Climb Bio reports 38% immunologic remission in kidney trial

Immunologic remission reached 38 per cent in the low-dose cohort as Climb Bio, Inc. NASDAQCLYM reported initial Phase 2 kidney-disease results on Saturday. The 200 mg group showed a mean 70 per cent reduction in disease-linked antibodies at 12 weeks.

PrisMN is testing budoprutug in primary membranous nephropathy, or pMN, at 200 mg, 600 mg and 1,000 mg, without a control group. Climb reported no treatment-related serious adverse events, adverse events leading to discontinuation, or deaths in the reported cohorts.

Climb is a small Massachusetts biotechnology developer working on antibody treatments for immune-mediated diseases. Its kidney programme aims to identify a dose for pivotal development.

Climb shares NASDAQCLYM closed at US$10.19 at 4:00 p.m. EDT on Oct. 23 in New York, before Saturday's announcement. Climb expects additional PrisMN data in 2027.

Five of 13 patients in the low-dose cohort achieved immunologic remission. The release did not provide a p value or confidence interval, and this early antibody response does not establish complete clinical remission.

The trial registry, updated Oct. 8, identifies treatment-emergent adverse events through week 48 as the primary endpoint. Complete remission and complete or partial remission at week 48 are secondary measures, alongside antibody levels, proteinuria and kidney function.

PrisMN plans to enrol about 45 adults across sequential, non-randomized dose cohorts. Patients must have disease-associated anti-PLA2R antibodies and persistent protein leakage into urine despite optimized background treatment.

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The higher-dose findings remain less mature: follow-up reached week 6 in the middle-dose cohort, compared with week 12 at the lowest dose. Most adverse events were mild or moderate.

At week 4, mean peripheral B-cell suppression was 98 per cent in the middle-dose group, compared with 74 per cent at the lowest dose. Climb said patients with substantial proteinuria cleared budoprutug faster, supporting evaluation of higher doses.

"The observed pharmacokinetics confirm that patients with pMN have increased clearance of budoprutug compared to patients who do not have proteinuria," Climb chief executive Aoife Brennan said in the release.

Budoprutug targets CD19-expressing B cells, including cells that produce disease-causing antibodies.

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Later-Stage Rivals Target Clinical Remission

Biogen Inc. NASDAQBIIB began its Phase 3 PROMINENT trial of felzartamab in June 2025. That study was designed to enrol about 180 adults and compare the anti-CD38 antibody with tacrolimus, using complete remission at week 104 as its primary endpoint. Biogen projected a readout in 2029.

Roche Holding AG SWXROP OTCMKTSRHHBY reported FDA priority review for Gazyva/Gazyvaro in pMN on July 15, with a decision expected by November 2026. Its MAJESTY trial reported complete remission in 36.9 per cent of treated patients versus 5.7 per cent with tacrolimus at two years.

Those clinical remission results cannot be compared directly with Climb's early immunologic remission rate because the studies measure different outcomes over different follow-up periods. Climb's later proteinuria and remission assessments will test whether the antibody changes accompany clinical improvement.

The broader iShares Biotechnology ETF NASDAQIBB closed at US$207.74 at 4:00 p.m. EDT on Oct. 23 in New York.

Climb held US$239.2 million in cash, equivalents and marketable securities at June 30. Its August financial update projected funding into the second half of 2028 under its operating plan.

The next PrisMN data are expected in 2027, while the registry estimates primary completion in October 2027. Longer follow-up and the highest-dose cohort will inform dose selection for Phase 3.