Incyte Corporation (Incyte (INCY)) just dropped some promising data on a drug that could change the game for people with the most common inherited bleeding disorder. On Monday, the company reported complete Phase 1/2 results for latarcibart (formerly VGA039), showing it dramatically cut bleeding episodes and looked safe in patients with von Willebrand disease (VWD).

VWD affects about 1% of the population, making it the most common inherited bleeding disorder. It's caused by a deficiency or malfunction of von Willebrand factor, a blood protein that helps platelets stick together to form clots. Without enough working VWF, patients can experience everything from easy bruising to life-threatening bleeds.

The study included 16 patients, all of whom completed six doses of latarcibart, given as a subcutaneous injection every four weeks. The results were striking: a median 81% reduction in annualized bleeding rate (ABR) across all VWD types and bleeding categories. That includes serious gastrointestinal bleeds and hemophilia-like joint and muscle bleeds, which are particularly tough to manage.

For patients who switched from intravenous VWF-containing prophylaxis—the current standard of care—bleed reductions ranged from 75% to 100%. That suggests latarcibart might actually be better than what's available now. For patients who hadn't been on IV prophylaxis before, seven entered the study with historical ABRs above 12 (a key threshold for the ongoing Phase 3 trial). In that group, ABR reductions ranged from 46% to 100%, with six of the seven patients seeing reductions greater than 73%.

Latarcibart also cut down on the need for rescue therapy. It reduced VWF-treated breakthrough bleeds by about 86%, and 70% of patients who previously needed VWF for breakthrough bleeding had zero such events while on the drug. Every single patient who entered the study with a significant bleeding burden chose to continue treatment in the open-label extension study—a strong vote of confidence.

Safety-wise, the drug looked clean. Investigators recorded only three treatment-emergent adverse events related to latarcibart: two Grade 2 headaches in one patient and one Grade 1 injection-site reaction. One serious adverse event—severe gastrointestinal bleeding—occurred in a patient with a history of frequent and severe GI bleeds, but it was deemed unrelated to the drug.

Latarcibart works by targeting Protein S to improve hemostasis (the process that stops bleeding). It's now in a pivotal Phase 3 trial called VIVID-6. If approved, it would be the first once-monthly subcutaneous prophylactic treatment for VWD, offering a much more convenient alternative to frequent intravenous replacement factor infusions.

Incyte picked up the drug in July 2026 through its acquisition of Vega Therapeutics Inc., a wholly owned subsidiary of Star Therapeutics LLC. The deal was worth $1.25 billion upfront, signaling Incyte's confidence in the asset.

As for the stock, Incyte shares were down 0.61% at $116.00 in premarket trading on Monday, according to market data. But with data like this, investors might be looking beyond the daily noise.