ROCKET-CLL: A randomized, open-label, multicenter, phase 3 study of rocbrutinib (LP-168) versus pirtobrutinib in covalent BTK inhibitor (cBTKi) in pretreated relapsed or refractory (R/R) chronic lymphocytic leukemia (CLL)/small lymphocytic lymphoma (SLL).

Abstract

TPS7100 Background: Bruton tyrosine kinase covalent inhibitors (cBTKi) have been transformative in CLL treatment. Despite achieving extended remissions, in most patients disease still relapses despite cBTKi therapy, often associated with BTK C481 mutations. Non-covalent BTKi (ncBTKi), including pirtobrutinib, can overcome this resistance (Sharman et al. ASCO . 2025). Pirtobrutinib received FDA approval in Dec 2025, for R/R CLL/CLL patients pretreated with cBTKi. Rocbrutinib (LP-168) is a highly selective next-generation BTKi that can covalently bind wild-type and gatekeeper mutations (T474X, commonly seen in patients relapsed after pirtobrutinib) and non-covalently target C481-mutated BTK , with preclinical efficacy in treatment-naïve and BTKi-resistant CLL (Gordon et al. IWCLL . 2025). In the rocbrutinib phase 1 trial (NCT04775745), encouraging safety and efficacy have been observed in CLL patients with prior exposure to BTKi and/or BCL2 inhibitor (BCL2i) (Woyach et al. Blood. 2025). Presented here is the design of a phase 3 trial aiming to compare the efficacy of rocbrutinib versus pirtobrutinib in cBTKi-pretreated R/R CLL/SLL patients. Methods: ROCKET-CLL (NCT07342478) is a randomized, open-label, multicenter, phase 3 study comparing rocbrutinib (Arm 1) to pirtobrutinib (Arm 2) in R/R CLL/SLL subjects who previously received treatments including covalent BTKi. Eligible subjects must require treatment per 2018 iwCLL criteria, have measurable lesions by CT, an ECOG performance score of 0-2, and adequate hematologic and other organ functions. About 306 subjects will be randomized 1:1 based on stratification factors such as 17p deletion/ TP53 mutation presence, reasons for discontinuing prior cBTKi, prior BCL2i treatment, and geographic region. Participants assigned to each arm will receive rocbrutinib (200 mg QD) or pirtobrutinib (200 mg QD) tablets continuously until disease progression, unacceptable toxicity, withdrawal, or other study discontinuation criteria are met. The primary endpoint is progression-free survival (PFS), assessed by an independent review committee (IRC) per iwCLL 2018 criteria with CLL (Hallek et al. 2018) and Lugano 2014 criteria with SLL (Cheson et al. 2014). Important secondary endpoints include overall survival (OS), time to next treatment (TTNT), event-free survival (EFS), overall response rate (ORR), duration of response (DOR), PFS assessed by investigator (INV), concordance between IRC and INV PFS, safety and tolerability, and population PK. Exploratory endpoints include health-related quality of life and biomarker assessment. Recruitment is ongoing. Clinical trial information: NCT07342478 .