Mezigdomide Plus Ixazomib

Mezigdomide is a novel cereblon E3 ligase modulator (CELMoD). It is an oral small-molecule compound that potentiates the cereblon-mediated ubiquitination of key cellular transcription factors (Ikaros and Aiolos), which ultimately results in multiple myeloma cell death and other immunomodulatory activity. Mezigdomide has demonstrated acceptable safety in two phase I clinical trials in combination with DEX as a "doublet," and as a "triplet" in combination with bortezomib and DEX. Early estimates of efficacy are high compared to historical date: 55% ORR in combination with DEX in a highly pre-treated and refractory patient population, and 75% in combination with bortezomib. By comparison, the most recent oral therapy approved by the FDA for RRMM was Selinexor, which demonstrated a 25% ORR in patients who received a median of 7 prior lines of therapy and 100% of whom were refractory to a PI, IMID and DARA. This comparison serves as very exploratory estimate as no conclusions can be drawn from cross-trial comparisons, especially with very small patient populations. While important efficacy measures such overall survival, progression-free survival and duration of response are maturing, these estimates suggest mezigdomide could be an efficacious, oral treatment option for patients with RRMM.