Quince Therapeutics Inc. (QNCX) had a brutal Thursday, with shares cratering almost 90% after the company delivered news no biotech wants to deliver: its pivotal Phase 3 trial didn't work.
The NEAT clinical trial was testing dexamethasone sodium phosphate encapsulated in autologous erythrocytes, mercifully shortened to eDSP, as a treatment for Ataxia-Telangiectasia. For those unfamiliar, A-T is a rare inherited neurodegenerative disorder caused by mutations in the ATM gene. Kids with this condition face progressive loss of coordination, visible blood vessels in their eyes and skin, a compromised immune system, and an elevated cancer risk. It's as serious as it sounds.
What the Numbers Showed
Quince enrolled 105 participants in the NEAT study. The primary analysis focused on 83 kids between six and nine years old, with another 22 participants aged 10 and up.
The trial's primary endpoint measured changes from baseline to month six using something called the Rescored modified International Cooperative Ataxia Rating Scale, or RmICARS, which tracks disease progression. The active treatment group showed a mean change of 0.94 compared to 2.24 in the placebo group. That difference of -1.30 sounds promising, but the p-value came in at 0.0851. In clinical trial speak, that means it missed statistical significance.
Things didn't improve with the key secondary endpoint either. The study looked at Clinical Global Impression of Severity scores from baseline to month six and struck out again with a p-value of 0.522.
There was a silver lining, at least on the safety front. The therapy was generally well tolerated without any clinically meaningful safety red flags. The most common side effects reported were pruritus (that's itching) and pyrexia (fever).
The Bigger Safety Picture
Interestingly, just a day before the trial results dropped, Quince had presented long-term safety data at the British Paediatric Neurology Association 2026. That data painted an encouraging picture for children on extended eDSP treatment.
Long-term treatment showed stable growth and metabolic parameters without the corticosteroid-related toxicities doctors typically worry about. Height and weight z-scores stabilized during treatment, with no signs of the growth suppression or weight gain you'd normally expect from corticosteroid therapy. That's particularly noteworthy since progressive growth problems are a hallmark of A-T.
The safety profile looked clean on other fronts too. No concerns emerged around glucose control or adrenal suppression, and no confirmed cases of adrenal insufficiency occurred, though the company notes routine monitoring remains advisable.
Price Action: QNCX stock traded down 2.22% at $0.26 during Friday's premarket session.
