WVE-006 RNA Editing Therapy Achieves MZ-Like Phenotype in Alpha-1 Antitrypsin Deficiency Phase 1b/2a Trial

Wave Life Sciences announced updated clinical data from the RestorAATion-2 trial on May 18, 2026, showing that WVE-006, an investigational N-acetylgalactosamine (GalNAc)-conjugated RNA editing oligonucleotide, produced major variant alpha-1 antitrypsin (M-AAT) levels consistent with the protective heterozygous Pi*MZ phenotype in patients with homozygous Pi*ZZ alpha-1 antitrypsin deficiency (AATD). The findings suggest potential for a subcutaneously administered therapy capable of addressing both pulmonary and hepatic disease manifestations, areas for which current approved treatments remain limited.¹

"Being able to have the patient safely make their own M protein while decreasing their Z protein levels through a reversible approach that avoids permanent genomic modifications, and, importantly, restores dynamic AAT production to protect patients during acute phase response, is a major step forward for the Alpha One patient community," said D. Kyle Hogarth, MD, professor of medicine, director of the Alpha One Antitrypsin Deficiency Clinical Resource Center, and director of Bronchoscopy at the University of Chicago Medicine, in a press release.¹

What were the trial design and key findings?

RestorAATion-2 (NCT06405633) is an ongoing open-label phase 1b/2a trial enrolling patients with the homozygous Pi*ZZ genotype across three dose cohorts (n=8 each), incorporating both single ascending dose and multiple ascending dose portions. Patients in the multidose arms received WVE-006 at 200 mg biweekly, 400 mg monthly, or 600 mg monthly over 12 weeks, followed by 12 weeks of follow-up. Circulating M-AAT, Z-AAT, and total AAT were quantified by liquid chromatography-tandem mass spectrometry.

In the 200 mg biweekly multidose cohort, M-AAT constituted 64.4% of total circulating AAT, in line with the range observed in heterozygous Pi*MZ individuals and with total AAT reaching 11.9 µM and Z-AAT reduction of 70.5%. Comparable results were observed with monthly 400 mg dosing, in which M-AAT reached 58.7% of total AAT, total AAT was 13.6 µM, and Z-AAT was reduced by 67.7%. RNA editing effects persisted at least three months after the final dose in both multidose cohorts. Three acute phase responses were documented across cohorts, each accompanied by dynamic AAT elevations (ranging from approximately 57.8% to 59.8% above pre-event levels in two cases, and 20.6 µM total AAT in a previously reported case), with C-reactive protein and AAT elevations significantly correlated (r=0.73, p<0.001, n=19).¹

All adverse events were mild to moderate, with no serious adverse events, no clinically meaningful liver function test elevations, and no liver toxicities reported to date.

What clinical context and unmet need are addressed?

AATD affects an estimated 100,000 individuals in the United States and is caused primarily by the Pi*ZZ genotype, in which misfolded Z-AAT accumulates in hepatocytes and circulating AAT levels are severely reduced.² The sole approved treatment — weekly intravenous plasma-derived AAT augmentation therapy — addresses only pulmonary manifestations and does not reduce hepatic Z-AAT burden or restore dynamic AAT responses.³ No therapies are currently approved for AATD-associated liver disease, which can progress to cirrhosis and hepatocellular carcinoma.⁴

What mechanism of action is employed by WVE-006?

WVE-006 employs adenosine-to-inosine (A-to-I) RNA base editing to correct the single-nucleotide mutation responsible for the Pi*Z variant at the RNA level, without modifying genomic DNA. This approach is mechanistically distinct from RNA interference, which silences gene expression, and from DNA base editing, which introduces permanent genomic alterations with associated risks of bystander edits and indels.⁵

GalNAc conjugation facilitates hepatocyte-selective uptake following subcutaneous administration, avoiding lipid nanoparticle delivery systems that have been associated with hepatic inflammation in clinical settings. The reversibility of RNA-level correction represents a potential safety advantage over permanent genomic modification strategies currently under investigation for monogenic liver diseases.⁵

What other implications can be gleaned from the trial data?

The RestorAATion-2 data are promising, but important limitations warrant acknowledgment. The trial remains early phase, with small cohort sizes (n=8 per arm) and an open-label design that precludes blinded efficacy assessment. The MZ-like phenotype benchmark is a pharmacodynamic endpoint; whether these protein-level changes translate into clinically meaningful reductions in forced expiratory volume decline, hepatic fibrosis progression, or exacerbation frequency remains to be established in larger, controlled trials.

The three acute phase response observations, while mechanistically compelling, are anecdotal at this stage. Regulatory feedback on an accelerated approval pathway is anticipated mid-2026, and data from the 600 mg monthly multidose cohort are expected in the second half of 2026.

References

1. Wave Life Sciences. Wave Life Sciences announces positive update on RestorAATion-2 trial: WVE-006 (GalNAc-RNA editing) achieves MZ-like phenotype across both biweekly and monthly dosing. Published May 18, 2026. Accessed May 20, 2026. https://ir.wavelifesciences.com/news-releases/news-release-details/wave-life-sciences-announces-positive-update-restoraation-2
2. Stoller JK, Aboussouan LS. Alpha1-antitrypsin deficiency. Lancet. 2005;365(9478):2225-2236. doi:10.1016/S0140-6736(05)66781-5
3. Sandhaus RA, Turino G, Brantly ML, et al. The diagnosis and management of alpha-1 antitrypsin deficiency in the adult. Chronic Obstr Pulm Dis. 2016;3(3):668-682. doi:10.15326/jcopdf.3.3.2015.0182
4. Strnad P, McElvaney NG, Lomas DA. Alpha1-antitrypsin deficiency. N Engl J Med. 2020;382(15):1443-1455. doi:10.1056/NEJMra1910234
5. Gillmore JD, Gane E, Taubel J, et al. CRISPR-Cas9 in vivo gene editing for transthyretin amyloidosis. N Engl J Med. 2021;385(6):493-502. doi:10.1056/NEJMoa2107454