Zenas BioPharma Advances Phase 3 Orelabrutinib Trial in Progressive Multiple Sclerosis

Zenas BioPharma, Inc. (ZBIO) announced an update on their ongoing clinical study.

Zenas BioPharma (ZBIO) is running a phase 3 trial called “A Phase 3, Randomized, Double-blind, Efficacy and Safety Study Comparing Orelabrutinib to Placebo in Patients With Non-active Secondary Progressive Multiple Sclerosis.” The goal is to test if its oral drug orelabrutinib can slow disability in secondary progressive multiple sclerosis, a tough stage of the disease with few treatment options.

The study tests orelabrutinib, an oral drug that blocks a protein involved in immune cell activity. The drug is designed to reach the central nervous system and may reduce damaging immune activity that contributes to disease progression.

Patients are randomly assigned to get either orelabrutinib or a placebo pill once a day. The trial is double blind, which means patients, doctors, and key study staff do not know who gets which treatment, and the main aim is to see if the drug works and is safe.

The study is interventional and uses a parallel design, so two groups run side by side and are compared over time. About two thirds of participants receive orelabrutinib and one third receive placebo, and patients are expected to stay on treatment for at least one year and up to five years.

The sponsor submitted the study in December 2025, marking the formal launch of this late stage program. The planned primary completion and final completion dates will mark when key outcome data and long term safety data are ready, which are the main catalysts investors will watch.

The latest update was posted on March 17, 2026, confirming the study remains in the recruiting phase. This suggests site activation and enrollment are underway, which is an important sign of operational progress for a late stage asset.

For ZBIO, a positive phase 3 readout in secondary progressive multiple sclerosis could support a key value driver in neurology. Success would position the company in a competitive field with players like Roche and Novartis that are building multiple sclerosis portfolios.

The market tends to reward evidence of progress on large, unmet needs like secondary progressive multiple sclerosis. As the trial moves toward mid stage and late stage milestones, traders may start to price in probability of success or delays, which can add volatility to ZBIO’s stock.

Investors should also watch how this program fits into the wider group of drugs blocking the same target, as the class has drawn interest from big pharma. Strong data could create partnership, licensing, or acquisition interest if efficacy and safety stack up well against rivals.

This phase 3 trial of orelabrutinib in non active secondary progressive multiple sclerosis is ongoing and recently updated, and more detailed information is available on the ClinicalTrials portal.

To learn more about ZBIO’s potential, visit the Zenas BioPharma, Inc. drug pipeline page.