Arrowhead’s Redemplo closes in on Ionis in the sHTG market

Ionis Pharmaceuticals, Inc. (NASDAQ: IONS) won US approval to expand Tryngolza into severe hypertriglyceridemia (sHTG) in June. In July, Arrowhead Pharmaceuticals Inc. (NASDAQ: ARWR) reported positive Phase 3 data for Redemplo (plozasiran) in sHTG, positioning Redemplo as a competing treatment.
Arrowhead plans to file a supplemental application with the U.S. Food and Drug Administration by the end of 2026 and has acquired a priority review voucher that could shorten the FDA review target to six months.

Visible Alpha consensus estimates put risk-adjusted Redemplo sales in sHTG at $40 million in 2027, with analysts assigning a 95% probability of approval, up from 82.5% before the Phase 3 readout. Sales are expected to rise to $308 million in 2028 and $1.4 billion in 2030, reaching peak sales of $3.5 billion in 2035.

Tryngolza has a similar long-term sales outlook. Consensus forecasts show sHTG sales of $66 million for Tryngolza in 2026, rising to $400 million in 2027 and $1.2 billion in 2029, before reaching peak sales of $3.3 billion in 2035. Ionis’ June approval made Tryngolza the first approved treatment specifically for sHTG, with the label also covering the reduction of the risk of acute pancreatitis.

Arrowhead, however, could have a convenience advantage if Redemplo wins approval in sHTG. The drug is administered once every three months, compared with monthly dosing for Tryngolza.

Redemplo is already approved in the US for familial chylomicronemia syndrome (FCS), the most severe form of sHTG, while Tryngolza received its initial US approval for FCS in December 2024.

Redemplo is Arrowhead’s only approved drug and its first commercial product, making the expansion into sHTG a significant opportunity to broaden the revenue base of its lead marketed asset.

This article was published by Visible Alpha, part of S&P Global Market Intelligence and not by S&P Global Ratings, which is a separately managed division of S&P Global.