Fixed-duration venetoclax-obinutuzumab for previously untreated patients with chronic lymphocytic leukemia: Follow-up of efficacy and safety results from the multicenter, open-label, randomized, phase III CLL14 trial
Abstract Number : 8027
Abstract Type : Poster Discussion Session
Indication : Chronic Lymphocytic Leukemia
Intervention : Obinutuzumab
Company : Roche
Technology : Monoclonal Antibody
Of the 432 enrolled patients, 216 were randomly assigned to receive VenG and 216 to receive ClbG. After a median follow-up of 39.6 months (interquartile range 36.75 - 43.04), progression-free survival continued to be superior for VenG as compared to ClbG (median not reached vs 35.6 months; hazard ratio [HR] 0.31 [0.22-0.44], p < 0.001). At 3 years, the estimated progression-free survival rate was 81.9% in the VenG arm and 49.5% in the ClbG arm. This benefit was consistently observed across all clinical and biological risk groups, including patients with TP53 mutation/deletion and unmutated IGHV status. Of note, PFS was also significantly longer for VenG treated patients with mutated IGHV status. Assessment of minimal residual disease 18 months after end of treatment showed that 47.2% of patients in the VenG arm had undetectable (u) uMRD ( < 10−4), 13% had low (L)-MRD (≥ 10−4 and < 10−2) and 7.9% high (H)-MRD (≥ 10−2), compared to 7.4% uMRD, 17.1% L-MRD, 26.9% H-MRD in the ClbG arm. No difference has been observed (HR 1.027, 95% CI 0.602-1.753, p = 0.921) for overall survival; median overall survival has not been reached in either group. Second primary malignancies were reported in 36 (17%) patients in the VenG arm and 22 (10.3%) in the ClbG arm. No new safety signals were observed.
The results suggest that the superior efficacy and deep remissions after fixed-duration VenG are maintained during extended follow-up, and show the long-term benefits of 12 cycles of VenG across all known risk categories.
Significant improvement in PFS (mPFS [email protected] mos follow up vs 35.6 mos) across all risk groups, after 18 mos of treatment 47.2% had uMRD vs 7.4