SAN FRANCISCO – Should patients with multiple myeloma receive maintenance therapy until progression?
, of The Ohio State University Comprehensive Cancer Center – Arthur G. James Cancer Hospital in Columbus, and , of the University of California San Francisco Health, faced off on this question at the National Comprehensive Cancer Network Hematologic Malignancies Annual Congress.
Dr. Shah said maintenance therapy improves survival in myeloma patients, so it follows that treating them until progression would confer a survival advantage. While Dr. Efebera agreed that maintenance can improve survival, she said the optimal duration of that treatment is unknown.
Treat until progression
Dr. Shah cited studies suggesting that maintenance improves progression-free survival (PFS) and may prolong overall survival (OS) in multiple myeloma.
A meta-analysis of data from the IFM 2005-02, CALGB 100104, and GIMEMA RV-MM-PI-209 trials showed that lenalidomide maintenance prolonged PFS and OS. The median PFS was 52.8 months in patients who received maintenance and 23.5 months in those who received placebo or observation (hazard ratio [HR], 0.48). At a median follow-up of 79.5 months, the median OS was not reached for the maintenance group and was 86.0 months for the no-maintenance group (HR, 0.75; P = .001;).
In the Myeloma XI trial, maintenance improved PFS, but not OS, in both transplant-eligible and ineligible patients. Overall, the median PFS was 39 months in the lenalidomide maintenance arm and 20 months in the observation arm (P less than .0001). Among transplant-eligible patients, the median PFS was 57 months and 30 months, respectively (P less than .0001). Among transplant-ineligible patients, the median PFS was 26 months and 11 months, respectively (P less than .0001;).
These data suggest maintenance can improve survival, “but the question is, how long should we have therapy,” Dr. Shah said. “No one has looked at this in a prospective manner, so we really have to look at our retrospective data.”
One study suggested a longer duration of lenalidomide maintenance improves PFS. The HR for progression or death was 0.39 for patients who received maintenance for 12-24 months, compared with those who received maintenance for less than 12 months. The HR was 0.13 for patients who received maintenance for more than 24 months, compared with less than 12 months ().
Dr. Shah also cited a pooled analysis of three phase 3 trials suggesting that continuous therapy is superior to fixed-duration therapy in patients with newly diagnosed myeloma. The median PFS was 32 months with continuous therapy and 16 months with fixed-duration therapy (P less than .001). The 4-year OS was 69% and 60%, respectively (P = .003;).
These data suggest that “continuous therapy, more therapy, has a survival advantage,” Dr. Shah said.
Don’t treat until progression
Dr. Efebera also discussed data from studies showing that lenalidomide maintenance can prolong survival in multiple myeloma. However, she said, it’s unclear how long maintenance should last.
Different durations of maintenance have proved effective in different trials. In the CALGB 100104 trial, the median duration of maintenance was 31 months (). In the meta-analysis of the CALGB, IFM, and GIMEMA trials, the median duration was 22 months. And in Myeloma XI, the median duration was 18 months.
As there is no randomized trial comparing different durations of maintenance, Dr. Efebera proposed that researchers conduct one. She said this “perfect study” would involve induction with an immunomodulatory agent, a proteasome inhibitor, dexamethasone, and perhaps an anti-CD38 therapy. Transplant-eligible patients would receive four cycles of induction before transplant. Transplant-ineligible patients would receive eight cycles of induction. Then, all patients would be randomized to lenalidomide maintenance for 3 years, 5 years, or 7-10 years.
Until a trial like this reveals the optimal duration of maintenance, we cannot conclude that treating patients until progression is better, Dr. Efebera said.
She added that maintenance has been shown to have detrimental effects, and these should be taken into consideration. For instance, neutropenia, other hematologic adverse events, and second primary malignancies have been shown to be more common among patients who receive lenalidomide maintenance ().
The cost of maintenance is another factor to consider. Researchers analyzed data from the CALGB 100104 and IFM 2005-02 trials to compare the cost of lenalidomide maintenance with no maintenance. In the CALGB 100104 trial, patients who received lenalidomide maintenance had 5.72 quality-adjusted life years (QALYs), and those who received no maintenance had 4.61 QALYs. The incremental cost-utility ratio (ICUR) was more than 277,000 euros per QALY.
In the IFM2005-02 trial, patients in the lenalidomide group had 5.13 QALYs, and those who didn’t receive maintenance had 4.98 QALYs. The ICUR was more than 1.5 million euros per QALY. The researchers said the high ICURs and budgetary impact add “uncertainty about the maximum prudent duration of the treatment” ().
Dr. Efebera reported relationships with Akcea Therapeutics, Janssen, and Takeda. Dr. Shah reported having no relevant financial relationships.