This section highlights FDA-related milestones and regulatory updates for drugs developed by Ionis Pharmaceuticals (IONS).
Over the past two years, Ionis Pharmaceuticals has reported clinical trial outcomes, regulatory submissions, approvals, and other FDA events for drugs and therapies such as
BIIB080/IONIS-MAPT, Donidalorsen, Eplontersen, ION373, ION582, Olezarsen, and Zilganersen. For definitions of regulatory abbreviations such as NDA, BLA, or PDUFA, see the event status legend.
BIIB080/IONIS-MAPT - FDA Regulatory Timeline and Events
BIIB080/IONIS-MAPT is a drug developed by Ionis Pharmaceuticals for the following indication: Mild Alzheimer's disease.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- BIIB080/IONIS-MAPT
- Announced Date:
- April 2, 2025
- Indication:
- Mild Alzheimer's disease
Announcement
Biogen Inc. announced that the U.S. Food and Drug Administration (FDA) has granted Fast Track designation to BIIB080, an investigational antisense oligonucleotide (ASO) therapy targeting tau, for the treatment of Alzheimer's disease.
AI Summary
Biogen Inc. announced that the U.S. Food and Drug Administration (FDA) has granted Fast Track designation to its investigational therapy BIIB080. This novel antisense oligonucleotide (ASO) is designed to target tau protein, which plays a key role in Alzheimer’s disease. Fast Track designation is granted to therapies that address serious conditions and unmet medical needs, allowing for a faster review process. Dr. Priya Singhal, Head of Development at Biogen, stated that the FDA’s decision underlines the urgent need for new treatments targeting tau pathology. BIIB080 is the first tau-targeting ASO to move into clinical development for Alzheimer’s disease and is currently being evaluated in a global Phase 2 study, offering hope for innovative treatment options to patients and their families.
Read Announcement
Donidalorsen (formerly IONIS-PKK-LRx) - FDA Regulatory Timeline and Events
Donidalorsen (formerly IONIS-PKK-LRx) is a drug developed by Ionis Pharmaceuticals for the following indication: Hereditary angioedema (HAE).
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- Donidalorsen (formerly IONIS-PKK-LRx)
- Announced Date:
- February 20, 2025
- Indication:
- Hereditary angioedema (HAE)
Announcement
Ionis Pharmaceuticals, Inc. announced that it will present additional data from the pivotal Phase 3 OASIS and OASISplus studies, as well as three year data from the Phase 2 open-label extension (OLE) study of donidalorsen, the company's investigational RNA-targeted prophylactic medicine for hereditary angioedema (HAE).
AI Summary
Ionis Pharmaceuticals recently announced that it will share new clinical data on donidalorsen—a promising RNA-targeted prophylactic medicine for hereditary angioedema (HAE). The company plans to present findings from its pivotal Phase 3 OASIS and OASISplus studies, as well as three-year data from a Phase 2 open-label extension study. These studies show that donidalorsen may help reduce the frequency of HAE attacks while significantly improving patients’ quality of life. Notably, the data suggest that patients switching from other prophylactic treatments experienced fewer attacks and felt better overall. In addition, the ease of donidalorsen administration, which can be done monthly or every two months using an autoinjector, offers a convenient treatment option. The data presentations are scheduled for the 2025 AAAAI/WAO Joint Congress in San Diego, California.
Read Announcement - Drug:
- Donidalorsen (formerly IONIS-PKK-LRx)
- Announced Date:
- May 31, 2024
- Indication:
- Hereditary angioedema (HAE)
Announcement
Ionis Pharmaceuticals, Inc. announced positive results from the Phase 3 OASIS-HAE and OASISplus studies of donidalorsen in patients with hereditary angioedema (HAE) demonstrating significant and sustained reduction in mean monthly HAE attack rates and continued attack rate improvement of >90% with one year of treatment for both monthly or every two-month dosing. Patients who switched to donidalorsen from prior prophylactic treatment also showed 62% further reduction in mean monthly HAE attack rates from baseline, and 84% of patients who switched reported a preference for donidalorsen.
AI Summary
Ionis Pharmaceuticals, Inc. announced positive results from its Phase 3 OASIS-HAE and OASISplus studies of donidalorsen for patients with hereditary angioedema (HAE). The studies showed that donidalorsen significantly reduced the mean monthly HAE attack rates, with more than 90% reduction observed over one year of treatment with both monthly and every two-month dosing. Patients experienced not only a sustained decrease in HAE attacks over time but also improvements in disease control and quality of life measures.
The results were especially notable in patients who switched from another prophylactic treatment. These individuals saw an additional 62% reduction in their monthly attack rates compared to their baseline measurements, and 84% of them preferred donidalorsen over their previous therapy. The drug also demonstrated a favorable safety and tolerability profile, making it a promising option for long-term HAE management.
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Eplontersen - FDA Regulatory Timeline and Events
Eplontersen is a drug developed by Ionis Pharmaceuticals for the following indication: Treatment for hereditary transthyretin-mediated amyloid polyneuropathy (ATTRv-PN).
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- Eplontersen
- Announced Date:
- March 10, 2025
- Indication:
- Treatment for hereditary transthyretin-mediated amyloid polyneuropathy (ATTRv-PN).
Announcement
Ionis Pharmaceuticals, Inc. announced that Ionis and AstraZeneca's WAINZUA (eplontersen) has been approved in the European Union (EU) for the treatment of hereditary transthyretin-mediated amyloidosis in adult patients with stage 1 or stage 2 polyneuropathy, commonly referred to as hATTR-PN or ATTRv-PN.
AI Summary
Ionis Pharmaceuticals, Inc. announced that its RNA-targeted medicine WAINZUA (eplontersen), developed with AstraZeneca, has been approved in the European Union for treating hereditary transthyretin-mediated amyloidosis in adults with stage 1 or stage 2 polyneuropathy (hATTR-PN or ATTRv-PN). This approval follows a positive opinion from the Committee for Medicinal Products for Human Use and is based on the NEURO-TTRansform Phase 3 trial. The trial demonstrated that over 66 weeks, patients receiving WAINZUA experienced consistent improvements in neuropathy impairment and quality of life compared to an external placebo. Notably, WAINZUA is the only approved treatment in the EU that can be self-administered monthly via an auto-injector, offering a convenient and effective option for patients managing this debilitating disease.
Read Announcement- Drug:
- Eplontersen
- Announced Date:
- May 23, 2024
- Indication:
- Treatment for hereditary transthyretin-mediated amyloid polyneuropathy (ATTRv-PN).
Announcement
Ionis Pharmaceuticals, announced that that it will present new subgroup analyses from Ionis and AstraZeneca's Phase 3 NEURO-TTRansform study of WAINUA™ (eplontersen) at the 2024 International Symposium on Amyloidosis (ISA) in Rochester, Minnesota, May 26-30. WAINUA was approved by the U.S. Food and Drug Administration (FDA) in December 2023 for the treatment of the polyneuropathy of hereditary transthyretin-mediated amyloidosis in adults, commonly referred to as hATTR-PN or ATTRv-PN.
AI Summary
Ionis Pharmaceuticals announced that it will present new subgroup analyses from the Phase 3 NEURO-TTRansform study of WAINUA™ (eplontersen) at the 2024 International Symposium on Amyloidosis in Rochester, Minnesota, from May 26-30. These analyses, conducted in collaboration with AstraZeneca, focus on the consistent benefits observed in neuropathy impairment and quality of life among various patient subgroups. WAINUA, which received FDA approval in December 2023, is approved for treating the polyneuropathy of hereditary transthyretin-mediated amyloidosis (hATTR-PN or ATTRv-PN) in adults. The presentation at the symposium highlights important data supporting the drug’s effectiveness across different segments, reinforcing its role in improving patient outcomes. This development is part of ongoing efforts to enhance treatment options for patients with this debilitating disease while continuing research to broaden the therapeutic impact of WAINUA in amyloidosis.
Read Announcement- Drug:
- Eplontersen
- Announced Date:
- May 23, 2024
- Indication:
- Treatment for hereditary transthyretin-mediated amyloid polyneuropathy (ATTRv-PN).
Announcement
AstraZeneca and Alexion, AstraZeneca Rare Disease, will showcase 14 studies, including real-world evidence (RWE), from their portfolio and pipeline of investigational amyloidosis therapies at the International Symposium on Amyloidosis (ISA), in Rochester, MN from May 26–30, 2024.
AI Summary
AstraZeneca and its Rare Disease division, Alexion, will present 14 studies at the 2024 International Symposium on Amyloidosis in Rochester, MN from May 26–30. The presentations include real-world evidence along with clinical data from studies on investigational therapies for amyloidosis. Among the showcased research, subgroup analyses from the Phase 3 NEURO-TTRansform study for WAINUA™ (eplontersen) highlight its use in treating polyneuropathy in patients with hereditary transthyretin-mediated amyloidosis.
The studies also feature additional investigational treatments like ALXN2220 and anselamimab that are being evaluated for ATTR and light chain amyloidosis. This comprehensive portfolio aims to deepen understanding of amyloidosis mechanisms and unmet treatment needs, reinforcing the companies’ commitment to advancing innovative therapy options for a broad range of amyloidosis patients.
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ION373 - FDA Regulatory Timeline and Events
ION373 is a drug developed by Ionis Pharmaceuticals for the following indication: Alexander disease.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- ION373
- Announced Date:
- July 18, 2024
- Indication:
- Alexander disease
Announcement
Ionis Pharmaceuticals, Inc. announced that that it has completed enrollment in the pivotal trial of zilganersen (ION373), an investigational RNA-targeted medicine in development for the treatment of children and adults with a rare, progressive and ultimately fatal neurological disorder known as Alexander disease (AxD).
AI Summary
Ionis Pharmaceuticals, Inc. announced that it has completed enrollment in the pivotal trial for zilganersen (ION373), an investigational RNA-targeted medicine being developed for Alexander disease (AxD). AxD is a rare, progressive condition that affects both children and adults, leading to severe neurological deterioration and a loss of motor and cognitive functions. The disease results from genetic variants in the GFAP gene, which lead to an abnormal buildup of protein in the brain.
This trial is a major step in testing a treatment that aims to slow or stabilize the progression of AxD by addressing its underlying cause. The study will evaluate improvements, including changes in walking speed using the 10-Meter Walk Test. Topline results are expected in the second half of 2025, marking an important milestone in the quest for a targeted therapy for this life-threatening condition.
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ION582 - FDA Regulatory Timeline and Events
ION582 is a drug developed by Ionis Pharmaceuticals for the following indication: Angelman syndrome.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- ION582
- Announced Date:
- June 11, 2025
- Indication:
- Angelman syndrome
Announcement
Ionis Pharmaceuticals, Inc. announced that Completion of enrollment anticipated in 2026
AI Summary
Ionis Pharmaceuticals, Inc. has announced a major milestone in its Phase 3 REVEAL study evaluating ION582 for Angelman syndrome. The global, randomized, double-blind, placebo-controlled trial is designed to assess the safety and efficacy of ION582, an investigational RNA-targeted antisense medicine, in children and adults with specific UBE3A gene mutations or deletions. A key detail from the announcement is that the completion of enrollment for this study is anticipated in 2026. During the 52-week treatment period, approximately 200 participants will be randomized to receive either ION582 or a placebo, followed by a long-term extension where eligible participants will receive ION582 for up to two years. The study aims to measure improvement, particularly in expressive communication, which is a challenging symptom for those with Angelman syndrome. This important effort reflects Ionis’s ongoing commitment to addressing the needs of underserved patient communities.
Read Announcement- Drug:
- ION582
- Announced Date:
- June 11, 2025
- Indication:
- Angelman syndrome
Announcement
Ionis Pharmaceuticals, Inc. announced that the first participant has been dosed in the global Phase 3 REVEAL study, which is designed to evaluate the efficacy and safety of ION582, an investigational medicine for the treatment of people living with Angelman syndrome (AS), a serious and rare neurodevelopmental disorder that leads to significant physical and cognitive impairments.
AI Summary
Ionis Pharmaceuticals, Inc. announced a major milestone as the first participant was dosed in its global Phase 3 REVEAL study. This study is testing the safety and effectiveness of the investigational medicine ION582 for people with Angelman syndrome (AS), a rare and serious neurodevelopmental disorder that causes significant physical and cognitive challenges.
The trial is a randomized, double-blind, and placebo-controlled study designed to enroll about 200 children and adults with AS who have a maternal UBE3A gene deletion or mutation. Over a 52‑week period, participants will be given quarterly doses of either ION582 or a placebo, and eligible patients will later have the chance to receive the drug for up to two additional years.
This important step reflects Ionis’s commitment to advancing new treatments for individuals with Angelman syndrome, who currently have no approved disease-modifying therapies.
Read Announcement- Drug:
- ION582
- Announced Date:
- July 22, 2024
- Indication:
- Angelman syndrome
Announcement
Ionis Pharmaceuticals, Inc announced positive results from the completed multiple ascending dose (MAD) portion of the Phase 1/2 open-label study of ION582 in people with Angelman syndrome (AS) demonstrating consistent and encouraging clinical improvement on measures assessing all functional domains including communication, cognition and motor function..
AI Summary
Ionis Pharmaceuticals has announced positive results from the multiple ascending dose portion of its Phase 1/2 open-label study of ION582 in people with Angelman syndrome. The study showed that ION582 provided robust and consistent benefits in communication, cognition, and motor function. According to the data, 97% of patients in the medium and high dose groups experienced meaningful overall symptom improvements as measured by the SAS-CGI-C, a tool that reflects clinical impressions. Clinical assessments using the Bayley-4 revealed improvements in key functional areas that exceeded those typically seen in natural history studies.
ION582 was well tolerated at all dose levels, further supporting its potential as a treatment for this rare neurodevelopmental disorder. These encouraging results have prompted Ionis to plan Phase 3 development in the first half of 2025, marking the treatment as a promising option for enhancing the lives of individuals with Angelman syndrome.
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Olezarsen (Formerly IONIS-APOCIII-L) - FDA Regulatory Timeline and Events
Olezarsen (Formerly IONIS-APOCIII-L) is a drug developed by Ionis Pharmaceuticals for the following indication: Severe hypertriglyceridemia.
This drug is approved by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- Olezarsen (Formerly IONIS-APOCIII-L)
- Announced Date:
- May 19, 2025
- Indication:
- Severe hypertriglyceridemia
Announcement
Ionis Pharmaceuticals, Inc. announced positive topline results from the Essence study of olezarsen in people with moderate hypertriglyceridemia (fasting triglycerides ≥150 mg/dL to <500 mg/dL) with or at risk for atherosclerotic cardiovascular disease (ASCVD).
AI Summary
Ionis Pharmaceuticals announced positive topline results from the Essence study, which evaluated olezarsen in nearly 1,500 people with moderate hypertriglyceridemia (fasting triglyceride levels between 150 mg/dL and less than 500 mg/dL) who have or are at risk for atherosclerotic cardiovascular disease. Participants, already on standard lipid-lowering therapies, received monthly doses of 50 mg or 80 mg of olezarsen. The study met its primary endpoint by showing a statistically significant 58% to 61% reduction in triglyceride levels compared to placebo at six months, with almost all patients achieving normal triglyceride levels below 150 mg/dL.
Olezarsen also met all key secondary endpoints and demonstrated a favorable safety and tolerability profile, with mainly mild injection site reactions reported. These encouraging results support the potential of olezarsen as a treatment option and contribute to the exposure database ahead of further pivotal trials for severe hypertriglyceridemia expected in 2025.
Read Announcement- Drug:
- Olezarsen (Formerly IONIS-APOCIII-L)
- Announced Date:
- December 19, 2024
- Indication:
- Severe hypertriglyceridemia
Announcement
Ionis Pharmaceuticals, Inc. announced that the U.S. Food and Drug Administration (FDA) has approved TRYNGOLZA™ (olezarsen) as an adjunct to diet to reduce triglycerides in adults with familial chylomicronemia syndrome (FCS), a rare, genetic form of severe hypertriglyceridemia (sHTG) that can lead to potentially life-threatening acute pancreatitis (AP).
AI Summary
Ionis Pharmaceuticals, Inc. announced that the U.S. Food and Drug Administration (FDA) has approved TRYNGOLZA™ (olezarsen) as an adjunct to diet for reducing triglycerides in adults with familial chylomicronemia syndrome (FCS). FCS is a rare genetic disorder that causes severe hypertriglyceridemia and can lead to acute pancreatitis, a life-threatening condition. The approval marks a breakthrough since TRYNGOLZA is the first treatment in the U.S. specifically aimed at significantly lowering triglyceride levels, thereby reducing the risk of dangerous pancreatitis episodes when used alongside a low-fat diet.
The medication is designed to be self-administered once a month via an auto-injector, offering patients a more manageable approach to managing their condition. Ionis Pharmaceuticals is optimistic that this approval will pave the way for further innovative treatments to help those affected by FCS.
Read Announcement- Drug:
- Olezarsen (Formerly IONIS-APOCIII-L)
- Announced Date:
- December 19, 2024
- Indication:
- Severe hypertriglyceridemia
Announcement
Ionis Pharmaceuticals, Inc. announced that that the U.S. Food and Drug Administration (FDA) has approved TRYNGOLZA™ (olezarsen) as an adjunct to diet to reduce triglycerides in adults with familial chylomicronemia syndrome (FCS), a rare, genetic form of severe hypertriglyceridemia (sHTG) that can lead to potentially life-threatening acute pancreatitis (AP).
AI Summary
Ionis Pharmaceuticals, Inc. announced that the U.S. Food and Drug Administration (FDA) has approved TRYNGOLZA™ (olezarsen) as an adjunct to diet for reducing triglycerides in adults with familial chylomicronemia syndrome (FCS). FCS is a rare genetic disorder that causes dangerously high triglyceride levels and can lead to life-threatening acute pancreatitis. With this approval, TRYNGOLZA becomes the first treatment in the U.S. specifically designed to manage FCS, offering a new option for patients who previously struggled with strict dietary restrictions.
The treatment is self-administered once a month using an auto-injector, and clinical trials have shown it significantly lowers triglyceride levels and reduces episodes of acute pancreatitis. This approval marks a significant advancement in the care for FCS patients, providing hope for improved quality of life and a reduction in serious, debilitating complications associated with the disease.
Read Announcement- Drug:
- Olezarsen (Formerly IONIS-APOCIII-L)
- Announced Date:
- June 25, 2024
- Indication:
- Severe hypertriglyceridemia
Announcement
Ionis Pharmaceuticals, announced that the U.S. Food and Drug Administration (FDA) has accepted for Priority Review the New Drug Application (NDA) for olezarsen, an investigational RNA-targeted medicine for the treatment of adults with familial chylomicronemia syndrome (FCS).
AI Summary
The U.S. Food and Drug Administration (FDA) has accepted for Priority Review the New Drug Application (NDA) submitted by Ionis Pharmaceuticals for olezarsen, an investigational RNA-targeted medicine aimed at treating adults with familial chylomicronemia syndrome (FCS). This rare and debilitating genetic disorder leads to extremely high triglyceride levels, increasing the risk of life-threatening acute pancreatitis episodes. With no approved treatments available, the FDA’s Priority Review designation highlights the urgent need for a new therapeutic option. The agency’s action date is set for December 19, 2024, which means a decision on olezarsen could be expected within the next six months. Ionis is partnering closely with the FDA during the review process, hoping that olezarsen will provide a much-needed treatment for patients suffering from this challenging condition.
Read Announcement- Drug:
- Olezarsen (Formerly IONIS-APOCIII-L)
- Announced Date:
- June 25, 2024
- Indication:
- Severe hypertriglyceridemia
Announcement
Ionis Pharmaceuticals, Phase 3 enrollment completed in CORE, CORE2 and ESSENCE evaluating olezarsen for the treatment of severe hypertriglyceridemia, with results expected in 2H 2025 –
AI Summary
Ionis Pharmaceuticals recently completed enrollment in three Phase 3 clinical trials—CORE, CORE2, and ESSENCE—designed to evaluate the investigational drug olezarsen for the treatment of severe hypertriglyceridemia. These studies focus on reducing dangerously high triglyceride levels that can lead to life-threatening complications such as acute pancreatitis. With enrollment now complete, the research teams are looking forward to analyzing the data, with results expected in the second half of 2025. The trials include patients with varying levels of elevated triglycerides, aiming to demonstrate whether olezarsen can offer a significant benefit for a condition that affects a large number of people in the United States. Ionis hopes that the outcomes will pave the way for a new treatment option that may address a critical need for patients suffering from severe hypertriglyceridemia.
Read Announcement- Drug:
- Olezarsen (Formerly IONIS-APOCIII-L)
- Announced Date:
- April 7, 2024
- Indication:
- Severe hypertriglyceridemia
Announcement
Ionis Pharmaceuticals, announced full results from the Phase 3 Balance study of Ionis' lead independent investigational medicine, olezarsen, for the treatment of adults with familial chylomicronemia syndrome (FCS).
AI Summary
Ionis Pharmaceuticals announced the full results of its Phase 3 Balance study evaluating olezarsen, an independent investigational medicine, for treating adults with familial chylomicronemia syndrome (FCS). The study showed that the 80 mg monthly dose of olezarsen met its primary endpoint by significantly reducing fasting triglycerides compared to a placebo. The treatment produced robust and sustained reductions in triglycerides and apolipoprotein C-III levels over a 12‐month period. Importantly, patients treated with olezarsen experienced far fewer acute pancreatitis events and all-cause hospitalizations than those who received the placebo.
These results, presented at the ACC 2024 and published in The New England Journal of Medicine, support olezarsen’s potential as a new treatment option for FCS—a rare and life-threatening disease with no approved therapies in the U.S. The promising safety and efficacy data encourage Ionis to pursue further regulatory approval for this breakthrough medicine.
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Zilganersen - FDA Regulatory Timeline and Events
Zilganersen is a drug developed by Ionis Pharmaceuticals for the following indication: for the treatment of children and adults Alexander disease (AxD).
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- Zilganersen
- Announced Date:
- October 1, 2024
- Indication:
- for the treatment of children and adults Alexander disease (AxD).
Announcement
Ionis Pharmaceuticals, announced that the U.S. Food and Drug Administration (FDA) has granted zilganersen Fast Track designation for the treatment of children and adults with an ultra-rare, progressive and ultimately fatal neurological disorder known as Alexander disease (AxD).
AI Summary
Ionis Pharmaceuticals has received Fast Track designation from the U.S. Food and Drug Administration (FDA) for zilganersen, an investigational medicine aimed at treating Alexander disease (AxD) in both children and adults. AxD is an ultra-rare, progressive neurological disorder that currently has no approved treatment and often leads to fatal outcomes. Zilganersen is designed to target the underlying process that causes harmful protein accumulation in brain cells, which contributes to the disease. By granting Fast Track designation, the FDA will help expedite the development and review of this promising treatment, addressing a critical unmet medical need for patients suffering from AxD. The pivotal Phase 1-3 study, conducted across 13 sites in eight countries, has already completed enrollment, and topline data is expected to be released in the second half of 2025.
Read Announcement
