UniQure’s chronic epilepsy gene therapy ‘should be on investors’ radar’

UniQure's AMT-260 Shows Promising Early Efficacy in Chronic Epilepsy Trial

uniQure's investigational gene therapy, AMT-260, has shown promising early results in the Phase 1/2a GenTLE trial for refractory mesial temporal lobe epilepsy (MTLE). In the low-dose cohort of six patients, three demonstrated a significant 79% to 100% reduction in disabling seizures over four to six months of follow-up. While other patients experienced variable changes, Stifel analysts view these findings as a "promising start" for uniQure and AMT-260, especially given the challenging patient population. The GenTLE trial is currently enrolling patients for a high-dose cohort, with an expected total recruitment of 12 patients and a primary completion date of November 30.

• In the low-dose cohort of the GenTLE trial, three out of six patients experienced a substantial decrease in disabling seizures, ranging from 79% to 100% from baseline during four to six months of follow-up. The remaining three patients showed variable responses, from a 33% decrease to a 36% increase, highlighting the early and open-label nature of the dataset.
• The investigational therapy AMT-260 is being evaluated in the Phase 1/2a GenTLE trial, specifically targeting patients with refractory mesial temporal lobe epilepsy (MTLE). The trial is actively enrolling patients for its high-dose cohort, aiming for a total recruitment of 12 patients, with a primary completion date set for November 30.
• Stifel analysts have characterized the early findings for AMT-260 as a "promising start," noting that a response in these refractory patients is unlikely to be by chance. This positive assessment comes in the context of recent market activity, including UCB's $650 million upfront acquisition of Neurona Therapeutics and its asset NRTX-1001, a cell therapy also being tested for drug-resistant MTLE.

AMT-260's Promising Early Efficacy and Safety in Refractory MTLE

Recent studies on mesial temporal lobe epilepsy (MTLE) have evaluated both open resective and minimally invasive surgical interventions with varying efficacy and safety profiles. A multicenter retrospective analysis spanning 20 epilepsy centers across 5 continents enrolled 1,167 patients undergoing microsurgical resection for drug-resistant MTLE. At one year, 74.2% achieved ILAE Class 1 or 2 seizure outcomes, with anterior temporal lobectomy (ATL) independently associated with improved seizure freedom even after adjusting for MRI findings, hemisphere dominance, bilateral tonic-clonic seizure history, age, and sex. Identifiable MRI lesions and a history of febrile seizures were confirmed as positive prognostic factors. On the safety side, postoperative neurological deficits occurred in 22.2% of patients — most frequently new quadrantanopia (11.2%) — with surgical revision required in 4.3% of cases within the first year and no in-hospital or 30-day mortality recorded. A separate retrospective cohort study of 168 adults with drug-resistant MTLE and hippocampal sclerosis who underwent ATL between 2006 and 2025 reported an Engel Class I seizure freedom rate of 95.2% at one year and 85.1% over a mean follow-up of 117.74 months. Longer preoperative epilepsy duration (p=0.009) and positive family history (p=0.021) emerged as risk factors for late recurrence, while histopathological subtype — predominantly HS-ILAE Type 1 (73.8%) — showed no significant association with seizure control (p>0.05).

MR-guided laser interstitial thermal therapy (LITT), specifically stereotactic laser amygdalohippocampotomy, has been evaluated in a growing body of literature. The largest aggregated experience, encompassing 554 patients with MTLE, reported Engel Class I seizure freedom in 57% of cases, with rates approximately 10% higher in mesial temporal sclerosis and lower in MRI-normal MTLE. A meta-analysis comparing LITT against open resective surgery (ORS) — incorporating 15 cohort studies with 3,873 patients — found LITT's overall seizure freedom rate of 52.5% (95% CI: 45.3%–59.7%) to be significantly lower than ORS at 67.1% (95% CI: 60.2%–73.9%) across the full dataset (RR 0.78, 95% CI: 0.70–0.88, p≤0.0001). However, in propensity score-matched analyses and subgroup analyses restricted to temporal lobe epilepsy, seizure freedom rates were statistically comparable (RR 0.85, p=0.30 and RR 0.88, p=0.34, respectively). Critically, LITT demonstrated a significantly more favorable safety profile: complication rates were lower (RR 0.54, 95% CI: 0.37–0.79, p<0.002), as were rates of ischemic stroke (RR 0.15, p=0.01) and permanent neurological deficits (RR 0.13, p<0.0001), with mean hospital stay nearly 3 days shorter than ORS (mean difference 2.95 days, p<0.00001).

A personalized neuroimaging biomarker study of 30 patients with MTLE who underwent MR-guided LITT provided additional mechanistic insight into outcome prediction. A hippocampal personalized NeuroMetabolic Signature (pNMS) ablative rate of 39.79% was significantly associated with seizure freedom (Pearson χ²=10.16, p=0.001; balanced accuracy=0.83). The asymmetry index derived from ¹⁸F-FDG PET independently predicted seizure outcomes (OR=1.43, p=0.02), with hippocampal atrophy identified as the dominant contributor to pNMS expression (Shapley value=−0.026) and correlating with metabolic asymmetry (Pearson's r=0.47, p<0.01). Collectively, these studies highlight a nuanced trade-off landscape in MTLE surgery: open ATL continues to offer the highest absolute rates of seizure freedom, while LITT delivers a meaningfully safer perioperative profile with comparable outcomes in well-selected populations, particularly those with mesial temporal sclerosis.

Designing GenTLE: Targeting Refractory MTLE with AMT-260

The clinical trial landscape for mesial temporal lobe epilepsy (MTLE) spans surgical, neurostimulation, pharmacological, and advanced imaging modalities, with study designs ranging from prospective randomized controlled trials to retrospective cohort analyses and systematic reviews. Endpoints have evolved from binary seizure freedom (Engel/ILAE classification) to encompass neuropsychological outcomes, quality of life, and predictive biomarker performance.

Navigating the Evolving Landscape for Refractory MTLE Therapies

Over the past five years, the surgical management of refractory mesial temporal lobe epilepsy (MTLE) has undergone meaningful refinement, with accumulating evidence reshaping both procedural selection and operative technique. Landmark randomized controlled trial data have reinforced the validity of resective surgery, while a 2026 meta-analysis of 11 studies encompassing 389 LITT and 557 open surgery patients clarified the comparative profile of laser interstitial thermal therapy (LITT) versus open resection: open surgery demonstrated higher rates of complete seizure freedom (68.1% vs. 53.7%, RR 0.81, p = 0.07), though this difference did not reach statistical significance. Adequate seizure freedom was similarly comparable between approaches (74.0% vs. 63.0%, p = 0.11), while LITT conferred significant procedural advantages — shorter hospital stays (3.4 vs. 6.8 days) and lower complication rates (18.3% vs. 30.0%, p < 0.01) — positioning it as a viable, less morbid alternative for appropriate candidates. Longer-term LITT follow-up data (18–81 months) further show that Engel Class I outcomes were achieved in 60.4% of patients, with seizure-freedom rates declining from 77.8% at 24 months to 50% beyond 61 months, underscoring the importance of patient selection and longitudinal monitoring.

Surgical technique has also evolved at the anatomical level. A 2025 study of 216 TLE patients — 158 with MTLE — demonstrated that failure to resect the temporal piriform cortex (tPC) was a significant independent predictor of seizure recurrence across the full cohort (p < 0.001, OR = 4.415, 95% CI 2.032–9.594). In the MTLE subgroup specifically, unresected tPC was associated with inferior seizure outcomes at both two-year (p = 0.012, OR = 3.362) and five-year (p = 0.014, OR = 5.750) follow-up, and patients with tPC resection had higher rates of antiseizure medication reduction and withdrawal at five years. This association was particularly pronounced in hippocampal sclerosis cases, reinforcing the conceptual importance of the hippocampus-amygdala-piriform complex as a core component of the epileptogenic zone in MTLE. Meanwhile, responsive neurostimulation (RNS) has emerged as a substantive alternative for patients ineligible for or refractory to resection: a 2025 meta-analysis of 207 patients across seven observational studies reported a mean seizure frequency reduction of 68.76% (95% CI 57.16–80.37%), a responder rate of 67.58%, and six-month seizure freedom in approximately 29% of patients.

Despite these therapeutic advances, systemic barriers continue to limit patient access to optimal care. A retrospective analysis of 1,362 patients with drug-resistant TLE in India spanning 2000–2014 revealed a mean duration of epilepsy before referral to a surgical center of 18.10 ± 9.44 years, with no statistically significant improvement in referral timing over the study period (p = 0.638). This persistent delay reflects a broader global challenge, particularly in lower-resource settings, where the evidence-to-practice gap remains substantial despite growing trial-level validation of surgical and neuromodulatory interventions. On the pharmacological front, investigational approaches — including α5-GABAR positive allosteric modulators, KCNQ2/3-targeting antiseizure agents, and preclinical disease-modifying candidates such as TXM-CB3 — signal an expanding pipeline, though none have yet generated sufficient clinical-stage data to alter current treatment algorithms for MTLE.