AnaptysBio Outlines Plans for Spin-Off and Jemperli Royalty Surge

Biopharma company details timeline for separating into royalty and operating entities

Mar. 12, 2026 at 3:24am

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AnaptysBio CEO Daniel Faga provided an update on the company's planned separation into two entities, with the current parent retaining royalty interests and the operating biopharma business being spun out as First Tracks Bio. Faga discussed the expected timeline for the separation, the growing royalty stream from GSK's Jemperli, and the clinical and commercial rationale for the assets in First Tracks Bio, including the lead program ANB033 in celiac disease and eosinophilic esophagitis.

Why it matters

The separation into a royalty-focused company and an operating biopharma entity allows AnaptysBio to unlock value from its royalty streams, particularly the growing Jemperli royalty, while providing a focused vehicle to advance its pipeline of immunology and inflammation programs. The spin-off also comes as AnaptysBio is engaged in litigation with GSK over the development of Jemperli combinations.

The details

Faga said the separation is expected to be completed in approximately 45 days, with the current AnaptysBio retaining the Jemperli and imsidolimab royalty streams. He said the Jemperli royalty rate escalates up to 25% on sales above $2.5 billion, and could approach $400 million annually at peak sales of $2.7 billion. The spun-out First Tracks Bio will focus on advancing the lead program ANB033, a CD122 antagonist in development for celiac disease and eosinophilic esophagitis.

  • AnaptysBio filed a Form 10 for the separation last week.
  • The separation is expected to be completed in approximately 45 days, by the end of April.
  • Jemperli is expected to receive pivotal data in rectal cancer later in 2026, with a potential approval timeline of 1-2 months.
  • First Tracks Bio expects data from the phase 1b celiac disease study of ANB033 in Q4 2026.
  • First Tracks Bio expects eosinophilic esophagitis data for ANB033 in 2027.

The players

AnaptysBio, Inc.

A clinical-stage biotechnology company focused on the discovery and development of therapeutic antibody product candidates in immunology and inflammation.

Daniel Faga

The CEO of AnaptysBio.

First Tracks Bio

The new biopharma company that will be spun out from AnaptysBio, expected to trade under the ticker FSTX.

GSK

The pharmaceutical company that acquired the rights to AnaptysBio's Jemperli program.

Keytruda

Merck's PD-1 inhibitor that is being evaluated in combinations with GSK's antibody-drug conjugates.

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What they’re saying

“We must not let individuals continue to damage private property in San Francisco.”

— Robert Jenkins, San Francisco resident (San Francisco Chronicle)

What’s next

A decision on AnaptysBio's motion to dismiss GSK's counterclaim is expected within 60 days, and the trial for AnaptysBio's claims against GSK is scheduled for July 14.

The takeaway

AnaptysBio's planned separation into a royalty-focused company and an operating biopharma entity allows it to unlock value from its growing Jemperli royalty stream while providing a dedicated vehicle to advance its immunology pipeline, led by the promising celiac disease and eosinophilic esophagitis program ANB033.