EFFICACY OF LONG-TERM LENALIDOMIDE TREATMENT OF MM PATIENTS WITH AT LEAST ONE PRIOR THERAPY BASED ON CZECH LOCAL DATA

Background:

Multiple myeloma is a hematological malignancy that usually relapses in spite of the clinical response to initial therapy. In two randomized phase III trials (MM-009 and MM-010), lenalidomide and dexamethasone significantly prolonged time to progression and overall survival (OS) in patients with relapsed/refractory multiple myeloma (rrMM) compared with dexamethasone alone. Lenalidomide with dexamethasone is now accepted as valid and effective treatment option for most patients with rrMM. We conducted analysis on Czech local data from the Registry of monoclonal gammopathies conpared the results of continuous lenalidomide plus dexamethasone therapy in clinical trial patients and patients treated according the health insurance coverage.

Aims:

Our aim was to demonstrate the clinical value of continuous lenalidomide treatment until disease progression in the absence of reimbursement restrictions on Czech local data.

Methods:

Totally, we collected and analyzed data from 250 MM patients with at least one prior therapy, all patients signed informed consent form of their data collection to Czech Registry of monoclonal gammopathies. 46 patients were treated by continuous lenalidomide plus dexamethasone within standard arm of some clinical trial and 204 patients obtained the same therapy, but maximally 8-10 cycles according the health insurance companies rules based on Czech Myeloma Group guidelines. We analyzed therapy response in both group of patients and also Kaplan-Meier survival estimates were compared between patients on continued treatment versus the patients treated with local reimbursement restrictions.

Results:

Overall, patient basic characteristics were comparable in both groups, with no significant p-values for any of the variables documented. Median of previous lines of therapy was 2 in both patient groups. Overall response rate was statistically significantly better in group of patients with continuous lenalidomide therapy (58.8 versus 38.9 %, p= 0.014). Overall survival (OS), time to progression (TTP), disease free survival (DFS) and duration of response (DOR) were all found to be statistically signifićantly longer (with p values between 0.001 and 0.005) in population treated in clinical trials. As with other therapies using combination of lenalidomide plus dexamethasone at first relapse is more effective regarding response rate and durability than using it after multiple salvage therapies. The results of continuous lenalidomide treatment within clinical trials was similar to those obtained in registration studies including observed side effects of therapy.

Summary / Conclusion:

Czech myeloma group confirmed on local data obtained from Registry of monoclonal gammopathies benefits of continuous lenalidomide plus dexamethasone treatment until disease progression. Continued lenalidomide treatment is associated with better therapy response results and also with a statistically clearly significant survival advantage. Our findings so confirmed results of some other studies dealing with similar themes.

Keywords: Maintenance, Multiple myeloma, Therapy

Abstrakta v časopise Haematologica 2013, Suppl1

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