Efficacy of Modified Vrd-Lite for Transplant Ineligible Multiple Myeloma

BACKGROUND:

High dose chemotherapy followed by autologous peripheral blood stem cell transplantation is an effective treatment for multiple myeloma. However, many patients with newly diagnosed multiple myeloma are transplant-ineligible because of their age and complications, result in a poorer prognosis than transplant-eligible patients. Furthermore, many of them cannot complete normal chemotherapy because of low tolerability. Here, we investigated the efficacy and safety of modified bortezomib with lenalidomide and dexamethasone (mVRD-lite) for transplant-ineligible patients with newly diagnosed multiple myeloma.

STUDY DESIGN:

A retrospective observational analysis was performed on patients who received mVRd-lite for the first line chemotherapy between Jan. 2016 and Mar. 2020 in our hospital. Patients who received high dose dexamethasone to reduce tumor burden, and patients who received bortezomib with dexamethasone or lenalidomide with dexamethasone as a reduction regimen of mVRd-lite were also included. We evaluated ORR, OS, PFS and adverse effect. mVRD-lite at first was administered over a 28-day cycle. Bortezomib 1.3 mg/m² weekly was administered subcutaneously on days 1, 8, 15 and 22. Lenalidomide 15 mg was given orally 18 days, omitted on days 1, 8, 15, which are the days of bortezomib administration. Dexamethasone 20 mg was given orally on days 1, 2, 8, 9, 15, 16, 22, which are the day of and day after bortezomib. We also reviewed patients background, especially complication of light-chain amyloidosis and considered the impact of cardiac amyloidosis on patient prognosis. This study was conducted with the permission of the Ethics Review Board in our hospital.

RESULTS:

The subjects analyzed totaled 40 transplant-ineligible patients. 11(27.5%) patients were AL amyloidosis associated with multiple myeloma and 8(20%) patients had cardiac amyloidosis. Median age at diagnosis was 73 (range 48-86) and Male:Female=1:1. Most of them were judged inadequate to transplantation due to their age, general condition, or complication. One patient was ruled unfit to transplantation, because of his refusion. The Revised International Staging System (R-ISS) were I in 5 (12.5%), II in 25 (62.5%) and III in 8 (20%). 5(25%) patients switched to maintenance therapy. 17(42.5%) patients discontinued treatment, because of adverse effect (cardiac failure 4 ; two of them combined with cardiac amyloidosis, rash 4, peripheral neuropathy 3, infection 3, etc). 2(5%) patients died during treatment by mVRd-lite, because of Grade 4 adverse effect, such as pneumonia. 11(27.5%) patients died during observation period and causes of death were primary disease and TRM. 1(2.5%) patient was died of heart failure associated with cardiac amyloidosis. The overall response rate(ORR) during treatment period of mVRd-lite was obtained in 34(85%), including sCR in 5 (12.5%), VGPR in 13 (32.5%) and PR in 14(30%). 2(5%) patients achieved MRD negative. SD were observed in 3(7.5%) patients. 3(7.5%) patients were not evaluated efficacy because of treatment interruption by adverse effect. Overall survival rate at two year is 64.3%, median OS was not reached, at a median follow-up of 20 months.

CONCLUSIONS:

Transplant-ineligible multiple myeloma patients are associated with poor prognosis. Modified RVD-lite is one of the appropriate therapeutic options, in the transplant-ineligible multiple myeloma patients. Twenty-five percent of patients with cardiac amyloidosis had treatment discontinued due to cardiac complications. Further study is needed for treatment of patients with multiple myeloma complicated with cardiac amyloidosis.