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Climb Bio, Inc.

For the period ended Mar 31, 2026. Filed May 7, 2026.

View on SEC.gov

About this filing

A company's report for each of its first three quarters. The financial statements are not audited. It shows how the business has moved since the last annual report, and what management says changed.

Mar 31, 2026 · Filed May 7, 2026

CLYM$10.29+16.0%Stored close · as of Nov 6, 2026

What changed in Management’s Discussion and Analysis?

Read the current filing

Previous report: 10-Q

Period ended 2025-09-30; filed 2025-11-06.

0001193125-25-268086

Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations

Current report: 10-Q

Period ended 2026-03-31; filed 2026-05-07.

0001193125-26-210357

Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations

The baseline is this issuer’s latest earlier reporting period of the same form that was filed before the current report. A previous 10-Q is a different quarter, not a year-over-year comparison. Amendments are excluded.

Compared 102 previous paragraphs and 97 current paragraphs.

37 unchanged; 33 reworded; 27 added; 23 removed; 9 previous and 0 current paragraphs rearranged.

Tables are not compared: 5 previous and 3 current tables excluded. Dates, whitespace, punctuation and numbering changes are ignored; changes to financial figures remain significant.

A changed paragraph is not evidence that risk increased or decreased. An unchanged paragraph does not establish that risk stayed the same.

Added paragraphs (27)

Current report

Our lead product candidate, budoprutug, is a clinical-stage anti-CD19 monoclonal antibody (mAb) designed to deplete CD19-positive B cells. CD19 plays a mechanistic role across all stages of B-cell development, and emerging clinical evidence continues to support the importance of CD19 in immune-mediated diseases. By targeting CD19, budoprutug has the potential to provide rapid, profound, and durable reductions in B cells and pathogenic autoantibodies, which may allow for a disease-modifying therapeutic approach. We have focused our initial development strategy for budoprutug on primary membranous nephropathy (pMN), immune thrombocytopenia (ITP), and systemic lupus erythematosus (SLE), which we believe each offer a strong mechanistic rationale for CD19-directed therapy.

Current report

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 expect to enroll the first patient in this study in the second quarter of 2026. 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.

Current report

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 report

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 report

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 report

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 report

The decrease in spend of $0.8 million related to the budoprutug program was driven primarily by a decrease in nonclinical and chemistry, manufacturing and controls costs of $3.0 million offset by increased costs of $2.2 million as we advanced our clinical trials of budoprutug in pMN, ITP and SC formulation of budoprutug in healthy volunteers.

Current report

The decrease in legacy programs was primarily due to certain programs, ETX-123 and ETX-155, that are no longer being pursued.

Current report

Personnel-related expenses increased by $0.6 million due primarily to increased headcount, partially offset by a decrease in stock-based compensation expenses of $0.3 million. The increase in other research and development expenses of $0.4 million was primarily due to consulting and regulatory expenditures incurred for non-specific programs.

Current report

For the three months ended March 31, 2026, there was an immaterial amount of cash provided by financing activities due to the exercise of stock options.

Current report

the number and scope of development, nonclinical and clinical programs we decide to pursue, and the timing, cost and progress of activities related to such programs;

Current report

the costs of manufacturing our product candidates by third parties;

Current report

the cost of regulatory requirements, regulatory submissions and timing of regulatory approvals;

Current report

There have been no material changes to our cash requirements from those disclosed in our Annual Report on Form 10-K for the year ended December 31, 2025.
Removed paragraphs (23)

Previous report

Our lead product candidate, budoprutug, is a clinical-stage anti-CD19 monoclonal antibody (mAb) which has the potential to address a broad range of B-cell mediated diseases. Budoprutug is designed to deplete CD19-positive B cells, including antibody secreting cells (plasma blasts), in order to directly reduce pathogenic autoantibodies. This reduction of autoantibodies has the potential to be a disease-modifying approach in the treatment of multiple immune-mediated diseases. We believe we are well-positioned to advance budoprutug across three distinct opportunity sets in immune-mediated disease: primarily IgG4-mediated diseases, primarily single organ IgG1-3 mediated diseases and complex systemic diseases.

Previous report

We are initially developing budoprutug in lead indications representing each of these three opportunity sets, namely primary membranous nephropathy (pMN), a primarily IgG4-mediated disease, immune thrombocytopenia (ITP), a primarily single organ IgG1-3 mediated disease, and systemic lupus erythematosus (SLE), a complex systemic disease, where we believe budoprutug has the potential to be differentiated from other therapies in development and improve patient outcomes.

Previous report

Each of our clinical trials of budoprutug in pMN, ITP and SLE will be conducted using an intravenous (IV) formulation of budoprutug. In parallel, we are advancing a subcutaneous (SC) formulation of budoprutug, which together with the IV formulation, may provide the opportunity for a patient-tailored approach to treatment. We obtained additional non-clinical data for the SC formulation in the first half of 2025, which demonstrated high bioavailability and favorable tolerability. In August 2025, we received clearance for our clinical trial application (CTA) to initiate a Phase 1 clinical trial in healthy volunteers with the SC formulation in Australia to evaluate bioavailability, pharmacokinetics, and pharmacodynamics. We are actively enrolling and dosing subjects in this trial and expect to have initial clinical data in the first half of 2026.

Previous report

Previously, we focused primarily on developing novel therapies for neuronal excitability disorders to address unmet needs in psychiatry, epilepsy, chronic pain, and other disorders of the peripheral and central nervous systems, and our lead program was ETX-123, a Kv7.2/3 potassium channel opener. In July 2023, we made the determination to pause further development of our Kv7 program, and we continue to evaluate our Kv7 program, including seeking a partner for further development.

Previous report

We have incurred significant operating losses since inception, as we have devoted substantially all of our resources to organizing and staffing our company, identifying, acquiring and in-licensing potential product candidates, business planning, raising capital, undertaking research, executing preclinical studies and clinical development trials, and providing general and administrative support for business activities. We incurred net losses of $12.9 million and $42.3 million for the three and nine months ended September 30, 2025, respectively. We had an accumulated deficit of $272.2 million as of September 30, 2025.

Previous report

On June 27, 2024, we acquired 100% of the share capital of Tenet Medicines, Inc. (Tenet) in exchange for 5,560,047 shares of our common stock, valued at $41.9 million, or $7.53 per share (the Acquisition). The Acquisition was accounted for as an asset acquisition. The total cost of the asset acquisition was $52.8 million, including transaction costs. We recognized in-process research and development (IPR&D) expense of $51.7 million for the year ended December 31, 2024, as the IPR&D was determined to have no future alternative use.

Previous report

On January 8, 2025, we entered into the Mabworks Agreement for rights to develop and commercialize CLYM 116 in the territory outside of Greater China. Under the terms of the Mabworks Agreement, we made an upfront cash payment of $9.0 million to Mabworks. We will be required to make certain additional payments upon the achievement of specified development, regulatory and commercial milestones, and to pay low- to mid-single digit tiered royalties on net sales outside of Greater China. The upfront payment of $9.0 million was included in research and development expenses in the first quarter of 2025.

Previous report

Acquired In-Process Research and Development, Related Party

Previous report

Our acquired IPR&D expense consists of the fair value of consideration transferred in the Acquisition allocated to assets acquired that were in the research and development phase and determined to not have any alternative future use.

Previous report

Research and development expenses increased from $6.2 million for the three months ended September 30, 2024 to $9.1 million for the three months ended September 30, 2025. The increase was due primarily to an increase of $2.7 million in costs incurred for our budoprutug program, which we acquired as part of the Acquisition on June 27, 2024. The increase was driven primarily by increased costs as we advanced our clinical trials of budoprutug in pMN, ITP and SLE, partially offset by lower manufacturing costs. Costs of $0.6 million for our CLYM116 program, which we licensed in January 2025, consisted primarily of manufacturing costs. Personnel-related expenses decreased by $0.9 million due primarily to prior year restructuring costs, partially offset by increased headcount.

Previous report

Comparison of the Nine Months Ended September 30, 2025 and 2024

Previous report

Research and development expenses increased from $8.4 million for the nine months ended September 30, 2024 to $33.0 million for the nine months ended September 30, 2025. The increase was due primarily to an increase in costs of $13.4 million for our budoprutug program, which we acquired as part of the Acquisition on June 27, 2024. The increase was driven primarily by increased costs as we advanced our clinical trials of budoprutug in pMN, ITP and SLE and increased manufacturing costs, and milestone payments under our license agreements. Costs of $9.9 million for our CLYM116 program, which we licensed in January 2025, consisted primarily of an upfront payment of $9.0 million under the Mabworks Agreement and manufacturing costs. Personnel-related expenses increased by $0.5 million due primarily to increased headcount and stock-based compensation expense, partially offset by a decrease due to prior year restructuring costs. Research and development expenses for the nine months ended September 30, 2025 and 2024 included stock-based compensation expense of $3.2 million and $2.3 million, respectively.

Previous report

Acquired In-Process Research and Development, Related Party

Previous report

Acquired IPR&D expense, related party was $51.7 million for the nine months ended September 30, 2024. This amount represents the recognition of IPR&D expense from the Acquisition completed on June 27, 2024.

Previous report

General and administrative expenses increased by $4.5 million from $11.1 million for the nine months ended September 30, 2024 to $15.6 million for the nine months ended September 30, 2025. The increase was primarily due to an increase in personnel-related expenses of $3.1 million from increased headcount and stock-based compensation expense. General and administrative expenses for the nine months ended September 30, 2025 and 2024 included stock-based compensation expense of $3.8 million and $1.6 million, respectively. Legal expenses also increased by $0.7 million.

Previous report

Interest income increased from $5.6 million for the nine months ended September 30, 2024 to $6.5 million for the nine months ended September 30, 2025 due to higher invested balances during the nine months ended September 30, 2025 as compared to the nine months ended September 30, 2024.

Previous report

For the nine months ended September 30, 2024, net cash provided by financing activities was $130.7 million, consisting of $119.7 million in proceeds received from the issuance of our common stock in the private placement completed in June 2024 in connection with the Acquisition and $10.9 million in proceeds from exercises of stock options.

Previous report

the terms of any collaborations and/or research and development agreements we may enter into, which may impact the cost, timing and development plans of one or more of our product candidate programs;

Previous report

In the normal course of business, we enter into contracts with CROs, CDMOs, and other third parties for preclinical studies and clinical trials, supply of materials and manufacturing services. These contracts do not contain material minimum purchase commitments and generally provide us with the option to cancel, reschedule and adjust our requirements based on our business needs, prior to the delivery of goods or performance of services. However, it is not possible to predict the maximum potential amount of future payments under these agreements due to the conditional nature of our obligations and the unique facts and circumstances involved in each agreement.

Previous report

We have a lease agreement, as amended, for office space in Wellesley Hills, Massachusetts with remaining fixed payments of $0.4 million through December 2026, with an option to extend the lease through December 2027 for additional fixed payments of $0.3 million.

Previous report

We have obligations under an asset purchase agreement (the Asset Purchase Agreement) with Acelyrin, Inc. (Acelyrin) with respect to Products (as defined in the Asset Purchase Agreement) and certain license agreements that obligate us to make specified milestone and royalty payments. The payment obligations under these agreements are contingent upon future events, such as our achievement of specified development, regulatory and commercial milestones, or generating product sales. We are unable to estimate the timing or likelihood of achieving these milestones or generating future product sales. See Note 7 to our unaudited condensed consolidated financial statements included in this Quarterly Report for a discussion of these milestone and royalty obligations.
Reworded paragraphs (33)

Previous wording

The following discussion and analysis of our financial condition and results of operations should be read in conjunction with our unaudited condensed consolidated financial statements and related notes included in this Quarterly Report and the audited financial statements and notes thereto as of and for the year ended December 31, 2024 and the related Management’s Discussion and Analysis of Financial Condition and Results of Operations, both of which are contained in our Annual Report on Form 10-K filed with the SEC on March 25, 2025. Some of the information contained in this discussion and analysis or set forth elsewhere in this Quarterly Report, including information with respect to our plans and strategy for our business, includes forward-looking statements that involve substantial risks and uncertainties. As a result of many factors, including those factors set forth in Part II, Item 1A. “Risk Factors” of this Quarterly Report, our actual results could differ materially from the results described in or implied by the forward-looking statements contained in the following discussion and analysis. For further information regarding our forward-looking statements, see “Cautionary Note Regarding Forward-Looking Statements” in this Quarterly Report.

Current wording

The following discussion and analysis of our financial condition and results of operations should be read in conjunction with our unaudited condensed consolidated financial statements and related notes included in this Quarterly Report and the audited financial statements and notes thereto as of and for the year ended December 31, 2025 and the related Management’s Discussion and Analysis of Financial Condition and Results of Operations, both of which are contained in our Annual Report on Form 10-K filed with the Securities and Exchange Commission (SEC) on March 5, 2026. Some of the information contained in this discussion and analysis or set forth elsewhere in this Quarterly Report, including information with respect to our plans and strategy for our business, includes forward-looking statements that involve substantial risks and uncertainties. As a result of many factors, including those factors set forth in Part II, Item 1A. “Risk Factors” of this Quarterly Report, our actual results could differ materially from the results described in or implied by the forward-looking statements contained in the following discussion and analysis. For further information regarding our forward-looking statements, see “Cautionary Note Regarding Forward-Looking Statements” in this Quarterly Report.

Previous wording

We are a clinical-stage biotechnology company committed to developing potential best-in-class therapeutics that address significant unmet need for the millions of patients living with immune-mediated diseases. We have built our pipeline by strategically acquiring or in-licensing product candidates that we believe have clear biological rationale, well-defined development paths and have the potential to address significant unmet needs.

Current wording

We are a clinical-stage biotechnology company committed to developing potential best-in-class therapeutics that address significant unmet need for patients living with immune-mediated diseases. We have built our pipeline by strategically acquiring or in-licensing product candidates that we believe have clear biological rationale, well-defined development pathways, and the potential to address multiple indications.

Previous wording

In March 2025, we received clearance from the FDA for a Phase 2, dose range finding clinical trial of budoprutug in pMN. Budoprutug was previously evaluated in a Phase 1b clinical trial in pMN, the results of which suggest that budoprutug may offer the opportunity to induce remission of pMN in patients with moderate to severe disease. In that clinical trial, three out of five patients (60%) that received four doses of budoprutug and completed at least 48-weeks of follow-up achieved a complete remission of proteinuria, an important clinical endpoint in pMN. In October 2025, we published long-term follow-up clinical data from the previously conducted Phase 1b clinical trial, which demonstrated long-term control of proteinuria for up to three years after initial dosing in four patients who received up to four doses of budoprutug. Additionally, in three of the patients, no further immunosuppressive treatment was required. In the trial, no treatment-related adverse events grade 3 or higher were observed. Notably, the FDA has granted budoprutug orphan drug designation for the treatment of pMN. We have initiated our Phase 2 clinical trial of budoprutug in pMN (PrisMN) in multiple countries, continue to pursue regulatory clearance to open additional trial sites outside the United States and expect to dose our first patient in the coming weeks. PrisMN, an open-label, dose-ranging Phase 2 clinical trial, is designed to further evaluate safety, pharmacokinetics, pharmacodynamics (including B cells, anti-PLA2R and total immunoglobulin), and preliminary efficacy, including complete and partial remission, and identify a dose to carry forward into Phase 3.

Current 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.

Previous wording

Separately, in March 2025, we received clearance from the FDA for our IND application to initiate an open-label, dose-escalation Phase 1b/2a clinical trial of budoprutug in patients with ITP to evaluate safety, tolerability, pharmacokinetics, pharmacodynamics, 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 data, including preliminary efficacy, from the Phase 1b/2a clinical trial in ITP in the second half of 2026.

Current 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.

Previous wording

In October 2024, we received clearance from the FDA for our IND application to initiate an open-label, dose-escalation Phase 1b clinical trial of budoprutug in patients with SLE to evaluate safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary efficacy, including B-cell depletion, autoantibody levels, and clinical activity. 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 insights into budoprutug activity after a single intravenous dose and will also inform future development efforts for the program broadly. We expect to have initial data, including preliminary efficacy, from the Phase 1b clinical trial in SLE in the second half of 2026.

Current 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.

Previous wording

In addition to budoprutug, we are also developing CLYM116, an anti-APRIL (A Proliferation-Inducing Ligand) mAb for patients with immunoglobulin A nephropathy (IgAN) and other B-cell mediated diseases. CLYM116 utilizes a novel mechanism of action to prevent APRIL signaling, potently blocking binding of APRIL to its receptors and also promoting lysosomal APRIL degradation via a pH-dependent bind-and-release design. Through its unique binding profile, and this ‘sweeper’ mechanism of action, CLYM116 has the potential to enable more rapid, deep and durable inhibition of APRIL signaling. We completed IND-enabling studies for CLYM116 and reported preclinical data from a completed nonhuman primate study comparing CLYM116 to sibeprenlimab, a first-generation anti-APRIL monoclonal antibody, in September 2025. The preclinical data demonstrated improvement versus sibeprenlimab, including high bioavailability, prolonged exposure, with an approximately two to three times longer half-life across doses, and deeper and more prolonged IgA reduction. Additional in vivo studies in mice showed enhanced APRIL elimination and antibody recycling relative to sibeprenlimab. In October 2025, we received clearance for our CTA to initiate a Phase 1 clinical trial in healthy volunteers with CLYM116 in Australia. We expect to dose the first subject by year-end 2025 and anticipate having initial clinical data from the 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. 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.

Previous wording

Since our inception, we have primarily funded our operations with net proceeds from the sale and issuance of shares of our redeemable convertible preferred stock, our initial public offering (IPO) of common stock in 2021, and the sale and issuance of shares in a private placement of our common stock that we completed in June 2024 in connection with the Acquisition. We do not have any products approved for sale and have not generated any revenue from product sales since our inception. Our ability to generate product revenue will depend on the successful development, regulatory approval and eventual commercialization of one or more of our product candidates, if approved. We cannot assure you that we will ever be profitable or generate positive cash flow from operating activities. We expect to continue to incur operating losses for the foreseeable future. Until such time, if ever, as we can generate significant revenue from product sales, we may finance our operations through equity offerings, debt financings, collaborations, strategic alliances and marketing, distribution or licensing arrangements. Adequate funding may not be available when needed or on terms acceptable to us, or at all.

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 initial public offering (IPO), and the sale and issuance of shares in private placements of shares of our common stock and pre-funded warrants to certain institutional investors. We do not have any products approved for sale and have not generated any revenue from product sales since our inception. Our ability to generate product revenue will depend on the successful development, regulatory approval and eventual commercialization of one or more of our product candidates, if approved. We cannot assure you that we will ever be profitable or generate positive cash flow from operating activities. We expect to continue to incur operating losses for the foreseeable future and will need to raise substantial additional capital in the future. Until such time, if ever, as we can generate significant revenue from product sales, we may finance our operations through equity offerings, debt financings, collaborations, strategic alliances and marketing, distribution or licensing arrangements. Adequate funding may not be available when needed or on terms acceptable to us, or at all.

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 potential worsening global economic conditions and the recent disruptions to, and volatility in, the credit and financial markets in the United States (U.S.) and worldwide, 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.

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 I, Item 1A, “Risk Factors” of this Annual Report on Form 10-K.

Previous wording

Based on our current operating plan, we estimate that our cash, cash equivalents and marketable securities will be sufficient to fund our planned operations through 2027. We have based this estimate on assumptions that may prove to be wrong, and 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 $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”.

Previous wording

Our operating expenses consist of (i) research and development expenses, (ii) acquired IPR&D expense, related party, and (iii) general and administrative expenses.

Current wording

Our operating expenses consist of research and development expenses and general and administrative expenses.

Previous wording

expenses incurred in connection with the preclinical and clinical development of our product candidates, including under agreements with CROs and consultants;

Current wording

expenses incurred in connection with the nonclinical and clinical development of our product candidates, including under agreements with CROs and consultants;

Previous wording

Our direct research and development expenses are tracked on a program-by-program basis and consist primarily of external costs, such as fees paid to CDMOs, CROs, consultants and contractors, in connection with our preclinical and clinical development activities. We do not allocate employee costs, costs associated with facility expenses, or other indirect costs, to specific programs because these costs are deployed across multiple product development programs and, as such, are not separately classified.

Current wording

Our direct research and development expenses are tracked on a program-by-program basis and consist primarily of external costs, such as fees paid to CDMOs, CROs, consultants and contractors, in connection with our nonclinical and clinical development activities. We do not allocate employee costs, costs associated with facility expenses, or other indirect costs, to specific programs because these costs are deployed across multiple product development programs and, as such, are not separately classified.

Previous wording

We expect our research and development expenses to increase substantially for the foreseeable future as we conduct our ongoing research and development activities. The process of conducting preclinical studies, acquiring drug product supply, and conducting clinical trials necessary to obtain regulatory approval is costly and time consuming. We may never succeed in achieving marketing approval for budoprutug, CLYM116, or any product candidate we may develop.

Current wording

We expect our research and development expenses to increase substantially for the foreseeable future as we conduct our ongoing research and development activities. The process of conducting nonclinical studies, acquiring drug product supply, and conducting clinical trials necessary to obtain regulatory approval is costly and time consuming. We may never succeed in achieving marketing approval for budoprutug, CLYM116, or any product candidate we may develop.

Previous wording

The timelines and costs associated with research and development activities are uncertain and can vary significantly among product candidates and development programs due to the inherently unpredictable nature of preclinical and clinical development. We anticipate that we will make determinations as to which indications to pursue in connection with our clinical development of budoprutug, CLYM116, or any product candidates we may develop and how much funding to direct to each such indication on an ongoing basis in response to preclinical and clinical results, regulatory developments, and ongoing assessments as to each such indication’s commercial potential.

Current wording

The timelines and costs associated with research and development activities are uncertain and can vary significantly among product candidates and development programs due to the inherently unpredictable nature of nonclinical and clinical development. We anticipate that we will make determinations as to which indications to pursue in connection with our clinical development of budoprutug, CLYM116, or any product candidates we may develop and how much funding to direct to each such indication on an ongoing basis in response to nonclinical and clinical results, regulatory developments, and ongoing assessments as to each such indication’s commercial potential. Our future research and development costs may vary significantly and differ materially from expectations, and a change in the outcome of variables with respect to the development of budoprutug, CLYM116, or any product candidates we may develop could significantly change the costs and timing associated with such development. See the section titled “Risk Factors—Risks Related to our Financial Position and Need for Additional Capital.”

Previous wording

We expect that our general and administrative expenses will increase for the foreseeable future as we continue to increase our general and administrative headcount to support our growth strategy and, if any product candidates receive marketing approval, commercialization activities, as well as to support our operations generally.

Current wording

We expect that our general and administrative expenses will increase for the foreseeable future, including increases in headcount as we continue to support our growth strategy and, if any product candidates receive marketing approval, commercialization activities, as well as to support our operations generally.

Previous wording

General and administrative expenses increased by $0.3 million from $5.5 million for the three months ended September 30, 2024 to $5.8 million for the three months ended September 30, 2025. The increase was due primarily to higher personnel-related expenses of $0.8 million from increased headcount and stock-based compensation expense, partially offset by a decrease due to prior year restructuring costs. General and administrative expenses for the three months ended September 30, 2025 and 2024 included stock-based compensation expense of $2.2 million and $1.2 million, respectively. The increase in personnel-related expenses was partially offset by higher legal expenses in the prior year.

Current 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.

Previous wording

Interest income decreased from $2.8 million for the three months ended September 30, 2024 to $2.0 million for the three months ended September 30, 2025, due primarily to lower invested balances during the three months ended September 30, 2025 as compared to the three months ended September 30, 2024.

Current wording

Interest income decreased from $2.3 million for the three months ended March 31, 2025 to $1.5 million for the three months ended March 31, 2026, due primarily to lower invested balances during the three months ended March 31, 2026 as compared to the three months ended March 31, 2025.

Previous wording

Foreign currency gain (loss) was not material in either of the three months ended September 30, 2025 or 2024.

Current wording

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

Previous wording

Since our inception, we have primarily funded our operations with net proceeds from the sale and issuance of shares of our redeemable convertible preferred stock, our IPO of common stock in 2021, and the sale and issuance of shares of our common stock in a private placement we completed in June 2024 in connection with the Acquisition. 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 September 30, 2025, we had cash, cash equivalents and marketable securities of $175.8 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 March 31, 2026, we had cash, cash equivalents and marketable securities of $146.3 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 and nine months ended September 30, 2025, 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 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.

Previous wording

For the nine months ended September 30, 2024, net cash used in operating activities was $10.0 million, resulting from our net loss of $65.5 million, partially offset by $55.4 million in non-cash charges, which consisted primarily of our IPR&D charge of $51.7 million. Cash provided by changes in our operating assets and liabilities was not meaningful as a decrease in prepaid expense and other current assets of $1.4 million was almost entirely offset by increases in accounts payable, accrued expense amounts and operating lease liabilities.

Current 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.

Previous wording

For the nine months ended September 30, 2025, net cash used in operating activities was $38.7 million, resulting from our net loss of $42.3 million and cash used by changes in our operating assets and liabilities of $1.9 million, partially offset by $5.5 million in non-cash charges. Cash used by changes in our operating assets and liabilities primarily consisted of an increase in other long-term assets of $1.5 million.

Current wording

For the three months ended March 31, 2025, net cash used in operating activities was $15.4 million, resulting from our net loss of $20.8 million, partially offset by $1.5 million in non-cash charges and $3.9 million from cash provided by changes in our operating assets and liabilities. Cash provided by changes in our operating assets and liabilities primarily consisted of increases in prepaid expenses and other current assets and accrued expenses and other liabilities of $1.9 million and $2.0 million, respectively.

Previous wording

For the nine months ended September 30, 2025, net cash used in investing activities was $22.7 million, consisting primarily of purchases of $103.1 million of marketable securities, partially offset by $80.6 million in proceeds received from maturities of marketable securities.

Current 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.

Previous wording

For the nine months ended September 30, 2024, net cash used by investing activities was $67.7 million, consisting primarily of purchases of $71.8 million of marketable securities, the issuance of a promissory loan of $5.0 million and cash paid of $4.6 million in connection with the Acquisition, partially offset by $13.8 million in proceeds received from maturities of marketable securities.

Current 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.

Previous wording

For the nine months ended September 30, 2025, there were no financing activities.

Current wording

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

Previous wording

We believe our existing cash, cash equivalents and marketable securities will be sufficient to fund our operations through 2027. We have based this estimate on assumptions that may prove to be wrong, and 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 $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.

Previous wording

the terms of any collaborations and/or research and development agreements we may enter into, which may impact the cost, timing and development plans of one or more of our product candidate programs;

Current wording

the terms of any collaborations, license or research and development agreements we may enter into;

Previous wording

the potential delays in our preclinical studies, our development programs and our clinical trial activities due to the effects of global events, including macroeconomic conditions and supply chain disruptions;

Current wording

the potential delays in our development programs and clinical trial activities due to the effects of global events, including macroeconomic conditions and supply chain disruptions;

Previous wording

the impact of inflationary pressures on salaries and wages, and costs of goods and transportation expenses, including the imposition of tariffs and other trade restrictions by the U.S., as well as reciprocal trade restrictions imposed by other countries (as further described Part II, Item 1A, “Risk Factors” of this Quarterly Report), among other things;

Current wording

the impact of inflationary pressures on salaries and wages, and costs of goods and transportation expenses, including the impact of tariffs and other trade restrictions;

Previous wording

the cost of commercialization activities if budoprutug, CLYM116, or any product candidates we may develop are approved for sale, including marketing, sales and distribution costs; and

Current wording

the cost of commercialization activities if any of our product candidates are approved for sale, including marketing, sales and distribution costs; and

Previous wording

Debt financing and equity financing, if available, may involve agreements that include covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures, or declaring dividends. If we raise funds through collaborations, or other similar arrangements with third parties, we may have to relinquish valuable rights to our technologies, future revenue streams, research programs or our product candidates or grant licenses on terms that may not be favorable to us and/or may reduce the value of our common stock. Our failure to raise capital or enter into such other arrangements when needed could have a negative impact on our financial condition and on our ability to pursue our business plans and strategies. If we are unable to raise additional funds through equity or debt financings when needed, we may be required to delay, limit, reduce or terminate our product development or future commercialization efforts, or grant rights to develop and market budoprutug, CLYM116, orany product candidates we may develop even if we would otherwise prefer to develop and market such product candidates ourselves.

Current wording

Debt financing and equity financing, if available, may involve agreements that include covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures, or declaring dividends. If we raise funds through collaborations, or other similar arrangements with third parties, we may have to relinquish valuable rights to our technologies, future revenue streams, research programs or our product candidates or grant licenses on terms that may not be favorable to us and may reduce the value of our common stock. Our failure to raise capital or enter into such other arrangements when needed could have a negative impact on our financial condition and on our ability to pursue our business plans and strategies. If we are unable to raise additional funds through equity or debt financings when needed, we may be required to delay, limit, reduce or terminate our product development or future commercialization efforts, or grant rights to develop and market budoprutug, CLYM116, orany product candidates we may develop even if we would otherwise prefer to develop and market such product candidates ourselves.

Previous wording

A summary of our critical accounting policies is presented in our audited consolidated financial statements and notes thereto as of and for the year ended December 31, 2024 included in our Annual Report on Form 10-K. There were no material changes to our critical accounting policies during the three or nine months ended September 30, 2025.

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 on Form 10-K.

Previous wording

We are an emerging growth company, as defined in the JOBS Act. Under the JOBS Act, emerging growth companies can delay adopting new or revised accounting standards issued after the enactment of the JOBS Act until those standards apply to private companies. Other exemptions and reduced reporting requirements under the JOBS Act for emerging growth companies include an exemption from the requirement to provide an auditor’s report on internal controls over financial reporting pursuant to the Sarbanes-Oxley Act, an exemption from any requirement that may be adopted by the Public Company Accounting Oversight Board regarding mandatory audit firm rotation, and less extensive disclosure about our executive compensation arrangements. We have elected to use the extended transition period for complying with new or revised accounting standards that have different effective dates for public and private companies until the earlier of the date that (i) we are no longer an emerging growth company or (ii) we affirmatively and irrevocably opt out of the extended transition period provided in the JOBS Act. As a result, our consolidated financial statements may not be comparable to companies that comply with the new or revised accounting pronouncements as of public company effective dates. We will remain an emerging growth company under the JOBS Act until the earliest of (i) the last day of our first fiscal year in which we have total annual gross revenue of $1.235 billion or more, (ii) the date on which we have issued more than $1.0 billion of non-convertible debt instruments during the previous three fiscal years, (iii) the date on which we are deemed a “large accelerated filer” under the rules of the SEC with at least $700.0 million of outstanding equity securities held by non-affiliates, or (iv) December 31, 2026.

Current wording

We are an emerging growth company, as defined in the JOBS Act. Under the JOBS Act, emerging growth companies can delay adopting new or revised accounting standards issued after the enactment of the JOBS Act until those standards apply to private companies. Other exemptions and reduced reporting requirements under the JOBS Act for emerging growth companies include an exemption from the requirement to provide an auditor’s report on internal controls over financial reporting pursuant to the Sarbanes-Oxley Act, an exemption from any requirement that may be adopted by the Public Company Accounting Oversight Board regarding mandatory audit firm rotation, and less extensive disclosure about our executive compensation arrangements. We have elected to use the extended transition period for complying with new or revised accounting standards that have different effective dates for public and private companies until the earlier of the date that (i) we are no longer an emerging growth company or (ii) we affirmatively and irrevocably opt out of the extended transition period provided in the JOBS Act. As a result, our consolidated financial statements may not be comparable to companies that comply with the new or revised accounting pronouncements as of public company effective dates. We will cease to be an emerging growth company on December 31, 2026.
Rearranged previous paragraphs (9)

Previous report — wording carried elsewhere

Our future research and development costs may vary significantly based on factors such as:

Previous report — wording carried elsewhere

the impact of inflationary pressures on salaries and wages, and costs of goods and transportation expenses, including the imposition of tariffs and other trade restrictions by the U.S., as well as reciprocal trade restrictions imposed by other countries (as further described Part II, Item 1A, “Risk Factors” of this Quarterly Report), among other things; and

Previous report — wording carried elsewhere

A change in the outcome of any of these variables with respect to the development of budoprutug, CLYM116, or any product candidates we may develop could significantly change the costs and timing associated with the development.

Previous report — wording carried elsewhere

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

Previous report — wording carried elsewhere

The following table sets forth our research and development expenses (in thousands):

Previous report — wording carried elsewhere

Foreign currency gain (loss) was not material in either of the nine months ended September 30, 2025 or 2024.

Previous report — wording carried elsewhere

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;

Previous report — wording carried elsewhere

the potential delays in our preclinical studies, our development programs and our clinical trial activities due to the effects of global events, including macroeconomic conditions and supply chain disruptions;

Previous report — wording carried elsewhere

our efforts to enhance operational systems and hire personnel to support development of budoprutug, CLYM116, or any product candidates we may develop.