What Rallybio does

Rallybio is a clinical-stage biopharmaceutical company developing therapeutics for rare and severe diseases, with therapeutic focus on complement dysregulation and hematology. Founded in 2017 and headquartered in New Haven, Connecticut, the company went public on NASDAQ in 2021 under the ticker RLYB and employs between 11 and 50 people. Its pipeline comprises four core programs: RLYB116, a once-weekly subcutaneous C5 inhibitor built on a licensed Affibody-Albumod fusion protein platform targeting paroxysmal nocturnal hemoglobinuria, generalized myasthenia gravis, and antiphospholipid syndrome; RLYB114, a PEGylated C5 Affibody for intravitreal treatment of complement-driven ophthalmic disease; RLYB332, an anti-matriptase-2 monoclonal antibody for iron overload and severe anemias; and RLYB212, an anti-HPA-1a antibody for prevention of fetal and neonatal alloimmune thrombocytopenia, co-developed with Johnson & Johnson.

Rallybio is pre-revenue with no commercialized products; reported Q3 2025 operating revenue was $0.22 million, supplemented by a one-time $20 million gain on the sale of its REV102 ENPP1 inhibitor program to Recursion Pharmaceuticals. Revenue mechanics, when products reach market, are expected to come from specialty pharmacy and hospital purchasing channels for rare-disease biologics, with potential global commercialization through a Big Pharma partner. Capital sources to date include a $145 million Series B in 2020 led by Pivotal bioVenture Partners, a $50 million public offering in November 2022, the J&J collaboration ($7 million+ in cash and equity), and the $215 million private placement backing the pending Avenzo Therapeutics merger.

Strategically, Rallybio has executed a defensive pivot: it divested REV102 in July 2025, implemented a 1-for-8 reverse stock split in February 2026 to maintain Nasdaq compliance, received a $50 million termination fee when its Candid Therapeutics reverse merger collapsed in May 2026, and announced a definitive merger with oncology developer Avenzo Therapeutics in June 2026 that would leave pre-merger Avenzo equityholders owning approximately 97.2% of the combined company under the ticker AVZO.

Name

Rallybio

Legal name

Rallybio Corporation

Website

https://rallybio.com

Company type

Public

Founded year

2017

Operating status

Operating

Headcount range

11–50 employees

Short description

Rallybio is a clinical-stage biopharmaceutical company developing complement and hematology therapeutics for rare diseases, with a pipeline led by subcutaneous C5 inhibitor RLYB116 and anti-matriptaste-2 antibody RLYB332. It is pre-revenue and is pursuing a reverse merger with Avenzo Therapeutics.

Ownership category

akta.pro rank

Product category

Biopharmaceuticals

NAICS

Biological Product (except Diagnostic) Manufacturing (325414)

SIC

Biological Products, (No Disgnostic Substances) (2836)

akta.pro primary industry

Microbiome-Derived Metabolite Therapeutics (postbiotics) (HLAAAFAB)

Keywords

• Rare disease therapeutics
• Complement inhibitors
• Biopharmaceutical development
• Monoclonal antibody therapies
• Hematology drug development

Headquarters

HQ city

Farmington

HQ country

United States

HQ region

North America

Offices1 record

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Technology or R&D, Personnel, Operations, Marketing or Sales, Supply Chain

Revenue model

1. Pharmaceutical Product Sales: Pre-revenue clinical stage company with no commercialized products. Revenue expected from future sales of rare disease therapeutics upon regulatory approval.
2. Partnership and Collaboration Revenue: Rallybio receives funding and equity investments from strategic partners including Johnson & Johnson for development of RLYB212 for FNAIT.
3. Milestone Payments: Rallybio earns milestone payments tied to clinical development and regulatory achievements, including upfront payments and development-based payments from collaborations.

Go-to-market motion1 record

Distribution channels3 records

Marketing channels5 records

Core offering

Rallybio is a clinical-stage biopharmaceutical company developing a pipeline of novel therapeutics for severe and rare diseases, with primary focus on complement dysregulation and hematology. The company's core pipeline includes RLYB116 (subcutaneous C5 inhibitor for complement-mediated diseases such as PNH, gMG, and APS), RLYB332 (anti-matriptase-2 antibody for iron overload diseases), RLYB114 (intravitreal C5 inhibitor for ophthalmic diseases), and RLYB212 (monoclonal antibody for FNAIT prevention). Rallybio has no commercialized products and is pre-revenue, relying on partnership funding and milestone payments.

Product overview

Rallybio is a clinical-stage biotech company developing a pipeline of novel therapeutics for severe and rare diseases, with focus areas in complement dysregulation and hematology. The core portfolio includes RLYB116 (subcutaneous C5 inhibitor for complement-mediated diseases including PNH, gMG, and APS), RLYB332 (matriptase-2 inhibitor for iron overload diseases), RLYB114 (C5 inhibitor for ophthalmic diseases), and RLYB212 (monoclonal antibody for FNAIT prevention). The company also had a partnership with AbCellera for an undisclosed metabolic disease program. Rallybio sold its REV102 ENPP1 inhibitor program to Recursion Pharmaceuticals.

Differentiator

Problem solved

Functional benefit

Products and services

• RLYB116 A novel, once-weekly, small volume, subcutaneously injected C5 inhibitor (antibody mimetic fusion protein) designed to inhibit Complement Factor 5 for complement-mediated diseases including paroxysmal nocturnal hemoglobinuria (PNH), generalized myasthenia gravis (gMG), and antiphospholipid syndrome (APS).
• RLYB332 A long-acting monoclonal anti-matriptase-2 antibody designed to inhibit MTP-2, thereby increasing hepcidin levels to treat diseases of iron overload and severe anemias including hereditary hemochromatosis, polycythemia vera, myelodysplastic syndrome, beta thalassemia, and sickle cell anemia.
• RLYB114 A C5-targeted Affibody molecule conjugated to polyethylene glycol (PEG) for complement-driven ophthalmic diseases, administered via intravitreal injection for conditions such as age-related macular degeneration (AMD).
• RLYB212 A monoclonal antibody therapeutic aimed at pregnant individuals at risk of fetal and neonatal alloimmune thrombocytopenia (FNAIT), designed to prevent the condition which is a rare but potentially fatal disease affecting fetuses and newborns.

Quantifiable outcome

• RLYB116 demonstrated complete and sustained inhibition of terminal complement at 300mg dose in healthy volunteers with favorable tolerability
• +2 more outcomes

Segments4 records

Ideal customer profiles2 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature3 records

Partnerships

Five partnerships are on record, tiered core and minor.

• Avenzo TherapeuticscoreStrategic or Co-development Partner · 1 June 2026Rallybio announced definitive merger agreement with Avenzo Therapeutics, a cancer drug developer. Combined company will operate as Avenzo Therapeutics and trade on Nasdaq under ticker AVZO. Concurrent $215 million private placement financing. Pre-closing Avenzo equityholders expected to own approximately 97.2% of merged entity. Deal expected to close Q4 2026.
• Candid TherapeuticscoreStrategic or Co-development Partner · 2 March 2026Rallybio announced merger agreement with Candid Therapeutics in a reverse merger transaction. Candid raised over $505 million in concurrent private financing. Combined company expected to have approximately $700 million cash at closing, operating as Candid Therapeutics with ticker CDRX. Deal expected to close mid-2026. Rallybio shareholders to own approximately 3.65% of combined entity.
• Recursion PharmaceuticalsminorStrategic or Co-development Partner · 8 July 2025Rallybio sold its interest in the REV102 ENPP1 inhibitor program to Recursion Pharmaceuticals for up to $25 million including $7.5 million upfront equity payment plus near-term milestones. Rallybio receives low single-digit royalties on future net sales.
• AffibodycoreTechnology or IntegrationRallybio has licensed Affibody technology for development of C5 inhibitors including RLYB116. The Affibody molecule provides high affinity binding to complement factor C5 for terminal complement inhibition.
• AbCelleraminorStrategic or Co-development PartnerPartnership with AbCellera for development of an undisclosed metabolic disease program. AbCellera provides antibody discovery technology.

Scale indicators11 records

Recent moves6 records

Expansion highlights5 records

Broad incumbents

• Alexion (AstraZeneca Rare Disease): Acquired by AstraZeneca for $39B in 2021, Alexion is the dominant player in complement-mediated disease therapeutics (Soliris, Ultomiris). Rallybio's RLYB116 C5 inhibitor is directly aimed at Alexion's PNH/gMG franchise, and Rallybio's founding team (Uden, Mackay) came from Alexion.
• BioMarin Pharmaceutical: Established rare disease biopharma with a portfolio of approved enzyme replacement therapies and gene therapies. BioMarin is comparable to Rallybio in rare disease focus and commercial infrastructure readiness, though at vastly greater scale.
• Vertex Pharmaceuticals: Major rare disease biopharma with multiple approved CF therapies and an emerging hematology/iron-overload program. Comparable in clinical-stage hematology focus (including programs targeting iron dysregulation analogous to Rallybio's RLYB332).
• Swedish Orphan Biovitrum (Sobi): Specialty rare disease biopharma with hematology and immunology franchises including complement therapies. Sobi's commercial rare-disease infrastructure and product portfolio are comparable in therapeutic focus to Rallybio's pipeline.
• Takeda Pharmaceutical: Global biopharma with significant rare disease, hematology, and plasma-derived therapy franchises. Takeda's rare hematology and immunology portfolio overlaps with Rallybio's RLYB116 and RLYB332 indications.

Direct peers

• Apellis Pharmaceuticals: Clinical-stage complement therapeutics company with approved C3 inhibitors (Empaveli, Syfovre) targeting PNH and geographic atrophy. Apellis competes head-to-head with Rallybio's RLYB116 in complement dysregulation and represents the most relevant next-generation complement peer.
• argenx: Commercial-stage biotech with FcRn antagonist Vyvgart (approved for gMG, expanding indications) — a direct competitor to Rallybio's complement-mediated gMG approach. argenx represents a parallel path to addressing complement/autoimmune-driven rare diseases.

Emerging players

• Ionis Pharmaceuticals: Antisense oligonucleotide platform company developing therapies for rare and serious diseases including complement-mediated disorders. Ionis represents an alternative modality (RNA-based) addressing overlapping complement disease biology.
• Alnylam Pharmaceuticals: RNAi therapeutics company with rare disease focus including hematology programs (e.g., Givosiran for AHP). Alnylam's rare disease development expertise and platform-driven pipeline parallel Rallybio's Affibody-platform model.

Others

• Recursion Pharmaceuticals: Tech-enabled drug discovery company that acquired Rallybio's REV102 ENPP1 inhibitor program for $25M in 2025. Recursion is a transaction counterparty (not a competitor) but exemplifies adjacent platforms operating in similar rare disease discovery space.

Market position

Strengths4 records

Weaknesses4 records

Competitive moat4 records

Key risks6 records

Key highlights6 records

Customer concentration

• Xtwitter.com/rallybio
• LinkedInlinkedin.com/company/rallybio

Revenue estimate

Valuation estimate

Number of profiles

Profiles5 records

Funding overview

Funding rounds4 records

Investors14 records

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M&A1 record

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Rallybio