Medically reviewed by Dr. Brian Koffman
The Bottom Line:
Long-term follow-up data confirms the sustained benefit of ibrutinib therapy for CLL / SLL, including uMRD, in a small subset of patients.
Who Performed the Research and Where Was it Presented:
Dr. Adrian Wiestner from the National Heart, Lung, and Blood Institute at NIH and colleagues presented the results at the American Society for Hematology (ASH) Annual Meeting 2023.
Background:
A decade ago, chemoimmunotherapy was the standard of care for chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma (SLL). However, it didn’t work well for older patients (>65) and patients with certain genetic variants such as deletion 17p. Clinical trials began testing a new therapy (PCI-32765) that inhibited Bruton tyrosine kinase (BTK), a key protein for B cell survival and proliferation. This therapy would eventually be named ibrutinib, and it received FDA approval for treating CLL in 2014. Researchers have continued to follow patients from some of those initial clinical trials and now have long-term follow-up data from over a decade.
Methods and Participants:
This was a phase 2 clinical trial of ibrutinib for treating CLL / SLL in patients over 65 or with deletion 17p. It began in 2012; researchers now have over ten years of follow-up data.
Results:
- This study covers a very long period. The average age at the start of the study was 69, which means the average age at this follow-up was even older.
- The median progression-free survival was a little over seven years.
- After ten years, the overall survival rate was 59% for all patients and 74% for treatment-naïve patients.
- At the time of analysis, 82% of patients had discontinued ibrutinib.
- Four in ten patients discontinued ibrutinib due to progressive disease.
- One in three patients discontinued due to side effects such as abnormal heart rhythm (atrial fibrillation), secondary cancers, infections, and dementia.
- 15% of patients achieved undetectable measurable residual disease (uMRD), and only one has relapsed thus far. This was unexpected because the traditional belief is that patients don’t reach uMRD on ibrutinib.
Conclusions:
Ibrutinib significantly improved patient outcomes compared with chemotherapy, which was the standard of care when the study started and ushered in a new era of targeted therapies. We have learned so much about ibrutinib and other targeted therapies over the last decade, thanks mainly to the patients who have participated in studies for years. Clinical trials are critical for developing new treatments, and they would not be possible without the participation of patients like you. Thank you to all the patients participating in clinical trials!
Links and Resources:
Watch the interview on the abstract here:
You can read the ASH abstract here: Long-Term Outcomes in Chronic Lymphocytic Leukemia Treated with Ibrutinib: 10-Year Follow-up of a Phase 2 Study.
Take care of yourself first.
Ann Liu, PhD
