Best Oligonucleotide / ASO CDMOs by Signal Score

← All Oligo/ASO CDMOs Best Clean FDA History Commercial Scale
10
CDMOs tracked
10
Fully scored
7
With FDA records
12
FDA inspections
34
EMA/MHRA GMP certs

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.

FDA inspection outcomes across these CDMOs: 6 NAI (no action), 5 VAI (voluntary action), 1 OAI (official action). Leading inspection & GMP sites: United States (10), Spain (8), Italy (7), Germany (4), Belgium (4).

Last updated 2026-06-09. Sourced from FDA, EMA EudraGMDP, MHRA GMDP, and ClinicalTrials.gov.

# CDMO Signal Score Quality FDA · GMP Capacity Programs
1
AJ
Ajinomoto Bio-Pharma Services
San Diego, CA · Osaka, JP
 85.6 100.0 0 insp · 1 GMP — 0 programs
2
BA
Bachem
Bubendorf, CH
 83.5 98.9 1 insp · 0 GMP — 0 programs
3
CD
Corden Pharma
Plankstadt, DE · Caponago, IT · Boulder, CO
 82.5 99.7 2 insp · 9 GMP — 0 programs
4
ND
Nitto Denko Avecia
Milford, MA
 80.3 100.0 2 insp · 0 GMP — 0 programs
5
KE
Kaneka Eurogentec
Seraing, BE
 80.3 100.0 0 insp · 4 GMP — 0 programs
6
CRA
Curia (RNA/Advanced)
Albany, NY · Albuquerque, NM
 79.4 99.9 2 insp · 16 GMP — 0 programs
7
AL
Agilent Technologies (Oligo GMP)
Santa Clara, CA
 74.2 100.0 2 insp · 0 GMP — 1 programs
8
SP
ST Pharm
Seoul, KR
 72.8 88.1 2 insp · 4 GMP — 0 programs
9
AX
Axolabs (Nuvisan)
Kulmbach, DE
 72.5 98.8 1 insp · 0 GMP — 3 programs
10
TL
TriLink BioTechnologies
San Diego, CA
 71.0 — — — 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.

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 Ajinomoto Bio-Pharma Services, Bachem, Corden Pharma. See the full ranked table above — scored on FDA, clinical, financial, and capacity data.
How many Oligonucleotide / ASO CDMOs have FDA inspection records?
CDMO Signal tracks 7 Oligonucleotide / ASO CDMOs with FDA inspection records and 34 EMA/MHRA GMP certificates across the group.
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