GEN · May 2026
Coverage of ParcelBio’s APEXm platform, the seed financing, and its planned ASGCT debut with preclinical data on durable mRNA expression and in vivo CAR-T.
Company research
Public company, workplace, funding, and market signals
Updated Jul 29, 2026
Overview
ParcelBio is a San Francisco biotech developing APEXm™, a next-generation mRNA platform designed to drive more durable, higher protein expression; its lead programs focus on in vivo CAR-T for autoimmune disease, plus oncology and encoded protein therapeutics.
Primary product
APEXm™ (Amplified and Prolonged EXpression mRNA) platform
Founded
2023
Headquarters
San Francisco, California, United States
Team size
1-10
Industry
Biotechnology Research
Sub-industry
mRNA therapeutics
Offices
135 Mississippi Street, San Francisco, CA 94107, United States
Business model
drug development
Funding
People & investors
Leadership
Co-Founder and CEO
Co-Founder and CSO
Director, Preclinical Pharmacology
Work & culture
Lean, founder-led, early-stage research culture with a public signal for an on-site San Francisco role that works directly with the founding team.
Visa sponsorship
Yes
Compensation
Public job postings show a San Francisco Sr. Research Associate/Associate Scientist role at $90K-$120K; broader company compensation bands were not found.
Benefits
Visa sponsorship available
Product & market
Pricing
Not publicly disclosed.
Differentiators
- —APEXm recruits native RNA-stabilizing machinery to extend expression.
- —Simple linear mRNA architecture instead of circular RNA.
- —Designed to improve potency and durability without viral delivery or ex vivo manufacturing.
- —Modular platform intended to work across proteins and cell types.
- —Lead focus on in vivo CAR-T for autoimmune disease.
Technology
APEXm™
linear mRNA architecture
RNA-stabilizing machinery recruitment
in vivo CAR-T
mRNA sequence design
IVT plasmid linearization
high-throughput screening
dsRNA ELISA
RNA TapeStation
Customers
Patients with autoimmune disease
Oncology patients
Patients needing therapeutic protein replacement
Competitors
Generate Biomedicines
Sensible Biotechnologies
Cisterna Biologics
Serna Bio
KymeraTx
BioNTech
ADMA Biologics
Engage Bio
MiNA Therapeutics
Scale & contact
Estimated revenue
$414K-$2.4M
Estimated monthly visits
1.7K
Traffic estimate as of Jun 2026
Latest news
The Pharma Letter · May 2026
Summarizes ParcelBio’s emergence from stealth, the Breyer-led seed round, and the company’s APEXm platform and preclinical autoimmune pipeline.
Business Wire · May 2026
Official financing announcement: $13 million seed round led by Breyer Capital with participation from General Catalyst, Y Combinator, Metaplanet, SurgePoint Capital, and ZAKA VC.
FirstWord Pharma · May 2026
Reports ParcelBio’s launch and seed funding, emphasizing its effort to solve mRNA durability and expression limitations and its autoimmune in vivo CAR-T lead program.
Endpoints News · May 2026
Launch coverage for ParcelBio, describing the company’s $13 million seed financing, its founders’ background at Orbital/Circ Bio, and its focus on longer-lasting mRNA therapies and in vivo CAR-T.
Jobs and careers at ParcelBio
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