[Efficacy and safety of VRD regimen of autologous hematopoietic stem cell transplantation in patients with newly diagnosed multiple myeloma]

Objective: To explore the stem cell collection rate and efficacy and safety of patients aged 70 and below with newly diagnosed multiple myeloma (MM) treated with the VRD (bortezomib, lenalidomide and dexamethasone) regimen followed by autologous stem cell transplantation (ASCT). Methods: Retrospective case series study. The clinical data of 123 patients with newly diagnosed MM from August 1, 2018, to June 30, 2020, at the First Affiliated Hospital of Soochow University and Suzhou Hopes Hematology Hospital, who were eligible for VRD regimen sequential ASCT, were collected. The clinical characteristics, efficacy after induction therapy, mobilization regimen of autologous stem cells, autologous stem cell collection rate, and side effects and efficacy of ASCT were retrospectively analyzed. Results: Of the 123 patients, 67 were males. The median patient age was 56 (range: 31-70) years. Patients with IgG, IgA, IgD, and light-chain types accounted for 47.2% (58/123), 23.6% (29/123), 3.2% (4/123), and 26.0% (32/123) of patients, respectively. In addition, 25.2% (31/123) of patients had renal insufficiency (creatinine clearance rate<40 ml/min). Patients with Revised-International Staging System (R-ISS) Ⅲ accounted for 18.2% (22/121) of patients. After induction therapy, the rates of partial response and above, very-good partial response (VGPR) and above, and complete response (CR)+stringent CR were 82.1% (101/123), 75.6% (93/123), and 45.5% (56/123), respectively. Overall, 90.3% (84/93) of patients were mobilized with cyclophosphamide+granulocyte colony-stimulating factor (G-CSF) and 8 patients with G-CSF or G-CSF+plerixafor due to creatinine clearance rate<30 ml/min and one of them was mobilized with DECP (cisplatin, etoposide, cyclophosphamide and dexamethasone)+G-CSF for progressive disease. The rate of autologous stem cell collection (CD34⁺cells≥2×10⁶/kg) after four courses of VRD regimen was 89.1% (82/92), and the rate of collection (CD34⁺cells≥5×10⁶/kg) was 56.5% (52/92). Seventy-seven patients treated with the VRD regimen sequential ASCT. All patients had grade 4 neutropenia and thrombocytopenia. Among the nonhematologic adverse events during ASCT, the highest incidence was observed for gastrointestinal reactions (76.6%, 59/77), followed by oral mucositis (46.8%, 36/77), elevated aminotransferases (44.2%, 34/77), fever (37.7%, 29/77), infection (16.9%, 13/77) and heart-related adverse events (11.7%, 9/77). Among the adverse events, grade 3 adverse events included nausea (6.5%, 5/77), oral mucositis (5.2%, 4/77), vomiting (3.9%, 3/77), infection (2.6%, 2/77), elevated blood pressure after infusion (2.6%, 2/77), elevated alanine transaminase (1.3%, 1/77), and perianal mucositis (1.3%, 1/77); there were no grade 4 or above nonhematologic adverse events. The proportion of patients who achieved VGPR and above after VRD sequential ASCT was 100% (75/75), and the proportion of patients who were minimal residual disease-negative (<10^-4 level) was 82.7% (62/75). Conclusion: In patients aged 70 and below with newly diagnosed MM treated with VRD induction therapy, the collection rate of autologous stem cells was good, and good efficacy and tolerability were noted after follow-up ASCT.