California-based biotech Arrowhead Pharmaceuticals has emerged as one of 2025’s most remarkable turnaround stories, achieving a key milestone with the FDA approval of Redemplo (plozasiran) for adults with familial chylomicronemia syndrome (FCS), an ultra-rare genetic disorder marked by dangerously high triglyceride levels and recurrent pancreatitis.

The approval, granted on November 18, 2025, validates Arrowhead’s RNA interference (RNAi) technology in a commercial setting and establishes the company’s first recurring product revenue stream. In clinical trials, Redemplo significantly reduced triglyceride levels and lowered the risk of potentially life-threatening pancreatitis episodes compared to placebo.

While FCS affects only a few thousand people worldwide, rare disease therapies are often priced at a premium, and analysts project Redemplo could generate more than $1 billion in annual sales by the early 2030s. Arrowhead has also partnered with Sanofi for Greater China rights to Redemplo, further extending its global reach.

Following the FCS approval, the FDA granted Breakthrough Therapy designation to plozasiran for severe hypertriglyceridemia (SHTG), a condition affecting millions globally and associated with elevated cardiovascular and pancreatitis risks. This designation is designed to accelerate development and regulatory review for therapies that may significantly improve patient outcomes.

Arrowhead is conducting two Phase 3 trials for patients with dangerously high triglyceride levels and expects to complete these studies by mid-2026, aiming to expand Redemplo’s approved uses later that year. If successful, the therapy could reach a broader cardiometabolic population, dramatically enhancing its potential impact on patient health and the company’s growth trajectory.

The approval has also been met with investor enthusiasm. As of December 11, 2025, Arrowhead’s stock traded near $70 per share, up from the low $40s just a month ago, reflecting strong confidence in the company’s pipeline and RNAi platform.