STRC Research

STRC Gene Therapy Landscape 2026

6 min read

STRC Gene Therapy Landscape 2026

Three active programs are building toward a human STRC gene therapy trial. Two academic, one commercial. The commercial one (Regeneron) has the resources to get there first. The academic ones (Pasteur, Holt) are producing the science that will support or accelerate it.

The Three Programs

1. Iranfar / Institut Pasteur (Christine Petit group)

Published January 2026 in Clinical and Translational Medicine. Dual AAV9-PHP.eB delivery of full-length STRC cDNA in Strc−/− mice. Restored stereocilin expression in ~60% of OHCs. ABR thresholds, DPOAE, and behavioral frequency discrimination all recovered. Durable at 100 days. Authors explicitly state intent to move to human trials.

Source: [source] 2026-01-iranfar-dual-aav-strc-ctm

2. Jeffrey Holt Lab (Boston Children’s Hospital / Harvard)

Published December 2021 in Science Advances. P1 neonatal dual-AAV injection. 50-60 dB ABR threshold rescue. OHC bundle morphology restored in 59-65% of cells. Key finding: STRC mutations don’t cause early OHC death — cells survive, they just lack the structural protein. This distinction is what makes adult treatment viable.

In 2022 Holt stated 4-6 year timeline to human trials. That puts first-in-human at 2026-2028.

Source: [source] 2021-12-holt-strc-dual-aav-science-advances

3. Regeneron AAV.104 (acquired from Decibel Therapeutics, 2023, $109M)

Regeneron bought Decibel’s cochlear gene therapy portfolio in 2023 for $109M. AAV.104 is their STRC program, built directly on Holt’s Science Advances work. Regeneron already has an active cochlear gene therapy in clinical trials — DB-OTO for OTOF/DFNB9 (the CHORD trial). DB-OTO has dosed 12 children ages 10 months to 16 years; 11/12 showed hearing improvement, 3/12 reached normal thresholds, benefit durable at 72 weeks.

AAV.104 is the logical next program. Same platform, same manufacturing, same regulatory infrastructure. Once DB-OTO clears, AAV.104 advances.

Source: [source] 2025-db-oto-chord-trial-nejm

Why the OTOF Precedent Matters for Misha

CHORD demolished the “early-life only” window assumption. Children up to 16 years old with lifelong deafness showed hearing improvement. That’s the most important single data point for Misha’s family right now. Misha is 4. He’s not “too late” by any data that currently exists.

STRC and OTOF are different proteins with different cochlear roles. The CHORD results don’t prove STRC therapy works. But they prove dual-AAV cochlear delivery works in children. That’s the honest unknown the field needed to clear.

Why DFNB16 Is a Good Target

DFNB16 is structurally favorable compared to most genetic deafnesses:

  • OHC bodies survive long-term. The hearing loss is structural, not degenerative.
  • Mild-to-moderate presentation in 96% of patients over 6+ years.
  • Stable in 75% of ears longitudinally. Average progression only 0.6 dB/year.
  • No phenotypic difference between compound het (Misha’s genotype) and biallelic deletion.

Natural history source: [source] 2024-genereviews-strc-dfnb16

Connection to Egor’s Own Compute

The STRC Mini-STRC Single-Vector Hypothesis is Egor’s independent program computing whether a truncated STRC (Ultra-Mini 1075-1775) fits in a single AAV while preserving the TMEM145-binding interface. If it works, single-vector is superior to dual-AAV on transduction efficiency. The Pasteur and Holt programs validate the target biology. Egor’s compute asks whether there’s a better delivery architecture.

These aren’t competing. They’re parallel. If Regeneron’s AAV.104 reaches trial first, Misha’s family benefits directly. If the single-vector approach is proven, it becomes the next-generation product.

Actual status of Misha’s family relationships (2026-04-22)

Not “need to contact” — already contacted, active correspondence, real plans in motion. Reflecting truth rather than sketching a fresh-start plan:

Holt lab (BCH / Harvard) — ACTIVE

  • First contact 2026-03-17. 8+ email exchanges through April. See Jeffrey Holt.
  • Reviewed mini-STRC design. Shared personal photos. Warm peer-level dialogue.
  • Confirmed willing to serve as Scientific Advisor on MISHA Foundation board (concrete commitment, see MISHA Foundation).
  • Asked Egor for permission to share mini-STRC analysis with his STRC minigene project team.
  • Published Derstroff et al. 2026 (TMEM145 paper) as co-author — specifically asked Egor if mini-STRC interacts with TMEM145. Egor’s AF3 data answered this in the affirmative (ipTM=0.74 GOLD domain).
  • Jeff flagged E1659A classification as VUS-high per his lab framework — enrollable in many clinical trial sites.
  • Identified as one of the leading STRC gene therapy researchers globally.

Shu Yilai Lab (Fudan EENT, Shanghai) — ACTIVE

  • Introduced through Holt (Jeff’s friend/colleague).
  • STRC gene therapy is Track 2 of their lab program — active drug development per Han Shuang.
  • Han Shuang — in vivo lead. Building humanized knock-in mouse model. Directly relevant to Misha’s c.4976A>C E1659A variant (considering: (a) point-mutation mouse model, (b) AAV rescue with variant-bearing cDNA).
  • Tang Honghai — reviewed Egor’s mini-STRC design, assessed “theoretically reasonable”. AAV packaging 4.7 kb limit is the real constraint; dual-AAV recombination is their backup.
  • Chen Liheng — geneticist Shu referred for consultation.
  • Long-read sequencing available at EENT clinic (book via WeChat).
  • See Shu lab and Shu lab.

Shanghai trip upcoming — green corridor arranged for Misha’s Fudan EENT access. Mouse model build on their infrastructure is in motion. Closer to the gene therapy trial path than either Pasteur or Regeneron for Misha specifically, because China’s regulatory speed on hearing gene therapy is already proven (OTOF first-in-human 2023, Shu central to it).

Petit group (Institut Pasteur) — INITIATED, not yet replied

  • Via Saaid Safieddine (Petit’s colleague, Jeff’s friend). Initial outreach made. No reply from Paris yet per 2026-03-31 update from Jeff.
  • Iranfar et al. 2026 CTM paper is their most recent; they’re the academic-timeline track.

Regeneron (AAV.104 ex-Decibel) — INDIRECT

  • Not directly contacted as of 2026-04-22. When their AAV.104 IND lands, real path via Holt’s network (he works with the same STRC biology) rather than cold patient-advocacy route.
  • Commercial-timeline track: follows DB-OTO clearance first.

What the 2026-04-22 landscape scan adds

  • Confirms the existing Holt + Shu strategy is the right strategy (dual-AAV STRC gene therapy), not a detour.
  • Iranfar 2026 CTM (Pasteur) is fresh external validation of the Holt 2021 result in a second academic lab.
  • DB-OTO CHORD trial (age up to 16) kills the “too late for Misha” worry that was implicit in earlier planning.
  • The 4PBA repurposing detour explored today is dead. Mini-STRC AAV + Shanghai mouse model is the real program.

What to track

  • NCT05788536 (CHORD / DB-OTO OTOF) — pediatric cohort expansion + publications.
  • Any Regeneron clinical trial registration referencing STRC or AAV.104.
  • Han Shuang’s mouse model milestones — this is the trial-adjacent work most relevant to Misha.
  • Petit group follow-up via Safieddine / Jeff.

Connections

Graph View

Backlinks