On October 21, 2025 Hoth Therapeutics, Inc. (NASDAQ: HOTH) reported FDA Orphan Drug Designation for HT-KIT and new preclinical data demonstrating >80% suppression of KIT expression and significant tumor-volume reduction by Day 8 in systemic mastocytosis and GIST models. HT-KIT, a precision antisense oligonucleotide (ASO) targeting KIT mRNA, also completed GLP-validated bioanalytical methods supporting IND-enabling studies; Japan Patent No. 7677628 extends platform protection to 2039.
Schedule your 30 min Free 1stOncology Demo!
Discover why more than 1,500 members use 1stOncology™ to excel in:
Early/Late Stage Pipeline Development - Target Scouting - Clinical Biomarkers - Indication Selection & Expansion - BD&L Contacts - Conference Reports - Combinatorial Drug Settings - Companion Diagnostics - Drug Repositioning - First-in-class Analysis - Competitive Analysis - Deals & Licensing
Schedule Your 30 min Free Demo!
Preclinical Summary (2025):
Potent gene-level target suppression: HT-KIT achieved >80% reduction of KIT mRNA/protein across in-vitro systems and in vivo models of systemic mastocytosis and GIST.
Rapid anti-tumor activity: In xenograft models, statistically significant tumor-volume reduction by Day 8 was observed, accompanied by apoptotic signaling consistent with KIT pathway knock-down.
Favorable tolerability in early studies: No dose-limiting toxicities observed in the reported preclinical work to date.
Bioanalytical readiness: GLP-validated bioanalytical methods completed to support pharmacokinetic, biodistribution, and exposure-response analyses for IND.
Mechanistic Rationale:
Unlike small-molecule TKIs that inhibit kinase activity, HT-KIT operates upstream at the transcript level, silencing both mutant and wild-type KIT. This mechanism is designed to bypass resistance pathways (secondary mutations, compensatory signaling) and reduce off-target liabilities, potentially improving durability and tolerability in KIT-driven diseases such as aggressive systemic mastocytosis (ASM), SM-AHN, mast cell leukemia (MCL), GIST, and select leukemias.
Orphan Drug Designation (U.S.) supports development in a rare disease with incentives including potential exclusivity upon approval, tax credits, and fee waivers.
Planned Next Steps (Near-Term):
Complete GLP toxicology and CMC packages; submit IND.
Initiate Phase 1/2 dose-escalation/expansion study in advanced systemic mastocytosis and other KIT-driven tumors with translational biomarkers of target engagement (KIT knock-down, tryptase/MRK signaling) and early efficacy readouts (ORR, DCR, PFS signals).
Continue regional IP expansion and evaluate strategic partnerships for development and commercialization.
"HT-KIT’s transcript-level suppression of KIT has now produced consistent anti-tumor performance across models, with a clean preclinical tolerability profile and GLP-ready analytics," said Robb Knie, Chief Executive Officer. "With Orphan Drug Designation secured and an IND-enabling package progressing, we are preparing for a disciplined entry into first-in-human evaluation."
About HT-KIT:
HT-KIT is a precision ASO designed to silence KIT at the mRNA level, aiming to overcome resistance and off-target toxicity seen with kinase inhibitors in systemic mastocytosis, GIST, and select leukemias.
(Press release, Hoth Therapeutics, OCT 21, 2025, View Source [SID1234656883])