Quince Therapeutics announced its once‑monthly steroid‑based therapy failed a Phase 3 trial in ataxia‑telangiectasia, a rare genetic disorder, and said it will stop development of the experimental program. The negative readout sent Quince shares sharply lower and prompted management to reassess the company’s pipeline priorities. The failure highlights the clinical risk in repurposing or optimizing steroid modalities for rare, genetically defined neurologic diseases. Quince said it will wind down work on the program and focus remaining resources on other pipeline assets and business development opportunities. For investors and rare‑disease stakeholders, the readout underscores the unpredictable nature of late‑stage trials in small populations and the need for robust biomarker and endpoint strategies in registrational programs.