Arrowhead shares surge 28 per cent on plozasiran trial data ahead of FDA filing
Investors bid Arrowhead Pharmaceuticals Inc. shares to a record high of $95.49 as the company prepares to submit a supplemental new drug application for plozasiran to treat severe hypertriglyceridemia.
Arrowhead Pharmaceuticals Inc. (NASDAQ: ARWR) shares surged up to 28 per cent to a record intraday high of $95.49 on 22 July 2026. The rally was driven by investor positioning ahead of the company’s planned submission of a supplemental new drug application (sNDA) to the US Food and Drug Administration (FDA) for plozasiran. The sNDA seeks approval for plozasiran to treat severe hypertriglyceridemia, an expansion of its current indication for familial chylomicronemia syndrome (FCS).
The price movement followed the release of strong results from two phase 3 clinical trials for the drug candidate. In these studies, a 25 mg dose of plozasiran administered once every three months reduced triglyceride levels by 79 per cent and 81 per cent, respectively, compared with a 27 per cent reduction in the placebo group. The treatment also reduced the overall number of acute pancreatitis cases by 78 per cent among patients with severe high triglycerides.
Arrowhead reported that plozasiran maintained a favourable safety profile with no major new safety concerns, side effects, or serious immune or blood platelet problems. The company intends to submit the sNDA to the FDA before the end of 2026, citing the robust data from the late-stage trials.
Plozasiran, also known as Redemplo, was previously approved by the FDA in November 2025 to treat patients with familial chylomicronemia syndrome. FCS is a rare genetic disorder affecting approximately 6,500 people in the US, characterised by triglyceride levels that can rise 10 to 100 times higher than normal. This elevation significantly increases the risk of acute, recurrent, and potentially fatal pancreatitis. Regulatory approvals for plozasiran to treat FCS have also been granted in Europe, Australia, and Canada.
Despite the positive clinical data and share price surge, hedge fund conviction in Arrowhead appears to have softened. Data from Insider Monkey indicates that while 53 hedge funds held positions in the stock, unchanged from the previous quarter, the value of their combined holdings declined by 8.9 per cent to $1.74 billion from $1.91 billion. This suggests that institutional investors are maintaining limited positions while awaiting further developments.
Arrowhead is scheduled to announce third-quarter earnings for the period ending 30 June 2026 after market close on 4 August 2026, accompanied by a conference call. The company will also present detailed results from the phase 3 trials at the ESC 2026 on 30 August 2026.
