Minimal Residual Disease Status and Long-Term Survival in CLL
Posted: Thursday, August 1, 2019
The status of undetectable minimal residual disease after upfront chemotherapy or chemoimmunotherapy for newly diagnosed patients with chronic lymphocytic leukemia (CLL) may be associated with long-term survival, according to a review and meta-analysis presented in Clinical Lymphoma, Myeloma & Leukemia. The findings provide evidence supporting the integration of undetectable minimal residual disease assessment as an endpoint in clinical trials of CLL, concluded Stefano Molica, MD, of the Azienda Ospedaliera Pugliese-ciaccio, Catanzaro, Italy, and colleagues.
“From a research standpoint, [minimal residual disease] studies should be useful to identify the optimal treatment combinations, given either simultaneously or consecutively, and to recognize groups of patients worth being monitored for [minimal residual disease] and in whom treatment discontinuation can be envisaged,” the authors observed.
In the quantitative meta-analysis, researchers utilized 11 studies comprising 2,457 patients with CLL who were treated with upfront chemotherapy or chemoimmunotherapy. A total of 9 studies featuring 2,088 patients provided data on the impact of minimal residual disease on progression-free survival, and 6 studies featuring 1,234 patients provided information on overall survival.
Tests of heterogeneity revealed significant differences among studies for progression-free and overall survival, which the investigators said highlighted the differences among the studies. Undetectable minimal residual disease status was associated with significantly better progression-free survival (P < .001) and in patients who achieved conventional complete remission (P = .01). Undetectable minimal residual disease predicted longer overall survival globally (P < .001), but not in patients who achieved complete remission (P = .82).
“Even though several patients were homogeneously treated with [fludarabine, cyclophosphamide, and rituximab] or [fludarabine, cyclophosphamide, and rituximab]–like regimens, all studies, irrespective of the therapies used, confirmed the impact of [minimal residual disease] status on outcome, indicating that the predictive value of [minimal residual disease] status was independent of the type of treatment used,” Dr. Molica and colleagues concluded.
Disclosure: The study authors’ disclosure information may be found at clinical-lymphoma-myeloma-leukemia.com.