Best Oligonucleotide / ASO CDMOs in China

· updated as new inspection, certificate, and trial data enters the platform
4
CDMOs tracked
2
Fully scored

Oligonucleotide CDMOs make antisense oligonucleotides (ASOs), siRNAs, and related nucleic-acid drugs by solid-phase synthesis, with downstream purification and conjugation (e.g. GalNAc). The segment has grown sharply alongside approved ASO and siRNA therapeutics.

Choosing an oligonucleotide CDMO turns on synthesis scale, chemistry breadth (phosphorothioate backbones, 2'-modifications, conjugation), purity, and a clean regulatory record. The rankings below score each CDMO on FDA inspections, GMP certification, clinical activity, and capacity.

Last updated 2026-08-17. Sourced from FDA, EMA EudraGMDP, MHRA GMDP, and ClinicalTrials.gov.

# CDMO Signal Score Quality FDA · GMP Capacity Programs
1
RR
RiboBio
Guangzhou, China
59.0 0 programs
2
HB
Hongene Biotech
Union City, CA (US operations); Shanghai, China (primary manufacturing)
56.5 0 programs
Asymchem / AsymBio
Tianjin, China (primary manufacturing); Morrisville, NC (US HQ)
Profiled 0 programs
WuXi STA (Shanghai SynTheAll Pharmaceutical Co., Ltd.)
Shanghai, China
Profiled 0 programs
How we score CDMOs →

What to evaluate in a Oligonucleotide / ASO CDMO

Synthesis scale
Match synthesizer scale (mmol to mol) to your clinical and commercial demand, and confirm the CDMO can scale without shifting the impurity profile.
Chemistry & conjugation
Confirm experience with your backbone and modifications (phosphorothioate, 2'-MOE/F) and any conjugation (GalNAc, lipid) your molecule requires.
Purity & analytics
Full-length product, deletion/addition impurities, and residual metals drive release. Look for established orthogonal analytics.
Regulatory track record
Cross-check FDA 483 history and EMA/MHRA GMP coverage — both shown above and on each profile.

How do the BioSecure Act and 1260H list affect Chinese CDMO selection for US programs?

US sponsors evaluating Chinese CDMOs currently face two active US regulatory considerations. The DoD 1260H list designates named Chinese companies as "Chinese Military Companies" — WuXi AppTec was added in June 2026. Listing itself doesn't restrict commercial pharma work but affects federally-funded research access and creates procurement complications for sponsors with government contracts. The BioSecure Act is proposed federal legislation that would restrict federally-funded research and Medicare/Medicaid drug programs from working with named Chinese biotech companies (specifically BGI, MGI, Complete Genomics, WuXi AppTec, and WuXi Biologics as of current drafts). The bill has not passed as of 2026-08 but has bipartisan support. CDMO Signal does not encode US political risk into the Signal Score — the composite reflects regulatory quality, operations, financial stability, and capacity. Sponsors evaluating a Chinese CDMO for US-supplying programs should evaluate US regulatory risk separately as a distinct decision layer.

Chinese CDMOs with FDA and EMA inspection posture

Chinese CDMOs supplying US and European markets need active FDA and EMA GMP certifications on the specific facility. The FDA and EMA both conduct facility inspections in China, and Chinese CDMOs' inspection outcomes have generally improved over the past decade. The Signal Score's Quality Compliance pillar captures FDA + EMA + MHRA data directly. Chinese CDMOs with cross-jurisdictional certification rank higher on this pillar than domestic-market-only competitors. Cross-check with the US region ranking — Chinese CDMOs appearing on both rankings have demonstrated cross-jurisdictional inspection posture, which materially reduces regulatory risk for programs supplying US markets.

Which modality classes have the strongest Chinese CDMO capability?

China's CDMO capability is strongest in biologics (both mAb and biosimilar), viral vectors (particularly AAV, with substantial commercial-scale capacity via WuXi Advanced Therapies and others), and mRNA (rapid post-COVID capacity build). Small molecule and API manufacturing capacity is also substantial but sits outside CDMO Signal's primary coverage focus. Cross-reference with modality pages to filter Chinese CDMOs by capability: biologics, AAV, mRNA, or the viral vector umbrella. Individual profile pages surface facility-level detail.

Oligonucleotide / ASO CDMOs — Frequently Asked Questions

Who are the top Oligonucleotide / ASO CDMOs?
By CDMO Signal's independent Signal Score, the top-ranked Oligonucleotide / ASO CDMOs include RiboBio, Hongene Biotech. See the full ranked table above — scored on FDA, clinical, financial, and capacity data.
What should I look for in an oligonucleotide CDMO?
Match synthesis scale to your demand, confirm experience with your backbone chemistry and any conjugation (e.g. GalNAc), prioritize strong purity analytics, and a clean FDA and EMA/MHRA record.
What therapeutics do oligonucleotide CDMOs make?
Antisense oligonucleotides (ASOs), siRNAs, aptamers, and related nucleic-acid drugs — increasingly with conjugation chemistries like GalNAc for targeted delivery.
Related modalities
Plasmid DNA CDMOs mRNA / LNP CDMOs Biologics / mAb CDMOs
Other Modalities
AAV CAR-T Lentiviral Cell Therapy mRNA/LNP Plasmid DNA Biologics Adenoviral Gene Editing Exosome Recombinant Proteins ADC Gene Therapy Cell & Gene Therapy Viral Vector