Climb Bio, Inc.'s SEC filings document a Nasdaq-listed clinical-stage biotechnology company developing therapeutics for immune-mediated diseases. The filings cover operating and financial results, Regulation FD pipeline disclosures, material-event reports and capital-structure information for common stock listed under the symbol CLYM.
Company filings also describe budoprutug and CLYM116 development disclosures, financing arrangements, executive and accounting officer changes, and governance matters presented in proxy materials. Proxy disclosures address director elections, auditor ratification, charter amendments, equity incentive plan provisions, stockholder voting procedures and other annual meeting matters.
Four reporting persons each report beneficial ownership of 3,070,000 Climb Bio, Inc. (CLYM) common shares: Deerfield Mgmt, L.P., Deerfield Management Company, L.P., Deerfield Partners, L.P. and James E. Flynn. The shares are held by Deerfield Partners, L.P.; Deerfield Mgmt, L.P. is its general partner, and Deerfield Management Company, L.P. is its investment advisor. Each reports 5.25% ownership and shared voting and dispositive power.
Climb Bio, Inc. (CLYM) is the issuer of common stock for which BlackRock, Inc. reported beneficial ownership of 2,895,165 shares, or 5.0% of the class, as of September 30, 2026. BlackRock reported sole voting power over 2,831,010 shares and sole dispositive power over 2,895,165 shares, with shared voting and dispositive power of zero.
The reported position reflects securities attributed to certain BlackRock business units and its subsidiaries and affiliates; it excludes securities attributed to business units whose ownership is disaggregated. Various persons have rights to receive dividends or direct proceeds from sales of the shares, but BlackRock stated that no one person's interest is more than 5% of Climb Bio's outstanding common shares.
Climb Bio, Inc. reported initial Phase 2 PrisMN results for budoprutug in primary membranous nephropathy (pMN), alongside a minimal change disease (MCD) case study presented at ASN Kidney Week 2026. In the 200 mg cohort, mean PLA2R antibody levels fell 70% at Week 12, and 5 of 13 patients (38%) achieved immunologic remission; patients with baseline PLA2R antibody levels below 175 RU/mL had a mean reduction of 80%.
Initial 600 mg data showed mean peripheral CD20+ B-cell suppression of 98% at Week 4, compared with 74% at 200 mg. A population pharmacokinetic analysis across budoprutug studies (n≈120) found that patients with high proteinuria (median UPCR 6.8 g/g) clear budoprutug ≥2-fold faster than non-proteinuric individuals. Treatment was generally well tolerated in the 200 mg and 600 mg cohorts, with follow-up through Week 12 and Week 6, respectively; most adverse events were Grade 1 or 2, with no treatment-related serious adverse events, adverse events leading to treatment discontinuation or deaths reported. Enrollment in the 1000 mg cohort is ongoing, with additional PrisMN data anticipated in 2027. A separate MCD case described one patient's three-year steroid-free remission after 100 mg budoprutug; the patient remained in remission for one year following B-cell reconstitution.
Climb Bio, Inc. (CLYM) and Beijing Mabworks Biotech Co., Ltd. reported additional Phase 1 results for CLYM116/MIL116, an anti-APRIL antibody being developed for IgA nephropathy. Two randomized, double-blind, placebo-controlled ascending-dose studies in healthy volunteers enrolled 46 participants in Australia and 42 in China. A single subcutaneous dose of 480 mg or higher produced at least 90% free APRIL suppression through 12 weeks; after an 800 mg dose, Gd-IgA1 was reduced approximately 70% and IgA approximately 60% at week 12. Exposure was linear, with no target-mediated drug disposition observed at doses of 160 mg or higher. The estimated half-life was approximately 33 days, based on the 800 mg dose and 320 mg multiple-ascending-dose cohort.
Climb Bio reported no treatment-related serious adverse events, dose-limiting toxicities or hypogammaglobulinemia. Injection-site reactions occurred in 5 of 88 participants; all were Grade 1 and resolved without intervention. Climb Bio is enrolling patients in the NAVIGATE-2 Phase 2 trial to evaluate every-12-week dosing, with initial data expected in the first half of 2027.
Climb Bio, Inc. reported exercise on September 28, 2026, of options held for the benefit of the RA Capital Healthcare Fund, three RA Capital Nexus funds and a separately managed account, for 70,000 common shares. Exercise prices were $1.29 for 40,000 shares, $3.00 for 10,000, $3.46 for 10,000 and $7.89 for 10,000. Andrew Levin is obligated to turn over shares received to RA Capital Management, L.P. to offset fees owed by the Fund. Reporting persons disclaim beneficial ownership except to the extent of their pecuniary interests.
Climb Bio, Inc. (CLYM) director Thomas Stephen Basil reported selling 100,000 shares of common stock on September 15, 2026 at a weighted average price of $13.6682 per share, in transactions executed under a Rule 10b5-1 trading plan adopted on June 16, 2026. After these sales, he reported owning 467,969 shares directly, which include 413,312 shares received for no consideration in a pro-rata in-kind distribution from Sera Medicines, LLC.
Climb Bio, Inc. (CLYM) has a director, Stephen Thomas, filing a notice under Rule 144 to potentially sell up to 100,000 shares of common stock. The shares relate to Performance Stock Units acquired from the issuer on August 7, 2025. As of September 15, 2026, 57,436,255 shares of common stock were outstanding and listed on NASDAQ.
Climb Bio, Inc. (CLYM) reported positive initial Phase 1 data for CLYM116, its anti‑APRIL monoclonal antibody being developed for IgA nephropathy. In healthy volunteers, a single 320 mg subcutaneous dose produced an estimated half‑life of about 29 days and dose‑proportional exposure without evidence of target‑mediated drug disposition at effective dose levels.
The 320 mg dose achieved near‑complete APRIL suppression, with more than 90% free APRIL reduction maintained through 10 weeks and above 75% through 12 weeks, alongside roughly 60–75% reductions in IgA, Gd‑IgA1, and IgM over 12 weeks. CLYM116 was generally well‑tolerated, with no serious adverse events, dose‑limiting toxicities, Grade ≥3 adverse events, discontinuations, or hypogammaglobulinemia; common treatment‑emergent events included headache, upper respiratory tract infection, and mild injection‑site reactions. Based on integrated PK/PD modeling, Climb Bio has defined a target regimen of an 800 mg loading dose followed by 400 mg every 12 weeks and is enrolling the NAVIGATE‑2 Phase 2 IgA nephropathy study, with initial data expected in the first half of 2027 and a Phase 3 initiation planned in 2027 subject to regulatory feedback.
Climb Bio, Inc. received an amended institutional ownership report from MPM BioImpact LLC stating that it no longer holds any of the company’s common stock. MPM BioImpact reports 0 shares beneficially owned, representing 0.0% of the class, with no voting or dispositive power over any shares.
Climb Bio, Inc. reports that its collaborator Beijing Mabworks Biotech Co., Ltd. has dosed the first patient with immunoglobulin A nephropathy in a Phase 2 clinical trial in China. The study is being conducted under a collaboration between the two companies focused on this kidney disease indication.