The GMMG-CONCEPT trial investigated isatuximab, carfilzomib, lenalidomide, and dexamethasone (Isa-KRd) in transplant-eligible (TE) and transplant-noneligible (TNE) patients with newly diagnosed multiple myeloma (NDMM) with exclusively high-risk disease for whom prospective trials are limited, aiming to induce minimal residual disease (MRD) negativity.

This academic, investigator-initiated, multicenter, phase II trial enrolled patients with high-risk NDMM (HRNDMM) defined by mandatory International Staging System stage II/III combined with del17p, t(4;14), t(14;16), or more than three 1q21 copies as high-risk cytogenetic aberrations (HRCAs). Patients received Isa-KRd induction/consolidation and Isa-KR maintenance. TE patients received high-dose melphalan. TNE patients received two additional Isa-KRd cycles postinduction. This prespecified interim analysis (IA) reports the primary end point, MRD negativity (<10, next-generation flow), at the end of consolidation. The secondary end point was progression-free survival (PFS).

Among 125 patients with HRNDMM (TE-intention-to-treat [ITT]-IA, 99; TNE-ITT, 26) of the IA population for the primary end point, the median age was 58 (TE-ITT-IA) and 74 (TNE-ITT) years. Del17p was the most common HRCA (TE, 44.4%; TNE, 42.3%); about one third of evaluable TE/TNE patients presented two or more HRCAs, respectively. The trial met its primary end point with MRD negativity rates after consolidation of 67.7% (TE) and 54.2% (TNE) of patients. Eighty-one of 99 TE-ITT-IA patients reached MRD negativity at any time point (81.8%). MRD negativity was sustained for ≥1 year in 62.6% of patients. With a median follow-up of 44 (TE) and 33 (TNE) months, median PFS was not reached in either arm.

Isa-KRd effectively induces high rates of sustainable MRD negativity in the difficult-to-treat HRNDMM population, regardless of transplant status, translating into a median PFS that was not yet reached after 44/33 months.