Quince Therapeutics’ stock has fallen by more than 90% after a Phase III trial of its Ataxia-Telangiectasia (A-T) drug failed to show benefit.
In the pivotal NEAT trial (NCT06193200), dexamethasone sodium phosphate encapsulated in autologous erythrocytes (eDSP) failed to show benefit in the primary endpoint, which measured the change from baseline to last efficacy visit at month six, using the rescored modified International Cooperative Ataxia Rating Scale (RmICARS). Quince stated that this change did not reach statistical significance. The mean change from baseline to month six was 0.94 in the active arm compared to 2.24 in the placebo arm.
The company’s stock fell by 92% after Quince shared the update, from $3.14 at market open on 29 January to $0.25 at market open on 30 January. The biotech now has a market cap of $9.5m.
The trial also failed to meet its key secondary endpoint of improvement in Clinical Global Impression of Severity (CGI-S) measured from baseline to month six.
eDSP, previously called EryDex, was generally well tolerated and there were no clinically meaningful safety concerns identified, with the most common adverse events (AEs) reported being pruritus and pyrexia.
The NEAT trial was an international, multicentre, randomised, double-blind, placebo-controlled clinical trial that enrolled 105 patients with A-T.
A-T is a rare inherited childhood disorder caused by a mutated ATM gene and affects the nervous system, immune system, and other body systems. Symptoms include movement problems, poor coordination, and speech issues. There are no approved treatments.
CEO of Quince, Dr Dirk Thye, said: “We express our compassion and hope for future therapeutic options to the A-T community. We have tremendous gratitude toward the patients, their families, academic investigators and study sites, as well as all Quince employees, who worked so diligently over many years on this programme.”
Quince’s update came just days after IntraBio’s Phase III trial (NCT06673056) of levacetylleucine, a modified form of the amino acid leucine, met its primary endpoints in A-T. As a result, the company is heading to the US Food and Drug Administration (FDA), European Medicines Agency (EMA), and additional global regulatory authorities for approval. In the study, the drug demonstrated a statistically significant and clinically meaningful -1.88 point improvement on the Scale for the Assessment and Rating of Ataxia (SARA) compared to placebo after 12 weeks. Given the absence of approved therapies, this trial was a notable development for A-T patients.
