Oligonucleotide & ASO CDMOs — Ranked by Signal Score
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), 6 VAI (voluntary action), 2 OAI (official action). Leading inspection & GMP sites: United States (12), Spain (8), Italy (5), Germany (4), Belgium (4).
Last updated 2026-05-21. 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 · 8 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 · 15 GMP | — | 0 programs |
| 7 |
AL
Agilent Technologies (Oligo GMP)
Boulder, CO
|
74.2 | 100.0 | 1 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 |
| 11 |
PP
PolyPeptide Group
Torrance, CA · Strasbourg, FR · Malmo, SE
|
64.8 | 70.9 | 3 insp · 0 GMP | — | 0 programs |
| 12 |
LG
LGC Biosearch Technologies
Petaluma, CA · Middleton, WI
|
63.0 | — | — | — | 0 programs |
| 13 |
SM
Sumitomo Chemical Advanced Medical
Tokyo, JP
|
63.0 | — | — | — | 0 programs |
| 14 |
AU
Aurigene Pharmaceutical Services
Hyderabad, IN
|
63.0 | — | — | — | 0 programs |
| 15 |
RR
RiboBio
Guangzhou, CN
|
59.0 | — | — | — | 0 programs |
| 16 |
HB
Hongene Biotech
Union City, CA
|
56.5 | — | — | — | 0 programs |
| 17 |
BS
Bio-Synthesis Inc.
Lewisville, TX
|
56.5 | — | — | — | 0 programs |
| 18 |
CG2
ChemGenes Corporation
Wilmington, MA
|
56.5 | — | — | — | 0 programs |
| 19 |
MM
Mermade (BioAutomation)
Irving, TX
|
56.5 | — | — | — | 0 programs |
| 20 |
GR
Glen Research
Sterling, VA
|
56.5 | — | — | — | 0 programs |
| — |
Roche / Genentech (Internal Manufacturing & CustomBiotech)
Basel, Switzerland
|
Profiled | — | — | — | 0 programs |
| — |
Olon Group
Rodano (Milan), Italy
|
Profiled | — | — | — | 0 programs |
| — |
Pyramid Pharma Services (Pyramid Laboratories, Inc.)
Costa Mesa, CA
|
Profiled | — | — | — | 0 programs |