Coya Therapeutics, Inc. (Nasdaq: COYA), a Houston-based biotechnology company developing treatments intended to regulate inflammatory immune responses, announced on October 14, 2026, that it plans to initiate an open-label extension of its ongoing Phase 2/3 ALSTARS study of COYA 302 in amyotrophic lateral sclerosis. The additional treatment period will allow eligible participants completing the existing 48-week programme to continue receiving the investigational combination therapy, while enabling researchers to collect longer-term safety, biomarker and disease progression information.
The extension is expected to begin in November 2026 as the first participants finish the existing study treatment schedule. Coya said the decision follows requests from investigators and patients interested in continued access to the therapy. However, interest in remaining on treatment is not evidence that COYA 302 has slowed disease progression, and the new extension will not replace the trial’s randomized efficacy assessment.
The announcement follows another important milestone on October 5, when Coya reported reaching its planned enrollment target of 120 participants in ALSTARS. The company is allowing additional eligible patients already undergoing screening to enter the study, potentially increasing the final population slightly. Topline results from the initial 24-week placebo-controlled phase are expected in early second-quarter 2027.
The expanded ALS programme also comes with a change in corporate priorities. Coya has postponed the planned initiation of a separate Phase 2 COYA 302 study in frontotemporal dementia from the second half of 2026 to 2027, concentrating resources on completing ALSTARS. Management maintained its expectation that existing cash resources will support operations into the second half of 2027, beyond the anticipated ALS data readout.
How will the new ALSTARS open-label extension differ from the existing trial?
ALSTARS, registered as NCT07161999, uses a multi-stage design intended to generate both controlled efficacy evidence and longer-term treatment information. During the first 24 weeks, participants are randomized in a 1:1:1 ratio to receive one of two COYA 302 dosing regimens or placebo. The randomized, double-blind structure allows investigators to compare changes in disease severity between active treatment and control groups.
Participants completing the initial period can then enter a further 24-week blinded active-treatment phase. Patients already receiving COYA 302 continue their assigned regimen, while those originally allocated to placebo are reassigned to one of the two active dosing regimens. This provides additional treatment exposure while preserving aspects of the blinded study structure.
The newly proposed open-label extension begins after participants complete the existing 48-week treatment period. Eligible individuals will have an opportunity to continue receiving COYA 302, and both investigators and participants will know the treatment being administered. Coya expects this stage to support additional assessments of safety, tolerability and potential treatment effects over a longer period.
These stages serve different scientific purposes. The first 24 weeks provide the principal randomized comparison against placebo, while the later periods offer information about longer exposure and outcomes among participants continuing treatment. Results from the open-label extension will be subject to limitations involving selection and the absence of a concurrent untreated control group.
The distinction matters because participants entering an extension may differ from those who discontinue earlier. Patients who remain eligible, tolerate the medicine and choose continued treatment may have a different disease trajectory from those unable to participate. Longer observation is useful, but it cannot automatically establish that the treatment prolongs survival or preserves function.
What will the 120-patient randomized study establish about ALS progression?
The primary endpoint of ALSTARS is the change in Amyotrophic Lateral Sclerosis Functional Rating Scale-Revised, known as ALSFRS-R, from baseline to Week 24 compared with placebo. The scale evaluates functioning across areas including speech, swallowing, mobility and breathing. Scores range from zero to 48, with lower values reflecting greater functional impairment.
ALS is a progressive neurological disease affecting motor neurons in the brain and spinal cord. As these neurons deteriorate, patients gradually lose voluntary muscle function and can experience severe disabilities affecting movement, communication, nutrition and respiration. Disease progression varies between individuals, making randomized trials especially important for identifying treatment-related changes.
Coya has described average ALSFRS-R decline as approximately one point per month, although individual rates can differ substantially. The ALSTARS study is intended to determine whether COYA 302 produces a statistically convincing difference from placebo over the controlled period. A favorable result would also require evaluation of effect size, baseline balance and the consistency of findings across study populations.
Secondary objectives include safety, tolerability, biological activity and inflammatory biomarkers. These measurements could help establish whether changes in immune regulation correspond with the clinical effects being investigated. However, favorable biomarker changes alone would not prove that a medicine slows functional decline.
The enrollment milestone makes the planned early second-quarter 2027 analysis more concrete. Nevertheless, completion of recruitment is an operational achievement rather than an efficacy result. Patients must complete the relevant follow-up, and the final data must be analyzed before conclusions about treatment effectiveness can be drawn.
How does COYA 302 attempt to modify inflammation through regulatory T cells?
COYA 302 combines proprietary low-dose interleukin-2 with CTLA-4 Ig, using two immune-regulating mechanisms that Coya believes could complement each other. Low-dose IL-2 is intended to support regulatory T cells, commonly known as Tregs. These cells help control excessive immune activity and maintain tolerance to the body’s own tissues.
The CTLA-4 Ig component is designed to interfere with immune costimulatory signaling and reduce activation of inflammatory cells. Together, the two components are intended to strengthen regulatory immune activity while suppressing inflammatory responses associated with activated monocytes, macrophages and other cells. The product is being developed for subcutaneous administration.
The biological rationale arises from evidence that immune dysfunction and neuroinflammation may contribute to ALS progression. Researchers have observed changes in regulatory T-cell function and inflammatory signaling in some patients with the disease. These observations have encouraged investigation of medicines designed to alter the immune environment surrounding vulnerable motor neurons.
However, ALS involves several disease processes, including neuronal degeneration, abnormal protein handling, metabolic disturbances and other biological abnormalities. Neuroinflammation is one component of this complex pathology rather than an established single cause of all ALS cases. Modifying inflammation may therefore be therapeutically relevant without necessarily addressing every mechanism responsible for disease progression.
Coya’s proposed combination attempts to influence more than one part of immune regulation. The possibility of additive or synergistic effects remains a development hypothesis that must be tested in clinical studies. The fact that the individual components affect immune pathways does not establish that their combination produces meaningful neurological benefit.
What did the earlier four-patient proof-of-concept study reveal?
The clinical rationale for ALSTARS was supported partly by an investigator-initiated open-label study involving four patients with ALS at Houston Methodist Hospital. Participants received the combination approach over 48 weeks, with investigators assessing tolerability, regulatory T-cell function, inflammatory biomarkers and changes in ALSFRS-R scores.
Coya reported that the mean ALSFRS-R score was 33.5 at baseline, 33.75 at Week 24 and 32 at Week 48. The participants had experienced a reported average decline of approximately 1.1 points per month before treatment. The company interpreted the relative stability during the study as an encouraging signal supporting further investigation.
Investigators also reported improvements in Treg suppressive function, including an increase from a mean of approximately 62.1% at baseline to 79.9% at Week 24 and 89.5% at Week 48. These observations provide evidence that the treatment was associated with measurable changes in the intended immune pathway. The small study also reported generally favorable tolerability, with mild injection-site reactions among the observed adverse effects.
Nevertheless, the findings cannot establish that COYA 302 slowed ALS progression. The investigation involved only four patients, was not randomized and had no concurrent placebo group. Comparing functional changes during treatment with an earlier period can also be affected by natural variability, measurement differences and regression toward the mean.
The current 120-patient randomized programme is intended to address these limitations. If COYA 302 produces a meaningful benefit over placebo under controlled conditions, the earlier mechanistic observations may help explain the result. Until then, the four-patient study remains preliminary evidence rather than confirmation of disease modification.
Why is the open-label extension useful for evaluating long-term safety?
Patients with ALS may need extended treatment to achieve and maintain a meaningful clinical effect. A therapy intended to influence immune function also requires monitoring for adverse events that might emerge after repeated administration. The newly announced extension could provide additional information beyond the existing 48-week schedule.
Safety considerations include potential effects associated with immune modulation, injection-site reactions, infections and other events that may occur during treatment. The complete risk profile of COYA 302 has not yet been established, and its component mechanisms do not guarantee that the combination will remain well tolerated during long-term exposure.
The extension may also help researchers examine whether biomarker changes persist with continued treatment. Regulatory T-cell activity and inflammatory measurements could provide information about biological responses over time. However, the relationship between those measurements and preservation of motor function must still be established.
Long-term ALS studies also face challenges involving patient retention, disease progression and changing supportive care requirements. Participants who become too unwell to continue may be underrepresented in later analyses, potentially making observed outcomes appear more favorable than those in the original enrolled population. Appropriate reporting of discontinuations and missing data will therefore be important.
The open-label extension has a practical access purpose as well. Eligible participants who have completed the study may wish to continue an experimental treatment rather than discontinue it while further research proceeds. That consideration is understandable, but it must remain distinct from a conclusion that the treatment has demonstrated effectiveness.
Why has Coya delayed its frontotemporal dementia programme?
Coya previously planned to initiate a separate Phase 2 study of COYA 302 in frontotemporal dementia during the second half of 2026. The company has now moved that expected start into 2027, citing its decision to concentrate financial and operational resources on the ongoing ALS programme. The delay is therefore a prioritization decision rather than an announced failure of the FTD treatment concept.
Frontotemporal dementia involves progressive neurological changes that can affect behavior, language and cognition. Some forms share aspects of neurodegenerative biology with ALS, and the conditions can occur together in certain disease settings. This overlap has encouraged investigation of therapies targeting biological mechanisms potentially relevant to both disorders.
However, evidence of immune abnormalities does not establish that the same treatment will produce equivalent benefits in two distinct conditions. The clinical endpoints, patient populations and disease trajectories differ. A treatment shown to affect ALS progression would still require appropriate evidence before conclusions about frontotemporal dementia could be drawn.
The delay also illustrates the resource demands of a multi-indication biotechnology programme. Clinical trials require expenditure on patient recruitment, monitoring, medicine manufacturing and data analysis. When a major randomized readout approaches, concentrating resources on one programme can reduce near-term execution risk.
Coya has not announced cancellation of the FTD programme. Its current expectation is to begin the study during 2027, although the exact timetable remains dependent on resources and operational progress.
How does the decision affect Coya’s financing and commercialization strategy?
Coya reported $43.2 million in cash and cash equivalents at June 30, 2026. Research and development expenditure was approximately $5 million during the second quarter, reflecting the expense of advancing its clinical programmes. The company has since reiterated that its available resources are expected to fund planned operations into the second half of 2027.
That guidance extends beyond the anticipated early second-quarter 2027 ALSTARS topline results. It provides a potential financial bridge through an important clinical decision point, although actual spending may differ from current forecasts. The announcement does not disclose a new financing transaction linked to the open-label extension.
Coya also has a development and commercialization agreement with Dr. Reddy’s Laboratories covering COYA 302 in ALS. The arrangement provides Dr. Reddy’s with commercialization rights across specified international territories, while Coya remains responsible for clinical development and the United States regulatory process. The commercial value of the agreement depends on successful development and eventual regulatory authorization.
In May 2026, the FDA granted COYA 302 Fast Track designation for ALS. That designation can facilitate communication and development processes for qualifying investigational medicines, but it is not an approval or proof of efficacy. The company must still establish an acceptable benefit-risk profile through its clinical programme.
The proposed extension may increase the amount of long-term evidence available for regulatory discussions. However, any additional costs must be balanced against the resources needed to complete and analyze the controlled trial. Management’s decision to delay FTD development reflects that financial tradeoff.
What will determine whether COYA 302 advances toward approval?
The most important forthcoming milestone is the 24-week randomized ALSTARS analysis expected in early second-quarter 2027. Investigators will assess whether COYA 302 reduces functional deterioration compared with placebo. A clinically meaningful difference supported by appropriate statistical analysis would strengthen the case for further regulatory development.
The findings will also need to be interpreted alongside safety and biomarker results. A favorable immune response without functional benefit would not establish that the medicine alters ALS progression. Conversely, evidence of functional preservation accompanied by consistent biological activity could provide a stronger foundation for understanding the treatment mechanism.
The extension will subsequently contribute information about longer exposure and potential durability. However, these findings will have different evidentiary limitations from the randomized comparison and must not be used interchangeably. Additional regulatory studies could still be necessary, depending on the strength of the results and the FDA’s assessment.
Coya’s October decision demonstrates continued investment in COYA 302 and responds to requests from participants who wish to remain on treatment. It also reinforces ALS as the company’s immediate development priority after reaching its enrollment target.
The key unanswered question remains whether dual immune modulation can produce a reproducible slowing of functional decline in ALS. The open-label extension may help characterize treatment over a longer period, but the controlled ALSTARS results will provide the decisive initial evidence for judging whether COYA 302 has the potential to become a disease-modifying therapy.
