Preclinical Development of a Novel Therapeutic to Rejuvenate Aging Muscle Stem Cells and Enhance Muscle Strength and Function Post Hip Fracture

摘要 Ridgeline的U44直接获得国家研究所颁发的第二阶段合作协议奖(U44AG074107) 衰老使RT-002的快速治疗开发研究成为可能，RT-002是一种新的口服疗法，可促进 老年创伤性髋部骨折患者的功能恢复和生活质量的提高。几个 关键研究在该奖项的第一年完成，成功地为Ridgeline赢得了第二年的资金。 特别是，该项目完成了体外跨物种(小鼠、大鼠、狗、小型猪、猴子、人)代谢物的研究 用培养的肝细胞鉴定RT-002，老年人肌肉的体外翻译效价- 衍生的祖细胞，在老年小鼠和大鼠体内的PK/PD研究，工艺优化和放大 ~4公斤类GMP批次RT-002的合成、非GLP和GLP毒性及安全性药理研究 在大鼠中，雄性和雌性狗对RT-002的体内口服耐受性和毒代动力学评估，以及 雄性和雌性小型猪体内PK/口服生物利用度和剂量递增耐受性的初步研究。 这一补充项目将有助于完成FDA规定的选定药物的安全性/毒性研究 迷你猪非啮齿动物物种。 我们关键的跨物种代谢研究表明，我们的临床候选NNMT抑制剂药物RT-002 在大鼠、小型猪和人肝细胞中代谢相似，具有类似的生物转化率和 完全相同的代谢物。相反，RT-002在小鼠和猴肝细胞中的周转率被发现 在狗的肝细胞中速度非常快，但可以忽略不计。重要的是，确定的主要代谢物RT- 人、大鼠和小型猪的肝细胞几乎不存在于狗的肝细胞中，原因是缺乏 犬肝脏中主要的RT-002代谢酶、乙醛氧化酶(AO)和N-乙酰转移酶(NAT)。已被占用 总而言之，狗不是表征安全和安全的合适的非啮齿动物物种 RT-002的毒理学效应，这进一步证实了在狗身上观察到的耐受性较差 RT-002口服给药。鉴于这些结果，小型猪被选为非啮齿动物物种进行必要的RT- 002本奖项建议的安全/毒理学研究。这一补充项目将完成必要的 RT-002对雄性和雌性小型猪的安全性/毒理学研究以确定RT-002的最大耐受量 002，并评估重复口服药物后的安全性和毒性。这种降低风险的结果 研究将进一步验证迷你猪是继续监管GLP的理想非啮齿动物物种选择 毒理学研究并使Ridgeline能够继续开发新的NNMT抑制剂临床候选RT- 002在本项目期结束前达到IND申请里程碑。

ABSTRACT Ridgeline’s U44 direct to Phase 2 cooperative agreement award (U44AG074107) from the National Institute on Aging has enabled rapid therapeutic development studies of RT-002, a novel oral therapeutic to promote full functional recovery and enhance the quality-of-life in elderly adults following traumatic hip fracture. Several critical studies were completed in Year 1 of the award which successfully earned the Year 2 funding for Ridgeline. Particularly, the project completed in vitro cross-species (mouse, rat, dog, mini-pig, monkey, human) metabolite identification for RT-002 using cultured hepatocytes, in vitro translational valdiations in aged human muscle- derived progenitor cells, in vivo PK/PD studies in aged mice and rats, process optimization and scale up synthesis of ~4 kilogram GMP-like batch of RT-002, non-GLP and GLP toxicity and safety pharmacology studies in rats, in vivo oral dosing tolerability and toxicokinetic assessments for RT-002 in male and female dogs, and preliminary in vivo PK/oral bioavailability and dose escalation tolerability study in male and female mini-pigs. This supplemental project will aid in the completion of the FDA-mandated safety/toxicity studies in the chosen mini-pig nonrodent species. Our pivotal cross-species metabolism studies showed that our clinical candidate NNMT inhibitor drug RT-002 was metabolized similarly in rat, mini-pig, and human hepatocytes, with comparable biotransformation rates and identical metabolites. In contrast, the turnover rates for RT-002 in mouse and monkey hepatocytes were found to be remarkably rapid but negligable in dog hepatocytes. Importantly, the primary metabolites identified for RT- 002 in human, rat, and mini-pig hepatocytes were nearly absent in dog hepatocytes due to the absence of the major RT-002 metabolizing enzymes, aldehyde oxidase (AO) and N-acetyltransferase (NAT) in dog liver. Taken together it was concluded that dogs are not the appropriate nonrodent species to characterize safety and toxicological effects of RT-002, which was further substantiated by the poor tolerability observed in dogs following RT-002 oral dosing. Given these result, mini-pigs are chosen as the non-rodent species for the necessary RT- 002 safety/toxicology studies as proposed in this award. This supplemental project will complete the necessary RT-002 safety/toxicology studies in male and female mini-pigs to establish the maximum tolerated dose of RT- 002 and evaluate safety and toxicity following repeated oral dosing of the drug. Outcomes from this de-risking study will further validate mini-pigs as an ideal choice of nonrodent species for continued regulated GLP toxicology studies and enable Ridgeline to continue developing the novel NNMT inhibitor clinical candidate RT- 002 to reach the IND-filing milestone by the end of this project period.