[Analysis of efficacy and safety of daratumumab-containing regimen in relapsed and refractory multiple myeloma patients].

To investigate the efficacy and safety in relapsed and refractory multiple myeloma (RRMM) patients with combination regimen of daratumumab. The clinical data of 42 RRMM patients admitted to Qingdao Municipal Hospital from December 2020 to November 2023 were retrospectively analyzed, which included 26 males and 16 females, with a median age of 59 (47, 82) years old. According to the number of courses of treatment with Daratumumab, patients were divided into three groups: long course group (≥9 courses, =21), medium course group (7-8 courses, =12), and short course group (≤6 courses, =9). The deadline for follow-up was November 10, 2023, and the follow-up period was 15.6 (6.0, 34.0) months. After completing at least 2 courses of treatment, patients were evaluated for efficacy, including stringent complete response (sCR), complete response (CR), very good partial response (VGPR), partial response (PR), minimal response (MR), stable disease (SD), and progressive disease (PD). Basic clinical characteristics of patients, overall response rate of treatment, and adverse reactions were statistically analyzed. Kaplan-Meier method was used to compare the differences of progression-free survival (PFS) in patients with different courses of treatment. Among the 42 patients, 15 (35.7%) had extramedullary disease or plasmacytic leukemia, 7 (16.6%) had amyloidosis, and 18 (42.9%) had renal insufficiency. In Mayo stage, 25 patients (59.5%) were at high risk of myeloma cytogenetic stratification, 8 patients (19%) were standard risk, 9 patients (21.4%) had no cytogenetic data. There were 16 patients with second-line treatment (38.0%), 13 patients with third-line treatment (31%), and 13 patients with more than fourth-line treatment (31%). All patients received at least 2 courses of treatment, achieving the best degree of disease response in 4 cases of sCR (9.5%), 3 cases of CR (7.1%), 10 cases of VGPR (23.8%), 11 cases of PR (26.2%), and 6 cases of MR (14.2%). The overall response rate (ORR) was 80.9% (34/42). The overall response rate was 100% (21/21) in the long course group, 91.6% (11/12) in the medium course group and 22.2% (2/9) in the short course group. Kaplan-Meier survival analysis showed that the duration of PFS was 5.0 (95%: 3.1-6.9) months in the short course group,>8.0 months in the medium course group, and>38.0 months in the long course group, the difference was statistically significant (<0.05). Grade≥3 adverse reactions were mainly neutropenia (3 cases) and thrombocytopenia (1 case). None of the patients discontinued treatment due to adverse reactions. Treatment of RRMM with a regimen containing Daratumumab requires a longer course of treatment to achieve maximum efficacy and the adverse reactions can be controlled.