Syndax Pharmaceuticals (SNDX) FDA Announcement summary

Introduction and purpose

• FDA approved Niktimvo (axatilimab/axatilimab-csfr), the first-in-class/only anti-CSF1R therapy, for chronic GVHD after failure of at least two prior systemic therapies in adults and pediatric patients ≥40 kg.

• The approval addresses a significant unmet need for patients with refractory chronic GVHD, a debilitating disease affecting about 50% of allogeneic stem cell transplant recipients and about 17,000 U.S. patients.

• Represents a breakthrough for patients with limited treatment options and high unmet medical need.

Details of approval or decision

• Niktimvo is indicated for adult and pediatric patients (≥40 kg) with cGVHD after failure of at least two prior systemic therapies, dosed at 0.3 mg/kg (max 35 mg) every two weeks via IV infusion.

• FDA approval was based on the AGAVE-201 pivotal, multicenter, open-label trial enrolling heavily pre-treated cGVHD patients.

• Niktimvo is co-commercialized by Incyte and Syndax in the U.S.; Incyte leads with 70% of sales effort and holds rights outside the U.S.

• FDA reviewed the Biologics License Application under Priority Review.

• Initial commercial presentation is a 50mg vial; 9mg and 22mg vials are expected to launch in late 2024 or early 2025.

Impact on industry and stakeholders

• Niktimvo offers a differentiated mechanism and broad, durable responses in heavily pretreated patients, potentially expanding to earlier lines and other fibrotic diseases.

• The US third-line cGVHD market is estimated at $1.5–2 billion, with about 6,500 eligible patients and strong physician interest.

• Incyte and Syndax plan to launch additional vial sizes to facilitate dosing and reduce waste.

• The approval triggers a $12.5 million milestone payment and is part of a collaboration with up to $450 million in potential milestones.

• Comprehensive patient support and payor engagement initiatives are in place to ensure access and adherence.