gene-therapy-briefs:-regeneron-wins-fda-approval-for-first-neurosensory-gene-therapy
Gene Therapy Briefs: Regeneron Wins FDA Approval for First Neurosensory Gene Therapy

Gene Therapy Briefs: Regeneron Wins FDA Approval for First Neurosensory Gene Therapy

Credit: Andrew Brookes / Getty Images / Cultura RF

The FDA has granted accelerated approval to Regeneron Pharmaceuticals’ Otarmeni™ (lunsotogene parvec-cwha) as the first gene therapy designed to restore a neurosensory function to normal levels.

Otarmeni is an adeno-associated virus vector-based gene therapy indicated for treating children and adults with severe-to-profound and profound sensorineural hearing loss, defined as any frequency >90 decibel hearing level [dB HL], associated with molecularly confirmed biallelic variants in the OTOF gene, preserved outer hair cell function, and no prior cochlear implant in the same ear.

Otarmeni (formerly DB-OTO) is the first and only in vivo gene therapy indicated for OTOF-related hearing loss. Regeneron said it will make Otarmeni available for free in the U.S.

The FDA based its accelerated approval decision on the improvement of hearing sensitivity as measured by average pure tone audiometry (PTA) at week 24 during the Phase I/II CHORD trial (NCT05788536). Twenty participants ages 10 months to 16 years received a single dose of Otarmeni via intracochlear infusion—10 patients in one ear, the other 10 in both ears. Data from CHORD showed:

  • 80% of participants (16 of 20) reported hearing improvements per pure tone audiometry assessments at ≤70 dB HL at 24 weeks, achieving the trial’s primary endpoint, while one additional participant achieved the threshold by week 48.
  • 70% (14 of 20) showed an auditory brainstem response (ABR) at ≤90 decibels at 24 weeks, achieving the trial’s key secondary endpoint.
  • Among participants followed to 48 weeks, all prior responders maintained a response to therapy, and 42% of all participants (five of 12) achieved normal hearing that included whispers (≤25 dB HL).

“This unprecedented breakthrough in gene therapy has already proven to be life-changing for many of the children in our clinical trial and their families,” said George D. Yancopoulos, MD, PhD, board co-chair, president and chief scientific officer of Regeneron. 1

The FDA said its accelerated approval may hinge upon verification and description of clinical benefit in the confirmatory portion of the CHOIRD trial, a first-in-human, multicenter, open-label trial designed to assess the safety, tolerability and preliminary efficacy of DB-OTO in infants, children, and adolescents with otoferlin variants.

Otarmeni is the first gene therapy, and second new molecular entity, to win FDA approval under the agency’s Commissioner’s National Priority Voucher (CNPV) pilot program.

Launched in October by FDA Commissioner Martin A. Makary, MD, CNPV awards vouchers to drug developers whose work is deemed to address a health crisis in the U.S., deliver more innovative cures, address unmet public health needs, and increase domestic drug manufacturing as a national security issue. The vouchers entitle companies to reviews of their final applications within a target timeframe of 1–2 months rather than the standard 10–12 months.

Intellia’s Lonvo-Z begins rolling BLA following positive Phase III data

Intellia Therapeutics has launched a rolling Biologics License Application (BLA) submission to the FDA seeking regulatory approval of lonvoguran ziclumeran (lonvo-z), after announcing positive topline results from the global Phase III HAELO trial (NCT06634420) in hereditary angioedema (HAE)—the first Phase III data reported for an in vivo gene editing therapy.

HAELO is a randomized, double-blind, placebo-controlled Phase III trial designed to evaluate the efficacy and safety of a one-time 50 mg dose of lonvo-z in adults and adolescents aged 16 years and older with Type I or Type II HAE. The trial’s key endpoints focused on the number of HAE attacks experienced by patients, quality of life, safety and tolerability. Eighty patients were enrolled with 52 receiving lonvo-z and 28, placebo.

HAELO met its primary endpoint. For the six-month efficacy evaluation period (weeks 5 to 28), a one-time infusion of lonvo-z reduced attacks by 87% vs. placebo, with a mean monthly attack rate of 0.26 in the lonvo-z arm vs. 2.10 in the placebo arm.

Other key findings from HAELO:

  • The trial met all key secondary endpoints with statistical significance (p<0.0001). These included a 62% rate of patients who were entirely attack free and therapy free in the lonvo-z arm for the six-month efficacy evaluation period, vs. 11% of patients in the placebo arm.
  • Lonvo-z showed favorable safety and tolerability data. The most common treatment emergent adverse events (TEAEs) during the primary observation period (infusion through week 28) were infusion-related reactions, headache and fatigue. All TEAEs reported as of the data cutoff (February 10, 2026) were mild or moderate, with no serious adverse events observed in the lonvo-z arm.
  • As of the data cutoff, all patients who received lonvo-z at baseline or in crossover after week 28 remained long-term prophylaxis (LTP) free.

“Today’s HAELO results represent a profound milestone for Intellia, the broader CRISPR and precision medicine fields and, most importantly, the HAE community,” said John Leonard, MD, Intellia’s president and CEO. “These data affirm lonvo-z’s potential, with one dose, to offer prolonged freedom from both attacks and the need for ongoing therapy.” 2

Intellia said researchers plan to present additional clinical data from HAELO at the 2026 European Academy of Allergy and Clinical Immunology Congress (EAACI), set for June 12-15 in Istanbul, Turkey (Abstract #100217).

Lonvo-z is designed to inactivate the kallikrein B1 (KLKB1) gene in order to permanently lower kallikrein and bradykinin levels. Lonvo-z is designed as a one-time treatment that is administered in an outpatient setting.

Intellia said it is preparing for a potential U.S. launch of lonvo-z in the first half of 2027.

J. Craig Venter Dies: Pioneer in gene discovery, genomics, and synthetic biology

Craig Venter, PhD, a pioneer in gene discovery, human genomics, and synthetic biology, died April 29 in San Diego after a brief hospitalization for unexpected side effects that arose from treatment of recently diagnosed cancer. He was 79.

Venter was founder, board chair, and CEO of the institute that bears his name in La Jolla, CA. Earlier at the National Institutes of Health (NIH), he helped pioneer gene discovery using expressed sequence tags (ESTs), enabling rapid identification of large numbers of human genes and accelerating genome mapping efforts.

He went on to lead efforts that produced the first draft sequences of the human genome. He and colleagues later published the first high-quality diploid human genome, a scientific milestone that demonstrated the importance of capturing genetic variation inherited from both parents.

Venter’s work helped define and advance modern genomics, as well as launched the field of synthetic biology, where he and his teams constructed the first self-replicating bacterial cell controlled by a chemically synthesized genome—proof that genomes could be designed digitally, built from chemical components, and like a computer, booted up to run a living cell.

Through the Sorcerer II Global Ocean Sampling Expedition, Venter and his teams used metagenomics to reveal microbial diversity, reporting the discovery of millions of new genes and expanding the known universe of protein families—work that added to knowledge and insight of the ocean microbiome and its role in planetary systems.

“Venter was controversial and often challenged the scientific orthodoxy, with critics accusing him of hype and going overboard on privatization,” said John Sterling, Editor in Chief of Genetic Engineering & Biotechnology News, who has known and worked editorially with Venter over the past 35 years. “To many, he was a visionary focusing on technological acceleration and blending academic science with the zeal of an entrepreneur. Supporters saw him as a pioneer who sped up genomics by years.” 3

In addition to founding the J. Craig Venter Institute (JCVI), Venter was a serial entrepreneur who co-founded Synthetic Genomics, Human Longevity, and most recently Diploid Genomics, advancing efforts designed to translate genomics and synthetic biology into tools for health and society.

He was also a fierce advocate for robust federal science funding, as well as for partnerships that accelerate progress across government, academia, and industry.

“Craig believed that science moves forward when people are willing to think differently, move decisively, and build what doesn’t yet exist,” said Anders Dale, president of JCVI. “His leadership and vision reshaped genomics and helped ignite synthetic biology. We will honor his legacy by continuing the mission he built—advancing genomic science, championing the public investments that make discovery possible, and partnering broadly to turn knowledge into impact.” 4

Rocket Pharma selling Priority Review Voucher for Kresladi™ for $180M

Rocket Pharmaceuticals has agreed to sell for $180 million the Rare Pediatric Disease Priority Review Voucher (PRV) it was awarded by the FDA after the agency granted accelerated approval of Kresladi™ (marnetegragene autotemcel).

Kresladi is an autologous hematopoietic stem cell-based gene therapy indicated to treat children with severe leukocyte adhesion deficiency-I (LAD-I) due to biallelic variants in ITGB2 without an available human leukocyte antigen-matched sibling donor for allogeneic hematopoietic stem cell transplant.

The indication was approved in March under accelerated approval based on increase in neutrophil CD18 and CD11a surface expression. The accelerated approval of Kresladi is subject to confirmation of its clinical benefit, to be based on an evaluation of longer-term follow-up data of treated patients in the ongoing Phase I/II trial (NCT03812263) and through a post-marketing registry. The study generated positive topline data showing 100% overall survival at 12 months post-infusion (and for the entire duration of follow-up) for all nine LAD-I patients with 18 to 42 months of available follow-up.

The accelerated approval followed a resubmission of Rocket’s Biologics License Application for Kresladi. The original submission was rejected by the FDA in 2024 through a Complete Response Letter that requested additional Chemistry, Manufacturing, and Controls (CMC) information, but did not raise safety or efficacy issues about the gene therapy.

Rocket said it plans to use proceeds from the PRV sale toward advancing its prioritized cardiovascular gene therapy pipeline, including clinical-stage programs in Danon disease, PKP2-associated arrhythmogenic cardiomyopathy (PKP2-ACM), and BAG3-associated dilated cardiomyopathy (BAG3-DCM).

“The monetization of our PRV, following the FDA approval of Kresladi, provides meaningful non-dilutive capital and extends our cash runway into the second quarter of 2028,” said Gaurav Shah, MD, Rocket Pharmaceuticals CEO. “This strengthens our ability to advance key clinical milestones across our cardiovascular gene therapy pipeline, with all programs on track.” 5

Passage Bio cuts staff 75%, launches strategic review

Passage Bio said it will eliminate 75% of its staff in a cost-cutting restructuring that is part of the company’s effort to review strategic alternatives.

“The Company expects that the aggregate severance and exit costs for the Restructuring Plan will be approximately $3.3 million, which will be recorded primarily in the second quarter of 2026,” Passage Bio said in a regulatory filing. 6

Passage Bio has said it plans to review strategic alternatives that may include merger or acquisition transactions, a reverse merger, a sale of assets of the company, strategic partnerships, licensing opportunities, or other potential paths.

The restructuring followed Passage Bio receiving feedback during a Type C meeting with officials at the FDA that indicated that the company will be required to complete a randomized controlled registrational trial evaluating its lead pipeline candidate PBFT02 as a treatment for frontotemporal dementia (FTD) with granulin (GRN) mutations.

PBFT02 is a gene replacement therapy that uses an adeno-associated virus serotype 1 (AAV1) viral vector to deliver, through intra cisterna magna (ICM) administration, a functional GRN gene that encodes the progranulin protein (PGRN).

The 75% workforce cut amounts to approximately 18 people, based on the 24 full-time employees it reported as of December 31, 2025, according to its annual report.

LEO Pharma acquires Replay for $50M upfront, milestones

LEO Pharma has agreed to acquire Replay, a developer of gene therapies for rare genetic dermatological conditions, in a deal that the buyer said will add deep expertise and a next-generation gene therapy platform to its pipeline, namely Replay’s high‑payload herpes simplex virus (HSV) delivery vector.

LEO Pharma plans to acquire Replay for $50 million upfront, plus milestone payments and tiered single-digit royalties.

Replay’s gene therapy platform is designed to leverage HSV’s capacity to deliver large genes, which according to LEO makes it well suited for addressing rare, genetically driven dermatological conditions. The genetically modified HSV therapy is formulated as a topical gel that targets the deficient gene when applied directly to the skin.

“Replay’s HSV gene therapy platform holds significant promise for patients with rare genetic skin diseases, and realizing its full potential requires focused expertise in medical dermatology—an area where LEO Pharma brings decades of leadership, scale and proven execution,” LEO Pharma CEO Christophe Bourdon said. “The acquisition aligns with our strategy of investing in the most impactful opportunities in dermatology and positions LEO Pharma at the forefront of next‑generation gene therapy.” 7

LEO Pharma agreed to acquire Replay after identifying Replay as a high‑potential opportunity using its artificial intelligence (AI) scouting platform, Innoviewer™. Replay’s lead pipeline drug program is a preclinical phase candidate designed to treat dystrophic epidermolysis bullosa (DEB).

MeiraGTx buys rights to XLRP treatment from J&J for $25M upfront

MeiraGTx Holdings has agreed to acquire from Johnson & Johnson (J&J) all interests in botaretigene sparoparvovec (bota-vec), a gene therapy being developed to treat X-linked retinitis pigmentosa (XLRP).

Under the companies’ asset purchase agreement, MeiraGTx agreed to pay J&J $25 million cash upfront, a one-time regulatory and commercial milestone payment tied to U.S. approval and U.S. sales performance of bota-vec for the treatment of XLRP, plus what MeiraGTx called a high double-digit royalty on global net sales starting in mid-2029.

The sale comes nearly a year after bota-vec failed the 95-patient, Phase III LUMEOS trial (NCT04671433)  by missing the study’s primary endpoint of demonstrating statistically significant vision-guided mobility in patients with XLRP, as measured by a Visual Mobility Assessment (VMA) or maze.

However, MeiraGTx has emphasized results showing that subjects treated with bota-vec were 2.4x more likely to respond than untreated subjects. A Low Luminance Questionnaire – Patient-Reported Outcome (LLQ PRO) showed significant benefit in mobility and dim light function, qualities tested by the VMA—thus indication, according to MeiraGTx, that the maze was not sensitive enough to capture these benefits.

The company characterized data from the LUMEOS trial’s secondary endpoints as very strong, with clinically meaningful and statistically significant improvements shown in each of three domains of vision.

MeiraGTx is the commercial manufacturer of bota-vec and had collaborated in its development with J&J from Phase I development onward. The FDA has granted Fast Track and Orphan Drug Designations to bota-vec, while the European Medicines Agency has granted Priority Medicines (PRIME), Advanced Therapy Medicinal Product (ATMP), and Orphan Drug designations to bota-vec.

“This is a unique opportunity to gain an asset at this stage in development with data supporting a meaningful benefit in patients with no alternative treatment, many of whom are waiting for this life changing therapy and hoping for expeditious approval,” said Alexandria Forbes, PhD, MeiraGTX’s president and CEO. 8

She added that MeiraGTx intends to start filing a Biologics License Agreement (BLA) with the FDA and applications for regulatory approval in the European Union and Japan as soon as possible.

References

1. Regeneron Pharmaceuticals. Otarmeni™ (lunsotogene parvec-cwha) Approved by FDA as First and Only Gene Therapy for Genetic Hearing Loss; Regeneron to Provide Otarmeni for Free in the U.S. April 23, 2026. (Last accessed May 1, 2026)

2. Intellia Therapeutics. Intellia Therapeutics Reports Positive Phase 3 Results in Hereditary Angioedema, Marking a Global First for In Vivo Gene Editing. April 27, 2026. (Last accessed May 1, 2026).

3. Genetic Engineering & Biotechnology News. Genomics Pioneer and Life Sciences Entrepreneur J. Craig Venter Dies at 79. April 30, 2026. (Last accessed May 1, 2026)

4. Craig Venter Institute. J. Craig Venter, genomics pioneer and founder of JCVI and Diploid Genomics, Inc., dies at 79. April 29, 2026. (Last accessed May 1, 2026)

5. Rocket Pharmaceuticals. Rocket Pharmaceuticals Announces $180 Million Sale of Priority Review Voucher. April 28, 2026. (Last accessed May 3, 2026)

6. Passage Bio. Form 8-K, filed April 28, 2026. (Last accessed May 5,2026)

7. LEO Pharma. LEO Pharma bolsters rare skin disease focus through acquisition of Replay gene therapy platform. April 30, 2026. (Last accessed May 3, 2026)

8. MeiraGTx Holdings. MeiraGTx Announces the Acquisition of Botaretigene Sparoparvovec (bota-vec) for the Treatment of X-linked Retinitis Pigmentosa (XLRP). April 16, 2026. (Last accessed May 3, 2026)