A clinical-stage Alexion Pharmaceuticals, focused on pioneering treatments for severe rare diseases.

Like a nascent Vertex Pharmaceuticals, dedicated to novel rare disease drug development.

• RLYB212: A monoclonal anti-HPA-1a antibody in Phase I clinical trial for the prevention of fetal and neonatal alloimmune thrombocytopenia (FNAIT).
• RLYB211: A polyclonal anti-HPA-1a antibody in Phase 1/2 clinical trial for the prevention of fetal and neonatal alloimmune thrombocytopenia (FNAIT).
• RLYB114: A pegylated complement factor 5 (C5)-targeted Affibody molecule in preclinical development for the treatment of complement-mediated ophthalmic diseases.
• RLYB116: A subcutaneously administered inhibitor of C5 in preclinical development for paroxysmal nocturnal hemoglobinuria and generalized myasthenia gravis.

Rallybio Corporation (RLYB) is a clinical-stage biotechnology company. Its product candidates, such as RLYB212, RLYB211, RLYB114, and RLYB116, are currently in various stages of clinical and preclinical development (Phase I, Phase 1/2, and preclinical).

As a clinical-stage company, Rallybio does not yet have any commercially approved products available for sale. Therefore, the company does not currently have major customers in the traditional commercial sense. Its operations are focused on research, development, and clinical trials rather than the sale of commercial products.

• Exscientia (EXAI)

Steve Uden, M.D. Co-Founder and Chief Executive Officer

Steve Uden is a Co-Founder and Chief Executive Officer of Rallybio, having been appointed CEO effective August 1, 2023. He has over 25 years of experience in R&D leadership roles at global pharmaceutical and biotech firms. Previously, he served as Head of Research at Alexion Pharmaceuticals, where he led collaborations and expanded its research capabilities to include small molecules, RNA-based therapies, and broader protein engineering. Prior to Alexion, Dr. Uden led R&D groups in Japan for Wyeth and Novartis Oncology and held positions at Pfizer. He co-founded Rallybio with Martin Mackay in 2018.

Jonathan I. Lieber, M.B.A. Chief Financial Officer and Treasurer

Jonathan I. Lieber joined Rallybio as Chief Financial Officer on February 1, 2023. He brings over 30 years of experience as a CFO for both public and private life sciences companies and as an investment banker. Most recently, he was the CFO of Applied Genetic Technologies Corporation (AGTC), a publicly traded gene therapy company, where he managed capital raising and oversaw various financial and operational functions. Before AGTC, he was a Managing Director at Danforth Advisors, a private equity-backed firm, providing CFO services and strategic advice to healthcare companies. His prior CFO roles include Histogenics, Repligen, Xcellerex (which was acquired by GE Healthcare), and Altus Pharmaceuticals. Mr. Lieber started his career in healthcare investment banking at Salomon Brothers/Salomon Smith Barney and SG Cowen.

Martin W. Mackay, Ph.D. Co-Founder and Executive Chairman

Martin Mackay is a Co-Founder and Executive Chairman of Rallybio. He served as CEO and Chairman of the Board from Rallybio's founding in 2018 until August 1, 2023, when he transitioned to Executive Chairman. Dr. Mackay has more than 30 years of experience in pharmaceutical and biotech R&D, holding leadership positions at companies such as Pfizer, AstraZeneca, and Alexion. His roles included Executive Vice President and Global Head of Research & Development at Alexion Pharmaceuticals and President of Research & Development at AstraZeneca. He also serves on the Boards of Directors for Charles River Laboratories, Novo Nordisk, and Springworks Therapeutics.

Steven Ryder, M.D. Chief Medical Officer

Steven Ryder possesses over 30 years of leadership experience in global healthcare development, with a notable background in rare diseases. Before joining Rallybio, Dr. Ryder was the Senior Vice President and Chief Development Officer at Alexion Pharmaceuticals, where he was responsible for the global development, registration, and approval of new drug candidates for rare diseases. His career also includes serving as the founding President of Astellas Pharma Global Development and 21 years in development at Pfizer.

Douglas Sheridan, Ph.D. Senior Vice President, Head of Research

Douglas Sheridan has more than 20 years of experience in research and development.

Key Risks to Rallybio (RLYB)

1. Clinical Development and Regulatory Approval Risk: Rallybio's business is highly dependent on the successful clinical development and regulatory approval of its product candidates. The recent discontinuation of RLYB212, previously a lead candidate for the prevention of fetal and neonatal alloimmune thrombocytopenia (FNAIT), after it failed to meet pharmacokinetic (PK) targets in a Phase 2 trial, highlights the inherent and significant risk in drug development. The company's current lead program, RLYB116 (a C5 inhibitor), is in a confirmatory Phase 1 pharmacokinetic/pharmacodynamic study for complement-driven diseases. The failure of RLYB116 or any other pipeline candidate to demonstrate efficacy, safety, or achieve regulatory approval would severely impact the company's prospects and ability to generate revenue.
2. Uncertainty and Value Realization from Merger and Asset Divestiture: Rallybio has recently announced a merger agreement with Candid Therapeutics, which is expected to result in the divestiture of Rallybio's "legacy assets." Current Rallybio shareholders are expected to receive Contingent Value Rights (CVRs) tied to potential proceeds from the sale of these assets, including the preclinical program REV102 and potentially others. There is significant risk regarding the successful and timely divestiture of these assets on favorable terms, and the ultimate value that Rallybio shareholders will realize through the CVRs. The success of the combined entity will also largely depend on Candid's early-stage pipeline.
3. Early-Stage Pipeline and Capital Intensive Nature of Biotech: Even with RLYB116 now the lead candidate, Rallybio's pipeline, particularly in the context of the forthcoming merger, remains largely in early stages of development (e.g., Phase 1, preclinical). Clinical-stage biotechnology companies are inherently capital-intensive, requiring substantial ongoing investment in research, development, and clinical trials. The discontinuation of RLYB212 led to a significant stock price drop and layoffs, underscoring the financial vulnerability associated with an early and concentrated pipeline. The company's ability to secure sufficient funding to advance its remaining pipeline and sustain operations, especially in light of past setbacks and the complexities of the merger, remains a key financial risk.

Rallybio (RLYB) is developing therapies for several severe and rare diseases, each addressing a distinct market opportunity:

• RLYB212 and RLYB211 for the prevention of Fetal and Neonatal Alloimmune Thrombocytopenia (FNAIT): Rallybio projects that RLYB212 alone could represent a market opportunity exceeding $1.6 billion in North America and major European countries. This estimation is based on an epidemiological study indicating that more than 30,000 pregnancies annually in these regions are at higher risk for FNAIT.
• RLYB114 for complement-mediated ophthalmic diseases: The broader global ophthalmic disease therapeutics market was valued at USD 35.54 billion in 2024 and is projected to grow to USD 60.56 billion by 2033, with North America holding a leading share. More specifically, the global complement inhibitors market, which includes therapies for complement-mediated disorders, was valued at USD 25.20 billion in 2024 and is projected to reach USD 273.59 billion by 2032. North America is the leading region in the complement inhibitors market.
• RLYB116 for Paroxysmal Nocturnal Hemoglobinuria (PNH) and Generalized Myasthenia Gravis (gMG):
  • For Paroxysmal Nocturnal Hemoglobinuria (PNH), the global treatment market size was estimated at USD 5.75 billion in 2024 and is projected to reach USD 9.96 billion by 2030. Another estimate places the global PNH drug market at approximately USD 4.45 billion in 2024, with a projection to grow to around USD 14.76 billion by 2034. The United States accounts for a significant portion of the PNH market.
  • For Generalized Myasthenia Gravis (gMG), the global treatment market size was valued at USD 1.8 billion in 2024 and is expected to grow to USD 3.8 billion by 2034. Another report estimated the global market to be USD 1.6 billion in 2025, anticipated to reach USD 2.8 billion by 2032. North America is expected to dominate the myasthenia gravis treatment market.

1. Clinical Advancement of RLYB116
   Rallybio's C5 inhibitor, RLYB116, demonstrated positive Phase 1 data in February 2026, showing complete and sustained inhibition of terminal complement. The company plans to initiate a Phase 2 clinical trial for immune platelet transfusion refractoriness in the second half of 2026, with topline data anticipated in 2027. The successful progression of RLYB116 through these clinical stages enhances its potential for future partnership deals, licensing agreements, or eventual commercialization, all of which would serve as significant revenue drivers.
2. Clinical Development of Cizutamig
   Following the merger with Candid Therapeutics in March 2026, Candid's lead candidate, Cizutamig, is slated to advance into several global Phase II clinical studies for myasthenia gravis and interstitial lung disease. The successful development and achievement of clinical milestones for Cizutamig represent a new and significant revenue growth opportunity for the combined company.
3. Milestone Payments from Strategic Collaborations
   Rallybio has a history of engaging in strategic collaborations, such as the multi-year, multi-target alliance with AbCellera for antibody discovery and the sale of its interest in REV102 to Recursion Pharmaceuticals, which generated $20 million in 2025. Future milestone achievements through existing or new strategic partnerships, including upfront payments or licensing fees for their pipeline candidates, are expected to be key contributors to revenue growth for the combined entity.

Share Issuance

• Rallybio completed its Initial Public Offering (IPO) in July 2021, issuing 7,130,000 shares of common stock at $13.00 per share, resulting in aggregate gross proceeds of approximately $92.7 million.
• A one-for-eight reverse stock split of its common stock was approved by stockholders in January 2026 and became effective on February 6, 2026, to help Rallybio regain compliance with Nasdaq's minimum bid price requirement.
• The company's 2021 Equity Incentive Plan includes an automatic annual increase in its share pool.

Inbound Investments

• Rallybio entered into a collaboration agreement with Johnson & Johnson in the second quarter of 2024, which generated revenue for the company.

Outbound Investments

• In July 2025, Rallybio announced the sale of its interest in REV102, an ENPP1 inhibitor, to its joint venture partner Recursion Pharmaceuticals for up to $25.0 million. This included an upfront equity payment of $7.5 million and potential near-term milestones.

Capital Expenditures

• Capital expenditures for Rallybio are typically low, consistent with a clinical-stage biotechnology company primarily investing in research and development rather than large physical assets. For instance, in Q4 2023, capital expenditures were $0.