Apogee Therapeutics, Inc.

Previous wording

Our pipeline comprises multiple antibody programs being developed initially for the treatment of I&I indications as monotherapies and combinations, including APG777, APG279, APG273, APG990, APG333 and APG808. With four validated targets in our portfolio, we are seeking to achieve best-in-class efficacy and dosing through monotherapies and combinations of our novel antibodies. Based on a broad pipeline and depth of expertise, we believe we can deliver value and meaningful benefit to patients underserved by today’s standard of care. We believe each of our programs has potential for broad application across multiple I&I indications.

Current wording

Our pipeline comprises multiple antibody programs being developed initially for the treatment of I&I indications as monotherapies and combinations, including zumilokibart (APG777), APG279 (zumilokibart + APG990), APG273 (zumilokibart + APG333), and APG808 (each a “program” or “product candidate”). With four validated targets in our portfolio, we are seeking to achieve best-in-class efficacy and dosing through monotherapies and combinations of our novel antibodies. Based on a broad pipeline and depth of expertise, we believe we can deliver value and meaningful benefit to patients underserved by today’s standard of care. We believe each of our product candidates has potential for broad application across multiple I&I indications.

Previous wording

APG777 is a subcutaneous (“SQ”) extended half-life monoclonal antibody (“mAb”) targeting IL-13. In August 2023, we announced the dosing of our first participant in our first clinical trial for APG777. In 2024, we announced positive interim safety and pharmacokinetic (“PK”) data from this trial with APG777 demonstrating a potential best-in-class PK profile, including a half-life of 77 days, supporting the potential for every three- to six- month maintenance dosing in AD. Single doses of APG777 demonstrated a deep and sustained effect on pharmacodynamic (“PD”) markers out to approximately 12 months. APG777 was well-tolerated across all dose groups. In May 2024, we announced the dosing of our first participant in the Phase 2 APEX trial. In July 2025, we announced positive 16-week data from the Part A portion of the APEX Phase 2 clinical trial of APG777.

Current wording

In March 2024, we announced positive interim safety and pharmacokinetic (“PK”) data from this trial with zumilokibart demonstrating a potential best-in-class PK profile, including a half-life of 77 days, supporting the potential for every three- to six- month maintenance dosing in AD. Single doses of zumilokibart demonstrated a deep and sustained effect on pharmacodynamic (“PD”) markers out to approximately 12 months. Zumilokibart was well-tolerated across all dose groups.

Previous wording

The APEX trial is a randomized, placebo-controlled study evaluating APG777 in patients with moderate-to-severe AD. Part A of the trial enrolled 123 adult patients who were randomized 2:1 to APG777 versus placebo and received an induction regimen dosing of 720mg at Weeks 0 and 2, followed by 360mg at Weeks 4 and 12. The primary endpoint for the induction arm of Part A was percentage change in Eczema Area Severity Index (“EASI”) score from baseline at Week 16. Secondary endpoints included EASI-75, EASI-90, Validated Investigator Global Assessment (“vIGA”) 0/1 and Itch Numeric Rating Scale (“NRS”) at Week 16. In non-head-to-head trial comparisons, the initial 16-week findings from Part A include efficacy results, which compare favorably versus standard of care across endpoints as well as rapid onset of itch relief and lesion reduction, and a favorable safety profile consistent with its class.

Current wording

In July 2025, we announced positive 16-week data from the Part A portion of the APEX Phase 2 clinical trial. Part A of the trial enrolled 123 adult patients who were randomized 2:1 to zumilokibart versus placebo and received an induction regimen dosing of 720mg at Weeks 0 and 2, followed by 360mg at Weeks 4 and 12. The primary endpoint for the induction arm of Part A was percentage change in Eczema Area Severity Index (“EASI”) score from baseline at Week 16. Secondary endpoints included EASI-75, EASI-90, Validated Investigator Global Assessment (“vIGA”) 0/1 and Itch Numeric Rating Scale (“Itch NRS”) at Week 16. In non-head-to-head trial comparisons, the initial 16-week findings from Part A included efficacy results, which compared favorably versus standard of care across endpoints, as well as rapid onset of itch relief and lesion reduction, and a favorable safety profile consistent with its class.

Previous wording

EASI-90 of 33.9% compared to placebo of 14.7% (p < 0.05). Treatment of patients with APG777 led to rapid onset of itch relief and achieved a statistically significant reduction by Week 1, with a 50.7% reduction of Itch NRS from baseline compared to placebo of 23.2% (p < 0.01) at Week 16. APG777 was well tolerated, with 56.1% of APG777-exposed patients experiencing treatment-emergent adverse events (“TEAEs”) (vs. 63.4% in placebo). The most common TEAEs, occurring in more than 5% of patients, were non-infective conjunctivitis (14.6% vs. 2.4% in placebo), upper respiratory tract infection (8.5% vs 12.2% in placebo), nasopharyngitis (4.9% vs. 12.2% in placebo), and pain in extremity (0.0% vs. 7.3% in placebo) with the latter three being numerically lower in APG777 treated patients compared to placebo. Serious TEAEs were rare for APG777-exposed patients (1.2% vs. 2.4% in placebo). The discontinuation rate due to adverse events was low for APG777-exposed patients (2.4%). There were no injection site reactions in the APG777 treated group.

Current wording

The Part A trial met its primary endpoint, with zumilokibart showing significantly greater least squares mean percent change from baseline at Week 16 with an EASI reduction of 71.0% compared to placebo of 33.8% (p < 0.001). Zumilokibart showed the highest absolute and placebo-adjusted EASI-75 of any biologic in a 16-week global study with 66.9% of patients treated with zumilokibart achieving EASI-75 compared to 24.6% on placebo (p < 0.001). Pre-specified sensitivity analysis showed consistent results in both moderate and severe patients based on baseline EASI score. The results demonstrated a vIGA 0/1 of 34.9% compared to placebo of 17.3% (p < 0.05) and an EASI-90 of 33.9% compared to placebo of 14.7% (p < 0.05). Treatment of patients with zumilokibart led to rapid and deep onset of itch relief and achieved a statistically significant reduction by Week 1, with a 50.7% reduction of Itch NRS from baseline compared to placebo of 23.2% (p < 0.01) at Week 16. Zumilokibart was well-tolerated, with 56.1% of zumilokibart -exposed patients experiencing treatment-emergent adverse events (“TEAEs”) (vs. 63.4% in placebo). The most common TEAEs, occurring in more than 5% of patients, were non-infective conjunctivitis (14.6% vs. 2.4% in placebo), upper respiratory tract infection (8.5% vs 12.2% in placebo), nasopharyngitis (4.9% vs. 12.2% in placebo), and pain in extremity (0.0% vs. 7.3% in placebo) with the latter three being numerically lower in zumilokibart treated patients compared to placebo. Serious TEAEs were rare for zumilokibart -exposed patients (1.2% vs. 2.4% in placebo). The discontinuation rate due to adverse events was low for zumilokibart -exposed patients (2.4%). There were no injection site reactions in the zumilokibart treated group. In addition, improvement in asthma and sinusitis, as measured by improvements in the Asthma Control Questionnaire and Sinonasal Outcome Test in patients with comorbid asthma or sinusitis, was observed, which reflect zumilokibart’s potential to broadly impact Type 2 inflammatory disease.

Previous wording

All Part A patients that benefited from treatment in the induction arm will have the opportunity to continue to APG777 maintenance treatment, which will evaluate three and six-month dosing intervals. In February 2025, we also announced that we had commenced dosing of the Part B portion of the APEX Phase 2 trial, and, in October 2025, we announced that we had increased the expected patient population to 320 patients. We expect to complete enrollment in the Part B portion of the APEX Phase 2 trial by the end of 2025. Part B is testing a higher and a lower dose of APG777. We anticipate topline maintenance data from Part A in the first quarter of 2026, 16-week topline induction data from Part B in the second quarter of 2026 and initiation of a Phase 3 trial in AD in the second half of 2026.

Current wording

In February 2025, we announced that we had commenced dosing of the Part B portion of the APEX Phase 2 trial. Part B is testing low, medium (Part A dose), and high dose regimens against placebo. In January 2026, we announced that we completed Part B enrollment ahead of schedule and exceeded target enrollment with a total of 347 patients. We expect to report 16-week topline induction data from Part B in the second quarter of 2026. Subject to positive results and regulatory alignment with the U.S. Food and Drug Administration (the “FDA”), we plan to initiate Phase 3 trials in AD in the second half of 2026, enabling a potential launch of zumilokibart for the treatment of AD in 2029.

Previous wording

In April 2025, we initiated a Phase 1b trial in patients with asthma with topline results expected in the first quarter of 2026. Results from this trial, in addition to topline induction data from the Part B portion of the APEX Phase 2 trial in AD, will allow us to determine dose selections for further expansion indications in 2027 and beyond, including but not limited to asthma and EoE. We expect to announce plans for Phase 2b trials in asthma and EoE in 2026. Based on our clinical data, we expect to further evaluate additional opportunities to develop APG777 for other I&I indications, including alopecia areata, chronic rhinosinusitis with nasal polyps (“CRSwNP”), chronic spontaneous urticaria, and prurigo nodularis.

Current wording

We expect that results from the Phase 1b trial of zumilokibart for the treatment of asthma, in addition to topline induction data from the Part B portion of the APEX Phase 2 trial in AD, will allow us to determine dose selections for further expansion indications in 2027 and beyond, including but not limited to asthma and EoE. We expect to announce plans for the Phase 2 ASPIRE trial for the treatment of asthma and the Phase 2 ELEVATE trial for the treatment of EoE in the second half of 2026. Based on our clinical data, we expect to further evaluate additional opportunities to develop zumilokibart for other I&I indications, including alopecia areata, chronic rhinosinusitis with nasal polyps, chronic spontaneous urticaria, and prurigo nodularis.

Previous wording

In addition, we plan to evaluate APG777 in combination with other investigational therapies within our pipeline to potentially enable greater efficacy for I&I conditions. The first of these combinations is APG279, which combines APG777 with APG990, our novel, SQ, half-life extended mAb targeting OX40L.

Current wording

In addition, we plan to evaluate zumilokibart in combination with other investigational therapies within our pipeline to potentially enable greater efficacy for I&I conditions. The first of these combinations is APG279, which combines zumilokibart with APG990, our novel, SQ, half-life extended mAb targeting OX40L. We are also evaluating APG273, which combines zumilokibart with APG333, our novel, SQ, half-life extended mAb targeting thymic stromal lymphopoietin (“TSLP”).

Previous wording

APG990 – anti-OX40L antibody, same mechanism of action as amlitelimab and APG279, a potential combination therapy of APG777 + APG990

Current wording

APG279 – Combination of zumilokibart (APG777) and APG990 – anti-OX40L antibody

Previous wording

We plan to develop APG777 and APG990 (“APG279”) together as a potential first-in-class coformulation for the treatment of AD by combining deep and sustained inhibition of Type 2 inflammation via APG777’s inhibition of IL-13 with broader inhibition of Type 1-3 inflammation through APG990’s inhibition of OX40L. APG279 has been shown to retain stability, injectability, and convenience of individual components in preclinical studies. In preclinical studies, APG279 has also demonstrated broad inhibition of Type 1, Type 2 and Type 3 inflammation, similar to what was seen with Janus kinase (“JAK”) inhibition, but with potential for better tolerability than JAK inhibitors. In preclinical toxicology studies, the combination of APG777 and APG990 showed no findings at any dose level, including the highest dose tested of 150-mg/kg per agent per week. We believe these combined mechanisms offer the potential for improved clinical responses over monotherapy while our planned approach of coformulating two extended half-life mAbs holds the potential for best-in-class dosing.

Current wording

We are developing zumilokibart and APG990 together as APG279, a potential first-in-class coformulation for the treatment of AD by combining deep and sustained inhibition of Type 2 inflammation via zumilokibart’s inhibition of IL-13 with broader inhibition of Type 1-3 inflammation through APG990’s inhibition of OX40L. APG990 is an SQ extended half-life mAb that utilizes advanced antibody engineering to target OX40L.

Previous wording

APG990 is an SQ extended half-life mAb that utilizes advanced antibody engineering to target OX40L. In August 2024, we initiated a Phase 1 clinical trial of APG990 in healthy volunteers and in March 2025, we announced positive interim safety and PK data from the APG990 Phase 1 clinical trial. PK data showed a half-life of approximately 60 days across doses tested. APG990, in single doses up to 1,200mg, was well tolerated and showed a favorable safety profile, consistent with other assets targeting OX40L.

Current wording

SQ APG990 evaluated in the study included 75mg, 150mg, 300mg, 600mg and 1,200mg. In March 2025, we announced positive interim safety and PK data from the trial. PK data showed a half-life of approximately 60 days across doses tested. APG990, in single doses up to 1,200mg, was well-tolerated and showed a favorable safety profile, consistent with other assets targeting OX40L. The most common (≥10%) TEAEs were headache. 53% of participants observed at least one TEAE and there were no Grade 3 TEAEs related to study drug or severe adverse events. No adverse events led to study discontinuation. There were no cases of pyrexia or chills.

Previous wording

In July 2025, we announced that we commenced dosing in the Phase 1b trial of APG279 against DUPIXENT in approximately 50 patients with moderate-to-severe AD with a data readout expected in the second half of 2026. The initial clinical trial of APG279 is being conducted as a coadministration of APG777 and APG990. We plan to advance the development of APG279 in future studies as a coformulation. The PK data for APG990, when considered together with APG279 coformulation data, provides the potential for dosing the combination two to four times per year with a single 2 mL coformulated injection.

Current wording

In July 2025, we commenced dosing in the Phase 1b trial of APG279 against DUPIXENT in patients with moderate-to-severe AD. Enrollment was completed with 86 patients, and we expect a data readout in the second half of 2026. The initial clinical trial of APG279 is being conducted as a coadministration of zumilokibart and APG990. We plan to advance the development of APG279 in future studies as a coformulation. The PK data for APG990, when considered together with APG279 coformulation data, provides the potential for dosing the combination two to four times per year with a single 2 mL coformulated injection.

Previous wording

APG333 – anti-TSLP antibody, same mechanism of action as TEZPIRE (tezepelumab) and APG273, a potential combination therapy of APG777 + APG333

Current wording

APG273 – Combination of zumilokibart (APG777) and APG333 - anti-TSLP antibody

Previous wording

In May 2025, we announced positive interim results from the Phase 1b trial of APG808 in patients with mild-to-moderate asthma. The trial was a double-blind, placebo-controlled, multiple-dose trial, which evaluated the safety and tolerability of APG808 in 22 adult patients with mild-to-moderate asthma. The trial also evaluated fractional exhaled nitric oxide concentration (“FeNO”), thymus and activation-regulated chemokine (“TARC”), and pSTAT6. Participants were randomized 3:1, receiving 600mg of APG808 or placebo on day 1 and day 29.

Current wording

In May 2025, we announced positive interim results from the Phase 1b trial of APG808 in patients with mild-to-moderate asthma. The trial was a double-blind, placebo-controlled, multiple-dose trial, which evaluated the safety and tolerability of APG808 in 22 adult patients with mild-to-moderate asthma. The trial also evaluated FeNO, thymus and activation-regulated chemokine (“TARC”), and pSTAT6. Participants were randomized 3:1, receiving 600mg of APG808 or placebo on day 1 and day 29.

Previous wording

The results demonstrated that APG808 was well-tolerated, with multiple doses of APG808 resulting in rapid suppression of FeNO, a biomarker of Type 2 inflammation that is associated with exacerbations in asthma, with a maximal robust FeNO decrease from baseline of 53% and sustained FeNO decrease from baseline of 50% at 12 weeks. APG808 also demonstrated sustained and near-complete reduction in pSTAT6 as well as deep reduction of TARC maintained through 12 weeks. The most common TEAEs observed were headache, injection site erythema, and upper respiratory tract infections. There were no Grade 3 TEAEs or severe adverse events, and no adverse events led to study discontinuation.

Current wording

The results demonstrated that APG808 was well-tolerated, with multiple doses of APG808 resulting in rapid suppression of FeNO, with a maximal robust FeNO decrease from baseline of 53% and sustained FeNO decrease from baseline of 50% at 12 weeks. APG808 also demonstrated sustained and near-complete reduction in pSTAT6 as well as deep reduction of TARC maintained through 12 weeks. The most common TEAEs observed were headache, injection site erythema, and upper respiratory tract infections. There were no Grade 3 TEAEs or severe adverse events, and no adverse events led to study discontinuation.

Previous wording

On October 10, 2025, pursuant to our Registration Statement on Form S-3, which became effective in August 2024 (File No 333-281503), we issued and sold an aggregate of 8,048,782 shares of common stock (inclusive of 1,097,561 shares of common stock pursuant to the exercise in full of the underwriters’ option to purchase additional shares) at a public offering price of $41.00 per share, and, in lieu of common stock to certain investors, pre-funded warrants to purchase up to 365,853 shares of common stock at a public offering price of $40.99999 per pre-funded warrant (the “October 2025 Offering”). The pre-funded warrants have an exercise price of $0.00001 per share and are exercisable immediately. The aggregate net proceeds from the offering were $324.1 million after deducting underwriting discounts and commissions and estimated offering expenses payable by the Company.

Current wording

On March 26, 2026, pursuant to our Registration Statement on Form S-3, which became effective in August 2024 (File No 333-281503), we issued and sold an aggregate of 5,750,000 shares of common stock (inclusive of 750,000 shares of common stock pursuant to the exercise in full of the underwriters’ option to purchase additional shares) at a public offering price of $70.00 per share (the “March 2026 Offering”). The aggregate net proceeds from the offering were $377.4 million after deducting underwriting discounts and commissions, and estimated offering expenses payable by us.

Previous wording

We have incurred significant operating losses since inception. Our ability to generate sufficient product revenue to achieve profitability will depend heavily on the successful development and eventual commercialization of any product candidates we may develop. We generated a net loss of $186.5 million for the nine months ended September 30, 2025. As of September 30, 2025, we had an accumulated deficit of $492.4 million. We expect to continue to incur significantly increased expenses for the foreseeable future if and as we:

Current wording

We have incurred significant operating losses since inception. Our ability to generate product revenue sufficient to achieve profitability will depend heavily on the successful development and eventual commercialization of any programs we may develop. We generated a net loss of $74.1 million for the three months ended March 31, 2026. As of March 31, 2026, we had an accumulated deficit of $635.9 million. We expect to continue to incur significantly increased expenses for the foreseeable future if and as we continue to operate our business.

Previous wording

expenses incurred under agreements with clinical trial sites that conduct research and development activities on our behalf;

Current wording

expenses incurred under agreements with clinical trial sites and clinical research organizations (“CROs”) that conduct research and development activities on our behalf, including clinical trial execution, project management, data management and related outsourced services;

Previous wording

Our primary focus since inception has been the identification and development of our pipeline programs. Our research and development costs primarily consist of external costs, such as fees paid to Paragon under the Option Agreements and the License Agreements. We do not separately track or segregate the amount of costs incurred under the Option Agreements due to the early-stage and discovery nature of the services. We do not allocate personnel-related costs by program because these resources are used and these costs are deployed across multiple programs under development, and, as such, are not separately classified.

Current wording

Our primary focus since inception has been the identification and development of our pipeline programs. Our research and development costs primarily consist of external costs, including CRO fees and fees paid to Paragon under the Option Agreements and the License Agreements. We do not separately track or segregate the amount of costs incurred under the Option Agreements due to the early-stage and discovery nature of the services. We do not allocate personnel-related costs by program because these resources are used and these costs are deployed across multiple programs under development, and, as such, are not separately classified.

Previous wording

We expect that our research and development expenses will increase substantially for the foreseeable future as we continue to invest in research and development activities for our programs, and any potential future programs, including investments in manufacturing. The success of programs we may identify and develop will depend on many factors, including the following:

Current wording

We expect that our research and development expenses will increase substantially for the foreseeable future as we continue to invest in research and development activities for our programs, and any potential future programs, including investments in clinical trials and manufacturing. The success of programs we may identify and develop will depend on many factors, including the following:

Previous wording

Any changes in the outcome of any of these variables with respect to the development of programs that we may identify could mean a significant change in the costs and timing associated with the development of such programs. For example, if the U.S. Food and Drug Administration (“FDA”) or another regulatory authority were to require us to conduct clinical trials beyond those that we currently anticipate will be required for the completion of clinical development of a program, or if we experience significant delays in our clinical trials due to patient enrollment or other reasons, we would be required to expend significant additional financial resources and time on the completion of clinical development. We may never obtain regulatory approval for any of our programs.

Current wording

Any changes in the outcome of any of these variables with respect to the development of programs that we may identify could mean a significant change in the costs and timing associated with the development of such programs. For example, if the U.S. Food and Drug Administration (“FDA”) or another regulatory authority were to require us to conduct clinical trials beyond those that we currently anticipate will be required for the completion of clinical development of a program, or if we experience significant delays in our clinical trials due to patient enrollment, macroeconomic events or other reasons, we would be required to expend significant additional financial resources and time on the completion of clinical development. We may never obtain regulatory approval for any of our programs.

Previous wording

General and administrative expenses consist primarily of personnel-related expenses, including salaries, bonuses, and equity-based compensation, for individuals in our executive, finance, legal, operations, human resources, business development, commercial and other administrative functions. Other significant general and administrative expenses include legal fees relating to corporate matters, professional fees for accounting, auditing, tax and administrative consulting services, insurance costs and recruiting costs. These costs relate to the operation of the business, unrelated to the research and development function, or any individual program.

Current wording

General and administrative expenses consist primarily of personnel-related expenses, including salaries, bonuses, and equity-based compensation, for individuals in our executive, finance, legal, IT operations, human resources, business development, commercial and other administrative functions. Other significant general and administrative expenses include legal fees relating to corporate matters, professional fees for accounting, auditing, tax and administrative consulting services, insurance costs and recruiting costs. These costs relate to the operation of the business, unrelated to the research and development function, or any individual program.

Previous wording

As of December 31, 2024, we had U.S. federal NOL carryforwards of approximately $68.1 million, which may be available to reduce future taxable income and have an indefinite carryforward period but are limited in their usage to an annual deduction equal to 80% of annual taxable income. We also had state net operating loss carryforwards of approximately $28.5 million, which will begin to expire in 2043 for state tax purposes. As of December 31, 2024, we also had U.S. federal and research and development tax credit carryforwards of approximately $10.5 million, which may be available to reduce future tax liabilities. We also had California research and development credit carryforwards of approximately $1.5 million. Additionally, we had Massachusetts research and development credit carryforwards of approximately $2.1 million. The U.S. federal and Massachusetts research and development tax credit carryforwards expire at various dates beginning in 2042 and the California research and development tax credit carryforwards do not expire. We have recorded a full valuation allowance against our net deferred tax assets at the balance sheet date.

Current wording

As of December 31, 2025, we had U.S. federal NOL carryforwards of approximately $250.7 million, which may be available to reduce future taxable income and have an indefinite carryforward period but are limited in their usage to an annual deduction equal to 80% of annual taxable income. We also had state net operating loss carryforwards of approximately $94.3 million, which will begin to expire in 2043 for state tax purposes. As of December 31, 2025, we also had U.S. federal and research and development tax credit carryforwards of approximately $16.7 million, which may be available to reduce future tax liabilities. We also had California research and development credit carryforwards of approximately $2.9 million. Additionally, we had Massachusetts research and development credit carryforwards of approximately $1.7 million. The U.S. federal and Massachusetts research and development tax credit carryforwards expire at various dates beginning in 2042 and the California research and development tax credit carryforwards do not expire. We have recorded a full valuation allowance against our net deferred tax assets at the balance sheet date.

Previous wording

Our provision for state income taxes was $0.1 million and $0.2 million for the three and nine months ended September 30, 2025, respectively. There was no provision for state income taxes for the three and nine months ended September 30, 2024.

Current wording

Our provision for state income taxes was $0.1 million and $0.1 million for the three months ended March 31, 2026 and 2025, respectively.

Previous wording

A discussion regarding our financial condition and results of operations for the three and nine months ended September 30, 2025 compared to the three and nine months ended September 30, 2024 is presented below.

Current wording

A discussion regarding our financial condition and results of operations for the three months ended March 31, 2026 compared to the three months ended March 31, 2025 is presented below.