Specific targeting of the KRAS mutational landscape in myeloma as a tool to unveil the elicited anti-tumor activity

The multiple myeloma (MM) mutational landscape has identified alterations in KRAS as the most recurring somatic variant. Combining DNA and RNA sequencing, we studied 756 patients and observed KRAS as the most frequently mutated gene in patients at diagnosis; in addition, we demonstrated the persistence or de novo occurrence of the KRAS aberration at disease relapse. Small molecule inhibitors targeting KRAS have been developed; however, they are selective for tumors carrying that KRASG12C mutation. Therefore, there is still a need to develop novel therapeutic approaches to target the KRAS mutational events found in other tumor types, including MM. We have used AZD4785, a potent and selective antisense oligonucleotide (ASO) which selectively targets and down-regulates all KRAS isoforms, as a tool to dissect the functional sequelae secondary to KRAS silencing in MM within the context of the bone marrow niche; and demonstrated its ability to significantly silence KRAS, leading to inhibition of MM tumor growth, both in vitro and in vivo, confirming KRAS as a driver and a therapeutic target in MM.