Ionis Pharmaceuticals Prepares for a Landmark Year as Key FDA Decisions and Phase 3 Data Loom
Ionis Pharmaceuticals (NASDAQ:IONS) laid out a sweeping agenda of regulatory milestones, clinical catalysts, and partnered programs at the RBC Capital Markets Global Healthcare Conference, signaling a decisive shift from a development-stage biotech to a commercial-stage player. Chief Development Officer Holly Kordasiewicz emphasized that the company is moving beyond its first two independent product launches into a broader late-stage pipeline and commercial rollout.
Kordasiewicz noted that Ionis executed its first two independent launches last year—TRYNGOLZA for familial chylomicronemia syndrome (FCS) and DAWNZERA for hereditary angioedema (HAE). Now the company is bracing for two Prescription Drug User Fee Act (PDUFA) decisions on wholly owned programs: TRYNGOLZA for severe hypertriglyceridemia (SHTG) in June, and zilganersen for Alexander disease by year-end.
→ 3 Rare Earth Stocks That Win No Matter What China Does Next
She also highlighted five Phase 3 readouts expected this year. Bepirovirsen, described as positive, is slated for presentation later this month at the European Association for the Study of the Liver (EASL) meeting. Other key data include CARDIO-TTRansform in ATTR cardiomyopathy and the HORIZON study of pelacarsen for Lp(a) reduction.
When RBC senior biotechnology analyst Luca Issi asked about the recently disclosed top-line results from Biogen’s tau program in Alzheimer’s disease, Kordasiewicz expressed genuine enthusiasm. She described the approach as a novel mechanism that uses an oligonucleotide to lower intracellular tau by blocking protein production—potentially offering a new way to tackle the disease.
She reported that Ionis’s Phase 1 study demonstrated robust reductions in cerebrospinal fluid tau and reversal of tau PET signals, calling it the first evidence of pathological tau clearance in an Alzheimer's brain. In the CELIA Phase 2 study disclosed by Biogen last week, Kordasiewicz noted that the biomarker findings were replicated and that cognitive endpoint benefits were also observed. “They are consistent with what has been seen with amyloid therapies and, in some cases, surpass it,” she said. The results met Biogen’s pre-specified criteria for advancing to Phase 3. Placebo performance appeared normal based on available biomarker and cognition data, and all doses showed benefit. More comprehensive data are expected at the Alzheimer’s Association International Conference (AAIC) in July.
Regarding TRYNGOLZA for severe hypertriglyceridemia, Kordasiewicz confirmed that discussions with regulators are on track ahead of the June 30 PDUFA date. Phase 3 efficacy data showed an 85% reduction in acute pancreatitis events among high-triglyceride patients, earning the therapy breakthrough therapy designation. When questioned about observed liver fat changes, Kordasiewicz clarified that Ionis does not view the finding as a safety signal and does not anticipate monitoring requirements, a REMS, or a boxed warning. She characterized it as an on-mechanism biomarker signal linked to rapid triglyceride lowering. Patients from CORE I and CORE II entering an open-label extension have been followed for over two years, with liver fat stabilizing and trending back toward baseline over time.
Kordasiewicz estimated that approximately 3 million patients in the U.S. have triglycerides above 500 mg/dL, with an initial focus on roughly 1 million high-risk individuals—those above 880 mg/dL and those above 500 mg/dL with a history of acute pancreatitis. Ionis set a wholesale acquisition cost of $40,000 after physician and payer research aimed at ensuring broad access. She also explained that peak revenue expectations for TRYNGOLZA have been raised from over $1 billion to more than $3 billion. The initial $2 billion projection was driven by demand research after Phase 3 results, while the subsequent increase to over $3 billion followed pricing analysis.
In Angelman syndrome, Kordasiewicz reported that the open-label HALO Phase 1 study showed improvements across motor, communication, and cognition domains, as measured by physician-administered, physician-reported, and parent-reported scales. Ionis is enrolling the Phase 3 REVEAL study and expects to complete enrollment this year, with a one-year primary endpoint reading out next year. She noted that Biogen had previously declined the program due to endpoint risk and a desire for more data, while Ionis regained rights as part of its strategy to build a neurology portfolio. Ionis is using expressive communication as the primary endpoint—a priority identified by caregivers—which showed the strongest early effect and most stable natural history in the company’s data. Ionis will monitor upcoming Ultragenyx data, particularly regarding placebo effects in Angelman syndrome over a one-year study period. Kordasiewicz estimated that about 100,000 individuals in the U.S. and major markets have Angelman syndrome, and said pricing would fall within the typical range for rare neurological diseases, though specifics are premature.
Discussing CARDIO-TTRansform in ATTR cardiomyopathy, Kordasiewicz noted that the study includes a contemporary patient population with 819 patients on tafamidis at baseline. However, the trial is not powered to show statistical significance for the add-on-to-tafamidis secondary analysis, which ranks sixth in the hierarchy. Expectations are based on prior silencer data, with any tafamidis findings representing potential upside. Regarding pelacarsen for Lp(a) reduction, she said the ongoing outcomes study is testing whether lowering the “largest untreated risk factor in cardiovascular disease” can yield clinical benefits. Feedback from key opinion leaders suggests a 10% to 15% relative risk reduction could support treatment, given human genetics linking Lp(a) to independent cardiovascular risk.
On zilganersen for Alexander disease, Kordasiewicz stated that Ionis achieved statistical significance on a clinically meaningful primary endpoint in an ultra-rare population and received breakthrough therapy designation. The disease is progressive, neurodegenerative, often fatal, and currently has no approved treatments. Ionis’s data showed stabilization on the motor endpoint, while secondary endpoints favored zilganersen. An expanded access program is open and enrolling.
Ionis Pharmaceuticals, Inc. is a biotechnology company focused on discovering and developing RNA-targeted therapies designed to modulate gene expression. Its proprietary antisense oligonucleotide (ASO) technology enables selective binding of short synthetic nucleic acid strands to messenger RNA (mRNA), thereby inhibiting or altering the production of disease-causing proteins. The pipeline spans neurological disorders, cardiovascular conditions, metabolic diseases, and rare genetic disorders.
This instant news alert was generated by narrative science technology and financial data from MarketBeat to provide readers with the fastest reporting and unbiased coverage. Please send any questions or comments about this story to [email protected].
The article "Ionis Pharmaceuticals Eyes Big Year With TRYNGOLZA Decision, 5 Phase 3 Readouts" was originally published by MarketBeat.
View MarketBeat's top stocks for May 2026.