Wainua (eplontersen)

One of 3 approved TTR silencers for hereditary ATTR polyneuropathy, and the only one designed for patients to inject themselves at home. Patisiran (Onpattro) is an IV infusion every 3 weeks; vutrisiran (Amvuttra) is a clinic injection every 3 months and is also approved for the heart form. Tafamidis and acoramidis, the oral stabilizers, are approved for the heart form only in the United States.

Eplontersen is a short, single strand of synthetic nucleic acid, called an antisense oligonucleotide, built to match the liver's instructions (messenger RNA) for making transthyretin, or TTR. A sugar tag called GalNAc steers it into liver cells, where it pairs with the TTR message and triggers its breakdown before the protein is made. Less TTR in the blood means less protein available to misfold and settle into nerves as amyloid. In its main trial, blood TTR fell by 81% at week 35 and stayed down. Because TTR also carries vitamin A, blood vitamin A drops too, which is why the label asks patients to take a vitamin A supplement at the recommended daily allowance.

Wainua has no boxed warning and no contraindications. The one labeled warning is reduced vitamin A: 95% of patients developed low levels, so the label advises taking the recommended daily allowance of vitamin A (not more) and seeing an eye doctor for night blindness, dry eyes or other vision changes. In the 144-patient main trial the most common side effects were vitamin A decreased, reported as a side effect (15%), vomiting (9%), protein in the urine (8%), injection site reactions (7%), blurred vision (6%) and cataract (6%). A slow heart rhythm called AV block was reported as a serious event in 3 patients (2%), 1 of them complete heart block. Antibodies against the drug developed in 37% of patients; the label says they raised the lowest (trough) drug levels but not overall drug exposure, and were not found to change the drug's safety or how well it worked, though the data are too limited to draw firm conclusions.

A monthly self-injected antisense drug for a rare genetic disease, sold by AstraZeneca and Ionis at specialty pricing. For insurance and cost help, AstraZeneca's WAINUA WAY program (through AstraZeneca Access 360) can be reached at 1-844-2-WAINUA (1-844-292-4682); see the patient assistance section for details.

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Approved for adults with the polyneuropathy of hereditary transthyretin-mediated amyloidosis. It is not approved for ATTR cardiomyopathy (wild-type or hereditary) or for the nerve symptoms of wild-type ATTR. Genetic confirmation of a TTR variant is part of the hereditary diagnosis.

Source: Wainua prescribing information

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The FDA approved Wainua on December 21, 2023 based on NEURO-TTRansform (NCT04136184), an open-label study of 144 adults with hereditary ATTR polyneuropathy who received eplontersen monthly, compared with the placebo group of an earlier inotersen trial. At week 35, nerve damage scores (mNIS+7) were 9.0 points better than the external placebo group and quality of life (Norfolk QoL-DN) 11.8 points better; at week 66 the nerve score gap had widened to 24.8 points (Coelho et al., JAMA 2023). Blood TTR fell 81.7% versus 11.2% on placebo. In ATTR cardiomyopathy, the 1,432-patient CARDIO-TTRansform trial (NCT04136171) did not meet its primary endpoint of cardiovascular death and recurrent cardiovascular events, announced July 9, 2026. In a prespecified subgroup taking eplontersen without a stabilizer, the risk was 29% lower (hazard ratio 0.71, nominally significant); in patients already on a stabilizer there was no treatment effect. Ionis said it and AstraZeneca would continue to analyze the full data set; no heart-form regulatory plans have been announced.

Ionis Pharmaceuticals developed eplontersen as the GalNAc-tagged successor to its first TTR antisense drug, inotersen (Tegsedi). The sugar tag delivers the drug to liver cells, so a 45 mg monthly dose replaced Tegsedi's 284 mg weekly dose, and the Wainua label carries none of the boxed warnings or required blood tests that Tegsedi did. AstraZeneca and Ionis commercialize it together in the United States, with AstraZeneca as the labeler. The FDA approved it as Wainua on December 21, 2023 for hereditary ATTR polyneuropathy; it is sold as Wainzua in the European Union. The label was updated in April 2026 to add a prefilled syringe for healthcare-provider use. On July 9, 2026 Ionis announced that the CARDIO-TTRansform heart trial had missed its primary endpoint.

ATTR treatment splits by organ. For hereditary polyneuropathy, the 3 silencers (patisiran, vutrisiran, eplontersen) all lower blood TTR by about 80% and differ mainly in how and how often they are given. For cardiomyopathy, tafamidis, acoramidis and vutrisiran are approved; eplontersen is not, after its heart trial missed its primary endpoint in July 2026. Inotersen (Tegsedi), the older antisense drug, is listed by the FDA as discontinued. Our ATTR treatment comparison on the blog lays the trial results side by side.