- Liu, Sixue;
- Dharanipragada, Prashanthi;
- Lomeli, Shirley H;
- Wang, Yan;
- Zhang, Xiao;
- Yang, Zhentao;
- Lim, Raymond J;
- Dumitras, Camelia;
- Scumpia, Philip O;
- Dubinett, Steve M;
- Moriceau, Gatien;
- Johnson, Douglas B;
- Moschos, Stergios J;
- Lo, Roger S
Metastasis and failure of present-day therapies represent the most common causes of mortality in patients with cutaneous melanoma. To identify the underlying genetic and transcriptomic landscapes, in this study we analyzed multi-organ metastases and tumor-adjacent tissues from 11 rapid autopsies after treatment with MAPK inhibitor (MAPKi) and/or immune checkpoint blockade (ICB) and death due to acquired resistance. Either treatment elicits shared genetic alterations that suggest immune-evasive, cross-therapy resistance mechanisms. Large, non-clustered deletions, inversions and inter-chromosomal translocations dominate rearrangements. Analyzing data from separate melanoma cohorts including 345 therapy-naive patients and 35 patients with patient-matched pre-treatment and post-acquired resistance tumor samples, we performed cross-cohort analyses to identify MAPKi and ICB as respective contributors to gene amplifications and deletions enriched in autopsy versus therapy-naive tumors. In the autopsy cohort, private/late mutations and structural variants display shifted mutational and rearrangement signatures, with MAPKi specifically selecting for signatures of defective homologous-recombination, mismatch and base-excision repair. Transcriptomic signatures and crosstalks with tumor-adjacent macroenvironments nominated organ-specific adaptive pathways. An immune-desert, CD8+-macrophage-biased archetype, T-cell exhaustion and type-2 immunity characterized the immune contexture. This multi-organ analysis of therapy-resistant melanoma presents preliminary insights with potential to improve therapeutic strategies.