patients had different outcomes: a patient with diffuse large B-cell lymphoma associated with Richter’s transformation had stable disease, and another patient with mantle cell lymphoma had progressive disease.
These findings bring the company-reported overall response rate in the BTK inhibitor combination cohort to 71% among seven evaluable patients. The two new responses were documented at Day 28; their durability will require longer follow-up.
Imugene Executive Chairman Paul Hopper said:
“Observing additional responses in our BTKi combination cohort provides compelling further validation of this strategy.”
Hopper highlighted the cohort’s prior progression on BTK inhibitors and described the responses as supporting continued investigation of azer-cel alongside BTK inhibition.
Broader Azer-Cel Trial Reports 75% Overall Response Rate
Across the Phase 1b study, Imugene reported an overall response rate of 75% among 55 evaluated patients.
The study includes three distinct populations. The CAR T-relapsed/refractory diffuse large B-cell lymphoma cohort had a reported response rate of 68% among 22 patients. The CAR T-naïve cohort had a response rate of 81% among 26 patients, while the BTK inhibitor combination cohort had a response rate of 71% among seven patients.
These results describe different clinical populations and treatment contexts. The pooled response rate should therefore be interpreted alongside the individual cohort findings, rather than as evidence of a uniform benefit across blood cancer subtypes.
An Off-the-Shelf CD19-Targeted CAR T Approach
Azer-cel is an investigational allogeneic CAR T-cell therapy made from healthy donor T cells and engineered to target CD19.
Its off-the-shelf approach is intended to reduce the time between treatment planning and administration by avoiding patient-specific cell manufacturing. According to Imugene, azer-cel can be available for administration within days.
The open-label Phase 1b study is ongoing in the United States and Australia, with enrollment continuing across 10 US sites and five Australian sites.
Longer Follow-Up Remains Essential
The update provides an early signal of activity in patients whose disease had progressed on BTK inhibitor treatment. However, the combination cohort remains small, and the announcement does not provide detailed new adverse-event results or duration-of-response data for the four newly assessed patients.
Further follow-up will be needed to clarify response durability and the combination’s safety profile. Imugene said additional clinical updates will be reported as enrollment continues and the data mature.
Read further on OncoDaily: FDA Approves Pirtobrutinib for First-Line CLL/SLL Without 17p Deletion, a First for Non-Covalent BTK Inhibitors
