Addex Therapeutics (NASDAQ:ADXN) provided a full-year 2025 financial results and corporate update, highlighting progress in its unpartnered chronic cough program, plans to move dipraglurant into studies for brain injury recovery, and ongoing work across partnered and investment assets.
Pipeline progress: chronic cough and post-stroke recovery
CEO Tim Dyer said 2025 included “several important achievements across our pipeline,” led by advancement of the company’s independent GABAB positive allosteric modulator (PAM) program for chronic cough. Dyer said Addex is continuing to complete preclinical characterization of its selected compound and recently reported “robust antitussive activity in a non-human primate chronic cough model,” along with “solid antitussive activity in an IPF model in guinea pigs.” He added the company is working to secure funding to move into IND-enabling studies.
R&D details: dipraglurant rationale and preclinical cough data
Head of Translational Science Mikhail Kalinichev described dipraglurant as an “orally available, highly selective mGlu5 negative allosteric modulator,” which Addex believes could improve rehabilitation outcomes after stroke or traumatic brain injury by targeting neuroplasticity early in rehabilitation. Kalinichev emphasized the unmet need in post-stroke recovery, noting that stroke is a major cause of chronic disability and that rehabilitation “is slow and often inadequate.”
Kalinichev pointed to evidence that mGlu5 inhibition may facilitate adaptive brain rewiring following stroke, referencing recently published results in the journal Brain showing daily dosing of an mGlu5 NAM (MTEP) improved sensorimotor function in rats compared with vehicle. He added that similar improvements were observed with dipraglurant and that imaging data in rodents suggested enhanced brain connectivity after stroke. Kalinichev said dipraglurant has a “fast onset of action and short half-life,” has shown tolerability in healthy subjects and Parkinson’s patients with “only mild to moderate CNS-related adverse effects,” and that Addex has drug product ready along with what he described as a strong patent position.
On chronic cough, Kalinichev outlined the rationale for GABAB PAMs, citing limitations in current treatments and noting baclofen (a GABAB agonist) is used off-label in cough patients. He said Addex’s pre-IND activities—“including in vivo proof of concept, non-GLP tox, and CMC”—have been completed, and that its clinical candidate showed “favorable efficacy, tolerability, and developability profiles.”
Kalinichev provided a series of preclinical readouts for the company’s candidate (referred to as compound A/compound 1A), including:
- Guinea pig cough frequency: consistent minimum effective dose of 1 mg/kg and ED50 of 6 mg/kg; no signs of tolerance after subchronic dosing; and a “more than 60-fold safety margin” based on respiratory depression and sedation biomarkers.
- Citric acid-induced cough in guinea pigs: dose-dependent reductions in cough number, with “70% reductions at the maximal doses,” and dose-dependent increases in latency to first cough. Kalinichev said compound A appeared well-tolerated with no marked respiratory rate changes up to 60 mg/kg, while reference drugs at higher doses reduced respiratory rate.
- ATP-potentiated citric acid cough model: in a head-to-head study, compound A and a P2X3 inhibitor showed similar efficacy and tolerability profiles.
- Seven-day subchronic dosing: no tolerance observed in cough frequency or latency to first cough, and no changes in respiratory rate, body temperature, or growth hormone release.
- IPF-related exacerbated cough model: in bleomycin-exposed guinea pigs treated for 28 days, chronic dosing with compound A produced “40% to 60%” reductions in cough counts and reversed latency-to-first-cough effects back toward intact controls; lung histopathology at day 28 showed lower Ashcroft scores and a lower percentage of affected lung versus vehicle-treated bleomycin animals.
- Non-human primate cough model: compound A produced “more than 60% reductions” at 2 mg/kg, with no effect at 0.6 and 1 mg/kg.
Kalinichev said IND-enabling studies are “planned and ready to start subject to receiving funding.”
Commercial and strategic updates: partners, spin-out, and investments
Dyer said that after Johnson & Johnson terminated development of ADX71149, Addex “regained the rights to this phase II asset with a high-value data set and significant materials.” He said the company is evaluating therapeutic indications for future development and is also discussing the asset with potential partners.
For the company’s partnered work with Indivior, Dyer said Indivior selected a compound for development in substance use disorders and completed IND-enabling studies. He reiterated that Addex is eligible for up to $330 million in regulatory, clinical, and commercial milestones under the agreement, plus tiered royalties “from high single digits up to low double digits” based on net sales.
Dyer also reviewed the 2024 spin-out of neuropsychiatric assets into Neurosterix, which raised $65 million from investors led by Perceptive Advisors. Addex retained a 20% equity interest. Dyer said Neurosterix started Phase 1 studies in 2025 for NTX-253, an M4 positive allosteric modulator, with Phase 1 expected to be completed “this quarter.”
In addition, Dyer highlighted Addex’s June 2025 investment in Stalicla, a private company focused on neurodevelopmental disorders. He said Stalicla has a patient stratification technology platform and has made progress advancing an autism patient stratification study and preparing its lead asset for a Phase 3 study in cocaine use disorders.
Financial results and cash runway
Dyer reported CHF 0.2 million of income in 2025, compared with CHF 0.4 million in 2024, attributing the decrease primarily to completion of the funded research phase of the Indivior collaboration in June 2024. He said the reduction was partially offset by the fair value of services received from Neurosterix Group at no cost.
R&D expenses were CHF 0.7 million, primarily related to the GABAB PAM program, down CHF 0.2 million year over year due mainly to completion of the Indivior research phase. General and administrative expenses were stable at CHF 2.3 million in both 2024 and 2025, with Dyer saying they primarily relate to professional services fees tied to corporate development activities.
Because Addex holds a 20% equity interest in Neurosterix, it accounts for the investment using the equity method under IFRS. Dyer said Addex’s share of Neurosterix’s net loss was CHF 4.0 million for the 12 months ended Dec. 31, 2025, compared with CHF 2.2 million for the period from April 2024 through December 2024. The finance net result was “close to nil” in both years, primarily due to foreign exchange differences on U.S. cash deposits.
Addex ended 2025 with CHF 1.6 million in cash, which Dyer said provides runway through mid-2026. He noted that cash burn has been “significantly reduced” following the Neurosterix spin-out, but added that current cash does not fund advancement of unpartnered programs into clinical development.
On cash flow, Dyer said the cash balance decreased by CHF 1.7 million during 2025, primarily due to combined cash used in operating and investing activities of CHF 2.9 million, partially offset by CHF 1.3 million from the sale of treasury shares during the year.
Q&A: target patient populations and program boundaries
During the Q&A, Kalinichev said Addex believes its chronic cough candidate may be suitable for a broad range of patients because it has a “balanced central peripheral activity profile.” He said the company sees a central component as important for reducing central sensitization in certain chronic cough patients, particularly those who do not respond to peripherally restricted P2X3 inhibitors but may respond to centrally acting therapies. Kalinichev said Addex’s initial intention is to confirm efficacy in patients with unexplained or refractory chronic cough, and then broaden the population in later studies.
Asked about psychiatric indications for mGlu7 NAM candidates, Dyer clarified that the mGlu7 candidate is housed at Neurosterix and Addex is “not at liberty to talk in detail.” Kalinichev then discussed academic and pharmacological findings in broad terms, noting studies in mGlu7 knockout mice suggest potential across anxiety, panic, agitation, aggressivity, depression, and possibly psychosis and mania.
In closing remarks, Dyer reiterated that Addex is seeking financial resources to advance its portfolio into clinical studies while continuing to evaluate indications for its regained Phase 2 asset and progress unpartnered programs.
About Addex Therapeutics (NASDAQ:ADXN)
Addex Therapeutics SA is a clinical-stage biopharmaceutical company specializing in the discovery and development of small-molecule allosteric modulators for central nervous system disorders. Founded in 1999 and headquartered in Geneva, Switzerland, with a U.S. research presence in Cambridge, Massachusetts, the company focuses on targeting metabotropic glutamate (mGlu) receptors and GABAB receptors to address unmet medical needs in neurology and psychiatry.
The company’s lead candidate, dipraglurant (ADX48621), is an mGlu5 negative allosteric modulator in clinical development for levodopa-induced dyskinesia in Parkinson’s disease.
