Lenalidomide plus high-dose dexamethasone versus lenalidomide plus low-dose dexamethasone as initial therapy for newly diagnosed multiple myeloma: an open-label randomised controlled trial.
BACKGROUND
High-dose dexamethasone is a mainstay of therapy for multiple myeloma. We studied whether low-dose dexamethasone in combination with lenalidomide is non-inferior to and has lower toxicity than high-dose dexamethasone plus lenalidomide.


METHODS
Patients with untreated symptomatic myeloma were randomly assigned in this open-label non-inferiority trial to lenalidomide 25 mg on days 1-21 plus dexamethasone 40 mg on days 1-4, 9-12, and 17-20 of a 28-day cycle (high dose), or lenalidomide given on the same schedule with dexamethasone 40 mg on days 1, 8, 15, and 22 of a 28-day cycle (low dose). After four cycles, patients could discontinue therapy to pursue stem-cell transplantation or continue treatment until disease progression. The primary endpoint was response rate after four cycles assessed with European Group for Blood and Bone Marrow Transplant criteria. The non-inferiority margin was an absolute difference of 15% in response rate. Analysis was by modified intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00098475.


RESULTS
445 patients were randomly assigned: 223 to high-dose and 222 to low-dose regimens. 169 (79%) of 214 patients receiving high-dose therapy and 142 (68%) of 205 patients on low-dose therapy had complete or partial response within four cycles (odds ratio 1.75, 80% CI 1.30-2.32; p=0.008). However, at the second interim analysis at 1 year, overall survival was 96% (95% CI 94-99) in the low-dose dexamethasone group compared with 87% (82-92) in the high-dose group (p=0.0002). As a result, the trial was stopped and patients on high-dose therapy were crossed over to low-dose therapy. 117 patients (52%) on the high-dose regimen had grade three or worse toxic effects in the first 4 months, compared with 76 (35%) of the 220 on the low-dose regimen for whom toxicity data were available (p=0.0001), 12 of 222 on high dose and one of 220 on low-dose dexamethasone died in the first 4 months (p=0.003). The three most common grade three or higher toxicities were deep-vein thrombosis, 57 (26%) of 223 versus 27 (12%) of 220 (p=0.0003); infections including pneumonia, 35 (16%) of 223 versus 20 (9%) of 220 (p=0.04), and fatigue 33 (15%) of 223 versus 20 (9%) of 220 (p=0.08), respectively.


CONCLUSIONS
Lenalidomide plus low-dose dexamethasone is associated with better short-term overall survival and with lower toxicity than lenalidomide plus high-dose dexamethasone in patients with newly diagnosed myeloma.


BACKGROUND
National Cancer Institute, Rockville, MD, USA.
Mayo Clinic, Rochester, Minnesota, USA. rajkumar.vincent@mayo.edu
S Vincent
SV
Rajkumar
Susanna
S
Jacobus
Natalie S
NS
Callander
Rafael
R
Fonseca
David H
DH
Vesole
Michael E
ME
Williams
Rafat
R
Abonour
David S
DS
Siegel
Michael
M
Katz
Philip R
PR
Greipp
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects / Q000627:therapeutic use*; D003907:Dexamethasone / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D057239:Early Termination of Clinical Trials; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D000077269:Lenalidomide; D008297:Male; D008875:Middle Aged; D009101:Multiple Myeloma / Q000175:diagnosis / Q000188:drug therapy* / Q000401:mortality; D016016:Proportional Hazards Models; D018570:Risk Assessment; D013792:Thalidomide / Q000008:administration & dosage / Q000031:analogs & derivatives; D013997:Time Factors; D016896:Treatment Outcome
D013792:Thalidomide; D003907:Dexamethasone; D000077269:Lenalidomide