Short-course lenalidomide plus low-dose dexamethasone in the treatment of newly diagnosed multiple myeloma-a single-centre pragmatic study.

PURPOSE: We assessed response to treatment, toxicity, time to progression, progression-free survival, and overall survival in patients newly diagnosed with multiple myeloma who were ineligible for or unwilling to undergo transplantation and who were treated with a combination of lenalidomide and low-dose dexamethasone for a fixed 6 cycles in a resource-constrained environment.
METHODS: This pragmatic study, conducted in a single tertiary cancer centre in South India, enrolled patients from May 2009 till April 2011. Treatment included lenalidomide 25 mg daily for 21 days, with dexamethasone 40 mg on days 1, 8, 15, and 22 of a 28-day cycle, for 6 cycles. Response was evaluated after the 3rd and 6th cycles of treatment. All patients were followed for 5 years.
RESULTS: The study enrolled 51 patients. Median age in the group was 61 years (range: 38-76 years). Immunoglobulin G or A myeloma constituted 70.6% of the diagnoses, and light-chain myeloma constituted 29.4%. Stages i, ii, and iii (International Staging System) disease constituted 21.4%, 28.6%, and 50% of the diagnoses respectively. All patients were transplantation-eligible, but 34 (66.7%) refused for economic reasons. After treatment, 19.6% of the patients achieved a stringent complete response; 35.3%, a complete response; 5.9%, a very good partial response; and 29.4%, a partial response, for an overall response rate of 90.2%. Stable disease was seen in 3.9% of patients, and progressive disease, in 5.9%. Grade 3 or greater nonhematologic and hematologic toxicity occurred in 35.2% and 11.7% of patients respectively. Pulmonary embolism occurred in 1 patient. No patient experienced deep-vein thrombosis or peripheral neuropathy. The median follow-up duration was 66 months. All patients experienced disease progression. Median progression-free survival was 16 months. In 10 patients, re-challenge with lenalidomide and dexamethasone achieved a second complete response. At the time of writing, 19 patients had died. The overall survival rate at 5 years was 62.74%. Median overall survival is not yet reached.
CONCLUSIONS: In a resource-constrained setting, lenalidomide with low-dose dexamethasone is an effective treatment with acceptable toxicity in patients newly diagnosed with multiple myeloma and not planned for transplantation. Complete responses were significantly more frequent than reported in the Western literature. Occurrence of clinical deep-vein thrombosis was rare, but hyperglycemia was common. An abbreviated course of treatment is suboptimal in multiple myeloma. Maintenance regimens should be advocated.