COYA 302 ALSTARS: enrollment reached, controlled efficacy remains unresolved

October 5, 2026: enrollment target reached

Coya announced that ALSTARS had reached its planned 120-patient enrollment, with some patients already in screening potentially still entering. The final randomized and treated totals therefore remain to be reported. The disclosure guides topline data to early second-quarter 2027, replacing the earlier first-quarter expectation as the latest company window. Enrollment is an operational achievement, not evidence that the combination slows ALS. No controlled ALSFRS-R results or arm-specific safety data accompanied this release. [1] [4]

The October announcement calls the study Phase 2/3, while earlier financial and program descriptions called it Phase 2. We preserve that dated terminology change without inferring a new regulatory agreement or that a single positive trial would necessarily support approval. The exact day of the last enrollment was not stated; October 5 records public disclosure.

Tregs, neuroinflammation and the combination rationale

ALS involves progressive motor-neuron loss, with immune and inflammatory processes potentially modifying disease progression. Regulatory T cells can restrain inflammatory activity, but their abundance and suppressive function are not identical. COYA 302 combines low-dose interleukin-2, intended to support Treg activity, with CTLA4-Ig, intended to dampen pro-inflammatory immune signaling. The hypothesis is that stimulating regulatory activity while reducing inflammatory activation could provide a broader effect than either mechanism alone. [1] [2] [6]

This is a disease-modifying hypothesis rather than a proven causal chain from a blood immune assay to preserved motor function. Peripheral biomarker changes may not measure target engagement in the spinal cord, and ALS is biologically heterogeneous. A useful clinical result needs a consistent functional effect, tolerable immune modulation and credible handling of respiratory decline, dropout and death. The mechanism does not predict that every patient or every genetic subtype will respond.

Exposure and the academic formulation distinction

The development product is administered subcutaneously. ALSTARS compares two dosing regimens with placebo, but the enrollment announcement does not provide their quantitative component doses or complete administration calendar. The academic pilot used commercially available IL-2 and abatacept; it must not be represented as definitive testing of the final COYA 302 formulation, manufacturing process or exposure profile. No quantitative human exposure–response threshold linking either component to ALSFRS-R preservation is established by the retrieved disclosures. [1] [2] [6]

Combination development also requires distinguishing the contribution of each component. A placebo-controlled combination study can estimate the effect of the assigned regimen, but without component-only arms it cannot independently quantify synergy. Immunological biomarkers can support biological plausibility and dose selection, yet should be analyzed with assay reproducibility, timing and missing samples documented before they are linked to a clinical claim.

Four-patient academic pilot: the original observations

The Houston Methodist proof-of-concept study treated four patients over 48 weeks with an additional eight-week washout. There was no randomized control and no blinding. Mean ALSFRS-R was 33.5±5.9 at baseline, 33.75±3.3 at Week 24 and 32.0±7.8 at Week 48. The reported pre-treatment decline averaged 1.1 points per month. Comparing a retrospectively characterized pre-treatment slope with a subsequent treated interval cannot remove regression to the mean, measurement variability or selection of slower progressors. [2] [3]

A lack of statistically significant decline in four patients is not an equivalence test proving stability. The wider Week-48 standard deviation also shows why the mean cannot describe every individual. Later biomarker reporting gave Treg suppressive function of 62.1±8.1 at baseline, 79.9±9.6 at Week 24 and 89.5±4.1 at Week 48, with reported p<0.01. Those repeated measurements are from the same small study, not three independent cohorts or a controlled validation of a surrogate endpoint.

ALSTARS: randomized function assessment

NCT07161999 is a randomized, double-blind, placebo-controlled multicenter study. The planned allocation is 1:1:1 between two subcutaneous regimens and placebo for 24 weeks, followed by a 24-week blinded active-treatment extension in which placebo recipients are rerandomized to active treatment. The primary endpoint is change from baseline in ALSFRS-R at Week 24. This 12-item scale measures daily functions across bulbar, limb and respiratory domains; the same total-point difference may reflect different domain patterns. [1] [5]

The enrollment notice does not supply actual per-arm numbers, full inclusion thresholds, background riluzole/edaravone distributions, power assumptions, rescue-treatment rules or the statistical handling of death and missing functional assessments. Those are unresolved extraction fields, not assumed protocol omissions. An analysis restricted to surviving completers could overstate benefit if deterioration causes differential dropout. The blinded placebo period is the cleanest assigned-treatment comparison; after placebo crossover the extension addresses durability and safety under a different causal comparison.

Small pilot safety cannot settle immune-modulation safety

The academic pilot described mild injection-site reactions as the most frequent event, without serious adverse events, deaths or discontinuations reported in four participants. Exact all-TEAE counts and a complete graded table were not provided. A four-person denominator cannot exclude uncommon infections or other immune-related complications. ALSTARS has not yet reported TEAE, SAE, death or discontinuation rates, and no zero is entered for those outcomes. [1] [2]

Mechanism-informed monitoring should consider infection, injection reactions and immune suppression alongside ALS-specific respiratory and nutritional deterioration. These are monitoring considerations, not adverse reactions newly observed in the randomized trial. Attribution and exposure duration matter, particularly after all extension participants receive active treatment. Clinical benefit will require the functional result and safety burden to be considered together rather than relying on an isolated Treg laboratory change.

Development responsibilities and funding

Coya leads U.S. development and regulatory work; Dr. Reddy’s is the licensing partner for territories described in the agreement, with Japan, South America and Mexico excluded from the cited arrangement. These are responsibilities within one program, not independent evidence. The August update reported $43.2 million of cash and equivalents at June 30, quarterly R&D of $5.0 million and a $6.6 million net loss, with management projecting runway into the second half of 2027. CEO Arun Swaminathan and president/CMO Fred Grossman oversee execution. That projection does not ensure successful retention, a positive functional result or regulatory acceptance of the eventual dataset. [1] [4]

Sources / References

1. Coya · ALSTARS enrollment · October 5, 2026
2. Coya · academic proof of concept · March 2023
3. Coya · biomarker disclosure · March 2024
4. Coya · Q2 2026 results
5. ClinicalTrials.gov · ALSTARS
6. Coya · 2025 Form 10-K