Addex Therapeutics, a clinical-stage biopharmaceutical company focused on developing innovative treatments for neurological disorders, has announced encouraging preclinical results for its GABAB positive allosteric modulator (PAM) candidate aimed at treating chronic cough associated with idiopathic pulmonary fibrosis (IPF).

The findings, derived from studies using a bleomycin-induced IPF exacerbated chronic cough model, demonstrated robust and sustained antitussive activity. The candidate significantly reduced cough frequency while increasing cough latency over the treatment period. In addition to symptomatic relief, the compound also showed improvements in lung pathology, including reduced fibrosis indicators such as lower Ashcroft scores and decreased affected lung tissue in treated subjects compared to untreated groups.

Importantly, the therapy maintained a favourable safety profile throughout the study. There were no significant changes in respiratory rate or body temperature, and the compound was well tolerated during chronic administration, supporting its potential for long-term use.

Chronic cough remains a major unmet medical need, particularly among patients with IPF, where persistent coughing severely impacts quality of life and exacerbates disease burden. Current treatment options are limited, and existing therapies such as baclofen—though clinically validated—are associated with side effects including sedation, short duration of action, and reduced efficacy over time.

Addex’s approach targets the GABAB receptor through an allosteric mechanism, offering potential advantages such as improved selectivity, better tolerability, and reduced risk of tolerance compared to traditional therapies that act on the receptor’s primary binding site.

The company highlighted that the combination of strong efficacy and safety observed in preclinical studies, including prior research in non-human primates, reinforces the therapeutic promise of this candidate as a novel treatment for chronic cough.

Beyond this programme, Addex Therapeutics continues to advance a broader pipeline of allosteric modulator-based therapies. Its lead candidate, dipraglurant, is being explored for applications in brain injury recovery, while partnerships and investments are supporting additional research in areas such as substance use disorders and neuropsychiatric conditions.