Randomized Trial of Lenalidomide, Bortezomib, Dexamethasone vs High-Dose Treatment With SCT in MM Patients up to Age 65

The PR rate is the percentage of participants achieving PR or better on treatment and was evaluated based on the IMWG criteria. PR was defined as > 50% reduction of serum M-protein and reduction in 24-h urinary M-protein by > 90% or to < 200mg per 24 hours. If the serum and urine M-protein are unmeasurable, a > 50% decrease in the difference between involved and uninvolved free light chain levels is required in place of the M-protein criteria. If serum and urine M-protein are unmeasurable, and serum free light assay is also unmeasurable, >50% reduction in plasma cells is required in place of M-protein, provided baseline bone marrow plasma cell percentage was > 30%. In addition to the above listed criteria, if present at baseline, a > 50% reduction in the size of soft tissue plasmacytomas was also required. Exact (Clopper-Pearson) confidence limits of 98.2857% represents Bonferroni adjustment for 7 tests (1-0.05/7) per statistical analysis plan for key secondary outcomes.

The VGPR rate is the percentage of participants achieving VGPR or better on treatment and was evaluated based on IMWG criteria. VGPR was defined as serum and urine M-protein detectable by immunofixation but not on electrophoresis or 90% or greater reduction in serum M-protein plus urine M-protein level <100mg per 24 hours.

The CR rate is the percentage of participants achieving CR or better on treatment and was evaluated based on IMWG criteria. CR was defined as the negative immunofixation on the serum and urine and disappearance of any soft tissue plasmacytomas and <5% plasma cells in bone marrow. Confirmation with repeat bone marrow biopsy was not needed.

DOR PR was estimated using the KM method and defined as the time from documented best response as CR to documented disease progression per IMWG criteria. Patients who have not progressed or died were censored at the date last known progression-free.

TTP was estimated using the KM method and defined as time from randomization to time of documented IMWG disease progression or censoring time (time of last disease evaluation for those alive, time to death among those who died). Patients initiating non-protocol therapy prior to progression or death were censored at the date of non-protocol therapy in the TTP analysis. The 5-year TTP endpoint is a probability.

OS was estimated using the KM method and defined as time from randomization to death due to any cause. Patients alive were censored at date last known alive. The 5-year OS endpoint is a probability.

Safety was evaluated throughout trial treatment, including ASCT, and through 30 days after receipt of the last dose of a trial drug. Treatment attribution and grade were based on the NCI CTCAE v4. The Grade 3 or Higher Treatment-Related Non-Hematologic AE Rate is percentage of participants who experienced any grade 3-5 treatment-related (possible, probable or definite attribution) non-hematologic adverse event based on CTCAEv4 as reported on case report forms. The difference in the rate of all grade 3 or higher toxicities was compared between the two groups using Fisher's exact test.

Second primary malignancy (SPM) is defined as the development of another new, unrelated cancer, regardless of treatment for previous malignancy attribution. The cumulative incidence of SPMs was estimated with death as a competing risk. SPMs were collected using an SAE form or MEDWATCH 3500A form, with intensity determined by using the NCI CTCAE version 4 as a guideline.

Treatment duration estimated using the KM method is defined as the time from registration (C1) to the time off treatment (event) or censored at date of last treatment.

Maintenance treatment duration estimated using the KM method is defined as the time from start of maintenance to the time off maintenance (event) or censored at date of last maintenance treatment.

Subsequent therapy rate was the percentage of participants who discontinued treatment and initiated subsequent non-protocol therapy.

The FACT/GOG-NTX assessment consists of 11 questions that are all used to construct 1 subscale to summarize symptoms of peripheral neuropathy, including sensory, motor, and auditory problems and cold sensitivity. (https://www.facit.org/measures/FACT-GOG-NTX) Each question has 4 possible responses from 0 (Not at all) to 4 (Very Much) which are reverse-scored and summed. This sum is then scaled by the number of questions answered by multiplying by 11 and then dividing by the number of questions that are non-blank, in order to keep all final scores proportional to one another even if some questions are left blank. The aggregate score ranges from 0 to 44, with higher scores indicating less neurotoxicity and lower scores indicating more neurotoxicity. Change from baseline is the difference

The EORTC QLQ-C30 assessment consists of 30 questions that are used to construct 15 distinct sub-scales (five function scales, nine symptom scales, and a global health status/QoL scale). The global health status/QoL scale is comprised of two questions each with a range of 6 (1=Very Poor to 7=Excellent). Scores on all sub-scales range from 0 to 100 after linear transformation of the raw scores, with higher scores representing better global health status and quality of life.

QALYs were estimated with a model beginning at initiation of first-line therapy by arm. A lifetime horizon, as well as subsequent lines of therapy, was examined using open-source Amua 0.3.0 software. Base case analysis was performed using 10,000 first-order Monte Carlo simulations. Conditional probabilities were extracted from Kaplan-Meier curves from pivotal clinical trials using WebPlotDigitizer. Costs were estimated from RED BOOK and DFCI charge reporting in US Dollars ($) after inflation adjustment to 2022 and 3% discounting, and QALYs effects were measured using EQ-5D data from Hatswell et al.