Tectonic Therapeutic, Inc.

Previous wording

The ongoing APEX Phase 2 clinical trial is a global, 24-week, placebo-controlled trial designed to evaluate the safety and efficacy of TX45 administered subcutaneously (“SC”) in subjects with Pulmonary Hypertension (“PH”) in Heart Failure with Preserved Ejection Fraction (“HFpEF”), known as PH-HFpEF, enriched for combined pre- and post-capillary pulmonary hypertension (“CpcPH”). We dosed our first subject in the APEX Phase 2 clinical trial in October 2024. Subjects are being randomized to 300 mg SC (2 ml injection) once monthly of TX45, 300 mg SC once every other week of TX45, or placebo. Change from baseline in PVR in the PVR>3 population is the primary endpoint of the trial. The trial is designed to enrich for patients with a PVR>3 aiming for 70% of patients enrolled. In January 2026, the Independent Data Monitoring Committee (“IDMC”) met to review unblinded data from the TX45 APEX Phase 2 clinical trial. The data included safety data (adverse experiences, vital signs, plasma volume and labs) as well as efficacy data (right heart catheterization and six-minute walk distance). Based on this review the IDMC concluded that the trial could continue without any modifications. We expect topline results from the APEX clinical trial late in the fourth quarter of 2026 or early in the first quarter 2027.

Current wording

The ongoing APEX Phase 2 clinical trial is a global, 24-week, placebo-controlled trial designed to evaluate the safety and efficacy of TX45 administered subcutaneously (“SC”) in subjects with Pulmonary Hypertension (“PH”) in Heart Failure with Preserved Ejection Fraction (“HFpEF”), known as PH-HFpEF, enriched for combined pre- and post-capillary pulmonary hypertension (“CpcPH”). We dosed our first subject in the APEX Phase 2 clinical trial in October 2024. Subjects were randomized to 300 mg SC (2 ml injection) once monthly of TX45, 300 mg SC once every other week of TX45, or placebo. Change from baseline in pulmonary vascular resistance (“PVR”) in the PVR>3 population is the primary endpoint of the trial. The trial is designed to enrich for patients with a PVR>3 aiming for 70% of patients enrolled. In July 2026, the Independent Data Monitoring Committee (“IDMC”) met to review unblinded safety and efficacy data from the TX45 APEX Phase 2 clinical trial, including approximately 80% of the expected patient exposure. The IDMC recommended the continuation of the study without modification. In June 2026, we completed enrollment in the APEX Phase 2 clinical trial, having enrolled 191 patients across 14 countries, with approximately 72% of enrolled patients in the enriched population of CpcPH patients with a PVR>3 WU at baseline. We expect topline results from the APEX clinical trial early in the first quarter of 2027.

Previous wording

Our second lead product candidate, TX2100, is being evaluated for the treatment of Hereditary Hemorrhagic Telangiectasia (“HHT”), the second most common genetic bleeding disorder with no approved therapy. TX2100 is a VHH-Fc fusion antagonist antibody that binds to APJ (also known as the apelin receptor; APLNR), a GPCR that mediates signaling by the pro-angiogenic peptide hormone apelin. A rodent surrogate of TX2100 demonstrated reductions in arteriovenous malformation (“AVM”) formation, bleeding, and anemia across the neonatal anti-BMP9/10 immunoblocked model and the more severe, adult inducible ALK1 knockout mouse model of HHT, supporting disease-modifying activity through APJ antagonism. TX2100 was further evaluated in non-human primates in IND-enabling GLP toxicology studies, including a 13-week repeat-dose study. In these studies, TX2100 was well tolerated at doses up to 100 mg/kg/week, with no treatment-related or target-related toxicities identified and no effects observed on cardiovascular, respiratory, neurological, renal, metabolic, or hematologic parameters. A formulation supporting subcutaneous dosing has been established, and drug substance and drug product manufacturing under Good Manufacturing Practice (“GMP”) have been completed to support initiation of a Phase 1a clinical trial. In February 2026, we randomized the first subject in the Phase 1a healthy volunteer clinical trial for TX2100. As of April 2026, four cohorts of healthy volunteers have been dosed. We expect to report topline results from the ongoing Phase 1a trial of TX2100 in healthy volunteers by the end of the third quarter of 2026. Assuming acceptable PK in the Phase 1a trial, a Phase 1b clinical trial to explore the safety and efficacy (hematological support, anemia, and epistaxis) of TX2100 in patients with hematologic-support dependent HHT and a Phase 2 clinical trial in patients with moderate to severe HHT are planned in early 2027.

Current wording

Our second lead product candidate, TX2100, is being evaluated for the treatment of Hereditary Hemorrhagic Telangiectasia (“HHT”), the second most common genetic bleeding disorder with no approved therapy. TX2100 is a VHH-Fc fusion antagonist antibody that binds to APJ (also known as the apelin receptor; APLNR), a GPCR that mediates signaling by the pro-angiogenic peptide hormone apelin. A rodent surrogate of TX2100 demonstrated reductions in arteriovenous malformation (“AVM”) formation, bleeding, and anemia across the neonatal anti-BMP9/10 immunoblocked model and the more severe, adult inducible ALK1 knockout mouse model of HHT, supporting disease-modifying activity through APJ antagonism. TX2100 was further evaluated in non-human primates in IND-enabling GLP toxicology studies, including a 13-week repeat-dose study. In these studies, TX2100 was well tolerated at doses up to 100 mg/kg/week, with no treatment-related or target-related toxicities identified and no effects observed on cardiovascular, respiratory, neurological, renal, metabolic, or hematologic parameters. A formulation supporting subcutaneous dosing has been established, and drug substance and drug product manufacturing under Good Manufacturing Practice (“GMP”) have been completed to support initiation of a Phase 1a clinical trial. In February 2026, we randomized the first subject in the Phase 1a healthy volunteer clinical trial for TX2100. As of June 2026, six single dose cohorts of healthy volunteers have been dosed. We expect to report topline results from the ongoing Phase 1a trial of TX2100 in healthy volunteers by the end of the third quarter of 2026. Assuming acceptable PK in the Phase 1a trial, a Phase 1b clinical trial to explore the safety and efficacy (hematological support, hemoglobin, and epistaxis) of TX2100 in patients with hematologic-support dependent HHT and a Phase 2 clinical trial in patients with moderate to severe HHT are planned in early 2027.

Previous wording

Costs that are deployed across multiple programs or platform activities and not directly attributable to any single program are recorded as platform development and unallocated research and development expenses, which include multi-program employee-related costs, cross-program licensing payments, laboratory supplies and related expenses, contract research, manufacturing and consulting services, facility-related and other expenses, including depreciation, and discovery efforts.

Current wording

Costs that are deployed across multiple programs or platform activities and not directly attributable to any single program are recorded as platform development and unallocated expenses, which include multi-program employee-related costs, cross-program licensing payments, laboratory supplies and related expenses, contract research, manufacturing and consulting services, facility-related and other expenses, including depreciation, and discovery efforts.

Previous wording

Research and development activities are central to our business. Later-stage clinical programs generally incur higher costs than early-stage programs due to the increased size and duration of trials. We cannot determine with certainty the timing of initiation, the duration or the completion costs of current or future preclinical studies and clinical trials of our product candidates due to the inherently unpredictable nature of preclinical and clinical development. Clinical and preclinical development timelines, the probability of success and development costs can differ materially from expectations. We will continue to evaluate which product candidates to pursue and the allocation of funding based on preclinical and clinical results, regulatory developments, and commercial potential. We expect our research and development expenses to increase significantly as we advance our product candidates through clinical development and initiate additional clinical trials. Our future expenses may vary significantly each period based on factors such as:

Current wording

Research and development activities are central to our business. Later-stage clinical programs generally incur higher costs than early-stage programs due to the increased size and duration of trials. We cannot determine with certainty the timing of initiation, the duration or the completion costs of current or future preclinical studies and clinical trials of our product candidates due to the inherently unpredictable nature of preclinical and clinical development. Preclinical and clinical development timelines, the probability of success and development costs can differ materially from expectations. We will continue to evaluate which product candidates to pursue and the allocation of funding based on preclinical and clinical results, regulatory developments, and commercial potential. We expect our research and development expenses to increase significantly as we advance our product candidates through clinical development and initiate additional and later stage clinical trials. Our future expenses may vary significantly each period based on factors such as:

Previous wording

per patient trial costs, based on the number of doses that patients receive;

Current wording

per patient clinical trial costs, based on the number of doses that patients receive;

Previous wording

the ability to manufacture our product candidates;

Current wording

the materials utilized to manufacture our product candidates;

Previous wording

Research and development expenses increased by $7.8 million for the three months ended March 31, 2026 compared to the three months ended March 31, 2025. The increase was primarily attributable to $6.4 million in expenses for CRO and CDMO costs related to the ongoing Phase 2 clinical trials of TX45, and a $1.4 million increase in employee-related expenses. The increase in employee-related expenses was driven by higher non-cash stock-based compensation expense, reflecting incremental equity awards granted to employees, including new hires and ongoing annual grants. In addition, we expanded our research and development team to support our programs, resulting in higher payroll and related costs.

Current wording

Research and development expenses increased by $0.9 million for the three months ended June 30, 2026, compared to the three months ended June 30, 2025. The increase was primarily attributable to $1.4 million in higher CRO and CDMO costs related to our ongoing Phase 2 clinical trials of TX45 and a $1.6 million increase in platform development and unallocated expenses, principally driven by higher employee-related expenses. The increase in employee-related expenses reflected higher non-cash stock-based compensation expense, driven by incremental equity awards granted to new hires and ongoing annual employee grants, and higher payroll and related costs associated with the continued expansion of our research and development team in support of our pipeline programs. These increases were partially offset by a $2.1 million decrease in costs related to our TX2100 program, primarily due to CDMO costs incurred in the prior-year period for the production of drug substance.

Previous wording

General and administrative expenses increased by $1.2 million for the three months ended March 31, 2026 compared to the three months ended March 31, 2025, primarily due to higher employee-related expenses. The increase in employee-related expenses was driven by higher non-cash stock-based compensation expense, reflecting incremental equity awards granted to employees, including new hires and ongoing annual grants.

Current wording

General and administrative expenses increased by $1.0 million for the three months ended June 30, 2026, compared to the three months ended June 30, 2025, primarily attributable to higher employee-related expenses. The increase in employee-related expenses was driven by higher non-cash stock-based compensation expense, reflecting incremental equity awards granted to employees, including new hires and ongoing annual grants.

Previous wording

Interest income decreased by $0.3 million for the three months ended March 31, 2026 compared to the three months ended March 31, 2025 primarily due to lower cash and cash equivalents.

Current wording

Interest income decreased by $1.4 million for the three months ended June 30, 2026, compared to the three months ended June 30, 2025, primarily due to lower cash and cash equivalents.

Previous wording

We do not currently have any approved products and have never generated any revenue from product sales. We have funded our operations primarily through the sale and issuance of common stock, convertible equity instruments, and proceeds from prior corporate transactions. We currently have an effective shelf registration statement on Form S-3 filed with the SEC, which we may use to offer from time to time any combination of common stock, preferred stock, debt securities, and warrants up to an aggregate amount of $400 million. Of this amount, we have the ability to sell up to $100 million of additional shares of our common stock to the public through an at the market offering program (“ATM”). During the three months ended March 31, 2026, we sold approximately 43,000 shares of common stock under the ATM for gross proceeds of $1.4 million. After deducting commissions and offering expenses, net proceeds were $1.3 million. This represents the first utilization of the ATM.

Current wording

We do not currently have any approved products and have never generated any revenue from product sales. We have funded our operations primarily through the sale and issuance of common stock, convertible equity instruments, and proceeds from prior corporate transactions. We currently have an effective shelf registration statement on Form S-3 filed with the SEC, which we may use to offer from time to time any combination of common stock, preferred stock, debt securities, and warrants up to an aggregate amount of $400 million. Of this amount, we have the ability to sell up to $100 million of additional shares of our common stock to the public through an at the market offering program (“ATM”). During the six months ended June 30, 2026, the Company sold 432,306 shares of its common stock under the ATM at an average price per share of $30.89 for gross proceeds of $13.4 million and net proceeds of $13.1 million after deducting commissions and offering expenses of $0.3 million. During the three months ended June 30, 2026, the Company sold 389,806 shares of its common stock under the ATM at an average price per share of $30.75 for gross proceeds of $12.0 million and net proceeds of $11.7 million after deducting commissions and offering expenses of $0.3 million.

Previous wording

As of March 31, 2026, we had $236.9 million in cash and cash equivalents and an accumulated deficit of $248.0 million. Based on our current business plans, management believes that our cash, cash equivalents and marketable securities on hand at March 31, 2026 are sufficient to meet our operating requirements for at least the next 12 months from the issuance of the consolidated financial statements included in this Quarterly Report. However, our estimates are based on assumptions that may prove to be incorrect, and we could exhaust our capital resources sooner than expected. We may require additional funding to support our research programs, clinical development, and general operations. There can be no assurance that additional financing, whether through public or private equity, debt, collaborations, or licensing arrangements, will be available on acceptable terms, or at all.

Current wording

As of June 30, 2026, we had $227.1 million in cash and cash equivalents and an accumulated deficit of $270.3 million. Based on our current business plans, management believes that our cash, cash equivalents and marketable securities on hand at June 30, 2026 are sufficient to meet our operating requirements for at least the next 12 months from the issuance of the consolidated financial statements included in this Quarterly Report. However, our estimates are based on assumptions that may prove to be incorrect, and we could exhaust our capital resources sooner than expected. We may require additional funding to support our research programs, clinical development, and general corporate operations. There can be no assurance that additional financing, whether through public or private equity, debt, collaborations, or licensing arrangements, will be available on acceptable terms, or at all.

Previous wording

The following table shows a summary of our cash flows for the three months ended March 31, 2026 and 2025:

Current wording

The following table shows a summary of our cash flows for the six months ended June 30, 2026 and 2025:

Previous wording

Net cash used in operating activities was $18.4 million for the three months ended March 31, 2026. Cash used in operations was primarily used to fund development of our product candidates, resulting in a net loss of $25.2 million, partially offset by non-cash charges of $4.0 million. Changes in operating assets and liabilities, including the timing of vendor payments and lease repayments, had an effect of $2.8 million on cash used in operating activities.

Current wording

Net cash used in operating activities was $39.9 million for the six months ended June 30, 2026. Cash used in operations was primarily used to fund development of our product candidates, resulting in a net loss of $47.5 million, partially offset by non-cash charges of $8.8 million. Changes in operating assets and liabilities, including the timing of vendor payments and lease repayments, had an effect of $1.1 million on cash used in operating activities.

Previous wording

Net cash used in operating activities was $13.1 million for the three months ended March 31, 2025. Cash used in operating activities was primarily used to fund our operations to develop our product candidates, resulting in a net loss of $15.9 million partially offset by non-cash charges of $3.0 million.

Current wording

Net cash used in operating activities was $27.8 million for the six months ended June 30, 2025. Cash used in operating activities was primarily used to fund our operations to develop our product candidates, resulting in a net loss of $35.9 million partially offset by non-cash charges of $6.5 million and changes in operating assets and liabilities related to the timing of the vendor payments of $1.6 million.

Previous wording

Net cash used in investing activities during the three months ended March 31, 2026 and 2025 was nominal and related to the purchase and sale of property and equipment.

Current wording

Net cash used in or provided by investing activities during the six months ended June 30, 2026 and 2025 was nominal and related to the purchase and sale of property and equipment.

Previous wording

Net cash provided by financing activities was $0.8 million for the three months ended March 31, 2026, primarily due to net proceeds of $1.3 million received from shares sold under the ATM offset by payments for employee taxes related to the net share settlement of equity awards, whereby a portion of vested shares was withheld to satisfy employees’ tax withholding obligations of $0.4 million.

Current wording

Net cash provided by financing activities was $12.5 million for the six months ended June 30, 2026, primarily due to net proceeds of $13.1 million received from shares sold under the ATM offset by payments for employee taxes related to the net share settlement of equity awards, whereby a portion of vested shares was withheld to satisfy employees’ tax withholding obligations of $0.5 million.

Previous wording

Net cash provided by financing activities was $178.1 million for the three months ended March 31, 2025, primarily due to net proceeds of $177.3 million from the sale of shares in a private offering and $1.0 million in proceeds from the exercise of stock options.

Current wording

Net cash provided by financing activities was $174.0 million for the six months ended June 30, 2025, primarily due to net proceeds of $173.1 million from the sale of shares in a private offering and $1.2 million in proceeds from the exercise of stock options.

Previous wording

We expect our expenses to increase in connection with our ongoing activities, particularly as we continue the research and development of, continue or initiate clinical trials of, and seek marketing approval for, our product candidates including our lead product candidates TX45 and TX2100. In addition, if we obtain marketing approval for TX45, TX2100 or any of our other product candidates, we expect to incur significant commercialization expenses related to program sales, marketing, manufacturing and distribution to the extent that such sales, marketing and distribution are not the responsibility of potential collaborators. Furthermore, we expect to incur additional costs associated with operating as a public company. Accordingly, we will need to obtain substantial additional funding in connection with our continuing operations. If we are unable to raise capital when needed or on attractive terms, we would be forced to delay, reduce or eliminate our research and development programs or future commercialization efforts.

Current wording

We expect our expenses to increase in connection with our ongoing activities, particularly as we continue the research and development of, continue or initiate clinical trials of, and seek marketing approval for, our product candidates including our lead product candidates TX45 and TX2100. In addition, if we obtain marketing approval for TX45, TX2100 or any of our other product candidates, we expect to incur significant commercialization expenses related to sales, marketing, manufacturing and distribution to the extent that such sales, marketing and distribution are not the responsibility of potential collaborators. Furthermore, we expect to incur additional costs associated with operating as a public company. Accordingly, we will need to obtain substantial additional funding in connection with our continuing operations. If we are unable to raise capital when needed or on attractive terms, we would be forced to delay, reduce or eliminate our research and development programs or future commercialization efforts.

Previous wording

the costs of operating as a publicly traded company;

Current wording

the costs of operating as a publicly traded company and supporting our anticipated organizational growth;

Previous wording

Identifying potential product candidates and conducting preclinical studies and clinical trials is a time-consuming, expensive and uncertain process that takes many years to complete, and we may never generate the necessary data or results required to obtain marketing approval and achieve product sales. In addition, our product candidates, if approved, may not achieve commercial success. Our commercial revenues, if any, will be derived from sales of product candidates that we do not expect to be commercially available for many years, if at all. Accordingly, we will need to continue to rely on additional financing to achieve our business objectives.

Current wording

Identifying potential product candidates and conducting preclinical studies and clinical trials is a time-consuming, expensive and uncertain process that takes many years to complete, and we may never generate the necessary data or results required to obtain marketing approval and achieve product sales. In addition, our product candidates, if approved, may not achieve commercial success. Our commercial revenues, if any, will be derived from sales of product candidates that we do not expect to be commercially available for many years, if at all. Accordingly, we will need to continue to rely on additional financing to achieve our business objectives. Adequate additional financing may not be available to us on acceptable terms, or at all. Until such time, if ever, as we can generate substantial product revenues, we expect to finance our cash needs through a combination of equity offerings, debt financings, collaborations, strategic alliances and licensing arrangements. Debt 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.

Previous wording

We have lease obligations for certain laboratory equipment and office and laboratory space under non-cancelable operating and finance leases. The leases expire at various times through 2029. Minimum lease payments under these agreements are $1.7 million in 2026, $1.9 million in 2027, $2.0 million in 2028, and $0.2 million in 2029. These amounts reflect enforceable obligations under non-cancelable contracts and do not include commitments that can be terminated without significant penalty.

Current wording

We have lease obligations for certain office and laboratory space and laboratory equipment under non-cancelable operating and finance leases. The leases expire at various times through 2029. Minimum lease payments under these agreements are $1.3 million for the remainder of 2026, $1.9 million in 2027, $2.0 million in 2028, and $0.2 million in 2029. These amounts reflect enforceable obligations under non-cancelable contracts and do not include commitments that can be terminated without significant penalty.