Induction Therapy With Continuous Alternate-Day Low Dose Lenalidomide Combined With Low-Dose Prednisone In Octogenarian Multiple Myeloma Patients

About 30% of patients with newly diagnosed multiple myeloma (NDMM) are older than 75 years. Immunomodulatory drugs (IMIDs) have improved response rates and outcomes of NDMM, except for patients older than 75 years more vulnerable to side effects of IMIDs because of their frailty and comorbidities.

We evaluated efficacy, toxicity and health-related quality of life (HRQOL) associated with continuous alternate-day low dose lenalidomide (LD-R, 10 mg on alternate days) and low dose prednisone (15 mg/day) (LD-RP) in 7 octogenarian NDMM patients (5 males and 2 females) with a median age of 82 years (range 80-87). All octogenarian patients had IgG MM, except 1 oligosecretory lambda chain MM; all were in Durie-Salmon stage III, except 1 in stage II, and had poor WHO performance status (median: 2, range 1-3). Patients were evaluated at baseline and every 6 months for HRQOL according to MM-specific questionnaire QLQ-MY20 of European Organisation for Research and Treatment of Cancer (EORTC). All patients received aspirin thromboprophylaxis, 57% of them requiring from diagnosis erythropoietin and zoledronic acid treatment. In these 7 octogenarian NDMM patients completing at least three months of therapy, the overall response rate (ORR) was 86%, including 1 complete remission (CR), 2 very good partial remission (VgPR) and 3 PR. After a median follow-up of 12 months (range 3-24), the quality of response improved with continuous LD-RP treatment with a cumulative median reduction in monoclonal protein levels of 85% (range 20-100%); none of the patients required discontinuation of treatment secondary to specific hematologic and/or extra-hematologic toxicity. In addition, QLQ MY-20 questionnaires revealed that 70% of patients treated with continuous LD-RP reported improvements of QOL scores. Two out of 7 octogenarian patients died (1 for progression after 12 months and 1 for sepsis no treatment-related), and 2-year overall survival and progression-free survival estimates were 41% and 75%, respectively. Noteworthy, all patients treated with continuous alternate-day LD-RP showed a progressive increase in the percentage of CD3+ CD56+ NK cells during the first 6 months of LD-RP therapy reaching a plateau maintained until +12 months after initiation of therapy: the median percentage of NK cells was 4% before LD-RP treatment versus 10%, 13%, 30%, 31%, and 27% at +1, +3, +6, +9 and +12 months, respectively. Mean fold increase of NK cells during LD-RP therapy was 1.5, 2.5, and 6.5 at +1, +3 and +6 months, respectively. Progressive increase of NK cells was concomitantly associated with reduction in tumor-linked monoclonal immunoglobulin in all patients and increased circulating NK cells further support that this drug may mediate its anti-MM effect, at least in part by modulating NK-cell number and function.

Our data provide evidence that continuous alternate-day low dose lenalidomide is a manageable and effective frontline treatment for octogenarian NDMM patients and increases circulating NK cells. These preliminary results require further validation in prospective larger studies.