Developer · IONS · United States
Ionis Pharmaceuticals, Inc.
Ionis Pharmaceuticals is a commercial-stage biotechnology company that discovers and develops RNA-targeted (antisense oligonucleotide) medicines for neurological, rare and cardiometabolic diseases. It is headquartered in Carlsbad, California.
Pipeline (1)
- Amyotrophic lateral sclerosisPhase 3Active
Deals & partnerships
- Nov 22, 2024Licensing dealOtsuka obtains exclusive worldwide license to ulefnersen (ION363) from IonisOtsuka entered an exclusive worldwide licensing agreement for rights to develop, manufacture and market ulefnersen (ION363), Ionis' antisense candidate for FUS-ALS. Terms include a $10 million upfront payment to Ionis plus regulatory/sales milestones and royalties; Ionis remains the discoverer and developer while Otsuka leads regulatory filings, manufacturing and commercialization globally.
Catalysts · 1 upcoming · 1 reported
- second half 2026Anticipated
Ulefnersen (ION363)forAmyotrophic lateral sclerosisTopline data
FUSION Phase 3 (ulefnersen vs placebo in FUS-ALS) — estimated primary completion in 2H 2026; would be the first controlled readout for a FUS-ALS therapy.
Recently reported
- 2025-06-07mixed
Ulefnersen (ION363)forAmyotrophic lateral sclerosisFull results
Lancet case series (n=12, investigator-initiated): jacifusen reduced CSF neurofilament light chain by up to 82.8% at 6 months; one participant showed objective functional recovery, another remained asymptomatic — but two deaths (deemed unrelated) and uncontrolled design temper interpretation.
Recent activity
- Aug 12, 2025Phase changeUlefnersen (ION363)·Amyotrophic lateral sclerosisPhase 3Ionis announced FUSION completed enrollment: 89 participants across ~25 sites in 16 countries; estimated primary completion 2H 2026.source ↗
- Jun 7, 2025ReadoutUlefnersen (ION363)·Amyotrophic lateral sclerosismixedLancet case series (n=12, investigator-initiated): jacifusen reduced CSF neurofilament light chain by up to 82.8% at 6 months; one participant showed objective functional recovery, another remained asymptomatic — but two deaths (deemed unrelated) and uncontrolled design temper interpretation.source ↗
- Nov 22, 2024Phase changeUlefnersen (ION363)·Amyotrophic lateral sclerosisPhase 3Otsuka obtained exclusive worldwide license from Ionis to develop and commercialize ulefnersen ($10M upfront plus milestones/royalties); Ionis continues FUSION with Otsuka cost reimbursement from 2025.source ↗
- Jun 14, 2021Phase changeUlefnersen (ION363)·Amyotrophic lateral sclerosisPhase 3Ionis initiated the pivotal Phase 3 FUSION trial (NCT04768972) of ION363 in FUS-ALS (randomized, double-blind, placebo-controlled).source ↗
- Jun 1, 2019Phase changeUlefnersen (ION363)·Amyotrophic lateral sclerosisPreclinicalFirst human dosing as 'jacifusen' under FDA compassionate/expanded access (single patient, Jaci Hermstad, FUS P525L), expanding into an investigator-initiated case series (Columbia; Shneider et al.).source ↗
