Annexon Reports $206.7 Million Net Loss for 2025, Driven by Increased Operating Expenses

Annexon, Inc. reported a net loss of $206.7 million for the year ended December 31, 2025, compared to a net loss of $138.2 million for the previous year. The increased loss was primarily driven by higher operating expenses, which totaled $216.4 million in 2025, a 40% increase from $154.1 million in 2024. Research and development expenses accounted for the largest portion of operating expenses, increasing by 55% to $184.7 million, due to advancements in the company's late-stage clinical programs. Interest and other income, net, decreased by 39% to $9.7 million, reflecting lower average cash and investment balances.

The company's research and development expenses were significantly impacted by several factors. Clinical and nonclinical outside service costs increased by 58% to $59.8 million, primarily related to the Phase 3 ARCHER II trial for vonaprument in geographic atrophy and the initiation of the FORWARD study for tanruprubart in Guillain-Barré Syndrome. Contract manufacturing expenses also saw a substantial increase of 133%, reaching $47.5 million, as the company prepared for global regulatory submissions for tanruprubart and transferred manufacturing technology for vonaprument to a commercial-ready facility. Compensation and personnel-related expenses within research and development rose by 28% to $45.5 million, driven by increased headcount.

General and administrative expenses decreased by 8% to $31.7 million, primarily due to ongoing corporate efficiencies and disciplined resource allocation. Consulting and professional services costs decreased by $2.6 million, and compensation and personnel-related expenses decreased by $1.2 million due to the full amortization of previously granted stock options. These decreases were partially offset by a $0.9 million increase in other expenses related to cloud-based infrastructure costs.

Looking ahead, Annexon plans to continue advancing its late-stage registrational programs for tanruprubart and vonaprument, as well as developing ANX1502, a novel oral small molecule for autoimmune conditions. The company anticipates reporting topline data from the Phase 3 ARCHER II trial in the fourth quarter of 2026 and plans to engage with the FDA with the goal of reaching alignment on its data package for tanruprubart in GBS for submission of a BLA in 2026. As of December 31, 2025, Annexon had cash and cash equivalents and short-term investments of $238.3 million, which it expects to fund operating expenses into the second half of 2027.