What Signify Bio does

Signify Bio is a Dallas-based, privately held biotechnology company developing in situ protein therapeutics—protein drugs produced directly inside the patient's body rather than manufactured externally as conventional biologics. The company's core technical stack combines proprietary nucleic acid payloads with non-viral lipid nanoparticle delivery, organized around three platforms: (1) the SEND (Signal peptide Engineered Nucleic acid Design) platform, which uses signal peptide engineering to control secretion into systemic circulation and localization to cellular organelles such as the cell membrane, nucleus, lysosome, mitochondria, and synapse; (2) the iPhos lipid nanoparticle delivery system, based on ionizable phospholipid nanoparticles engineered for maximized endosomal escape and tissue specificity, compatible with subcutaneous, intramuscular, and intravenous administration; and (3) computational methods for the design and discovery of novel signal peptide sequences.

The company was co-founded by Daniel J. Siegwart, Ph.D. (Director of the Program in Genetic Drug Engineering at UT Southwestern) and RA Session II (former founder/CEO of Taysha Gene Therapies, ex-BridgeBio), with technology originating from the Siegwart Lab at UT Southwestern Medical Center, with which Signify maintains a strategic partnership providing access to scientific talent, scalable LNP manufacturing, and pre-clinical models. Additional senior leadership includes CSO David Morrissey, Ph.D. (ex-Pfizer Head RNA Accelerator, ex-Intellia SVP Platform & Delivery), VP of Translational Biology Morag Stewart, Ph.D. (ex-Pfizer CTI, ex-Flagship Pioneering), and Co-founder/CTO advisor Lukas J. Farbiak, Ph.D. (UT Southwestern).

Signify Bio is pre-revenue and operates as a platform R&D-stage company with 11–50 employees focused on advancing the SEND and iPhos platforms toward therapeutic applications in genetic disorders and chronic diseases. The business model is not yet commercial: there are no approved products, no disclosed pricing, and no commercial customers. Future revenue mechanisms are not explicitly stated but would likely follow standard biotech pathways—internal therapeutic development, platform out-licensing, or strategic pharma partnerships—contingent on regulatory progress. The company launched in June 2025 with an oversubscribed $15 million seed round led by Actium Group, with participation from the Gates Foundation Strategic Investment Fund, Danaher Ventures, Eli Lilly, and BrightEdge (ACS venture arm).

Name

Signify Bio

Legal name

Signify Bio

Website

https://signifybio.com

Company type

Private

Founded year

2025

Operating status

Operating

Headcount range

11–50 employees

Short description

Signify Bio is a Dallas-based biotechnology company developing in situ protein therapeutics via three proprietary platforms—SEND nucleic acid design, iPhos lipid nanoparticles, and computational signal peptide engineering—to enable personalized protein production directly within patients' bodies for genetic and chronic disorders.

Ownership category

akta.pro rank

Product category

Biotechnology / Protein Therapeutics

NAICS

Research and Development in Biotechnology (except Nanobiotechnology) (541714), Biological Product (except Diagnostic) Manufacturing (325414), Pharmaceutical Preparation Manufacturing (325412)

SIC

Biological Products, (No Disgnostic Substances) (2836), Pharmaceutical Preparations (2834), Services-Commercial Physical & Biological Research (8731)

akta.pro primary industry

Synthetic Biology & Genetic Circuit Design Platforms (pathway engineering, chassis development) (HLAAAIAD)

akta.pro secondary industries

Protein Engineering & Directed Evolution Platforms (enzyme/therapeutic protein optimization) (HLAAAIAC), Engineered Protein Therapeutics (de novo/AI-designed proteins, novel scaffolds) (HLAAAAAJ)

Keywords

• In situ protein therapeutics
• Nucleic acid therapeutics
• Lipid nanoparticle delivery
• Signal peptide engineering
• MRNA therapeutics

Headquarters

HQ city

Dallas

HQ country

United States

HQ region

North America

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Technology or R&D, Personnel, Operations, Infrastructure

Marketing channels1 record

Core offering

Signify Bio develops proprietary nucleic acid and lipid nanoparticle platforms (SEND, iPhos iPLNPs, and computational signal peptide design) that enable the in situ production of protein therapeutics directly within the human body. The platforms support modular control over protein secretion into systemic circulation and localization to cellular organelles, and are compatible with subcutaneous, intramuscular, and intravenous routes of administration for the treatment of chronic and genetic disorders.

Product overview

Signify Bio is a biotechnology company developing in situ protein therapeutics by combining three proprietary platforms: the SEND platform for controlling secretion and localization of nucleic acid encodable proteins, the iPhos lipid nanoparticle delivery system for tissue-specific delivery with maximized endosomal escape, and computational methods for designing novel signal peptides. Together, these platforms transform the human body into a biofactory for precise, targeted protein production.

Differentiator

Problem solved

Functional benefit

Products and services

• SEND Platform (Signal peptide Engineered Nucleic acid Design) Modular biotechnology platform that enables control over the secretion and subcellular localization of any nucleic acid-encodable protein of interest, supporting secretion of proteins into systemic circulation and localization to cellular organelles including the cell membrane, nucleus, lysosome, mitochondria, and synapse. Aimed at biotechnology and pharmaceutical researchers developing personalized protein therapeutics for chronic and genetic disorders.
• iPhos Lipid Nanoparticle Delivery System (iPLNPs) Novel non-viral lipid nanoparticle delivery system based on ionizable phospholipid (iPhos) lipid nanoparticles engineered to maximize endosomal escape and tissue specificity, enabling dose-dependent protein secretion from diverse cell types via subcutaneous, intramuscular, and intravenous routes of administration. Aimed at therapeutic developers requiring targeted in vivo delivery of nucleic acid-encoded protein therapeutics.
• Computational Methods for Signal Peptide Design and Discovery Computational biology methods used to design and discover novel signal peptide sequences that direct protein trafficking pathways, used in combination with the SEND platform and iPhos delivery system to engineer personalized protein therapeutics. Aimed at biotechnology researchers and therapeutic developers.

Segments1 record

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

One partnership is on record.

• UT Southwestern Medical Center (UTSW)coreStrategic or Co-development Partner · 5 June 2025Signify Bio was originally conceived in the Siegwart Lab at UT Southwestern. The strategic partnership provides access to: world-class team of scientists and cutting-edge technology; scalable LNP manufacturing and nucleic acid generation; broad expertise ranging from chemical synthesis to pre-clinical models; core competency in chemistry and engineering. Co-founder Daniel J. Siegwart serves as Director of the Program in Genetic Drug Engineering at UTSW.

Scale indicators1 record

Recent moves5 records

Expansion highlights5 records

Broad incumbents

• Moderna: Moderna is the dominant mRNA-LNP therapeutics platform, with extensive IP, manufacturing scale, and clinical-stage programs across protein-encoding mRNA. Directly comparable modality to Signify Bio's mRNA-encoded in situ protein approach, though at vastly greater scale and with broader pipeline scope.
• BioNTech: BioNTech is a leading mRNA therapeutics company developing protein-encoding mRNA vaccines and cancer immunotherapies. Comparable to Signify Bio in core nucleic acid payload and LNP delivery, with established clinical and manufacturing capabilities Signify Bio lacks.
• Alnylam Pharmaceuticals: Alnylam is the established leader in RNA interference therapeutics with lipid nanoparticle and conjugate delivery platforms. Comparable to Signify Bio in nucleic acid-based therapeutic approach and protein-level disease intervention, with vastly deeper clinical and commercial experience.

Direct peers

• Intellia Therapeutics: Intellia is a clinical-stage gene editing company developing in vivo CRISPR/Cas9 therapies using LNP delivery. Signify Bio's CSO David Morrissey is a former Intellia SVP, and both companies pursue in situ nucleic acid-based therapeutic production, though Intellia focuses on gene editing versus protein expression.
• ReCode Therapeutics: ReCode is a clinical-stage genetic medicines company developing lipid nanoparticle-delivered mRNA therapeutics for respiratory and CNS diseases. Co-founded by Signify Bio's scientific co-founder Daniel Siegwart, ReCode is a direct LNP/mRNA peer with overlapping platform technology and team lineage.
• Arcturus Therapeutics: Arcturus is a clinical-stage mRNA medicines company developing lipid nanoparticle delivery systems for protein-encoding therapeutics and vaccines. Comparable to Signify Bio in the combined LNP delivery + protein-encoding payload space, with deeper clinical experience and established manufacturing partnerships.

Emerging players

• Taysha Gene Therapies: Taysha is a clinical-stage gene therapy company developing AAV-delivered therapies for CNS diseases. Signify Bio's CEO RA Session II is the former founder/CEO of Taysha, providing strong leadership lineage overlap. Both target genetic disorders but use different delivery modalities (AAV vs LNP/mRNA).
• Generation Bio: Generation Bio is developing non-viral lipid nanoparticle delivery systems for nucleic acid therapeutics, including DNA and mRNA payloads. Closely comparable to Signify Bio in non-viral delivery approach for in vivo genetic medicine, though at an earlier clinical stage and with different payload modalities.
• Verve Therapeutics: Verve is a clinical-stage cardiovascular company developing in vivo base editing therapies using LNP delivery. Comparable to Signify Bio in LNP-based in vivo nucleic acid therapeutics, with a focused cardiovascular indication strategy and clinical-stage validation.

Others

• BridgeBio Pharma: BridgeBio is a clinical-stage genetic disease company with multiple subsidiaries developing protein-targeted therapies. Signify Bio's CEO RA Session II was formerly CBO of BridgeBio's gene therapy subsidiaries, providing leadership lineage overlap. Strategic rather than direct technical peer.

Market position

Strengths4 records

Weaknesses4 records

Competitive moat3 records

Key risks5 records

Key highlights5 records

Customer concentration

Revenue estimate

Valuation estimate

Number of profiles

Profiles5 records

Funding overview

Funding rounds1 record

Investors5 records

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

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

Frequently asked questions about Signify Bio