Ionis Pharmaceuticals is drawing attention in the biotech sector following the launch of its antisense oligonucleotide therapies, with its initial release of Tryngolza for familial chylomicronemia syndrome (FCS) surpassing market expectations.
At the J.P. Morgan Healthcare Conference in January, Ionis CEO Brett Monia commented on the company’s progress: “I think we made our point. I don’t think it’s seeping in well enough yet, but it will.” Monia referred to results from a Phase 3 trial of bepirovirsen, developed in partnership with GSK, which demonstrated what GSK described as a “statistically significant and clinically meaningful functional cure rate” for chronic hepatitis B. While specific data were not disclosed, GSK confirmed that the trial met its primary endpoint and announced plans to present more details at the European Association for the Study of the Liver meeting this spring. A new drug application is expected to be filed in the first quarter.
Monia stated that the functional cure rate observed was approximately 15–20%, compared to existing treatments that achieve rates between 1–3%.
In addition to bepirovirsen, Ionis independently launched Dawnzera for hereditary angioedema prevention and Tryngolza for FCS last year. According to Monia, “Ionis has been historically an R&D organization. Now we built the commercial capabilities to support the launches that occurred.”
Tryngolza generated about $102 million in revenue during 2025. Analyst firm William Blair projected in January that sales could reach $2 billion by 2034.
The company also reported positive Phase 3 results for Tryngolza targeting severe hypertriglyceridemia (sHTG), showing significant reductions in triglycerides and supporting an FDA application submitted at year-end. William Blair described Tryngolza as potentially “transformational” if approved for sHTG.
Initial performance in FCS has been seen as evidence of Ionis’ effective salesforce within cardiometabolic diseases and promising for future expansion into broader indications such as sHTG. If successful, this would mark Ionis’ entry into treatments for more common diseases.
Ionis faces competition from Arrowhead Pharmaceuticals, whose plozasiran received approval for FCS in November 2025 and is undergoing Phase 3 trials for sHTG. With approval in FCS secured, Monia explained that Ionis priced Tryngolza at $595,000 annually due to its rarity but indicated pricing would decrease if approved for a more common indication like sHTG.
“Let’s face the facts: the FCS market—we pretty much created it, and we’re doing extremely well. There’s not much left for a competitor to come in,” Monia said.
William Blair estimated that Tryngolza’s price point could fall between $10,000 and $20,000 per year if approved for sHTG—substantially lower than Arrowhead’s planned cost of $60,000 per year.
Beyond cardiometabolic disease products, Ionis also advanced zilganersen—a therapy targeting Alexander disease—demonstrating clinical benefit in a Phase 3 trial last year. The company intends to submit an approval application this quarter; currently, children with Alexander disease rarely survive past age four according to Monia.
Ionis continues progressing several partnered programs alongside major pharmaceutical companies including AstraZeneca, Roche and Novartis. Four additional Phase 3 readouts are anticipated this year.
Reflecting on recent achievements Monia stated: “It seems like [2025] was the greatest year in our history, based on all of the achievements we made and how we transformed the company… And I expect to make the same claim in December of this year.”
Ionis is scheduled to report earnings and provide further updates on February 25.
