Continuous Lenalidomide Therapy in Patients with POEMs Syndrome

Background: POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes) syndrome is a rare plasma cell dyscrasia. The treatment of POEMS syndrome has not been standardized, and the progression-free survival after first-line therapy remains unsatisfactory. This study aimed to assess the efficacy of continuous lenalidomide therapy in POEMS syndrome.Methods: A total of 128 patients who had finished lenalidomide-dexamethasone as a first-line therapy were included, with 59 patients in the continuous single-agent lenalidomide group and 69 in the observation group. The patients’ baseline characteristics, treatment responses, and survival outcomes were compared.Findings: The hematological CR (CRH) rate increased from 46% to 54% in the continuous therapy group and from 50% to 53% in the observation group. The improvement in VEGF response was observed in 36·4% and 8·8% of the non-CRV patients, respectively. With a median follow-up of 50·8 months, the median PFS in the continuous therapy and observation groups was 47·9 months and 36·4 months (HR 0·63 [95% CI 0·38-1·07]; p=0·09), respectively. Subgroup analysis revealed that the median PFS was significantly longer in the continuous therapy group than in the observation group in patients at medium to high risk (not reached vs. 35·0 months, HR 0·34; p=0·02), in non-CRH patients (42·6 vs. 17·8 months, HR 0·48; p=0·049), and in non-CRV patients (25·3 vs. 12·8 months, HR=0·45; p=0·03).Interpretation: Continuous lenalidomide therapy could improve responses and reduce the risk of progression, especially in high-risk patients and in those with inadequate remission. Continuous lenalidomide therapy may be considered as part of standard therapy in these patients.Funding Information: National Natural Science Foundation of China (Grant No. 81974011, for LJ), CAMS Innovation Fund for Medical Sciences (Grant No. 2021-1-I2M-019, for LJ).Declaration of Interests: All the authors declare no competing financial interests.Ethics Approval Statement: A total of 128 patients with complete baseline evaluation and follow-up data were included. All patients signed written informed consent forms. The study was approved by the Institutional Review Board of Peking Union Medical College Hospital.