Zenas BioPharma (ZBIO) presented an updated view of its capital position and clinical pipeline at the Morgan Stanley 24th Annual Global Healthcare Conference on Monday, highlighting a cash runway that extends through the second quarter of 2029 provided obexelimab receives FDA approval.
The company ended the second quarter with approximately $674 million in cash and a current ratio of 9.93. Management said additional milestone tranches would unlock if obexelimab is approved for IgG4-related disease (IgG4-RD): $75 million from Royalty Pharma and a further $75 million tranche from Pharmakon under the terms of its existing loan agreement.
Obexelimab's priority review cutoff date for the IgG4-RD indication is set for late May 2025. Zenas expects mid-cycle review data in early November, late-cycle review in March, and label feedback in April 2025. Clinical data from the Phase III program will be presented at the IgG4-RD Biennial Symposium and the American College of Rheumatology meeting in late October and November 2024. The Phase II-B study in systemic lupus erythematosus (SLE), sponsored by SunStone, is expected to report results by year-end 2024.
The Phase III trial met its primary endpoint and all key secondary endpoints. Open-label extension data showed 92% protection from disease flare at six months. Serious adverse events and Grade 3 infections were lower in the obexelimab arm compared with placebo.
Zenas estimated the addressed patient population in the U.S. at roughly 20,000 diagnosed and treated individuals, with a total addressable market of 30,000 to 40,000 patients. About 10,000 to 12,000 require chronic therapy due to frequent flares. Using the annual cost of Efgartigimod alfa (UPLIZNA) at $300,000 — with first-year costs noted at $450,000 — management calculated a domestic market opportunity of approximately $3 billion for obexelimab.
Survey data presented at the conference showed 43% of clinicians favored weekly subcutaneous dosing versus just 5% who preferred six-month intravenous infusions. Seventy-five percent of patients indicated a preference for self-administered subcutaneous injections. Approximately half of IgG4-RD patients are over age 65, and more than one-third have concurrent illnesses.
On the pipeline front, ZB021, an oral IL-17 inhibitor, is expected to report initial clinical data by year-end 2024. ZB022, a brain-penetrant TYK2 inhibitor, is projected to enter the clinic in 2025, with single- and multiple-dose data also expected that year. Orelabrutinib, licensed from InnoCare in October 2023, has two global Phase III trials underway in progressive multiple sclerosis.
The company's SLE study uses an all-comer design with biomarker subpopulation analysis, targeting BICLA as its primary endpoint alongside SRI4 results. Screen failure rates are expected to exceed 50%.
