Climb Bio has launched an at-the-market offering to raise up to $100 million through the sale of its common stock. The company entered into an Open Market Sale Agreement with Jefferies LLC, dated June 12, 2026, authorizing the investment bank to act as sales agent. Shares will be sold from time to time at prevailing market prices on the Nasdaq Global Market, where Climb Bio's stock trades under the symbol CLYM.

The offering allows Climb Bio to offer shares with a par value of $0.0001 per share. The last reported sale price on June 11, 2026, was $10.91 per share. Sales under the agreement will be conducted in brokers' transactions or otherwise at market prices at the time of sale, as defined in Rule 415(a)(4) under the Securities Act of 1933.

Jefferies is not obligated to sell any specific number or dollar amount of securities. The firm will use commercially reasonable efforts consistent with its normal trading and sales practices. There are no arrangements for funds to be held in escrow, trust, or similar accounts.

Key Offering Details

Climb Bio, Inc. announced initial data from the ongoing Phase 1b portion of its Phase 1b/2a study evaluating budoprutug, an anti-CD19 monoclonal antibody, in adults with primary immune thrombocytopenia (ITP). The data, presented at the European Hematology Association (EHA) Congress 2026 in Stockholm, Sweden, demonstrate an encouraging safety and tolerability profile, robust B-cell depletion, and meaningful platelet responses in heavily pretreated patients. These findings suggest budoprutug may offer a differentiated approach for patients who often cycle through multiple therapies without achieving sustained responses.

The ongoing Phase 1b/2a study is evaluating budoprutug in patients with primary ITP to inform dose and regimen selection and assess safety and the depth and duration of platelet response and B-cell depletion. "Patients with chronic ITP often cycle through multiple therapies without achieving a sustained response," said Edgar D. Charles, M.D., Chief Medical Officer of Climb Bio. "These initial data suggest that targeting CD19 with budoprutug may offer a differentiated approach in ITP, enabling robust B-cell depletion, durable platelet responses, and an acceptable safety and tolerability profile."

Study Design

The Phase 1b portion of the study (NCT07043946) is evaluating three ascending doses of intravenous budoprutug—250 mg, 500 mg, and 1000 mg—administered in two doses 14 days apart. As of June 1, 2026, 15 patients had been enrolled across the 250 mg (n=6) and 500 mg (n=9) dose cohorts. Patients were heavily pretreated, with a median of 6 to 7.5 prior lines of therapy and disease duration ranging from 0.5 to 40 years.

Safety and Tolerability

Budoprutug was generally well tolerated at both the 250 mg and 500 mg dose levels. There were no serious adverse events, no treatment discontinuations due to adverse events, and no infusion-related reactions reported. All adverse events observed were Grade 1 to Grade 2.

Clinical Activity

In the 250 mg dose cohort, B-cell levels were depleted by an average of over 90% by Week 4. The mean platelet count increased by 111,000 platelets/µL at Week 24. Durable platelet responses were achieved in four out of six patients in this cohort, with two patients experiencing platelet levels greater than 100 x 10^3/µL for over 24 weeks.

Notably, of the four patients who had previously been treated with rituximab, three responded to treatment with budoprutug, two with durable and complete responses. Enrollment in the 1000 mg cohort is ongoing, with additional data anticipated by year-end 2026.

Analyst Commentary and Stock Performance

William Blair analyst Matt Phipps noted that the recent rally in Climb Bio's shares reflects growing investor confidence following positive budoprutug updates and increasing enthusiasm for APRIL-targeting therapies in IgA nephropathy (IgAN). Phipps reiterated an Outperform rating on the stock. Investors are looking ahead to the company's late-summer R&D spotlight event, where initial Phase 1 healthy volunteer data for CLYM116 are expected. Additionally, initial Phase 2 data for budoprutug in primary membranous nephropathy and Phase 1b data in systemic lupus erythematosus are anticipated in the fourth quarter.

Climb Bio stock is trading higher by almost 2% on Friday, continuing its longer-term uptrend. The stock is trading above its 20-day SMA ($10.91), 50-day SMA ($9.89), 100-day SMA ($8.01), and 200-day SMA ($5.28). The 52-week high stands at $12.48. Key resistance is identified at $12.00, while key support is near $9.50. At the time of publication, Climb Bio shares were up 1.83% at $11.11.