Day 90 CR not a good endpoint for auto-HSCT, doc says

Maintenance largely consisted of lenalidomide. Sixty-five percent of patients in the bu-mel arm and 63% in the mel arm received the drug. Fewer patients received bortezomib—8% and 16%, respectively—or lenalidomide plus ixazomib—10% and 9%, respectively.

Survival

At a median follow-up of 19.5 months, bu-mel was associated with significantly longer PFS than mel alone (P=0.047). And a multivariate analysis showed that bu-mel was an independent predictor of PFS.

Dr Qazilbash noted that there was no significant difference in overall survival between the bu-mel and mel arms (P=0.97), but the follow-up is less than 2 years, so this is expected.

“Bu-mel was associated with a significantly lower day 90 CR rate, a significantly higher rate of grade 3-4 non-hematologic toxicity, no significant difference in transplant-related mortality . . . , and a significantly longer PFS,” Dr Qazilbash summarized.

He therefore concluded that, based on this study, day 90 CR is not an adequate endpoint for auto-HSCT trials. This trial was amended to change the primary

endpoint from day 90 CR to PFS, and accrual has been increased to 205 patients.

Dr Qazilbash and others involved in this study received research funding from Otsuka, makers of busulfan. Dr Qazilbash also reported relationships (advisory

board, honoraria) with Celgene, Millennium, and Onyx.

*Information in the abstract differs from that presented at the meeting.