POSITIVE RESULTS

Chemomab's nebokitug hits safety bar in PSC as sponsor merges to pivot into RA

The Phase 2 SPRING trial met its primary safety endpoint and showed biomarker improvement in primary sclerosing cholangitis, but Chemomab is folding into Scipher Medicine to chase a 2028 rheumatoid arthritis readout instead.

By AppliedXLJuly 8, 2026Trial NCT04595825

Executive Summary

Chemomab's antibody cleared its primary safety bar in a rare bile-duct disease and showed favorable biomarker movement over nearly a year of follow-up, giving the sponsor a positive readout after a program that ran years past its original guidance.
Rather than press the biomarker signal toward a Phase 3 in the disease it was designed for, the sponsor is merging with a precision-medicine diagnostics company and redirecting the same antibody into a rheumatoid arthritis trial that will not read out until 2028.
No other program targets the same chemokine in this disease, so the result carries no competitor benchmark; the broader field of rare cholestatic liver disease treatments is instead crowded with small-molecule bile-acid and PPAR-pathway drugs testing different mechanisms.
A safety endpoint met with biomarker improvement is not a demonstrated clinical benefit, and the sponsor's own regulatory plan leaves the confirmatory efficacy question to a future partner or Phase 3 that has not been funded or scheduled.

The readout

The Phase 2 SPRING trial (NCT04595825) enrolled 77 patients with primary sclerosing cholangitis (PSC), a rare disease that scars and narrows the bile ducts, and tested nebokitug, a monoclonal antibody that neutralizes the chemokine CCL24, against placebo. Chemomab reported the trial achieved its primary safety endpoint at 15 weeks, with a safety profile it characterized as favorable, and that inflammatory and fibrotic biomarkers improved through both the 15-week and 48-week observation windows. The primary measure was safety and tolerability rather than a clinical efficacy endpoint, so the result establishes that the antibody can be dosed without the safety signal that would stop further development, not that it changes disease course. NCT04595825+1

A delayed disclosure

The trial's registry history shows a program that moved considerably from its original design. Chemomab first targeted a 2022 primary completion date, pushed it to 2024-09-01 by March 2023, and the trial did not post results until July 2, 2026, more than three years after enrollment began in October 2020. Enrollment itself moved from 45 to 93 and settled at 77 patients across three separate revisions, and the trial's status flipped from Active-not-recruiting to Unknown status in February 2026 before returning to Active-not-recruiting two months later and then Completed. The result posted 1,285 days after the sponsor's original 2022 readout window closed, a gap that reflects a program that took years longer to disclose than initially guided rather than a data quality issue in the result itself. NCT04595825

The merger and the pivot

Chemomab announced the same day that it will merge with Scipher Medicine Corporation in a stock transaction, with the combined company operating as Scipher Medicine and trading under the ticker SCIP. The combined company's stated plan is to advance nebokitug into a Phase 2 trial in rheumatoid arthritis, using Scipher's AI Network Medicine platform to select patients likely to respond, with a topline readout expected in H1 2028. The disclosure describes the PSC data as supportive context for that pivot, citing nebokitug's favorable safety profile and biomarker activity, while any further PSC development is described only as a potential partnering opportunity, with no funded Phase 3 or defined timeline attached. Chemomab

The competitive field

No other industry trial has tested a CCL24-targeting agent in primary sclerosing cholangitis, and none of the target's few other clinical programs, run in asthma and related eosinophilic conditions by sponsors including GlaxoSmithKline, AstraZeneca, and Sanofi, address this indication. The PSC field itself is populated mostly by small-molecule bile-acid and PPAR-pathway candidates, including Ipsen's elafibranor and Dr. Falk Pharma's norucholic and norursodeoxycholic acid programs, none of which share nebokitug's mechanism. That isolation means the SPRING result has no direct mechanistic comparator to benchmark against, and the field's own difficulty is not established by any prior CCL24 x PSC failure, since none has occurred.

This analysis was produced using AI-assisted reporting systems, AppliedXL data, and official public records. These systems undergo editorial review, quality checks, and regular audits by human experts. Errors may still occur, as with any automated system. Always consult the linked primary sources. Read our AI Editorial Policy.