Genomic mechanisms of resistance to venetoclax in multiple myeloma with t(11;14)(CCND1;IGH).

Journal: Blood

This study evaluated why only some patients with t(11;14)(CCND1;IGH) multiple myeloma benefit durably from venetoclax.

Key points:

  • Population and methods:
    • 44 whole-genome/whole-exome–sequenced samples from 34 patients with t(11;14) myeloma treated with venetoclax.
    • Findings were validated in an independent cohort of 21 additional venetoclax-treated patients.
    • Ten patients had paired samples before venetoclax and at progression.
  • Baseline predictors of inferior outcome on venetoclax:
    • Mutations in the RAS pathway (e.g., KRAS/NRAS and related signaling alterations) were strongly associated with shorter progression-free survival.
    • This association with poor PFS was confirmed in the independent validation cohort.
    • Among patients without RAS-pathway mutations, gain of 1q was also linked to shorter PFS, indicating it is an additional adverse genomic feature in this setting.
  • Mechanisms of acquired resistance (paired pre/post samples):
    • At progression on venetoclax, clonal selection frequently involved:
    • Genomic events affecting the BCL2/MCL1 axis (shifting dependency away from BCL2).
    • Additional RAS pathway alterations.
    • Emergence or enrichment of high-risk lesions such as TP53 loss and CDKN2C loss.
  • Clinical implication:
    • In t(11;14) myeloma, venetoclax sensitivity is modulated by co-occurring genomic events.
    • Comprehensive genomic profiling (RAS-pathway status, 1q gain, TP53/CDKN2C and BCL2/MCL1 alterations) can identify patients at higher risk for primary resistance or early progression on venetoclax and clarify mechanisms of acquired resistance.

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