Aldeyra's roller coaster month ends with 'positive' phase 2 chronic cough readout

June has been something of a roller coaster month for Aldeyra Therapeutics. The immune-focused biotech has dived from the highs of a phase 3 win down to an FDA rejection and has now leveled out on some positive, if uninspiring, midstage data.

The latest readout comes from ADX‑629, one of Aldeyra’s reactive aldehyde species (RASP) modulators that the company has been testing in conditions as varied as psoriasis, asthma, COVID-19 and now chronic cough. The latest phase 2 data, which the biotech has claimed as a win, saw 51 patients with refractory or unexplained chronic cough administered either ADX‑629 or placebo for 14 days, followed by a 14-day washout period before being switched to the opposite cohort.

The primary endpoint of the phase 2 study was safety, not a measure of efficacy. When it came to the secondary endpoints, Aldeyra pointed to a “statistically significant” reduction in cough frequency, although in reality this meant a p-value of just 0.01 for the reduction in awake cough frequency and 0.001 for the fall in 24-hour cough frequency when compared to placebo. Aldeyra noted that "quality of life and clinical impression scales did not consistently change between treatment groups over the two-week treatment periods."

No serious adverse events were reported during the trial, while the level of adverse events was similar for patients taking ADX‑629 and placebo, the company noted. No patients discontinued due to adverse events.

“Consistent with previously demonstrated activity in clinical trials of patients with psoriasis, asthma and COVID-19, the reduction in cough frequency observed in the phase 2 clinical trial in chronic cough supports the potentially broad-based activity of ADX‑629 as a novel, immune-modulating therapeutic approach,” CEO Todd Brady, M.D., Ph.D., said in the Tuesday morning release.

“We look forward to discussing the results with regulatory authorities as we consider the expansion of clinical testing to include patients with co-morbid conditions of frequent coughing and active inflammation,” Brady added.

While unlikely to get investors’ hearts racing—the company’s stock edged up almost 6% to $7.96 in early hours trading. Today’s data drop will be a welcome new page after the FDA rejected Aldeyra’s application last week to approve drug candidate ADX-2191 in primary vitreoretinal lymphoma, a rare and aggressive cancer. The regulator cited a lack of any new clinical trial data to support the submission.

It wasn’t all bad news for the company in June, however. Earlier this month, the biotech posted a phase 3 win for another RASP modulator called reproxalap in allergic conjunctivitis.

Aldeyra’s wide-ranging ambitions for ADX‑629 mean there are plenty more opportunities to set a positive narrative this year. Away from cough, the company has phase 2 trials for the drug in atopic dermatitis, idiopathic nephrotic syndrome and Sjögren-Larsson syndrome, which are all expected to read out in the second half of 2023. As if that wasn’t a broad enough remit for one therapy, the biotech also plans to launch a midstage trial in moderate alcohol-associated hepatitis later this year.