April Bio Gains Momentum as Partner Evommune Files for NYSE Listing

April Bio (CEO Sang-hoon Cha) is drawing attention as its technology heads to the U.S. market. Expectations have risen sharply following its partner Evommune’s filing for a New York Stock Exchange (NYSE) listing, positioning April Bio’s proprietary SAFA platform for broader recognition in U.S. capital markets.

After the IPO announcement, April Bio shares surged on October 10, hitting a 52-week intraday high of $23.68 before closing at $24.07, up 12.07%, giving the company a market capitalization of approximately $540 million.

Evommune, which develops therapeutics for chronic inflammatory diseases, filed its NYSE listing on October 9. The number of shares and price range have not yet been disclosed. Morgan Stanley, Leerink Partners, Evercore ISI, and Cantor Fitzgerald will serve as joint bookrunners.

One of Evommune’s key assets, APB-R3 (EVO301), originated from April Bio and was licensed out last year in a deal worth up to US $475 million, including a US $15 million upfront payment and milestone-based proceeds. APB-R3 is a protein-based therapeutic designed to block the interleukin-18 (IL-18) inflammatory pathway using April Bio’s proprietary SAFA (Self-Activating Fc-fusion Approach) platform.

April Bio’s SAFA technology extends the half-life of protein therapeutics by fusing a Fab antibody fragment (SL335) to the drug, enabling high-affinity binding with serum albumin—a protein that naturally circulates in the bloodstream for long periods. This fusion allows therapeutics to remain active and stable in the body far longer than conventional biologics.

APB-R3 leverages this approach to maintain in-vivo stability of IL-18 binding protein (IL-18BP). By preventing IL-18 from attaching to its receptor and triggering excessive immune activation, the drug aims to suppress abnormal autoimmune responses.

The candidate is currently in a Phase 2 clinical trial for moderate-to-severe atopic dermatitis, with interim data expected in 1H 2026. The program was recently expanded to include ulcerative colitis (UC), suggesting promising early efficacy signals. Industry observers interpret this expansion as a positive indicator of internal trial progress.

Beyond Evommune, April Bio maintains a growing network of global partnerships. In 2021, the company licensed APB-A1 to Denmark-based Lundbeck in a deal worth about US $400 million.

APB-A1 targets CD40L (CD154), a surface protein involved in T-cell and B-cell communication. By interrupting this signaling pathway, the antibody therapy reduces inflammatory immune responses commonly seen in autoimmune diseases. The drug is now in a Phase 2 trial for Thyroid Eye Disease (TED), with potential extensions to multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), and myasthenia gravis (MG).

Both APB-R3 and APB-A1 are expected to deliver pivotal data in early 2026. Analysts suggest that favorable outcomes—combined with Evommune’s NYSE debut—could strengthen April Bio’s global credibility and significantly raise its corporate valuation.

An April Bio spokesperson commented, “Evommune’s U.S. listing underscores strong confidence in the clinical potential of APB-R3. Based on next year’s results and milestone inflows, we plan to reinvest aggressively in expanding our pipeline.”