Ionis Pharmaceuticals Shares Surge 34.84% on Landmark Olezarsen Trial Results Trading Volume Hits $910M After 1765% Spike

Ionis Pharmaceuticals (IONS) surged 34.84% on Sept. 2, with a trading volume of $0.91 billion, a 1765.18% increase from the prior day. The stock’s rally followed the release of pivotal Phase 3 trial data for olezarsen, a treatment for severe hypertriglyceridemia (sHTG). The drug demonstrated a placebo-adjusted 72% reduction in fasting triglycerides and an 85% reduction in acute pancreatitis events, marking the first therapy to achieve such outcomes for sHTG. The studies, involving nearly 1,100 patients, showed favorable safety and tolerability, with injection site reactions being the most common adverse event. Ionis plans to submit a supplemental new drug application by year-end.

Olezarsen’s results position Ionis to address a significant unmet need in sHTG treatment, a condition affecting 3 million U.S. patients. The drug’s mechanism targets apoC-III, a liver-produced protein linked to triglyceride metabolism. Over 90% of participants in the trials chose to continue into an open-label extension, underscoring patient confidence. The webcast scheduled for Sept. 2 at 8:30 a.m. ET will provide further details on the data. Additionally, olezarsen’s safety profile aligns with its potential for broader adoption in high-risk populations.

Ionis highlighted the potential for olezarsen to become its third independent launch in under two years, with approval expected to expand access to a prevalent patient population. The company’s leadership emphasized the transformative impact of the therapy, particularly for those with recurrent acute pancreatitis risks. The data reinforce Ionis’ focus on RNA-targeted medicines and its pipeline in cardiometabolic diseases.

Backtesting of olezarsen’s Phase 3 data showed consistent efficacy across 80 mg and 50 mg doses, with both achieving statistically significant reductions in triglycerides (p<0.0001). The 85% reduction in pancreatitis events (p=0.0002) was observed in a pooled analysis of placebo groups over 12 months. Safety outcomes remained balanced, with serious adverse events less frequent in treatment groups. These results support the drug’s potential to redefine sHTG management if regulatory clearance is granted.