Chemical. CAS 2381037-82-5. Formula C20H23F6N7O3. MW 523.4. RBN-2397 is a potent NAD competitive small molecule inhibitor of PARP-7. RBN-2397 selectively inhibits PARP-7 and demonstrates >50-fold selectivity for inhibition of PARP-7 over all PARP family members as measured by biochemical assays. RBN-2397 inhibits PARP-7-dependent MARylation IC50 = 2nM in cell biochemical assay and inhibits cells proliferation in NCI-H1373 lung cancer cells IC50 = 20nM. By selectively inhibiting PARP-7 in tumor cells, RBN-2397 has been shown to directly inhibit cellular proliferation and restore Type I interferon signaling to stimulate an innate and adaptive antitumor immune response. Targeting cytosolic nucleic acid sensing pathways and the Type I interferon IFN response is an emerging therapeutic strategy being explored in oncology. The PARP family consists of seventeen enzymes that regulate fundamental biological processes including response to cellular stress.