What Shapes Phase III Gene Therapy CTIS Timelines?
Clinical Trial Intelligence

What Shapes Phase III Gene Therapy CTIS Timelines?

20 July 2026

Across 33 Phase III gene therapy trials submitted through the European Union Clinical Trials Information System (CTIS), the median end-to-end review was 108 days with a 55.1-day standard deviation (SD). Country-specific CTIS Part II decisions had a 100-day median and a much wider 224.4-day SD. Only 27.3% of trials were authorised within 30 days, while Q4 submissions, programmes with 16 or more EU sites, and trials planning at least 151 participants were most consistently associated with 90-day-or-longer reviews.

Trials included
33
Phase III gene therapy EU submissions
End-to-end median
108 days
SD 55.1 days
CTIS Part II median
100 days
SD 224.4 days
Within 30 days
27.3%
9 of 33 trials

How long do EU CTIS reviews take?

The trial-level end-to-end timeline—from initial CTIS submission to first EU authorisation—had a median of 108 days and SD of 55.1 days. Country-level CTIS Part II review, calculated separately for each Member State decision, had a median of 100 days and SD of 224.4 days.

Overall EU CTIS review timelines
Trial-level end-to-end review
108 days
Median · SD 55.1 · interquartile range 29–124 · range 6–175 days
Country-specific CTIS Part II
100 days
Median · SD 224.4 · interquartile range 38.3–267 · range 7–806 days
Interpretation

The similar medians conceal very different variability: trial-level authorisation clustered within a narrower window, while Member State Part II timelines had a pronounced long tail. Planning should therefore use country-specific dispersion rather than applying the overall 108-day benchmark to individual countries.

What percentage of trials clear each review interval?

Only 9 of 33 trials (27.3%) received first EU authorisation within 30 days. The cumulative share rose to 15 of 33 (45.5%) by 60 days, 16 of 33 (48.5%) by 90 days, 22 of 33 (66.7%) by 120 days, and 30 of 33 (90.9%) by 150 days.

Cumulative first EU authorisation rate
Within 30 days27.3%
9 of 33 trials
Within 60 days45.5%
15 of 33 trials
Within 90 days48.5%
16 of 33 trials
Within 120 days66.7%
22 of 33 trials
Within 150 days90.9%
30 of 33 trials
Within 180 days100.0%
33 of 33 trials
Interpretation

The 108-day median sits beyond the three-month mark: 17 of 33 trials (51.5%) required at least 90 days, and 11 of 33 (33.3%) required at least 120 days. A 150-day planning allowance captured 90.9% of observed first-authorisation timelines.

How do CTIS Part II timelines differ by country?

Among countries with at least three observed decisions, Greece had the lowest median CTIS Part II timeline at 36 days, followed by Czechia at 55 days and Hungary at 61 days. Bulgaria had the highest median at 224 days, followed by Denmark at 187 days and Spain at 180 days.

Country-specific CTIS Part II review time
CountryDecisionsMedian daysSD days
Finland 1 23.0
Greece 5 36.0 37.7
Sweden 2 38.5 17.7
Czechia 3 55.0 74.8
Slovakia 1 61.0
Hungary 3 61.0 121.7
Portugal 3 74.0 102.7
France 18 77.0 198.0
Croatia 1 82.0
Netherlands 6 91.5 284.3
Poland 5 115.0 104.4
Germany 16 115.0 266.5
Italy 20 150.0 247.5
Austria 2 163.0 132.9
Belgium 8 165.5 305.9
Spain 21 180.0 261.0
Denmark 4 187.0 117.2
Latvia 1 217.0
Lithuania 1 221.0
Bulgaria 3 224.0 157.1
Interpretation

The most decision-rich countries also showed substantial dispersion: France recorded a 77-day median with 198.0-day SD across 18 decisions, Germany 115 days with 266.5-day SD across 16, Italy 150 days with 247.5-day SD across 20, and Spain 180 days with 261.0-day SD across 21.

How often does country Part II finish within common intervals?

Across country-level CTIS Part II decisions, 25 of 124 (20.2%) finished within 30 days, 50 of 124 (40.3%) within 60 days, 59 of 124 (47.6%) within 90 days, and 64 of 124 (51.6%) within 120 days.

Cumulative country-level CTIS Part II completion
Within 30 days20.2%
25 of 124 country decisions
Within 60 days40.3%
50 of 124 country decisions
Within 90 days47.6%
59 of 124 country decisions
Within 120 days51.6%
64 of 124 country decisions
Within 180 days60.5%
75 of 124 country decisions
Within 365 days79.8%
99 of 124 country decisions
Interpretation

Country Part II showed a heavier tail than the trial-level process: even at 180 days, only 75 of 124 decisions (60.5%) had completed, and 99 of 124 (79.8%) completed within one year.

Which factors are associated with faster or delayed authorisation?

Faster-than-median authorisation was defined as under 108 days. Substantial delay was assessed at 60 days or longer and at least 90 days. The strongest descriptive signals were submission timing, EU site footprint, planned sample size, randomisation, population type, orphan status, and therapeutic area.

Most associated with faster than median
Other-quarter submissions
62.5%
15 of 24 were faster than the 108-day median; median 41.5 days.
Fewer than 16 sites
59.3%
16 of 27 were faster than median; median 42.0 days.
Non-randomised design
61.9%
13 of 21 were faster than median; median 42.0 days.
Paediatric trials
61.9%
13 of 21 were faster than median; median 42.0 days.
Orphan-designated trials
59.1%
13 of 22 were faster than median; median 38.5 days.
Most associated with 90+ days
16+ sites
100.0%
6 of 6 required at least 90 days; median 128.5 days.
Oncology trials
100.0%
5 of 5 required at least 90 days; median 112.0 days.
Q4 submissions
88.9%
8 of 9 required at least 90 days; median 129.0 days.
151+ participants
88.9%
8 of 9 required at least 90 days; median 124.0 days.
Randomised trials
75.0%
9 of 12 required at least 90 days; median 123.5 days.
Trial-level factor comparison
Factor contrastMedian daysFaster than 10860+ days90+ days
Submission timing
Q4 submissions vs Other quarters
129.0 vs 41.5 11.1% vs 62.5% 88.9% vs 41.7% 88.9% vs 37.5%
Country footprint
6+ countries vs 1–2 countries
117.5 vs 38.5 37.5% vs 66.7% 62.5% vs 41.7% 62.5% vs 33.3%
Site footprint
16+ EU sites vs Fewer than 16 sites
128.5 vs 42.0 0.0% vs 59.3% 100.0% vs 44.4% 100.0% vs 40.7%
Planned sample
151+ participants vs Fewer than 151
124.0 vs 41.5 11.1% vs 62.5% 88.9% vs 41.7% 88.9% vs 37.5%
Trial design
Randomised vs Non-randomised
123.5 vs 42.0 25.0% vs 61.9% 75.0% vs 42.9% 75.0% vs 38.1%
Population
Non-paediatric vs Paediatric
119.0 vs 42.0 25.0% vs 61.9% 75.0% vs 42.9% 75.0% vs 38.1%
Designation
Non-orphan vs Orphan
112.0 vs 38.5 27.3% vs 59.1% 72.7% vs 45.5% 72.7% vs 40.9%
Therapeutic area
Oncology vs Non-oncology
112.0 vs 45.0 0.0% vs 57.1% 100.0% vs 46.4% 100.0% vs 42.9%
Modality mix
Multi-modality regimen vs Gene therapy only
109.0 vs 81.0 44.4% vs 53.3% 55.6% vs 53.3% 55.6% vs 46.7%
Interpretation

Operational scale was the clearest delay signal. Every trial with 16 or more EU sites required at least 90 days, compared with 40.7% of trials with fewer sites. Similarly, 88.9% of trials planning at least 151 participants and 88.9% of Q4 submissions required at least 90 days. Smaller, non-randomised, paediatric, and orphan-designated programmes more often completed below the 108-day median.

Definitions

End-to-end CTIS timelineCalendar days from initial EU CTIS submission to the first authorisation date for the trial.
CTIS Part IICountry-specific review of local documents and requirements; it is not an end-to-end trial timeline.
MedianThe middle observed duration after ordering timelines from shortest to longest.
Standard deviationDispersion around the mean; large values indicate highly variable review durations and long tails.