Primrose Bio

What Primrose Bio does

Primrose Bio, Inc. is a privately held biotechnology company headquartered at 10790 Roselle Street, San Diego, California. The company was formed in 2023 through the merger of Primordial Genetics, Inc. and the Pfenex division of Ligand Pharmaceuticals, combining protein expression, RNA polymerase, and combinatorial strain engineering platforms under a single corporate entity. Primrose Bio operates three integrated technology platforms for biotherapeutics and vaccine manufacturing: Pfenex Expression Technology, a Pseudomonas fluorescens-based microbial expression platform reported to achieve 10-20x higher protein yields than E. coli, CHO, and yeast systems and to have been used in six FDA-approved biologics; Prima RNApols, a portfolio of engineered RNA polymerases (including ExTend and ExTend Cap AU) for mRNA and self-amplifying mRNA manufacturing with reported up to 5x higher mRNA yields and ~90% reduction in dsRNA byproducts compared to T7 polymerase; and PeliCRM197, the only commercially sold recombinant CRM197 used in marketed conjugate vaccines such as VAXNEUVANCE, Pneumosil, and MenFive. A fourth enabling technology, Function Generator, is a patented combinatorial gene-fusion platform for ultra-high-throughput strain engineering, and the company also offers Pfast, an accelerated protein screening service.

The company monetizes across multiple revenue streams. It sells research-grade and GMP-grade PeliCRM197 from milligrams to kilograms, with research-grade units listed at $250 per 1 mg and $2,000 per 20 mg, and GMP-grade product quote-based above 10 grams. It sells Prima RNApols under its own e-commerce storefront and through GMP channels under ISO 13485:2016 quality systems. It licenses Pfenex Expression Technology, Prima RNApols, and Function Generator to pharmaceutical and biotechnology partners, evidenced by a commercial license to Arcturus Therapeutics and long-standing integrations at Merck, Jazz Pharmaceuticals, the Serum Institute of India, Alvogen, and Arcellx. It provides fee-based protein expression services starting at $30,000. Distribution combines direct enterprise sales for GMP and bulk orders, e-commerce for research-grade products, technology licensing arrangements, and CDMO partnerships (notably with Intravacc for conjugate vaccines).

The company's primary customers are vaccine developers, therapeutic protein developers, and mRNA therapeutics developers across North America, Europe (Netherlands via Intravacc), and South Asia (India via Serum Institute). The company employed between 51 and 100 staff as of recent reporting and has raised approximately $23 million in a 2024 SEC-registered exempt offering, with 1315 Capital as a significant equity investor. Leadership comprises CEO Drew Burch (appointed October 2025, previously at Maravai LifeSciences and Thermo Fisher Scientific), President & COO Diane Retallack (a founding figure of Pfenex with 25+ years in protein expression), CTO Helge Zieler (former CEO and corresponding author on the Function Generator PNAS publication), and CFO Simon Latimer.

Name

Primrose Bio

Legal name

Primrose Bio, inc.

Website

https://primrosebio.com

Company type

Private

Founded year

2023

Operating status

Operating

Headcount range

11–50 employees

Short description

Primrose Bio is a San Diego-based biotechnology company operating the Pfenex Expression Technology, Prima RNApols, and PeliCRM197 platforms to manufacture biologics, conjugate vaccines, and mRNA therapies for pharmaceutical and biotech customers globally.

Ownership category

akta.pro rank

Product category

Bioprocessing and Biologics Manufacturing Tools

NAICS

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

SIC

Biological Products, (No Disgnostic Substances) (2836)

akta.pro primary industry

mRNA & Nucleic Acid Manufacturing Services (mRNA/saRNA/Plasmid DNA) (HLAGAGAC)

akta.pro secondary industries

Plasmid DNA & mRNA Manufacturing Services (HLAAAKAE), Synthetic Biology & Genetic Circuit Design Platforms (pathway engineering, chassis development) (HLAAAIAD), Protein Engineering & Directed Evolution Platforms (enzyme/therapeutic protein optimization) (HLAAAIAC), GMP Quality, Validation & Regulatory Support (GMP/CSV/Qualification) (HLAGAGAL)

Keywords

• Microbial protein expression
• RNA polymerase enzymes
• Conjugate vaccine carrier proteins
• Biologics manufacturing platform
• MRNA therapeutics production

Headquarters

HQ city

San Diego

HQ country

United States

HQ region

North America

Offices1 record

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Technology or R&D, Operations, Marketing or Sales, Infrastructure

Revenue model

1. Protein Expression Services: Contract strain engineering and process development services using Pfenex Expression Technology. Services include high-throughput screening, process development, and technology transfer for GMP manufacturing. Revenue from project fees and milestone payments.
2. CRM197 Carrier Protein Sales: Sale of research-grade and GMP-grade PeliCRM197 carrier proteins for conjugate vaccine development. Products sold in various sizes from milligrams to kilograms with different pricing for research vs GMP grades.
3. RNA Polymerase Products: Sale of Prima RNApols RNA polymerase enzymes for mRNA manufacturing. Available for research use and GMP-grade for clinical/commercial manufacturing. Includes ExTend, ExTend Cap AU, and custom polymerase products.
4. Technology Licensing: Licensing of proprietary technology platforms including Pfenex Expression Technology, Prima RNApols, and Function Generator to pharmaceutical and biotechnology partners for product development and manufacturing.

Pricing tiers

Go-to-market motion3 records

Distribution channels4 records

Marketing channels6 records

Core offering

Primrose Bio develops, manufactures, and licenses proprietary microbial protein expression and mRNA manufacturing technologies for pharmaceutical and biotechnology customers. The company's three core platforms are Pfenex Expression Technology (a Pseudomonas fluorescens-based expression platform used in six approved biologics), Prima RNApols (engineered RNA polymerase enzymes for mRNA manufacturing), and PeliCRM197 (the only commercially available CRM197 carrier protein used in approved conjugate vaccines such as VAXNEUVANCE and Pneumosil). Revenue is generated through direct sales of research and GMP-grade reagents, contracted protein expression and process development services, and technology licensing arrangements.

Product overview

Primrose Bio operates as an integrated technology platform company offering three major product lines for biologics and nucleic acid manufacturing: (1) Pfenex Expression Technology® - a Pseudomonas fluorescens-based microbial expression platform with 6 approved products and up to 20x higher yields than conventional systems; (2) Prima RNApols™ - engineered RNA polymerase enzymes for mRNA manufacturing including self-amplifying mRNA, with ExTend and ExTend Cap AU variants; and (3) PeliCRM197® - the only commercially available recombinant CRM197 carrier protein used in approved conjugate vaccines (VAXNEUVANCE®, Pneumosil®, MenFive®). The company also offers Function Generator™ for ultra-high throughput combinatorial gene engineering and Pfast™ for accelerated protein screening. These technologies serve pharmaceutical companies including Merck, Jazz Pharmaceuticals, Serum Institute of India, Alvogen, Arcellx, and Arcturus for vaccine and therapeutic protein production.

Differentiator

Problem solved

Functional benefit

Brands

• Pfenex Expression Technology: A Pseudomonas fluorescens-based microbial expression platform for recombinant protein production, used in six approved biologic products with up to 20x higher yields than conventional systems.
• PeliCRM197
• Prima RNApols
• Function Generator

Products and services

• Pfenex Expression Technology A Pseudomonas fluorescens-based microbial expression platform designed for high-yield recombinant protein production, supporting high-throughput screening, process development, and scalable manufacturing from 1L to 180,000L fermentation. The platform is 100% compatible with existing microbial infrastructure and has been used in six approved biologics including VAXNEUVANCE, Rylaze, and Teriparatide Injection, with up to 20x higher yields than E. coli, CHO, and yeast systems. Offered via licensing and contracted services to pharmaceutical and biotechnology customers.
• PeliCRM197 A recombinant CRM197 diphtheria toxin mutant carrier protein produced via Pfenex Expression Technology for conjugate vaccine development. The only commercially available CRM197 used in FDA-approved vaccines (VAXNEUVANCE, Pneumosil, MenFive), offered in research grade (1mg and 20mg lyophilized) and GMP-grade formats from milligrams to kilograms with FDA Drug Master File and regulatory support. Sold to vaccine developers globally.
• Prima RNApols Proprietary engineered RNA polymerase enzymes for mRNA manufacturing that improve yields up to 5x, reduce dsRNA byproducts, and enhance cap incorporation compared to standard T7 RNA polymerase. Available in research use and GMP-grade formats under ISO 13485:2016 certified quality systems for clinical and commercial mRNA manufacturing. Sold to mRNA therapeutics developers and licensed to pharmaceutical partners.
• Prima RNApols ExTend An RNA polymerase variant engineered specifically for long-template mRNA manufacturing including self-amplifying mRNA (saRNA). Offers superior performance over T7 polymerase with higher mRNA quality, reduced dsRNA formation, enhanced downstream purification efficiency, and higher yield at lower input costs. Available in IVT kit format for research use, with GMP-grade under ISO 13485:2016.
• Prima RNApols ExTend Cap AU A next-generation RNA polymerase optimized for AU cap analogs, designed to maximize capping efficiency and minimize dsRNA in self-amplifying mRNA manufacturing. Features high AU capping efficiency (98%), ultra-low dsRNA (~90% reduction), and cost-efficient production with reduced template, enzyme, and cap analog requirements. Available for research use with GMP-grade under ISO 13485:2016.
• Function Generator An ultra-high throughput combinatorial gene fusion technology that creates large libraries of novel gene combinations by combining protein-coding sequences across entire genomes. Generates tens of millions of gene combinations for strain engineering, achieving gain-of-function traits for improved protein production, stress tolerance, and metabolic efficiency in microbial hosts. Protected by 10+ granted patents worldwide and offered as a technology platform.
• Pfast Protein Expression Evaluation Service Accelerated protein expression screening service offering 10-day evaluation of protein titer and quality through combinatorial screening using the Pfenex Expression Technology platform. Enables rapid identification of optimal expression conditions and robust production strains with response within two days. Service engagements start at $30,000 for protein expression evaluation and development, with BSL-1 and BSL-2 support.

Quantifiable outcome

• 10-20x higher protein yields compared to E.coli, CHO, and yeast systems
• +6 more outcomes

Named customers6 records

Segments4 records

Ideal customer profiles4 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature5 records

Partnerships

Three partnerships are on record, tiered core and key.

• IntravacccoreStrategic or Co-development Partner · 1 June 2026Strategic partnership renewal to enhance conjugate vaccine development and manufacturing. Intravacc provides antigen conjugation expertise and GMP production capabilities while Primrose Bio supplies PeliCRM197 carrier protein. Creates a full-service solution from development through manufacturing for third parties.
• Serum Institute of IndiacoreStrategic or Co-development Partner · 10 January 2025Collaboration to develop a novel multi-antigen vaccine. Primrose responsible for developing manufacturing strains using Pfenex Expression Technology. Serum Institute responsible for further development and commercialization. Long-standing relationship including VAXNEUVANCE, Pneumosil, and MenFive partnerships.
• ExPLoRNA TherapeuticskeyTechnology or Integration · 3 September 2024Strategic partnership to jointly develop and market products for mRNA medicines. Co-development of RNA polymerases and capping compounds optimized together for enhanced mRNA quality, manufacturing performance, and therapeutic safety. Combines Prima RNApols with ExPLoRNA's AvantCap cap analogs.

Scale indicators8 records

Recent moves7 records

Expansion highlights6 records

Broad incumbents

• Cytiva: Cytiva (part of Danaher) supplies bioprocessing equipment, resins, and consumables for protein and nucleic acid manufacturing including its own expression systems. Broad incumbent providing infrastructure into which Primrose's technologies plug.
• Bio-Techne: Bio-Techne offers proteins, reagents, and GMP biologics manufacturing services, including carrier proteins and protein expression services. Larger incumbent with overlapping catalog products (e.g., cytokines, growth factors, GMP proteins) and a CDMO segment serving similar customers.
• Catalent: Catalent (acquired by Novo Holdings) provides biologics, cell therapy, and mRNA CDMO services. Overlaps with Primrose on biologics process development and as a destination for mRNA therapeutic manufacturing.
• Thermo Fisher Scientific (Patheon CDMO): Thermo Fisher's Patheon CDMO provides biologics drug substance and drug product services, including viral vector and mRNA capabilities. Former employer of Primrose's CEO Drew Burch and a broad incumbent in outsourced biomanufacturing.
• Lonza: Lonza is a leading global CDMO for biologics and cell/gene therapies with microbial and mammalian expression capabilities. Broad incumbent competing for outsourced biologics manufacturing mandates that overlap with Primrose's Pfenex platform use cases.
• WuXi Biologics: WuXi Biologics is one of the world's largest biologics CDMOs offering end-to-end development and manufacturing services. Comparable as a competing destination for biopharma protein expression work that might otherwise be served by Pfenex Expression Technology.

Direct peers

• Aldevron: Now part of Danaher's Cytiva, Aldevron supplies plasmids, mRNA, and recombinant proteins to biopharma developers. Directly comparable to Primrose Bio as a provider of high-quality biologic and nucleic acid manufacturing inputs and services, including similar CRM197-adjacent franchise in conjugate vaccines.
• TriLink BioTechnologies: Operates within Maravai and supplies mRNA capping analogs, modified nucleotides, and CleanCap reagents used in mRNA manufacturing. Direct competitor to Prima RNApols franchise, particularly in cap analog and mRNA enzyme inputs.
• Maravai LifeSciences: Maravai is a leading provider of nucleic acid products and services to biopharma, including CleanCap mRNA capping technology and TriLink mRNA synthesis. Direct competitor to Prima RNApols and adjacent competitor to Pfenex, with overlap in mRNA manufacturing supply chain.
• Repligen: Repligen provides bioprocessing tools, filtration, and chromatography solutions for biologics and mRNA manufacturing. Comparable as a provider of critical inputs into recombinant protein and nucleic acid production workflows used by the same pharma customer base.

Market position

Strengths5 records

Weaknesses4 records

Competitive moat5 records

Key risks6 records

Key highlights7 records

Customer concentration

• LinkedInlinkedin.com/company/primrose-bio
• Xx.com/PrimroseBio
• Facebookfacebook.com/Primrosebio

Compliance1 record

Revenue estimate

Valuation estimate

Number of profiles

Profiles7 records

Funding overview

Funding rounds7 records

Investors7 records

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

M&A1 record

Investments

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

Frequently asked questions about Primrose Bio