Retrospective Analysis of the Efficacy and Safety of Modified Bortezomib-Lenalidomide-Dexamethasonelite (modified RVD-lite) Therapy for Transplant Eligible Patients with Newly Diagnosed Multiple Myeloma

[Background]

Thecombination therapy consisting of bortezomib, lenalidomide and dexamethasone (RVD) for newly diagnosed multiple myeloma has been one of the standard induction therapies in recent years. However, 9-23 % of patients discontinued treatments because of severe adverse events in the previous reports (SWOG S077, IFM2009). Thus, it has not been clarified ifthe dosing schedule of RVD is appropriate. Here, we investigated the efficacy and safety of modified RVD-lite for 45 transplant eligible patients with newly diagnosed multiple myeloma (NDMM).

[Patients and methods]

We retrospectively analyzed 45 transplant eligible patients with NDMM who received modified RVD-lite for induction therapy between February 2016 and March 2018. The median age was 58 years old (range 36~66), and 6 (13.3%) patients were AL amyloidosisassociated with multiple myeloma. Patients received bortezomib 1.3 mg/m²once weekly subcutaneous (SC) on days 1, 8, 15, 22, lenalidomide 15 mg/day on days 2-7, 9-14, 16-21 and dexamethasone 40mg on days 1, 8, 15, 22. The Revised International Staging System (R-ISS) wereI in 13 (28.9%), II in 30 (66.7%) and III in 2 (4.4%). High-risk cytogenetics, defined as the presence of deletion 17, t(4;14) and t(14;16) by FISH analysis, were identified in 5 (11.1%) patients. After 4 cycles of modifiedVRd-lite, we evaluated the efficacy and adverse events.

[Results]

The overall response rate (ORR) after four 28-day cycles of modifiedRVD-lite was obtained in 41 (91.1%), including sCR in 6 (13.3%) and CR in 5 (11.1%). SD and PD were observed in 2 patients (4.4%) and 1 patient (2.2%), respectively. One patient was not evaluated efficacy, because a patient changed modifiedRVD-lite to ixazomib, lenalidomideand dexamethasone therapy for grade 3 peripheral neuropathy. Thirty-eight of 45 patients (84.4%) received autologous stem cell transplantation (ASCT) after at least 4 courses of modifiedVRd-lite. The median number of CD34⁺cells/kg collected was 4.83 x 10⁶(range, 1.1-11.9). All patients received melphalan at doses of 200 mg/m². In these patients, response after ASCT were sCR in 15(41.7%), CR in 2 (5.6%), VGPR in 8 (22.2%) and PR in 8 (22.2%). Three of seven patients who did not received ASCT will receive ASCT ina few months. Among other 4 patients who did not receive ASCT, 2 patients chose other therapies without ASCT, and 2 patients could not receiveASCT because they showed no improvement in cardiac AL amyloidosis. Grade 3 or higher adverse events (AEs) were observed in 17 (37.8%). Most frequent grade 3 or higher AE was neutropenia (grade 3:17.8%, grade 4:6.7%). Only one patient (2.2 %) discontinued modifiedRVD-lite because of grade 3 peripheral neuropathy.

[Conclusions]

The ORR after 4 cycles ofmodifiedRVD-lite was high (91.1%). These results might be related to low rate of discontinuation of treatment. Also, the ORR after ASCT was comparable to the results previously published (N Engl J Med .2017 Apr 6:376(14):1311). AEs in modified RVD-lite were feasible and manageable in most patients. Our results suggest that modifiedRVD-lite is very feasible and effective treatment for patients with transplant eligible NDMM.