Neurona Therapeutics’ rezanecel demonstrates durable seizure reduction past the one-year mark in drug-resistant mesial temporal lobe epilepsy at the AAN Annual Meeting, Gilead Sciences and Arcus Biosciences’ TIGIT inhibitor domvanalimab fails its pivotal Phase 3 lung cancer trial triggering two further study terminations, Merck and Eisai’s Keytruda triplet regimen fails to improve survival in Phase 3 renal cell carcinoma, and Novo Nordisk’s etavopivat delivers a 27% reduction in vaso-occlusive crises and a 48.7% haemoglobin response in sickle cell disease. Here, Life Science Daily News brings you the most significant clinical trial results 24 April 2026.
Neurona Therapeutics’ Rezanecel Demonstrates Durable Seizure Reduction in Drug-Resistant Epilepsy at AAN 2026 — as UCB Announces $1.15 Billion Acquisition
Neurona Therapeutics presented on 22 April 2026 updated clinical data from its ongoing open-label Phase 1/2 trials evaluating rezanecel (NRTX-1001), an allogeneic, off-the-shelf interneuron cell therapy, in patients with drug-resistant mesial temporal lobe epilepsy (MTLE). The data were presented at the 2026 American Academy of Neurology (AAN) Annual Meeting, held in Chicago and online from 18–22 April.
The updated dataset spans two ongoing Phase 1/2 trials: NCT05135091 evaluating rezanecel in drug-resistant unilateral MTLE, and NCT06422923 in drug-resistant bilateral MTLE. Across the unilateral MTLE programme, results continue to show durable seizure reduction past the one-year timepoint, with a consistent safety profile in line with prior reports. The bilateral MTLE study is now generating preliminary efficacy and safety data, with the company describing the early findings as promising across a patient population that is underserved by current standard-of-care options including lobectomy, ablative surgery, and neurostimulation devices.
Rezanecel comprises GABAergic interneurons derived from pluripotent stem cells and is designed to be administered as a single, one-time treatment. The therapy has received Regenerative Medicine Advanced Therapy (RMAT) designation from the FDA and Priority Medicines (PRIME) designation from the European Medicines Agency (EMA). Neurona is preparing to initiate its Phase 3 EPIlepsy Cell Therapy (EPIC) trial — a randomised, sham-controlled, double-blind study — with first patient enrolment planned for the second half of 2026.
UCB acquisition: On 18 April 2026, Belgian biopharmaceutical company UCB announced it would acquire Neurona Therapeutics for $650 million upfront, with up to $500 million in additional milestone payments. The acquisition centres on rezanecel and signals UCB’s strategic commitment to regenerative medicine and its established epilepsy franchise. The transaction is expected to close by the end of Q2 2026, pending regulatory clearances. If rezanecel ultimately receives approval, it could represent the first regenerative cell therapy indicated for drug-resistant epilepsy.
Gilead and Arcus Biosciences’ TIGIT Inhibitor Fails Phase 3 in Lung Cancer, Triggering One Additional Trial Termination
Gilead Sciences and Arcus Biosciences disclosed on 20 April 2026, via an Arcus SEC filing, that their anti-TIGIT antibody domvanalimab failed to meet its primary endpoint in the pivotal Phase 3 STAR-121 trial in lung cancer. STAR-121 was evaluating domvanalimab in combination with Arcus’s anti-PD-1 antibody zimberelimab and chemotherapy versus Merck’s Keytruda (pembrolizumab) plus chemotherapy in patients with previously untreated metastatic non-small cell lung cancer (NSCLC). An independent data monitoring committee recommended discontinuing the trial based on a pre-specified futility analysis. Specific hazard ratio and patient-level data had not been publicly disclosed at time of publication.
The failure marks a further setback for the TIGIT class, which has now accumulated multiple high-profile Phase 3 disappointments across several development programmes. Following the STAR-121 readout, Arcus and Gilead also announced the termination of the Phase 2 EDGE-Lung study of domvanalimab in NSCLC. In a separate disclosure, Gilead confirmed it will not exercise its option to extend collaboration rights under the 2020 partnership agreement, with the option period set to expire on 14 July 2026.
TIGIT — T-cell immunoreceptor with immunoglobulin and ITIM domain — has been an intensely pursued checkpoint inhibitor target given its role in dampening anti-tumour immune responses. Despite strong preclinical rationale and early clinical signals, the class has struggled to demonstrate survival benefit in large randomised trials. The Gilead and Arcus failure follows earlier Phase 3 setbacks for TIGIT inhibitors from other developers, raising broader questions about patient selection, combination strategies, and the optimal role for TIGIT blockade in the immuno-oncology landscape.
Editorial note: Full primary endpoint details and hazard ratio data were not available at time of publication.
Merck and Eisai’s Keytruda Triplet Regimen Fails to Meet Co-Primary Endpoints in Phase 3 Renal Cell Carcinoma Trial
Merck and Eisai announced on 21 April 2026 that the Phase 3 LITESPARK-012 trial failed to meet its co-primary endpoints of progression-free survival (PFS) and overall survival (OS) in patients with advanced clear cell renal cell carcinoma (RCC). The trial evaluated a triplet regimen comprising Merck’s Welireg (belzutifan), the PD-1 checkpoint inhibitor Keytruda (pembrolizumab), and Eisai’s Lenvima (lenvatinib) versus the established doublet of Keytruda plus Lenvima in the first-line setting. Neither PFS nor OS was significantly improved at a pre-specified interim analysis.
LITESPARK-012 also evaluated a second investigational arm — MK-1308A, a co-formulation of pembrolizumab and Merck’s anti-CTLA-4 antibody quavonlimab, plus Lenvima — which similarly failed to meet the dual primary endpoints. Safety profiles for both combination regimens were consistent with those observed in prior studies.
Welireg is a first-in-class HIF-2α inhibitor already approved for certain RCC indications as a monotherapy, while Keytruda and Lenvima are an established doublet with proven efficacy in first-line RCC. The Phase 3 failure suggests that the clinical benefit of a triplet approach did not translate beyond what is achievable with the existing approved regimen. Merck and Eisai have other active programmes for Welireg, including a pending FDA supplemental application for Welireg plus Lenvima in previously treated patients with advanced RCC, with a PDUFA date of 4 October 2026.
Editorial note: Specific hazard ratio data were not confirmed at time of publication.
Novo Nordisk’s Etavopivat Demonstrates Meaningful Reductions in Vaso-Occlusive Crises and Improved Haemoglobin Response in Sickle Cell Disease
Novo Nordisk announced on 20 April 2026 the topline Phase 3 results from the HIBISCUS trial evaluating etavopivat in sickle cell disease (SCD). The randomised, double-blind, placebo-controlled trial enrolled 385 patients aged 12 years or older and ran for 52 weeks. Etavopivat met both co-primary endpoints, demonstrating a 27% reduction in annualised vaso-occlusive crisis (VOC) events and a haemoglobin response rate of 48.7% at 24 weeks (versus 7.2% on placebo), with patients also experiencing approximately a four-month delay to their first VOC event compared with those on placebo.
Etavopivat is an oral, once-daily pyruvate kinase R (PKR) activator that works by increasing the activity of the PKR enzyme in red blood cells, improving their energy metabolism and reducing the sickling process that underlies the pathophysiology of SCD. PKR activation has emerged as a mechanistically distinct approach to SCD management compared with fetal haemoglobin inducers such as hydroxyurea or gene-based therapies. Novo Nordisk has stated it plans to submit for regulatory approval of etavopivat in the second half of 2026; if successful, the drug would add a new oral, disease-modifying option to a treatment landscape that has evolved significantly in recent years with the approval of gene therapies and other targeted agents.
The FDA has granted etavopivat Fast Track, Rare Pediatric Disease, and Orphan Drug designations; the European Medicines Agency has also granted Orphan Drug designation. Full data from the HIBISCUS trial are expected to be presented at a scientific conference later in 2026.
Editorial note: Statistical significance values and complete secondary endpoint data were not confirmed at time of publication via a full data release. Topline numerical data are drawn from the Novo Nordisk press release of 20 April 2026.
Looking Ahead
This week’s clinical trial results 24 April 2026 reflect the full complexity of the current pharmaceutical pipeline — from regenerative breakthroughs to class-wide setbacks and meaningful advances in haematology. Rezanecel’s durable Phase 1/2 data in drug-resistant epilepsy raise genuine hope for a patient population that has lacked transformative options, and UCB’s $1.15 billion acquisition of Neurona underscores industry confidence in the programme ahead of the Phase 3 EPIC trial. The STAR-121 TIGIT failure from Gilead and Arcus deepens questions about the class’s viability in lung cancer, while the LITESPARK-012 setback in RCC is a reminder that combination complexity does not automatically translate to survival benefit. Novo Nordisk’s etavopivat data, by contrast, offer the sickle cell community a credible new oral candidate with differentiated efficacy signals. Life Science Daily News will continue to bring you accurate, timely coverage of the clinical trial results 24 April 2026 that matter most across the global life sciences pipeline.
This clinical trials roundup is produced by the Life Science Daily News editorial team. All stories are selected and written independently.
