Analogy 1: An early-stage Biogen, focused on blood, muscle, and lung disorders.

Analogy 2: A clinical-stage Vertex Pharmaceuticals, specializing in rare blood and bone diseases.

Analogy 3: A younger Regeneron, but concentrating on different therapeutic areas.

• KER-050 (elosakembat): A novel ACVR2A ligand trap in clinical development for the treatment of hematological disorders such as Myelodysplastic Syndromes (MDS) and Myelofibrosis (MF).
• KER-012: An oral ACVR1/ACVR2B inhibitor being investigated for the treatment of Pulmonary Arterial Hypertension (PAH) and other fibrotic and oncological indications.
• KER-065: An oral ACVR1/BMP inhibitor in development for the treatment of anemia in various hematological conditions.

Keros Therapeutics (KROS) is a clinical-stage biopharmaceutical company focused on discovering, developing, and commercializing novel treatments for a wide range of debilitating diseases.

As a clinical-stage company, Keros Therapeutics does not currently have any approved products on the market generating sales revenue. Therefore, it does not have "major customers" in the traditional sense of selling products or services at this time.

The company's primary focus is on research and development, funded mainly through equity financing. Future potential revenue for Keros Therapeutics would typically come from:

• Licensing or collaboration agreements with larger pharmaceutical companies (representing a business-to-business model).
• Eventual direct product sales after regulatory approval, either through its own commercialization efforts or through partners, to distributors, pharmacies, and healthcare providers (which would then serve individual patients).

Because Keros Therapeutics does not currently sell products, it does not primarily sell to other companies nor primarily to individuals. Consequently, there are no major customer companies to list, nor categories of individual customers to describe, based on current sales activity.

Jasbir S. Seehra, Ph.D., Chief Executive Officer, President, and Chair of the Board

Dr. Seehra has served as Chief Executive Officer of Keros Therapeutics since December 2015 and became President in August 2025. He was appointed Chair of the Board in July 2024. Prior to joining Keros, Dr. Seehra served as Chief Scientific Officer at Ember Therapeutics. He was also a Co-founder and Chief Scientific Officer of Acceleron Pharma. Previously, he held the position of Vice President of Biological Chemistry at Wyeth and led the small molecule lead discovery effort at Genetics Institute, where he contributed to building their drug discovery capabilities. Dr. Seehra holds a B.Sc. and Ph.D. in Biochemistry from the University of Southampton and completed postdoctoral work at the Massachusetts Institute of Technology. He also serves on the board of directors of Eloxx Pharmaceuticals.

Keith Regnante, Chief Financial Officer

Mr. Regnante joined Keros Therapeutics as Chief Financial Officer in February 2020. Before Keros, he served as Chief Financial Officer at Wave Life Sciences, a period that included significant organizational growth, clinical pipeline advancements, and multiple capital raises. Prior to Wave, Mr. Regnante was a Vice President of Finance at Shire, where he managed finance for a global Research & Development organization. He also held various positions of increasing responsibility at Biogen, leading finance teams for Corporate Finance, Research & Development, and Business Development. Earlier in his career, he worked as a Consultant with The Boston Consulting Group. Mr. Regnante earned his MBA from the MIT Sloan School of Management and a BA in Economics from Tufts University.

Lorena Lerner, Ph.D., Chief Scientific Officer

Dr. Lerner was promoted to Chief Scientific Officer in August 2025. Before this promotion, she served as the company's Senior Vice President for Research.

Esther Cho, Senior Vice President & General Counsel

Ms. Cho serves as the Senior Vice President and General Counsel at Keros Therapeutics.

John Oram, Senior Vice President, Program and Portfolio Management

Mr. Oram is the Senior Vice President of Program and Portfolio Management at Keros Therapeutics.

1. Clinical Trial Success and Product Development: Keros Therapeutics' business heavily relies on the successful development, regulatory approval, and commercialization of its product candidates, including KER-065 and elritercept. There is a significant risk of delays in initiating, enrolling, or completing clinical trials, and early or interim results may not accurately predict final outcomes. A notable recent example is the voluntary halting of all dosing in the Phase 2 TROPOS trial for cibotercept (KER-012) due to safety concerns related to pericardial effusion adverse events, which led to a substantial drop in the company's stock value. The failure of any key product candidate in clinical trials or to gain regulatory approval would materially harm the business.
2. Limited Operating History, Historical Losses, and Need for Additional Funding: Keros has a limited operational history and has consistently incurred losses. As a clinical-stage company, it requires substantial capital to fund its research and development activities, including ongoing and future clinical trials, and potential commercialization efforts. While the company has reported sufficient cash and cash equivalents to fund operations into 2029, the need for additional financing is a recurring risk, especially if development timelines are extended or expenses increase beyond current projections.
3. Competition and Intellectual Property: The biopharmaceutical industry is highly competitive, and Keros competes with numerous third parties that are developing or have developed products for similar therapeutic uses. Maintaining and protecting its intellectual property (e.g., patents, trade secrets) is crucial to Keros's ability to commercialize its product candidates and sustain its business. The failure to obtain, maintain, or protect its intellectual property could significantly undermine its competitive position.

Merck's recently approved drug, Sotatercept (brand name Winrevair), poses a clear emerging threat to Keros Therapeutics. Sotatercept, which received FDA approval in March 2024, is a first-in-class activin receptor type IIA-Fc fusion protein developed for the treatment of Pulmonary Arterial Hypertension (PAH). It operates by rebalancing TGF-beta superfamily signaling, a mechanism conceptually similar to Keros's own pipeline candidate KER-012, which is also being developed for PAH and other fibrotic and cardiovascular disorders. Sotatercept has demonstrated significant efficacy in Phase 3 trials (STELLAR trial), establishing itself as a disease-modifying therapy and setting a new high bar in the PAH treatment landscape. This creates a formidable competitive environment for Keros's KER-012, which will need to demonstrate superior efficacy, safety, or other compelling advantages to capture market share against an already approved, highly effective, and pioneering drug in the same therapeutic area.

KER-050 (elritercept)

• Myelodysplastic Syndromes (MDS): The market for MDS is projected to reach $1.5 billion globally by 2030.
• Myelofibrosis (MF): The myelofibrosis market in the seven major markets (7MM), which includes the United States, EU4 (Germany, Spain, Italy, France), the United Kingdom, and Japan, was approximately $2.2 billion in 2024. This market is anticipated to grow to $5.6 billion by 2034, with a compound annual growth rate (CAGR) of 9% from 2025 to 2034. The United States alone accounted for nearly $1.7 billion of this market in 2024.

KER-012 (cibotercept)

• Pulmonary Arterial Hypertension (PAH): The global Pulmonary Arterial Hypertension drug market is estimated at $8.58 billion in 2025 and is projected to reach $12.81 billion by 2032, with a CAGR of 5.9% from 2025 to 2032. Another estimate values the global market at $8.48 billion in 2025, reaching $13.50 billion by 2034, with a CAGR of 5.30%. The U.S. PAH market size was approximately $2.31 billion in 2024 and is expected to grow to around $3.90 billion by 2034, demonstrating a CAGR of 5.37% from 2025 to 2034. North America held the largest revenue share of 41% in the PAH market in 2024.

KER-065

• Obesity: The weight loss market is expected to exceed $100 billion globally by 2030.
• Duchenne Muscular Dystrophy (DMD): The global Duchenne Muscular Dystrophy market across the seven major markets is expected to reach $5.2 billion by 2033.

1. Milestone Payments from Elritercept (KER-050) Partnership with Takeda: Keros Therapeutics is eligible to receive significant development, commercial, and sales milestone payments totaling up to $1.1 billion, in addition to tiered annual net sales royalties, as part of its global license agreement with Takeda Pharmaceuticals for elritercept (KER-050). Takeda's plan to advance elritercept into a Phase 3 clinical trial for myelodysplastic syndromes (MDS) positions Keros to recognize these milestone payments as the development progresses.
2. Royalties from Elritercept (KER-050) Sales: Beyond milestone payments, Keros Therapeutics stands to generate future revenue from tiered annual net sales royalties on elritercept if successfully commercialized by Takeda. This long-term revenue stream will commence upon market approval and sales of the drug.
3. Advancement and Potential Commercialization of KER-065 for Duchenne Muscular Dystrophy (DMD): Keros plans to initiate a Phase 2 clinical trial for KER-065 in patients with Duchenne muscular dystrophy (DMD) in the first quarter of 2026. Successful progression through clinical trials and eventual commercialization of KER-065, addressing a significant unmet medical need in a market with few therapies, could become a substantial driver of revenue growth.

Share Repurchases

• Keros Therapeutics announced a comprehensive $375 million capital return program in October 2025.
• As part of this program, Keros repurchased approximately $181 million in shares from ADAR1 Capital Management and Pontifax Venture Capital at $17.75 per share, with these transactions closing on October 15, 2025.
• The company plans to launch a tender offer by the end of October 2025 to repurchase up to an additional $194 million of common stock at $17.75 per share.

Share Issuance

• Keros Therapeutics went public in 2020, raising net proceeds of $100.1 million through an initial public offering at $16 per share.
• In November 2020, the company conducted a public offering, raising $130 million by issuing 2,600,000 shares at $50 per share.
• In January 2024, Keros closed an upsized underwritten public offering of 4,025,000 shares of common stock at $40.00 per share, which included the full exercise of the underwriters' option.

Inbound Investments

• Keros Therapeutics entered into a global license agreement with Takeda Pharmaceuticals U.S.A., Inc. for its product candidate, elritercept (formerly KER-050).
• Under this agreement, Keros received an upfront payment of $200 million and is eligible for potential development, registration, and commercial milestone payments exceeding $1.1 billion, in addition to tiered royalties.
• Keros received a $10 million development milestone payment in July 2025 following the dosing of the first patient in Takeda's Phase 3 trial for myelodysplastic syndromes (MDS).

Capital Expenditures

• Keros Therapeutics anticipates that its cash and cash equivalents as of September 30, 2025, after accounting for the $375.0 million capital return program, will be sufficient to fund its operating expenses and capital expenditure requirements into the first half of 2028.
• The proceeds from the January 2024 public offering were expected to fund the company's operating expenses and capital expenditure requirements into 2027.