[Outcomes of lenalidomide-based treatment for 57 patients of relapsed or refractory multiple myeloma]

Objective: To investigate the clinical efficacy and safety of lenalidomide (Revlimid, R) -based chemotherapy in the treatment of relapsed/refractory multiple myeloma (MM) patients. Methods: 57 consecutively relapsed/refractory MM patients were retrospectively analyzed from June 2013 to February 2016. All the patients received lenalidomide-based chemotherapy. Results: ① 60.4% patients had international staging system (ISS) stage Ⅲ, 37.9% patients had revised international staging system (R-ISS) stage Ⅲ, and 53.3% patients harbored at least one of the high-risk cytogenetic abnormalities[del (17p) and/or t (4;14) and/or t (14;16) ]. ②The patients received median 6 cycles of R (range: 1-32). The overall response rate (ORR) was 58.9% (33/56) , among which 8.9% was complete response (CR) , 19.8% was very good partial response (VGPR) , and 30.4% was partial response (PR). In addition, 10.7% patients attained minor response (MR). Total clinical benefit was 69.6%. Patients with more than 1 line of prior therapy, or previously thalidomide-resistance, or R-ISS stage Ⅲ disease showed significantly lower ORR. ③With a median follow-up of 27 months, the median progression free survival (PFS) , the median interval to PR, the median duration of response (DOR) , and the median overall survival (OS) was 8 months, 2 months, 8 months, and 19 months, respectively. Univariate prognostic analysis showed that abnormal karyotype, R-ISS stage Ⅲ and response inferior to PR were negative prognostic factors for PFS and OS. While the multivariate prognostic analysis showed that abnormal karyotype and R-ISS stage Ⅲ were independent prognostic factors. ④In the safety aspect, the most common grade 3-4 non-hematology adverse events (AEs) were infection (17.5%) , rash (1.8%) and thromboembolism (1.8%) , and the most common grade 3-4 hematology AEs were neutropenia (7.0%) and thrombocytopenia (3.5%). Totally 3 patients (5.3%) discontinued R because of AEs, and 2 cases (3.5%) of secondary primary malignancies were observed. Conclusion: The R-based treatment is effective and safe in the treatment of relapsed/refractory MM patients in China. Abnormal karyotype and R-ISS stage Ⅲ were independent negative prognosis factors in this cohort.