Best Biologics / mAb CDMOs in United Kingdom
· updated as new inspection, certificate, and trial data enters the platform
6
CDMOs tracked
3
Fully scored
1
With FDA records
4
FDA inspections
8
EMA/MHRA GMP certs
Biologics CDMOs manufacture monoclonal antibodies, fusion proteins, and other large molecules in mammalian (typically CHO) cell culture. It is the largest and most mature segment of contract manufacturing, spanning early clinical supply through multi-thousand-litre commercial production.
Selecting a biologics CDMO turns on bioreactor scale and modality fit (mAb, bispecific, fusion protein), titer and cell-line strategy, fill-finish, and — above all — a clean regulatory record at commercial scale. The rankings below score each CDMO on FDA inspection history, EMA/MHRA GMP certification, clinical-program activity, and capacity.
FDA inspection outcomes across these CDMOs: 0 NAI (no action), 4 VAI (voluntary action), 0 OAI (official action). Leading inspection & GMP sites: UNITED KINGDOM (7), United Kingdom (2), United States (2), UNITED STATES (1).
Last updated 2026-08-31. Sourced from FDA, EMA EudraGMDP, MHRA GMDP, and ClinicalTrials.gov.
| # | CDMO | Signal Score | Quality | FDA · GMP | Capacity | Programs |
|---|---|---|---|---|---|---|
| 1 |
BR
BioReliance (Merck)
Glasgow, UK · Rockville, MD
|
81.0 | 98.8 | 4 insp · 8 GMP | — | 0 programs |
| 2 |
Abzena
San Diego, CA; Bristol, PA; Cambridge, UK
|
64.0 | — | — | Available | 0 programs |
| 3 |
Catachem Inc.
Oxford, CT
|
61.5 | — | — | 0 programs | |
| — |
Upperton Pharma Solutions
Nottingham, UK
|
Profiled | — | — | — | 0 programs |
| — |
Biopharma Group
Swindon, United Kingdom
|
Profiled | — | — | — | 0 programs |
| — |
Genzyme (Sanofi)
Cambridge, MA (division of Sanofi, HQ: Paris, France)
|
Profiled | — | — | — | 0 programs |
What to evaluate in a Biologics / mAb CDMO
Scale & bioreactor fit
Match validated bioreactor scale (from a few hundred litres clinical to 2,000L+ commercial) and single-use vs stainless to your dose and indication. Confirm titer expectations for your construct.
Cell line & process development
Ask whether the CDMO offers its own expression platform/cell line or works from yours, and how process development and tech transfer are handled.
Regulatory track record
Biologics programs heading to BLA/MAA need a strong commercial-scale inspection history. Cross-check FDA 483s, warning letters, and EMA/MHRA GMP coverage — all shown above.
Drug substance to drug product
Confirm whether the CDMO covers fill-finish and formulation in-house or coordinates a separate site, which affects timelines and comparability.
How has post-Brexit MHRA / EMA divergence affected UK CDMO selection?
Since 1 January 2021 the UK has operated MHRA as an independent regulator distinct from EMA. Practically this means: (1) UK manufacturing for EU-market supply requires a separate EMA GMP certificate, held by an EU-based Qualified Person; (2) EU manufacturing for UK-market supply requires MHRA acceptance, though MHRA has continued to recognize EMA GMP inspections under transitional arrangements; (3) the batches themselves may need to be released twice (once by an EU QP for EU supply, once by a UK QP for UK supply). CDMOs with UK + EU footprints are increasingly common in response; UK-only CDMOs need to arrange separate EU QP release for European supply. The Signal Score's Quality Compliance pillar captures both MHRA and EMA GMP certificates, so dual-jurisdiction CDMOs typically rank higher on this pillar.
Which UK CDMOs also cover FDA (US) regulatory geography?
UK CDMOs with US FDA inspection history qualify to supply US-market programs; those without FDA posture are limited to UK + EU. British CDMOs with FDA inspection density typically rank higher on the Signal Score's Quality Compliance pillar because that pillar aggregates FDA + EMA + MHRA data directly. Cross-check with the US region ranking — CDMOs appearing on both UK and US rankings have demonstrated multi-jurisdictional inspection posture, which materially reduces regulatory tech-transfer risk for programs supplying both markets.
How CDMO Signal identifies UK manufacturing presence
UK region attribution derives from each CDMO's declared facility locations. A location string containing UK-specific tokens (England, Scotland, Wales, Northern Ireland, London, Oxford, Cambridge, Liverpool, Manchester, Edinburgh, or 'UK'/'United Kingdom') places the CDMO in the UK region. Multi-site CDMOs appear in every applicable region — a Cambridge + Basel + Boston CDMO shows on UK, Europe, Switzerland, and USA rankings. Sponsors evaluating for a specific program should verify facility-level detail on the individual CDMO profile page — a CDMO with UK presence may only run some processes there and route others through their non-UK sites.
Biologics / mAb CDMOs — Frequently Asked Questions
Who are the top Biologics / mAb CDMOs?
By CDMO Signal's independent Signal Score, the top-ranked Biologics / mAb CDMOs include BioReliance (Merck), Abzena, Catachem Inc.. See the full ranked table above — scored on FDA, clinical, financial, and capacity data.
How many Biologics / mAb CDMOs have FDA inspection records?
CDMO Signal tracks 1 Biologics / mAb CDMO with FDA inspection records and 8 EMA/MHRA GMP certificates across the group.
What should I look for in a biologics CDMO?
Match bioreactor scale and modality (mAb, bispecific, fusion protein) to your program, confirm cell-line and process-development support, and prioritize a clean FDA and EMA/MHRA record at the scale you'll commercialize at.
What is the difference between a biologics CDMO and a cell or gene therapy CDMO?
Biologics CDMOs make large molecules (antibodies, proteins) in bioreactors at litre-to-thousands-of-litre scale. Cell and gene therapy CDMOs make living cells or viral vectors in much smaller, often per-patient batches under different containment and analytics.
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