CB-1158-analog, also known as Numidargistat-analog and INCB01158-analog, is a potent and orally active arginase inhibitor with IC50=89 nM) . CB-1158 blocked myeloidcell-mediated suppression of T cell proliferation in vitro and reduced tumor growth in multiple mouse models of cancer, as a single agent and in combination with checkpoint blockade, adoptive T cell therapy, adoptive NK cell therapy, and the chemotherapy agent gemcitabine. CB-1158 increased tumor-infiltrating CD8+ T cells and NK cells, inflammatory cytokines, and expression of interferon-inducible genes. CB-1158 may be potentially useful in renal cell cancer, breast cancer, non-small cell lung cancer, acute myeloid leukemia, and other tumor types where arginase-secreting MDSCs are known to play an immunosuppressive role. (see ADDITIONAL INFORMATION in this web page for CB-1158 structure confusion).
PC-046 is a potent tubulin-binding agent, which was originally identified for development based on selective activity in deleted in pancreas cancer locus 4 (DPC4 SMAD4) deficient tumors. PC-046 has growth inhibitory activity in a variety of tumor types in vitro, and efficacy in SCID mice was shown in human tumor xenografts of MV-4-11 acute myeloid leukemia, MM.1S multiple myeloma, and DU-145 prostate cancer. Pharmacokinetic studies demonstrated relatively high oral bioavailability (71 %) with distribution to both plasma and bone marrow. No myelosuppression was seen in non-tumor bearing SCID mice given a single dose just under the acute lethal dose. The COMPARE algorithm in the NCI-60 cell line panel demonstrated that PC-046 closely correlated to other known tubulin destabilizing agents (correlation coefficients ≈0.7 for vincristine and vinblastine). Mechanism of action studies showed cell cycle arrest in metaphase and inhibition of tubulin polymerization. Overall, these studi......