Long-Term Ibrutinib Yields Deep, Durable Responses in Chronic Lymphocytic Leukemia

Share this content:
No PFS or OS events were reported for treatment-naive elderly patients.
No PFS or OS events were reported for treatment-naive elderly patients.

Long-term ibrutinib yields good depth and duration of response among patients with chronic lymphocytic leukemia (CLL) regardless of TP53 status, according to a study published in Blood.1

Chemoimmunotherapy — the current standard of care for CLL — leads to high rates of remission but patients still face many challenges, including a high rate of relapse (particularly among those with TP53 mutations) and dose-limiting toxicities that reduce the effectiveness of treatment. Previous studies suggested that ibrutinib may be a therapeutic alternative.

For this open-label phase 2 study (ClinicalTrials.gov Identifier: NCT01500733), researchers enrolled 86 patients with CLL regardless of treatment history to receive ibrutinib 420 mg once daily. Patients were enrolled into a TP53 aberration cohort (51 patients) or an elderly patient cohort (35 participants).

After a median follow-up of 4.8 years, 57% of patients remained in the study: 23.3% and 5.8% of patients discontinued treatment because of progressive disease and adverse events, respectively.

The overall response rate at 6 months in the TP53 cohort was 95.8% (95% CI, 85.7%-99.5%) and 93.9% (95% CI, 79.8%-99.3%) in the elderly patient cohort. Response to treatment deepened over time: 29.2% of patients in the TP53 cohort and 27.3% of patients in the elderly cohort had a complete response. At 4 years, minimum residual disease (MRD) in peripheral blood was 3.8x10-2, and 8.3% of patients had MRD negative (< 10-4) remission.

In the TP53 cohort, the estimated 5-year progression-free survival (PFS) rate was 74.4% among treatment-naive patients vs 19.4% among patients with relapsed/refractory disease (P = .0002). In the elderly cohort, the 5-year PFS rate was 64.8% among patients with relapsed/refractory disease.

The 5-year overall survival (OS) rate was 85.3% among treatment-naive patients vs 53.7% among patients with relapsed/refractory disease (P = .023) in the TP53 cohort. The 5-year OS rate was 71.6% among elderly patients with relapsed/refractory disease.

No PFS or OS events were reported for treatment-naive elderly patients.

The safety profile remained consistent with previous findings. Most adverse events (AE) were transient and limited to grade 1 or 2. The most frequently observed grade 3 or worse AEs were infection (9.3%) and atrial fibrillation (5.8%).


  1. Ahn IE, Farooqui MZ, Tian X, et al. Depth and durability of response to ibrutinib in CLL: 5-year follow-up of phase II study. Blood. 2018 Feb 26. doi: 10.1182/blood-2017-12-820910 [Epub ahead of print]

Related Resources

You must be a registered member of Cancer Therapy Advisor to post a comment.

Sign Up for Free e-newsletters

Regimen and Drug Listings


Bone Cancer Regimens Drugs
Brain Cancer Regimens Drugs
Breast Cancer Regimens Drugs
Endocrine Cancer Regimens Drugs
Gastrointestinal Cancer Regimens Drugs
Gynecologic Cancer Regimens Drugs
Head and Neck Cancer Regimens Drugs
Hematologic Cancer Regimens Drugs
Lung Cancer Regimens Drugs
Other Cancers Regimens
Prostate Cancer Regimens Drugs
Rare Cancers Regimens
Renal Cell Carcinoma Regimens Drugs
Skin Cancer Regimens Drugs
Urologic Cancers Regimens Drugs