Gene therapy is delivered through viral vectors — AAV, lentiviral, and adenoviral being the three dominant platforms. AAV dominates in vivo systemic delivery (rare disease, ophthalmology, neurology); lentivirus is the workhorse for ex vivo cell engineering including CAR-T; adenoviral vectors remain relevant for vaccines and select gene therapy programs. Most gene therapy CDMOs specialize in one or two vector platforms, and platform experience is the first filter in any sponsor's shortlist.
The ranking below aggregates every CDMO tracked as a gene therapy manufacturer across these platforms. For platform-specific rankings, use the dedicated pages: <a href="/modality/aav">AAV CDMOs</a>, <a href="/modality/lentiviral">Lentiviral Vector CDMOs</a>, <a href="/modality/adenoviral">Adenoviral Vector CDMOs</a>. For sponsors evaluating end-to-end programs that combine vector manufacturing with downstream cell processing, the <a href="/modality/cell-and-gene-therapy">cell and gene therapy view</a> extends this list with cell therapy CDMOs.
FDA inspection outcomes across these CDMOs: 1 NAI (no action), 0 VAI (voluntary action), 0 OAI (official action). Leading inspection & GMP sites: United States (1).
Last updated 2026-08-31. Sourced from FDA, EMA EudraGMDP, MHRA GMDP, and ClinicalTrials.gov.
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CDMO
Signal Score
Quality
FDA · GMP
Capacity
Programs
1
LB
Lotte Biologics
Incheon, KR · Syracuse, NY
83.7
100.0
1 insp · 0 GMP
—
0 programs
2
SK
SK pharmteco
Dublin, Ireland. Rancho Cordova, CA. King of Prussia, PA. Houston, TX. Korea. France.
The first shortlist filter for any gene therapy program is vector platform. AAV for in vivo systemic; lentiviral for ex vivo cell engineering; adenoviral for vaccines and select high-expression programs. Filter by platform first, then compare within the platform.
Regulatory record on-platform
A CDMO with a strong FDA record on AAV manufacturing doesn't automatically de-risk lentiviral work — inspections are facility- and process-specific. Verify the inspection record on the exact platform and site your program will use.
Capacity match to phase
Early clinical AAV runs at 50-200L; commercial can reach 1000-2000L single-batch. Lentiviral commercial supply is a much narrower field. Confirm the CDMO's capacity headroom at your target phase before shortlisting.
Analytics maturity
Vector analytics — capsid ratio, titer, potency, RCL for lentivirus — drive lot release. A CDMO with qualified, established assays de-risks comparability and tech transfer.
What has driven South Korea's rise as a biologics manufacturing hub?
South Korea's biologics CDMO growth (2015-present) has been driven by three factors: (1) Samsung Biologics' massive Songdo capacity build (Plants 1-5 total >600,000L mammalian cell culture, one of the largest single-city concentrations of biologics capacity globally); (2) Celltrion's biosimilar-driven commercial capacity, exported globally; (3) national policy focus on biopharmaceutical export as a strategic industry. Korean CDMOs supplying US and EU markets typically hold MFDS + FDA + EMA certifications concurrently — the Signal Score's Quality Compliance pillar captures all three. For biologics programs specifically, South Korea offers commercial-scale capacity availability that is genuinely scarce in the US and EU.
How do Samsung Biologics and Celltrion compare on CDMO offerings?
Samsung Biologics operates primarily as a contract manufacturer (CDMO) with dedicated commercial biologics capacity at Songdo; Celltrion combines internal biosimilar development with CDMO services, with significant capacity dedicated to their own commercial products. For pure CDMO engagements, Samsung Biologics is typically the more scale-available option; for programs where biosimilar development experience is a plus, Celltrion's integrated model can add value. Both hold FDA and EMA certifications. Cross-check with the biologics CDMO ranking for the broader Korean biologics landscape and individual profile pages for facility-level detail.
South Korean CDMOs supplying US and EU markets — regulatory considerations
South Korean CDMOs supplying US and EU markets need active FDA and EMA GMP certifications on the specific facility. Both regulators have inspection experience with major Korean biologics sites, and inspection outcomes have generally been favorable. For programs supplying UK specifically, post-Brexit MHRA acceptance of MFDS + EMA-recognized inspections has continued under transitional arrangements — sponsors should confirm current MHRA policy at RFP stage. The Signal Score's Quality Compliance pillar captures FDA + EMA + MHRA data directly, so Korean CDMOs with cross-jurisdictional posture rank higher on this pillar than domestic-market-only competitors.
Gene Therapy CDMOs — Frequently Asked Questions
Who are the top Gene Therapy CDMOs?
By CDMO Signal's independent Signal Score, the top-ranked Gene Therapy CDMOs include Lotte Biologics, SK pharmteco, Helixmith. See the full ranked table above — scored on FDA, clinical, financial, and capacity data.
How many Gene Therapy CDMOs have FDA inspection records?
CDMO Signal tracks 1 Gene Therapy CDMO with FDA inspection records and 0 EMA/MHRA GMP certificates across the group.
What should I look for in a gene therapy CDMO?
Match the vector platform to your program first (AAV / lentiviral / adenoviral). Then verify the CDMO's on-platform inspection record, capacity at your target phase, analytics maturity for that vector type, and a clean FDA and EMA/MHRA record. The individual platform pages have platform-specific detail.
How many gene therapy CDMOs does CDMO Signal track?
63 CDMOs are tracked as gene therapy manufacturers — the union of AAV, lentiviral, adenoviral, and generally-tagged gene therapy CDMOs. Each is scored independently on the standard four-pillar Signal Score composite.