Climb Bio, Inc.

Previous wording

We acquired the rights to our product candidates through license and asset purchase agreements. We have worldwide rights to develop and commercialize budoprutug for all indications, except for oncology. We have rights to develop and commercialize CLYM116 for all indications worldwide outside of mainland China, Hong Kong, Macau, and Taiwan (Greater China).

Current wording

We acquired the rights to our product candidates through license and asset purchase agreements. We have worldwide rights to develop and commercialize budoprutug for all indications, except for oncology. We have rights to develop and commercialize CLYM116 for all indications worldwide outside of mainland China, Hong Kong, Macau, and Taiwan (Greater China). Additional information about our business, our products, and our product candidates is included in Part I. Item 1., “Business” included in our Annual Report.

Previous wording

In March 2025, we received clearance from the FDA for a Phase 2, dose range finding clinical trial of budoprutug in pMN, known as PrisMN. We have initiated our Phase 2 clinical trial of budoprutug in pMN patients with persistent proteinuria despite optimized renin-angiotensin-aldosterone system (RAAS) inhibition in multiple countries and are actively enrolling patients. PrisMN, an open-label, dose-ranging Phase 2 clinical trial, is designed to further evaluate safety, pharmacokinetics (PK), pharmacodynamics (PD) (including B cells, anti-PLA2R (Phospholipase A2 Receptor) and total immunoglobulin), and preliminary efficacy, including complete and partial remission, and to identify a dose to carry forward into Phase 3. The FDA granted budoprutug orphan-drug designation for the treatment of pMN in January 2023 and FastTrack Designation for pMN in April 2026. We expect to have initial data, including B-cell and anti-PLA2R data from the low dose cohort (200 mg at 12-24 weeks) in the Phase 2 clinical trial in pMN in the fourth quarter of 2026.

Current wording

In November 2025, we dosed the first patient in our Phase 2 clinical trial of budoprutug in pMN patients with persistent proteinuria despite optimized renin-angiotensin-aldosterone system (RAAS) inhibition, known as PrisMN. PrisMN, an open-label, dose-ranging Phase 2 clinical trial, is designed to further evaluate safety, pharmacokinetics (PK), pharmacodynamics (PD) (including B cells, anti-PLA2R (Phospholipase A2 Receptor) and total immunoglobulin), and preliminary efficacy, including complete and partial remission, and to identify an optimal dose for Phase 3. The FDA granted budoprutug orphan-drug designation for the treatment of pMN in January 2023 and Fast Track Designation for pMN in April 2026. Enrollment is now ongoing in the second cohort (600 mg) of the PrisMN trial, and we expect to have initial data, including B-cell and anti-PLA2R data from the low dose cohort (200 mg at 12-24 weeks) at a medical meeting in the fourth quarter of 2026.

Previous wording

Separately, in March 2025, we received clearance from the FDA for an open-label, dose-escalation Phase 1b/2a clinical trial of budoprutug in patients with ITP to evaluate safety, tolerability, PK, PD, and preliminary efficacy, including B cell depletion and platelet counts. We have also received regulatory clearance for this trial in multiple countries outside the United States, and we continue to activate sites and enroll and dose patients. Results from this trial are expected to provide a deeper understanding of budoprutug activity and dosing and will inform future development efforts in ITP and other immune-mediated diseases. We expect to have initial B-cell and platelet data from the low dose cohort (250 mg at 24 weeks) in the Phase 1b/2a clinical trial in ITP in June 2026, with additional data from the higher dose cohort[s] anticipated by the end of 2026.

Current wording

In June 2025, we dosed the first patient in our open-label, dose-escalation Phase 1b/2a clinical trial of budoprutug in patients with ITP, which is designed to evaluate safety, tolerability, PK, PD, and preliminary efficacy, including B-cell depletion and platelet counts. Results from this trial are expected to provide a deeper understanding of budoprutug activity and dosing and will inform future development efforts in ITP and other immune-mediated diseases.

Previous wording

In October 2024, we received FDA clearance for a Phase 1b clinical trial of budoprutug in moderate to severe SLE. We are actively enrolling patients in this global, open-label, dose-escalation Phase 1b trial. In this trial, a single dose of budoprutug will be administered in moderate to severe SLE patients to evaluate safety, tolerability, PK, PD, and preliminary efficacy, including B-cell depletion, autoantibody levels, and clinical activity. We expect to have initial B-cell data from the global Phase 1b clinical trial in SLE in the fourth quarter of 2026.

Current wording

In July 2025, we dosed the first patient in our global, open-label, dose-escalation Phase 1b clinical trial of budoprutug in moderate to severe SLE. In this trial, a single dose of budoprutug will be administered in moderate to severe SLE patients to evaluate safety, tolerability, PK, PD, and preliminary efficacy, including B-cell depletion, autoantibody levels, and clinical activity. Enrollment is ongoing and we expect to have initial B-cell data from the global Phase 1b clinical trial in SLE in the fourth quarter of 2026. In December 2025, we received clearance of our IND to initiate a separate, parallel Phase 1b/2a clinical trial in SLE patients in China, which will complement our ongoing global Phase 1b clinical trial and also seek to enroll SLE patients who have lupus nephritis (LN). We dosed the first patient in this trial in June 2026 and are actively enrolling. The data from these trials in SLE are expected to provide insights into budoprutug activity and will also help to inform future development efforts for our program broadly.

Previous wording

The above described clinical trials of budoprutug in pMN, ITP and SLE utilize an intravenous (IV) formulation of budoprutug. In parallel, we are advancing a high-concentration subcutaneous (SC) formulation of budoprutug, which may offer a differentiated convenience profile and potential commercial advantage. In September 2025, we initiated a Phase 1 clinical trial of the SC formulation of budoprutug in healthy volunteers in Australia. We have completed dosing and announced topline data from this trial in May 2026. The SC formulation of budoprutug was generally well-tolerated and resulted in robust B-cell depletion, which was similar to the IV formulation at matched doses. These results support the continued development of the SC formulation, and we plan to initiate a multiple dose study in autoimmune disease patients to evaluate full B-cell depleting doses and optimal dosing regimen.

Current wording

In parallel, we are advancing a high-concentration subcutaneous (SC) formulation of budoprutug, which may offer a differentiated convenience profile and potential commercial advantage. We completed a Phase 1 clinical trial of the SC formulation of budoprutug in healthy volunteers in Australia and announced topline data from this trial in May 2026. The SC formulation of budoprutug was generally well-tolerated and resulted in robust B-cell depletion, which was similar to the IV formulation at a matched dose. The results support the advancement of the SC formulation to a multiple dose study in autoimmune disease patients to evaluate full B-cell depleting doses and optimal dosing regimen. We expect initial data from this trial in 2027.

Previous wording

In addition to budoprutug, we are developing CLYM116, a next generation anti-APRIL (A PRoliferation-Inducing Ligand) mAb for the treatment of patients with immunoglobulin A nephropathy (IgAN) and other B-cell mediated diseases. CLYM116 is a highly potent, Fc-engineered antibody that prevents APRIL signaling by potently blocking the binding of APRIL to its receptors and promoting lysosomal APRIL degradation through a pH-dependent bind-and-release ‘sweeper’ mechanism. Through this unique binding profile and half-life extending Fc-engineering, CLYM116 has the potential to enable deep and durable inhibition of APRIL signaling and IgA production. In October 2025, we received clearance for our CTA in Australia to initiate a Phase 1 clinical trial of CLYM116 in healthy volunteers. We initiated the Phase 1 clinical trial in healthy volunteers in November 2025 and are actively enrolling subjects. We intend to present PK and PD modeling data from nonhuman primates to humans, as well as initial safety data from the ongoing Phase 1 study in healthy volunteers and anticipate having initial PK/PD data from this Phase 1 trial in mid-2026.

Current wording

In addition to budoprutug, we are developing CLYM116, a next generation anti-APRIL (A PRoliferation-Inducing Ligand) mAb for the treatment of patients with immunoglobulin A nephropathy (IgAN) and other B-cell mediated diseases. CLYM116 is a highly potent, Fc-engineered antibody that prevents APRIL signaling by potently blocking the binding of APRIL to its receptors and promoting lysosomal APRIL degradation through a pH-dependent bind-and-release ‘sweeper’ mechanism. Through this unique binding profile and half-life extending Fc-engineering, CLYM116 has the potential to enable deep and durable inhibition of APRIL signaling and IgA production.

Previous wording

Separately, our partner, Mabworks, received clearance for their IND in December 2025 and initiated a Phase 1/2 clinical trial of CLYM116 in China designed to evaluate the safety, tolerability, PK, and PD in healthy volunteers and IgAN patients.

Current wording

In December 2025, we dosed the first subject in our Phase 1 clinical trial in healthy volunteers designed to evaluate the safety, tolerability, PK, and PD of CLYM116. Separately, in February 2026, our partner, Mabworks, initiated a Phase 1/2 clinical trial in China in healthy volunteers and IgAN patients and enrollment is ongoing. In June 2026, we completed dosing in our Phase 1 trial and presented positive translational pharmacometrics modeling and initial Phase 1 safety data for CLYM116 at European Renal Association Congress. We anticipate reporting PK and PD data from our Phase 1 study in healthy volunteers at our next R&D Spotlight on September 3, 2026, and expect additional Phase 1 updates from us and our partner, Mabworks at a medical meeting later this year.

Previous wording

If we fail to obtain necessary capital when needed on acceptable terms, or at all, it could force us to delay, limit, reduce or terminate our product development programs, commercialization efforts or other operations. Insufficient liquidity may also require us to relinquish rights to product candidates at an earlier stage of development or on less favorable terms than we would otherwise choose. Our ability to raise additional funds may be adversely impacted by the potential worsening of global economic conditions and the recent disruptions to, and volatility in, worldwide credit and financial markets, resulting from increased volatility in the trading prices for shares in the biopharmaceutical industry, or otherwise. Further, imposition of tariffs and other trade restrictions by the U.S., as well as reciprocal trade restrictions imposed by other countries, could adversely affect global economies, financial markets and the overall environment in which we do business, as further described in Part I, Item 1A, “Risk Factors” of this Annual Report on Form 10-K.

Current wording

If we fail to obtain necessary capital when needed on acceptable terms, or at all, it could force us to delay, limit, reduce or terminate our product development programs, commercialization efforts or other operations. Insufficient liquidity may also require us to relinquish rights to product candidates at an earlier stage of development or on less favorable terms than we would otherwise choose. Our ability to raise additional funds may be adversely impacted by the potential worsening of global economic conditions and the recent disruptions to, and volatility in, worldwide credit and financial markets, resulting from increased volatility in the trading prices for shares in the biopharmaceutical industry, or otherwise. Further, imposition of tariffs and other trade restrictions by the U.S., as well as reciprocal trade restrictions imposed by other countries, could adversely affect global economies, financial markets and the overall environment in which we do business, as further described in Part II, Item 1A, “Risk Factors” of this Quarterly Report on Form 10-Q.

Previous wording

Cash, cash equivalents, and marketable securities were $146.3 million as of March 31, 2026. Based on its current operating plan, the Company expects this balance to fund operations into 2028, excluding the gross proceeds received from the April 2026 Private Placement (as defined below). The Company is currently evaluating the impact of the recently completed financing on its operating plan and expects to provide updated cash runway guidance at a later date. We have based our current estimate on assumptions that may prove to be wrong and that may change following our evaluation of our operating plan. We could use our available capital resources sooner than we currently anticipate, in which case we would be required to obtain additional financing, which may not be available to us on acceptable terms, or at all. See “—Liquidity and Capital Resources”.

Current wording

Cash, cash equivalents, and marketable securities were $239.2 million as of June 30, 2026. Based on our current operating plan, we expect this balance to fund operations into the second half of 2028. We have based our current estimate on assumptions that may prove to be wrong and that may change following our evaluation of our operating plan. We could use our available capital resources sooner than we currently anticipate, in which case we would be required to obtain additional financing, which may not be available to us on acceptable terms, or at all. See “—Liquidity and Capital Resources.”

Previous wording

On April 27, 2026, we entered into a securities purchase agreement (the Securities Purchase Agreement) with certain institutional accredited investors (the Investors), including an affiliate of RA Capital Management L.P., pursuant to which we issued and sold to the Investors in a private placement an aggregate of 9,481,000 shares of our common stock at a price of $9.50 per share and, to certain Investors in lieu of shares, pre-funded warrants to purchase 2,106,000 shares of our common stock at a price of $9.4999 per pre-funded warrant (the 2026 Private Placement). The 2026 Private Placement closed on April 29, 2026. The Company received aggregate gross proceeds from the 2026 Private Placement of approximately $110.0 million, before deducting placement agent fees and offering expenses.

Current wording

In April 2026, we entered into a securities purchase agreement (the Securities Purchase Agreement) with certain institutional accredited investors (the Investors), including an affiliate of RA Capital Management L.P., pursuant to which we issued and sold to the Investors in a private placement an aggregate of 9,481,000 shares of our common stock at a price of $9.50 per share and, to certain Investors in lieu of shares, pre-funded warrants to purchase 2,106,000 shares of our common stock at a price of $9.4999 per pre-funded warrant (the 2026 Private Placement). We received aggregate net proceeds from the 2026 Private Placement of approximately $103.4 million, after deducting placement agent fees and other offering expenses.

Previous wording

The following table sets forth our results of operations (in thousands):

Current wording

The following table sets forth our results of operations for the three and six months ended June 30, 2026 and 2025(in thousands):

Previous wording

Research and development expenses decreased from $17.3 million for the three months ended March 31, 2025 to $9.4 million for the three months ended March 31, 2026. The decrease was due primarily to the $9.0 million upfront payment and associated transaction costs made during the three months ended March 31, 2025 in connection with the Mabworks Agreement and our license of CLYM116 with no similar payment made during the three months ended March 31, 2026. This decrease related to the CLYM116 program was offset by $1.1 million of nonclinical and clinical costs incurred during the three months ended March 31, 2026 for which there were no similar costs incurred during the three months ended March 31, 2025.

Current wording

Research and development expenses decreased from $23.9 million for the six months ended June 30, 2025 to $19.1 million for the six months ended June 30, 2026. The decrease was primarily due to the $9.0 million upfront payment and associated transaction costs made during the six months ended June 30, 2025 in connection with the Mabworks Agreement and our license of CLYM116 with no similar payment made during the six months ended June 30, 2026, partially offset by approximately $2.7 million of spend associated with the advancement of our clinical and preclinical pipeline as well as an additional $1.5 million in personnel-related expenses incurred during the six months ended June 30, 2026.

Previous wording

General and administrative expenses increased by $0.1 million from $5.7 million for the three months ended March 31, 2025 to $5.8 million for the three months ended March 31, 2026. The increase was due primarily to higher personnel-related expenses of $0.3 million from increased headcount and higher consulting fees of $0.1 million, partially offset by a decrease in legal fees of $0.3 million. General and administrative expenses for the three months ended March 31, 2026 and 2025 included stock-based compensation expense of $1.0 million and $1.1 million, respectively.

Current wording

General and administrative expenses increased from $4.1 million for the three months ended June 30, 2025 to $5.6 million for the three months ended June 30, 2026. The increase was primarily due to higher personnel-related expenses of $1.5 million, including increased stock-based compensation of $0.7 million, driven by increased headcount.

Previous wording

Foreign currency (loss) was not material in either of the three months ended March 31, 2026 or 2025.

Current wording

Foreign currency (loss) was not material in either of the three and six months ended June 30, 2026 or 2025.

Previous wording

Since our inception, we have primarily funded our operations with proceeds from the sale and issuance of shares of our redeemable convertible preferred stock, our IPO, the sale and issuance of shares of our common stock and pre-funded warrants to purchase shares of our common stock in private placements including the 2026 Private Placement. We have not generated any revenue from product sales or otherwise. We have incurred net losses from operations since our inception and anticipate we will continue to incur net losses for the foreseeable future. As of March 31, 2026, we had cash, cash equivalents and marketable securities of $146.3 million.

Current wording

Since our inception, we have primarily funded our operations with proceeds from the sale and issuance of shares of our redeemable convertible preferred stock, our IPO, the sale and issuance of shares of our common stock and pre-funded warrants to purchase shares of our common stock in private placements including the 2026 Private Placement. We have not generated any revenue from product sales or otherwise. We have incurred net losses from operations since our inception and anticipate we will continue to incur net losses for the foreseeable future. As of June 30, 2026, we had cash, cash equivalents and marketable securities of $239.2 million.

Previous wording

In March 2025, we entered into an Equity Distribution Agreement (the Distribution Agreement) with Oppenheimer & Co. Inc., as agent (Oppenheimer), pursuant to which we may offer and sell shares of our common stock from time to time through Oppenheimer having an aggregate offering price of up to $22.4 million in an at the market offering. During the three months ended March 31, 2026, we did not issue and sell any shares of our common stock pursuant to the Distribution Agreement.

Current wording

In March 2025, we entered into an Equity Distribution Agreement (the Distribution Agreement) with Oppenheimer & Co. Inc., as sales agent (Oppenheimer), pursuant to which we may offer and sell shares of our common stock from time to time through Oppenheimer having an aggregate offering price of up to $22.4 million in an at the market offering. We terminated the Distribution Agreement effective as of June 11, 2026. We did not incur any termination penalties as a result of the termination of the Distribution Agreement. As of the effective date of the termination of the Distribution Agreement, we had not sold any shares of Common Stock pursuant to the Distribution Agreement.

Previous wording

For the three months ended March 31, 2026, net cash used in operating activities was $14.4 million, resulting from our net loss of $13.7 million and cash used by changes in our operating assets and liabilities of $2.1 million, partially offset by $1.4 million in non-cash charges. Cash used by changes in our operating assets and liabilities primarily consisted of a decrease in accounts payable and accrued expenses and other current liabilities of $1.4 million and $1.5 million, respectively, partially offset by an increase of prepaid expenses and other current assets of $0.9 million.

Current wording

For the six months ended June 30, 2025, net cash used in operating activities was $26.6 million, resulting from our net loss of $29.4 million, partially offset by $1.9 million in non-cash charges and cash provided by changes in our operating assets and liabilities of $0.9 million. Changes in our operating assets and liabilities primarily consisted of a decrease in prepaid expense and other current assets of $1.3 million and an increase in accounts payable and accrued expenses and other current liabilities of $1.1 million, partially offset by an increase in other long-term assets of $1.4 million.

Previous wording

For the three months ended March 31, 2025, net cash used by investing activities was $42.8 million, consisting primarily of purchases of $58.8 million of marketable securities, partially offset by $16.0 million in proceeds received from maturities of marketable securities.

Current wording

For the six months ended June 30, 2026, net cash used in investing activities was $70.2 million, consisting primarily of purchases of $127.5 million of marketable securities, offset by $57.5 million in proceeds received from maturities of marketable securities.

Previous wording

For the three months ended March 31, 2026, net cash used in investing activities was $13.0 million, consisting primarily of purchases of $44.9 million of marketable securities, partially offset by $31.9 million in proceeds received from maturities of marketable securities.

Current wording

For the six months ended June 30, 2025, net cash used in investing activities was $38.0 million, consisting primarily of purchases of $79.4 million of marketable securities, partially offset by $41.5 million in proceeds received from maturities of marketable securities.

Previous wording

For the three months ended March 31, 2025, there were no financing activities.

Current wording

For the six months ended June 30, 2025, there were no financing activities.

Previous wording

Cash, cash equivalents, and marketable securities were $146.3 million as of March 31, 2026. Based on our current operating plan, we expect this balance to fund operations into 2028, excluding the gross proceeds received from the April 2026 Private Placement. The Company is currently evaluating the impact of the recently completed financing on its operating plan and expects to provide updated cash runway guidance at a later date. We have based our current estimate on assumptions that may prove to be wrong and that may change following our evaluation of our operating plan. We could exhaust our available capital resources sooner than we expect. We anticipate that our expenses will increase for the foreseeable future as we continue to advance our current product candidatesand any product candidates we may develop, expand our corporate infrastructure, and incur costs associated with potential commercialization.

Current wording

Cash, cash equivalents, and marketable securities were $239.2 million as of June 30, 2026. Based on our current operating plan, we expect this balance to fund operations into the second half of 2028. We have based our current estimate on assumptions that may prove to be wrong and that may change following our evaluation of our operating plan. We could exhaust our available capital resources sooner than we expect. We anticipate that our expenses will increase for the foreseeable future as we continue to advance our current product candidatesand any product candidates we may develop, expand our corporate infrastructure, and incur costs associated with potential commercialization.

Previous wording

the progress, costs and results of our clinical trials of budoprutug in pMN, ITP, and SLE, our Phase 1 clinical trial of the SC formulation of budoprutug, our Phase 1 clinical trial of CLYM116, and any future clinical trials of our product candidates;

Current wording

the progress, costs and results of our clinical trials of budoprutug in pMN, ITP, and SLE, our clinical trial of the SC formulation of budoprutug, our clinical trials of CLYM116, and any future clinical trials of our product candidates;

Previous wording

There have been no material changes to our critical accounting policies and estimates from those disclosed in our audited consolidated financial statements and notes thereto as of and for the year ended December 31, 2025 included in our Annual Report on Form 10-K.

Current wording

There have been no material changes to our critical accounting policies and estimates from those disclosed in our audited consolidated financial statements and notes thereto as of and for the year ended December 31, 2025 included in our Annual Report.

Previous wording

See Note 2 to our unaudited condensed consolidated financial statements included in this Quarterly Report.

Current wording

Refer to Note 2, Significant Accounting Policies, to our unaudited condensed consolidated financial statements included in this Quarterly Report.