Arginase 1/2 Inhibitor OATD-02: From Discovery to First-in-man Setup in Cancer Immunotherapy.

Pharmacologic inhibition of the controlling immunity pathway enzymes arginases 1 and 2 (ARG1 and ARG2) is a promising strategy for cancer immunotherapy. Here, we report the discovery and development of OATD-02, an orally bioavailable, potent arginases inhibitor. The unique pharmacologic properties of OATD-02 are evidenced by targeting intracellular ARG1 and ARG2, as well as long drug-target residence time, moderate to high volume of distribution, and low clearance, which may jointly provide a weapon against arginase-related tumor immunosuppression and ARG2-dependent tumor cell growth. OATD-02 monotherapy had an antitumor effect in multiple tumor models and enhanced an efficacy of the other immunomodulators. Completed nonclinical studies and human pharmacokinetic predictions indicate a feasible therapeutic window and allow for proposing a dose range for the first-in-human clinical study in patients with cancer. SIGNIFICANCE: We have developed an orally available, small-molecule intracellular arginase 1 and 2 inhibitor as a potential enhancer in cancer immunotherapy. Because of its favorable pharmacologic properties shown in nonclinical studies, OATD-02 abolishes tumor immunosuppression induced by both arginases, making it a promising drug candidate entering clinical trials.

Discovery and optimization of novel pyrazole-benzimidazole CPL304110, as a potent and selective inhibitor of fibroblast growth factor receptors FGFR (1-3).

The FGFR family is characterized by four receptors (FGFR 1-4), binding to 18 ligands called fibroblast growth factors (FGFs). Aberrant activation of FGFs and their FGFRs has been implicated in a broad spectrum of human tumors. We employed the scaffolds hybridization approach, scaffold-hopping concept to synthesize a series of novel pyrazole-benzimidazole derivatives 56 (a-x). Compound 56q (CPL304110) was identified as a selective and potent pan-FGFR inhibitor for FGFR1, -2, -3 with IC50s of 0.75 nM, 0.50 nM, 3.05 nM respectively, whereas IC50 of 87.90 nM for FGFR4. Due to its favorable pharmacokinetic profile, low toxicity and potent anti-tumor activity in vivo, compound 56q is currently under evaluation in phase I clinical trial for the treatment of bladder, gastric and squamous cell lung cancers (01FGFR2018; NCT04149691).