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# Fast Track for Retinal Therapy
- URL: https://www.fdaweb.com/fast-track-for-retinal-therapy/
- Published: 2022-01-10T12:00:00.000Z
- Updated: 2026-09-14T17:27:59.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5150897

FDA has granted 4D Molecular Therapeutics a fast track designation for 4D-125 for treating patients with inherited retinal dystrophies due to defects in the retinitis pigmentosa GTPase regulator (RPGR) gene, including X-linked Retinitis Pigmentosa (XLRP). 4D-125 is described by the company as a targeted R100-based product candidate, which was designed to deliver a functional copy of the RPGR gene to photoreceptors in the retina.

4D Molecular Therapeutics says it is currently enrolling patients in an on-going Phase 1/2 clinical trial, the primary objectives of which are to evaluate the safety and maximum tolerated dose of 4D-125\. Secondary endpoints include assessments of clinical activity, including both visual function and anatomical endpoints, it says.

XLRP is a rare inherited X-linked recessive genetic disorder that causes progressive vision loss and blindness in boys and young men. There are currently no approved therapies for the disorder. About 70% of cases are caused by mutations in the RPGR gene, according to the company.