Following a successful clinical trial looking at the combination of ibrutinib and venetoclax as a front-line treatment for patients with chronic lymphocytic leukemia (CLL), a second study looked at the same combination for patients with relapsing/remitting CLL, with similar positive results. 

The results from the trial were presented at the recent annual meeting of the American Society of Hematology. 

Researchers enrolled 80 patients, where 73 were available for analysis (median age, 61.5 yrs; range, 32-79). Overall,  38% patients had a TP53 aberration. Median follow-up was 22.3 months. 

Patients received three cycles of ibrutinib (420 mg daily) after which venetoclax was added for 24 cycles. After the three cycles of ibrutinib alone, none of the patients achieved bone marrow undetectable MRD (BM U-MRD) status. After the addition of venetoclax, 10% of the patients achieved BM U-MRD status after 3 cycles. After 6 cycles, 22% of patients achieved the same level of remission, and after 12 cycles, 48% achieved BM U-MRD status. By the end of the 24 cycles, 67% of patients had achieved BM U-MRD remission levels.

Two patients in the trial had CLL progression after the 24 cycles of combined therapy. One of the patients achieved remission after 24 cycles but relapsed three months later before responding to ibrutinib alone. The second patient was MRD+ at 24 cycles and continued taking IBR for two years after the study. The patient relapsed after a few months and is now in remission again after CD19 CAR-T therapy. One patient in the trial developed Hodgkin’s transformation. Two patients died due to infection complications while receiving the ibrutinib monotherapy. 

In reviewing the data, researchers determined that “combined [venetoclax] and [ibrutinib] is an effective well-tolerated chemotherapy” for patients with relapsing/remitting CLL.