Ionis Pharmaceuticals (IONS) Stock News

Ionis (Nasdaq: IONS) announced that the U.S. FDA granted Breakthrough Therapy designation to zilganersen for Alexander disease (AxD), a rare, progressive neurological disorder with no approved disease-modifying treatments.

The FDA decision is supported by pivotal study topline results: zilganersen 50 mg improved 10-Meter Walk Test gait speed by 33.3% versus control (p=0.0412) at week 61, with favorable safety and consistent secondary endpoint benefits. Ionis plans an NDA submission in Q1 2026 and is working to start a U.S. Expanded Access Program.

Ionis said this designation may expedite review and follows a recent Breakthrough Therapy designation for another program, underscoring the company’s late-stage pipeline focus.

Ionis (Nasdaq: IONS) announced that the U.S. FDA granted Breakthrough Therapy designation to olezarsen for use as an adjunct to diet to reduce triglycerides in adults with severe hypertriglyceridemia (sHTG; TG ≥500 mg/dL) on December 1, 2025.

The designation is based on Phase 3 CORE and CORE2 results showing up to 72% placebo‑adjusted triglyceride reduction, an 85% reduction in acute pancreatitis events, and nearly 90% of treated patients achieving TG <500 mg/dL. Data were published in The New England Journal of Medicine and presented at AHA. Ionis said it is on track to submit a supplemental new drug application to the FDA by the end of the year.

Ionis Pharmaceuticals (Nasdaq: IONS) and Otsuka announced the CHMP has adopted a positive opinion for DAWNZERA (donidalorsen) for routine prevention of hereditary angioedema (HAE) in adults and adolescents aged 12 and older.

The opinion is now with the European Commission, with a decision expected in Q1 2026. CHMP based its recommendation on Phase 3 OASIS-HAE and OASISplus results showing a significant, sustained reduction in mean monthly HAE attack rate, including with autoinjector self-administration. DAWNZERA received FDA approval in August 2025.

Ionis (NASDAQ: IONS) priced $700.0 million aggregate principal of 0.00% convertible senior notes due 2030, with an underwriter option for an additional $70.0 million. The offering is expected to close on November 17, 2025, with estimated net proceeds of approximately $682.8 million (or $751.2 million if the option is exercised).

Ionis expects to use about $267.6 million of net proceeds to repurchase $200.0 million aggregate principal of its 0% convertible notes due 2026 via concurrent repurchase transactions and the remainder for additional repurchases, repayment at maturity, and general corporate purposes. Initial conversion rate is 10.1932 shares per $1,000 (approx. $98.10 per share), a ~35.0% premium to the Nov 12, 2025 share price. Notes mature Dec 1, 2030 and are non‑interest bearing.

Ionis (Nasdaq: IONS) announced management will participate in investor fireside chats at two upcoming conferences: the Stifel 2025 Healthcare Conference on Thursday, November 13, 2025 and the Jefferies Global Healthcare Conference on Tuesday, November 18, 2025.

A live webcast of both presentations will be available on the company's Investors & Media website and replays will be posted within 48 hours; replays will be archived for a limited time.

Ionis (NASDAQ: IONS) announced on November 11, 2025 a proposed private placement of $700.0 million aggregate principal amount of Convertible Senior Notes due 2030, with an initial purchaser option for up to an additional $70.0 million. The notes will be unsecured, pay interest semiannually, and on conversion may be settled in cash, shares, or a combination at Ionis’ election. The offering is to qualified institutional buyers under Rule 144A.

Use of proceeds: Ionis expects net proceeds to be used to repurchase or repay its 0% Convertible Senior Notes due 2026, including possible concurrent negotiated repurchases, with any remainder for general corporate purposes. Pricing, interest rate, and conversion rate will be determined at pricing.

Ionis (Nasdaq: IONS) reported positive pivotal Phase 3 CORE and CORE2 results for olezarsen in severe hypertriglyceridemia (sHTG) on November 8, 2025. In nearly 1,100 patients, olezarsen achieved up to a 72% placebo-adjusted mean reduction in fasting triglycerides at six months with sustained reductions to 12 months.

Key outcomes: 86% of treated patients reached TGs <500 mg/dL; adjudicated acute pancreatitis events fell by 85% (p<0.001); NNT=20 overall, NNT=4 in highest-risk subgroup. Data were presented at AHA and published in NEJM. Ionis plans an FDA supplemental NDA submission by year-end and will host a webcast Nov 8 at 3:00 p.m. ET.

Ionis (Nasdaq: IONS) announced long-term clinical data for DAWNZERA (donidalorsen) presented at ACAAI 2025 showing durable HAE control and a favorable safety profile.

Key results: in the OASISplus open-label extension at Week 52 DAWNZERA showed a 94% (Q4W, n=69) and 95% (Q8W, n=14) mean HAE attack rate reduction from baseline; the OASISplus switch cohort (n=64) achieved a 68% improvement versus prior prophylaxis at one year. Phase 2 OLE reported a 97% mean attack reduction over four years, median attack-free interval of 2.7 years, and 71% attack-free >1 year. Safety: most TEAEs were mild/moderate, no serious TEAEs related to DAWNZERA; hypersensitivity including anaphylaxis is a listed risk.

Ionis (Nasdaq: IONS) reported Q3 2025 results and program updates on October 29, 2025. Total revenue was $157M in Q3 (+17% YoY) and $740M year-to-date (+55% YoY). TRYNGOLZA net product sales were $32M in Q3 and $57M YTD; WAINUA sales generated $59M in Q3. The company raised full-year 2025 guidance to $875–900M revenue and increased TRYNGOLZA sales guidance to $85–95M. Non-GAAP operating loss guidance was tightened to $275–300M, and cash was confirmed at > $2.1B.

Clinical and regulatory highlights: olezarsen Phase 3 showed up to 72% triglyceride reduction and 85% reduction in acute pancreatitis events (sNDA on track by year-end); zilganersen met its pivotal endpoint (10MWT mean difference 33.3%) with NDA planned Q1 2026; DAWNZERA U.S. launch underway.