NKGen Biotech Reports Combined Phase 1 Troculeucel Data Demonstrating Dose-Responsive Cognitive Improvements and Biomarker Correlations in Alzheimer's Disease at AD/PD 2026™
Pooled analyses in patients with moderate Alzheimer's show dose-related cognitive benefit and signs of durability.
100% of patients remained stable or improved, with 50% improving from moderate to mild cognitive function.
Exploratory plasma GFAP correlations are consistent with observed clinical outcomes.
Findings support further evaluation of troculeucel's immunomodulatory approach in the ongoing Phase 2 trial.
SANTA ANA, Calif., March 23, 2026 (GLOBE NEWSWIRE) -- NKGen Biotech, Inc. (OTC:NKGN) ("NKGen" or the "Company"), a clinical-stage biotechnology company focused on the development and commercialization of innovative autologous and allogeneic natural killer ("NK") cell therapeutics, today announced new data presented at the International Conference on Alzheimer's and Parkinson's Diseases and Related Neurological Disorders ("AD/PD™ 2026"), held March 17-21, 2026, in Copenhagen, Denmark and virtually.
NKGen's combined Phase 1 analyses from two previously completed open-label Phase 1 trials of troculeucel in Alzheimer's disease (AD) demonstrated encouraging signs of biological activity, with 92% of patients having stable and/or improved cognitive function. Subsequent additional analyses focusing solely on the moderate stage population demonstrated clear dose‑responsive cognitive trends with no observed decline across all treated patients. Higher doses were associated with more frequent clinically meaningful improvements and early indications of durability were seen at the final 12-month assessment in patients. Importantly, exploratory plasma Glial Fibrillary Acidic Protein (GFAP)1 results showed strong, consistent correlations with established clinical measures, reinforcing the potential of troculeucel's immunomodulatory approach and supporting its continued evaluation in the ongoing Phase 2 trial.
"As most of the attention has focused on treating the Mild Cognitive Impairment (MCI) Alzheimer's population, we wanted to focus on the moderate stage disease population for which there is no effective disease modifying therapy. Despite the rapid rate of cognitive decline typically seen in moderate stage patients, we were able to stop or improve cognitive decline in 100% of our patients, with 50% improving from moderate to mild stage. These results indicate that troculeucel demonstrates biological activity with dose-related cognitive trends in moderate Alzheimer's disease and provides important translational insights as we advance our ongoing Phase 2 study for moderate stage disease which is actively enrolling," said Paul Y. Song, M.D., Chairman and Chief Executive Officer of NKGen Biotech. "We believe the consistency observed across cognitive measures, the preliminary durability observations, and the associated GFAP biomarker correlations support the potential of troculeucel to address this unmet need and further support its immunomodulatory mechanism in Alzheimer's disease."
Oral Presentation Shows Encouraging Dose‑Responsive Cognitive Activity and Maintenance of Benefit with Troculeucel in Moderate Alzheimer's Disease
Pooled analysis of two previously reported open‑label Phase 1 studies (NCT04678453; NCT06189963) evaluating troculeucel in moderate AD showed encouraging and consistent signs of biological activity across dose levels ranging from 1 to 6 billion cells. At the three‑month assessment, all patients showed stability or improvement across multiple standardized cognitive measures, with higher doses associated with greater directional benefit and more frequent achievement of clinically meaningful change. Early durability signals were also observed in those patients followed for up to 12 months, and troculeucel continued to demonstrate a favorable safety profile with no treatment‑related adverse events reported.
Cognitive Outcomes (3‑Month Assessment; n=6 moderate AD patients)
- 100% of patients were stable or improved across all established minimal clinically important difference (MCID) thresholds:
- Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog; ± 4 points)
- Clinical Dementia Rating-Sum of Boxes (CDR-SB; ± 2 points)
- Alzheimer's Disease Composite Score (ADCOMS; ± 0.1 points)
- No cognitive decline was observed in any patient.
- Higher doses (4–6B cells) were associated with greater directional improvement and more frequent MCID exceedance.
- 50% of patients improved from the moderate to mild range on CDR‑SB at three months.
Durability (Up to 12 Months)
- In the two patients remaining on therapy for 12 months, improvements across cognitive measures were maintained throughout treatment, suggesting early durability of effect.
Safety
- Troculeucel was very well‑tolerated, with no treatment‑related adverse events reported across both Phase 1 studies.
Poster Presentation Highlights Strong and Consistent Plasma GFAP Correlations Supporting Its Potential as a Non‑Invasive Biomarker of Clinical Status in Alzheimer's Disease
In a separate poster presentation, NKGen reported exploratory plasma GFAP analyses from all AD patients treated across the two Phase 1 studies described above, demonstrating strong and consistent correlations between GFAP levels and established clinical measures of disease severity. These findings were observed at baseline, maintained following troculeucel treatment, and further strengthened in patients receiving higher cell doses, reinforcing the potential of plasma GFAP as a reliable, non-invasive biomarker of neuroinflammation and clinical status. The consistency of these correlations across timepoints and dose levels provides important translational support as NKGen advances troculeucel's clinical development.
Data summary:
- Plasma GFAP demonstrated strong and statistically significant correlations with cognitive status at baseline, supporting its role as a biomarker of disease severity in Alzheimer's disease.
- Baseline plasma GFAP levels correlated with CDR-SB (r=0.60, p=0.044) and ADCOMS (r=0.64, p=0.030)
- GFAP–cognition correlations remained robust following troculeucel treatment
- After three months of therapy, plasma GFAP continued to correlate with CDR-SB (r=0.57, p=0.056) and ADCOMS (r=0.66, p=0.022), demonstrating consistency of biomarker–clinical relationships over time
- In moderate AD patients receiving ≥4 billion cells (n=4), correlations strengthened further, with statistically significant associations observed across timepoints for CDR-SB (r=0.76, p=0.009) and ADCOMS (r=0.71, p=0.018)
- Pooled longitudinal analyses across disease severities and timepoints reinforced the reliability of plasma GFAP as a clinical-status biomarker, with strong correlations observed for CDR-SB (r=0.56, p=0.001) and ADCOMS (r=0.50, p=0.004)
- These findings support the continued evaluation of plasma GFAP as a non-invasive biomarker of neuroinflammation and clinical status in Alzheimer's disease.
A copy of the presentations will be made available on the Company's website under the Scientific Publications section, once the event has concluded. Additionally, previously disclosed scientific data on troculeucel for neurodegenerative disease can be accessed on the same page. For the latest updates on our clinical trials and regulatory announcements, please visit the Company's News page. Note that results reported are from the completed Phase 1 trials and do not include results from the Company's ongoing Phase 2 trial, which is actively enrolling.
About Troculeucel
Troculeucel is a novel cell-based, patient specific, ex vivo expanded autologous NK cell immunotherapeutic drug candidate. NKGen is developing troculeucel for the treatment of neurodegenerative disorders and a broad range of cancers. Troculeucel is the International Nonproprietary Name ("INN") for SNK01 assigned by the World Health Organization ("WHO"). The WHO INN approval of troculeucel establishes a universally recognized nonproprietary drug name for SNK01 and marks a significant step on NKGen's journey toward bringing this therapy to market.
About NKGen Biotech
NKGen is a clinical-stage biotechnology company focused on the development and commercialization of innovative autologous and allogeneic NK cell therapeutics. NKGen is headquartered in Santa Ana, California, USA. For more information, please visit www.nkgenbiotech.com.
Forward-Looking Statements
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1 GFAP is a structural protein released by activated astrocytes and serves as a widely recognized blood-based biomarker of neuroinflammation in Alzheimer's disease, with elevated plasma or CSF levels consistently associated with greater disease severity, faster progression, and more extensive amyloid-related pathology.
