Comparative efficacy of Bruton tyrosine kinase inhibitors in high-risk relapsed/refractory CLL: a network meta-analysis

• A network meta-analysis of BTKis found zanubrutinib to be the most efficacious treatment for patients with high-risk R/R CLL.

• Zanubrutinib demonstrated reduced risk of progression/death compared to ibrutinib, acalabrutinib, and bendamustine or idelalisib+rituximab.

Bruton tyrosine kinase inhibitors (BTKis) have led to changes in the treatment algorithm for patients with high-risk relapsed/refractory chronic lymphocytic leukemia (R/R CLL), defined based on the presence of genetic mutations. Given the lack of head-to-head trials comparing next-generation BTKis used to treat high-risk R/R disease, a network meta-analysis (NMA) was performed to estimate their relative efficacy. High-risk populations were defined based on the pre-specified definitions within each trial, including patients with del(17p) and/or TP53 mutations in ALPINE (n=150), and ASCEND (n=86), and del(17p)/del(11q) in ELEVATE-RR (n=533). Bayesian NMAs found zanubrutinib to be the most efficacious treatment for high-risk patients, with significantly reduced risk of progression or death compared with ibrutinib (hazard ratio [95% credible interval (CrI)]: 0.49 [0.31, 0.78]), acalabrutinib (0.55 [0.32, 0.94]), and bendamustine + rituximab or idelalisib + rituximab (BR/IR) (0.12 [0.05, 0.26]). Differences in overall survival demonstrated a numerical trend favoring zanubrutinib (probability better ≥80%) compared to ibrutinib (hazard ratio [95% credible interval]: 0.59 [0.31, 1.11]), acalabrutinib (0.72 [0.35, 1.50]) and BR/IR (0.65 [0.23, 1.75]). Rates of response also demonstrated trends favoring zanubrutinib compared to acalabrutinib, with significant results compared to ibrutinib. The NMA suggests that the most efficacious BTKi for patients with high-risk R/R CLL is zanubrutinib.