FDA Clears IND for NTS231, Second NRF2 Degrader to Enter Clinical Development
核心洞察
Nutshell Therapeutics (搜索) received FDA IND clearance for NTS231 (搜索), a covalent allosteric molecular glue degrader of NRF2 (搜索), to begin clinical development in the United States.
NTS231 (搜索) is the first NRF2 (搜索) degrader from China and the second globally to enter clinical development, reaching IND approval within 24 months of target nomination.
Preclinical data show dose-dependent single-agent activity across CDX and PDX models of LUSC, LUAD, ESCC and HNSCC, plus synergy with chemotherapy, targeted agents and ADCs.
Nutshell Therapeutics (搜索) (Shanghai) Co., Ltd. has received FDA investigational new drug clearance for NTS231 (搜索), a covalent allosteric molecular glue degrader of NRF2 (搜索), allowing the company to launch clinical development in the United States. NTS231 is the first NRF2 degrader molecule from China and the second globally to enter clinical development, according to the company.
The program targets the NRF2 (搜索) pathway, which Nutshell describes as a key driver of tumor survival and treatment resistance in multiple cancer types.
An AI-Discovered Molecular Glue Against KEAP1
NTS231 (搜索) emerged from ALLOSTAR, Nutshell's proprietary AI-driven allosteric drug discovery platform, which integrates computer-aided drug design, medicinal chemistry and experimental techniques. Through the platform, the company identified NTS231 as a potent and selective small molecule that covalently binds KEAP1 (搜索) and induces degradation of NRF2 (搜索).
Mechanistically, NTS231 (搜索) irreversibly links to the Cys151 residue of KEAP1 (搜索) and stabilizes a KEAP1 conformation that favors CUL3 (搜索) interaction and assembly of a functional KEAP1-CUL3 E3-ligase complex. That assembly drives NRF2 (搜索) degradation, suppresses NRF2 signaling and inhibits cancer cell viability. The company said it completed IND approval within 24 months from target nomination.
Preclinical Efficacy Across Solid Tumor Models
In preclinical studies, NTS231 (搜索) showed in vitro activity non-inferior to VVD-130037, a clinical-stage compound with the same targeting mechanism, while demonstrating superior pharmacokinetic properties. Across multiple cell-derived xenograft and patient-derived xenograft models carrying diverse NRF2 (搜索), KEAP1 (搜索) or CUL3 (搜索) mutations or NRF2 hyperactivation, the molecule produced dose-dependent antitumor efficacy as a single agent in lung squamous cell carcinoma (搜索), lung adenocarcinoma (搜索), esophageal squamous cell carcinoma (搜索) and head and neck squamous cell carcinoma (搜索).
Combination activity was also observed with chemotherapy, targeted therapies and antibody-drug conjugates. In chemotherapy-resistant LUSC PDX models harboring KEAP1 (搜索) and other mutations, NTS231 (搜索) plus paclitaxel significantly enhanced tumor growth inhibition compared with either single agent. In a proof-of-concept CDX model of NFE2L2 (搜索)-amplified LUAD, NTS231 combined with a TROP2 ADC (搜索) improved efficacy and led to tumor regression, with decreased expression of NRF2 (搜索)-regulated efflux transporters, a change the company suggests may sensitize tumors to ADC payloads and mitigate resistance.
In 28-day Good Laboratory Practice toxicology studies in rats and dogs, NTS231 (搜索) showed a favorable safety profile and a wide safety margin.
An Unmet Need in NRF2-Driven Tumors
Constitutive NRF2 (搜索) activation occurs in many human cancers through genetic alterations in NFE2L2 (搜索), the gene encoding NRF2, and its regulatory genes KEAP1 (搜索) and CUL3 (搜索). Approximately 12% of cancer patients profiled in The Cancer Genome Atlas carry mutations in at least one of these three genes, with prevalence above 30% in LUSC and above 20% in LUAD. Preliminary estimates cited by the company indicate more than 1.5 million annual new cancer cases worldwide harbor NRF2, KEAP1 or CUL3 alterations or other aberrant NRF2 pathway activation.
This population is largely ineligible for most targeted therapies because NRF2 (搜索), KEAP1 (搜索) and CUL3 (搜索) alterations are mutually exclusive with EGFR, ALK, ROS1 and BRAF genetic lesions. Immunotherapy also yields limited efficacy in these patients, as the mutations are strongly associated with an immunologically cold tumor microenvironment that drives therapeutic resistance. Constant NRF2 pathway activation from NRF2, KEAP1 or CUL3 mutations can additionally confer resistance to standard chemotherapy.
By directly targeting the KEAP1 (搜索)-NRF2 (搜索) regulatory axis, NTS231 (搜索) is positioned as a potential new approach for patients with NRF2, KEAP1 or CUL3 (搜索) mutations, as well as tumors characterized by NRF2 pathway hyperactivation.