# Acalabrutinib Versus Ibrutinib in Previously Treated Chronic Lymphocytic Leukemia: Results of the First Randomized Phase III Trial

Source: https://onco.cc/key-papers/paper-acalabrutinib-cll-j-clin-oncol-2021/  
OnCo record `paper-acalabrutinib-cll-j-clin-oncol-2021` (Key paper). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Phase 2 or 3 results paper on Acalabrutinib in Chronic lymphocytic leukaemia, in Journal of Clinical Oncology (2021), one of the most cited Europe PMC records with Acalabrutinib in its title.

## Summary

Purpose: Among Bruton's tyrosine kinase inhibitors, acalabrutinib has greater selectivity than ibrutinib, which we hypothesized would improve continuous therapy tolerability. We conducted an open-label, randomized, noninferiority, phase III trial comparing acalabrutinib and ibrutinib in patients with chronic lymphocytic leukemia (CLL).

Methods: Patients with previously treated CLL with centrally confirmed del(17)(p13.1) or del(11)(q22.3) were randomly assigned to oral acalabrutinib 100 mg twice daily or ibrutinib 420 mg once daily until progression or unacceptable toxicity. The primary end point was independent review committee-assessed noninferiority of progression-free survival (PFS).

Results: Overall, 533 patients (acalabrutinib, n = 268; ibrutinib, n = 265) were randomly assigned. At the data cutoff, 124 (46.3%) acalabrutinib patients and 109 (41.1%) ibrutinib patients remained on treatment. After a median follow-up of 40.9 months, acalabrutinib was determined to be noninferior to ibrutinib with a median PFS of 38.4 months in both arms (95% CI acalabrutinib, 33.0 to 38.6 and ibrutinib, 33.0 to 41.6; hazard ratio: 1.00; 95% CI, 0.79 to 1.27). All-grade atrial fibrillation/atrial flutter incidence was significantly lower with acalabrutinib versus ibrutinib (9.4% v 16.0%; P =.02); among other selected secondary end points, grade 3 or higher infections (30.8% v 30.0%) and Richter transformations (3.8% v 4.9%) were comparable between groups and median overall survival was not reached in either arm (hazard ratio, 0.82; 95% CI, 0.59 to 1.15), with 63 (23.5%) deaths with acalabrutinib and 73 (27.5%) with ibrutinib. Treatment discontinuations because of adverse events occurred in 14.7% of acalabrutinib-treated patients and 21.3% of ibrutinib-treated patients.

Conclusion: In this first direct comparison of less versus more selective Bruton's tyrosine kinase inhibitors in CLL, acalabrutinib demonstrated noninferior PFS with fewer cardiovascular adverse events.

Indexed on Europe PMC as PubMed record 34310172 (DOI 10.1200/jco.21.01210). Its title names Acalabrutinib and its text names Chronic lymphocytic leukaemia; PubMed types it as a clinical trial report (Clinical Trial, Phase III, Comparative Study, Equivalence Trial, Research Support, Non-U.S. Gov't, research-article, Multicenter Study, Randomized Controlled Trial, Research Support, N.I.H., Extramural). It was matched automatically to the idea "BTK degraders to pre-empt resistance in frontline CLL" and no figure has been checked by an editor.

## Fields

- Kind: Key paper
- Last checked: 2026-09-22
- Tags: europepmc-ingest
- Journal: Journal of Clinical Oncology
- Year: 2021
- DOI: 10.1200/jco.21.01210
- Authors: Byrd JC, Byrd JC, Hillmen P, et al.
- What it means: One of the most cited trial reports Europe PMC returns for Acalabrutinib in Chronic lymphocytic leukaemia, so it is a natural first reading for anyone weighing the idea it is linked from. The record was linked automatically by title and abstract; read the abstract above and the paper itself before relying on any figure.
- Caveats: Matched by Acalabrutinib in the title and Chronic lymphocytic leukaemia in the title or abstract of the Europe PMC record; the summary reproduces the record's abstract and no figure has been verified against the full paper.; Chosen as a phase 2 or 3 report by the record's publication type or its own wording, not by reading the paper.

## Sources

- J Clin Oncol 2021: https://doi.org/10.1200/jco.21.01210
- PubMed: https://pubmed.ncbi.nlm.nih.gov/34310172/
- Europe PMC: https://europepmc.org/article/MED/34310172

## Connected records

- journals: [Journal of Clinical Oncology](https://onco.cc/journals/jco/)
- ideas: [BTK degraders to pre-empt resistance in frontline CLL](https://onco.cc/ideas/idea-btk-degrader-frontline/)

---
JSON: https://onco.cc/api/v1/entities/paper-acalabrutinib-cll-j-clin-oncol-2021.json