Among patients with chronic lymphocytic leukemia (CLL), eradication of minimal residual disease (MRD) with alemtuzumab consolidation therapy after chemotherapy improves progression-free and overall survival, according to findings published in the British Journal of Haematology.1
MRD status after treatment is associated with remission duration and survival among patients with CLL. Researchers evaluated the impact of post-chemotherapy alemtuzumab consolidation on outcomes among patients with persistent low levels of detectable disease despite achieving a complete or partial remission.
For the open-label, phase 2 CLL207 study (ClinicalTrials.gov Identifier: NCT00458523), investigators screened the blood of patients with CLL who had received induction chemotherapy for MRD 6 to 24 months after chemotherapy. Patients with MRD-positive disease received alemtuzumab subcutaneously 3 times per week for 6 weeks. Those who were MRD-negative or non-responders after a marrow assessment discontinued therapy, while MRD-positive patients with 1 + log reduction received 6 additional weeks of immunotherapy consolidation.
Eighty-three percent of patients achieved MRD eradication from blood and bone marrow at the end of consolidation, with 38% remaining MRD-negative in the blood 6 months later.
Among the 18 patients who were MRD-negative at 6 months, median time to MRD relapse was 46 months. Patients who were MRD-negative at baseline who investigators followed up with had a similar median time to relapse.
The 5-year progression-free survival rate was significantly higher for patients who were MRD-negative at 6 months compared with MRD-positive patients (78% vs 39%; P = .010). The 5-year overall survival rate was also significantly better among MRD-negative patients (89% vs 64%; P = .029).
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Thirty-six percent of alemtuzumab-treated patients reported serious adverse events, of which 19 were a result of treatment. One death was related to alemtuzumab therapy.
- Varghese AM, Howard DR, Pocock C, et al. Eradication of minimal residual disease improves overall and progression-free survival in patients with chronic lymphocytic leukaemia, evidence from NCRN CLL207: a phase II trial assessing alemtuzumab consolidation. Br J Haematol. 2016 Dec 29. doi: 10.1111/bjh.14342 [Epub ahead of print]