Zenas acquires BTK inhibitor in Phase 3 trials for progressive MS
Phase 3 trial in SPMS expected to start in early 2026
Zenas Biopharma has acquired global rights to develop the BTK inhibitor orelabrutinib to treat multiple sclerosis (MS) and other diseases.
The deal with orelabrutinib’s developer, Innocare Pharma, includes rights to two other investigational therapies.
Zenas will pay Innocare up to $100 million in cash and up to 7 million common shares in upfront and near-term payments. The agreement includes the potential for more than $2 billion in long-term milestone payments, as well as royalties on sales if any of the therapies is approved.
“This strategic collaboration will leverage our shared focus to accelerate the development of orelabrutinib and help maximize its clinical and commercial potential on a global scale, particularly in MS,” Jasmine Cui, PhD, co-founder, chairwoman, and CEO of Innocare, said in a press release from the two companies.
The deal comes shortly after Innocare launched a Phase 3 clinical trial (NCT07067463) to test orelabrutinib in people with primary progressive MS (PPMS). That study is expected to enroll about 705 adults, ages 18 to 60, who will be randomly assigned to take a daily, 80 mg dose of orelabrutinib or a placebo for up to 120 weeks, or nearly 2.5 years.
Company sees ‘tremendous opportunity’ for therapy in PPMS, SPMS
The trial’s main goal is to determine whether the therapy can delay 12-week confirmed disability progression, or an increase in disability levels that’s sustained for at least 12 weeks. Other measures of progression will be assessed as secondary goals.
Having secured rights to orelabrutinib for MS, Zenas is now planning a second Phase 3 trial to test the therapy against a placebo in people with secondary progressive disease (SPMS). That trial is expected to start early next year.
“We are prioritizing the tremendous opportunity ahead with orelabrutinib in PPMS and SPMS,” said Lonnie Moulder, founder and CEO of Zenas.
MS is marked by inflammation that damages healthy cells in the brain and spinal cord. Bruton’s tyrosine kinase (BTK) is an enzyme that’s integral to the inflammatory activity of certain immune cells, including B-cells and microglia, that play key roles in driving MS.
By blocking BTK, orelabrutinib aims to tamp down disease-driving inflammation, including the chronic brain inflammation that’s thought to contribute to the gradual progression of disability seen in people with progressive forms of MS.
“BTK inhibition is a validated mechanism for the treatment of progressive forms of MS, and there is immense scientific interest in its potential to impact inflammation compartmentalized in the [brain and spinal cord] and thereby potentially impact disability progression independent of relapse activity,” said Lisa von Moltke, MD, Zenas’ head of research and development and chief medical officer.
”Orelabrutinib has the potential to transform the treatment paradigm for this devastating disease.”
“We believe the differentiated, potentially best-in-class profile of orelabrutinib could make a meaningful difference for patients with PPMS and SPMS, which have few treatment options. With our late-stage development capabilities and expertise in MS, we are well positioned to execute on the pivotal, global, Phase 3 development of orelabrutinib,” von Moltke said.
An earlier Phase 2 trial (NCT04711148) tested orelabrutinib against a placebo in more than 150 people with relapsing-remitting MS (RRMS), and results indicated the therapy was highly effective in reducing signs of disease activity on MRI scans.
“Given the statistically significant and clinically meaningful data from the Phase 2 trial … orelabrutinib has the potential to transform the treatment paradigm for this devastating disease,” Cui said.
The acquisition of orelabrutinib expands Zenas’ pipeline of investigational MS therapies. The company is also developing obexelimab, a treatment for relapsing forms of MS. A Phase 2 study called MoonStone (NCT06564311) is testing obexelimab in relapsing MS patients, with results expected in the coming months.
“We expect to report obexelimab topline 12-week primary endpoint results from the Phase 2 MoonStone trial in patients with [relapsing MS] early in the fourth quarter of 2025 and 24-week data in the first quarter of 2026,” Moulder said. “We anticipate making a program decision based on these data and the evolving landscape for the development of new therapies for [relapsing MS] in early 2026.”
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