HIGH POINT, N.C. — October 7, 2026
vTv Therapeutics announced that the U.S. Food and Drug Administration (FDA) has granted Orphan Drug Designation to HPPD (HPP8668), the company’s investigational oral, first-in-class Nrf2/Bach1 modulator being developed for sickle cell disease. The regulatory milestone supports vTv’s efforts to advance HPPD as a potential treatment for a serious inherited blood disorder with significant unmet medical needs. The designation also strengthens the company’s ability to pursue strategic partnering discussions for the program while it continues to prioritize its lead late-stage type 1 diabetes program, cadisegliatin. vTv said the FDA designation represents an important development milestone for HPPD and provides additional support for the program’s potential as a novel oral therapeutic approach in sickle cell disease.
HPPD Targets Fetal Hemoglobin and Oxidative Stress
HPPD is designed to modulate the Nrf2/Bach1 pathway, with preclinical studies suggesting effects on fetal hemoglobin (HbF), oxidative stress and red blood cell sickling. In studies conducted at Augusta University using the Townes sickle cell disease mouse model, oral HPPD was reported to be active and well tolerated, increased fetal hemoglobin and reduced oxidative stress and sickling of red blood cells. The company said HPPD induced HbF in a time- and dose-dependent manner, with effects comparable to or exceeding hydroxyurea in the preclinical model. These findings provide the scientific rationale for continued investigation of HPPD as a potential disease-modifying therapy. However, HPPD remains an investigational program, and its safety and efficacy have not been established in humans.
Orphan Designation Supports HPPD Partnering Strategy
The FDA Orphan Drug Designation provides an important regulatory milestone as vTv evaluates the next development path for HPPD. Sickle cell disease is a chronic inherited disorder associated with hemolytic anemia, recurrent vaso-occlusive pain crises, oxidative stress and progressive organ damage. Although fetal hemoglobin induction is an established disease-modifying strategy, patients can continue to experience inadequate responses, tolerability challenges or persistent complications. vTv said the regulatory designation strengthens the company’s position in partnering discussions for HPPD while allowing management to maintain its primary focus on advancing cadisegliatin in type 1 diabetes. The company is seeking to develop HPPD as an oral therapy with a differentiated mechanism that could potentially address multiple aspects of sickle cell disease biology.
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vTv Prioritizes Cadisegliatin in Type 1 Diabetes
Alongside the HPPD milestone, cadisegliatin (TTP399) remains vTv Therapeutics’ lead late-stage development program. Cadisegliatin is an oral small-molecule glucokinase activator being investigated as a potential adjunctive treatment for type 1 diabetes. The candidate is designed to selectively increase liver glucokinase activity independently of insulin, supporting investigation of its potential effects on hepatic glucose uptake and glycogen storage. Cadisegliatin has received FDA Breakthrough Therapy Designation and is being evaluated in a U.S. Phase 3 program. The company’s current strategy therefore combines continued late-stage development of cadisegliatin with potential partnering opportunities for HPPD. The FDA’s Orphan Drug Designation for HPPD adds regulatory recognition to vTv’s sickle cell disease program while the company evaluates future development and commercialization opportunities for the candidate.
Source::vTv Therapeutics, press release
