Phase II Gene Therapy CTIS Review Timelines
Clinical Trial Intelligence

How Fast Are Phase II Gene Therapy CTIS Reviews and Why Do They Vary?

20 July 2026

Across 63 Phase II gene therapy trials, the median interval from initial EU CTIS submission to first authorization was 104 days (SD 57.2). Country-level CTIS Part II review was substantially more variable: the median was 201.5 days (SD 240.7) across 114 country assessments. Orphan trials reached a first authorization faster, yet their later country Part II assessments were much more likely to exceed 90 days.

63
Phase II trials
Combined EU gene therapy cohort
104
Median EU end to end days
Initial CTIS submission to first authorization
201.5
Median Part II days
Country submission to latest decision
59.6%
Part II at least 90 days
68 of 114 country assessments

First EU authorization typically arrived in 104 days

The trial-level EU end-to-end interval had a median of 104 days and an SD of 57.2 days. Half of trials fell between 33 and 123 days, while the observed range was 1 to 293 days. This metric belongs to the overall CTIS submission and is not assigned to individual countries.

Overall CTIS timeline comparison
104 days
EU end to end
SD 57.2 · IQR 33–123 · n=63
201.5 days
Country CTIS Part II
SD 240.7 · IQR 36–445 · n=114
End to end: initial CTIS submission to first CTIS authorization. Part II: earliest country Part II submission to latest country decision or authorization.
Interpretation

The median country Part II interval was 97.5 days longer than the median first-authorization interval, and its SD was 4.2 times larger. EU launch planning therefore needs separate assumptions for first authorization and later country completion.

Only 36.5% of trials reached first authorization within 60 days

Thirteen of 63 trials (20.6%) reached a first CTIS authorization within 30 days, 23 of 63 (36.5%) within 60 days, and 28 of 63 (44.4%) within 90 days. By 120 days, the cumulative share increased to 46 of 63 trials (73.0%).

Cumulative first EU authorization rate
≤30 days20.6%
13/63
≤60 days36.5%
23/63
≤90 days44.4%
28/63
≤104 days50.8%
32/63
≤120 days73.0%
46/63
≤180 days95.2%
60/63
Interpretation

A 60-day assumption covered only about one third of Phase II gene therapy submissions. A 120-day planning window captured 73.0%, while 180 days captured 95.2%.

Country Part II performance split into fast and very delayed clusters

Across 114 country assessments, 39 (34.2%) concluded within 60 days and 47 (41.2%) within 90 days. At the other end, 34 assessments (29.8%) exceeded 365 days. The distribution therefore did not resemble the more compact first-authorization timeline.

Cumulative country CTIS Part II decision rate
≤30 days20.2%
23/114
≤60 days34.2%
39/114
≤90 days41.2%
47/114
≤120 days43.9%
50/114
≤180 days48.2%
55/114
≤365 days70.2%
80/114
Interpretation

Country completion risk remained material well beyond three months: 68 of 114 Part II assessments (59.6%) lasted at least 90 days, and only 80 of 114 (70.2%) concluded within one year.

Belgium, the Netherlands and Poland had the lowest multi-trial medians

Among countries with at least five assessments, Belgium had a median Part II interval of 26.5 days, the Netherlands 31 days, and Poland 31 days. Spain had the highest median at 286 days, followed by Germany at 253.5 days and Italy at 238 days.

Country CTIS Part II median and variability
CountrynMedian daysSD≤60 days≥90 days
Bulgaria 1 15 0.0 100.0% 0.0%
Belgium 8 26.5 282.9 62.5% 37.5%
Netherlands 13 31 251.3 69.2% 30.8%
Poland 6 31 238.1 66.7% 33.3%
Hungary 3 59 18.3 66.7% 0.0%
Romania 1 63 0.0 0.0% 0.0%
Norway 1 89 0.0 0.0% 0.0%
Ireland 2 144 119.0 50.0% 50.0%
Slovenia 1 154 0.0 0.0% 100.0%
France 20 225.5 222.7 25.0% 70.0%
Italy 19 238 224.9 10.5% 78.9%
Germany 14 253.5 213.6 28.6% 71.4%
Austria 2 264.5 183.5 0.0% 50.0%
Sweden 4 271 256.4 25.0% 75.0%
Spain 19 286 250.6 26.3% 73.7%
Countries are ordered by median Part II days. SD is the population standard deviation; a single observation therefore has SD 0.0. End-to-end timing is intentionally not shown by country.
Interpretation

Country medians alone understate risk where SD is large. Belgium, the Netherlands and Poland combined low medians with occasional very long assessments, while France, Italy, Germany and Spain each had at least 70.0% of assessments lasting 90 days or more.

Orphan status shortened first authorization but lengthened later Part II review

Orphan trials reached first EU authorization in a median 44 days versus 115 days for non-orphan trials. However, their country Part II median was 448 days versus 81 days, and 34 of 39 orphan country assessments (87.2%) lasted at least 90 days.

Faster first authorization
Orphan designation
44 vs 115 days
18/26 orphan trials (69.2%) were below the 104-day cohort median, versus 13/37 (35.1%) without orphan status.
Longer country completion
Orphan Part II expansion
448 vs 81 days
87.2% of orphan assessments reached 90 days, compared with 45.3% of non-orphan assessments.
Faster first authorization
Adaptive design
88 vs 112 days
18/32 adaptive trials (56.3%) were below median versus 13/31 non-adaptive trials (41.9%).
Longer country completion
Dose escalation
242 vs 88 days
71.7% of escalation-design assessments reached 90 days versus 49.2% without escalation.
Interpretation

The factors associated with a rapid first authorization were not necessarily associated with rapid multinational completion. The orphan result is the clearest example and supports separate forecasting for the first authorized member state and the remaining Part II pathway.

Route, blinding and operational model were associated with Part II delay

Systemic intravenous gene therapy assessments had a median Part II duration of 430 days and an 87.8% rate of at least 90 days. Other local or mixed routes had a median of 30 days and a 19.0% rate. Open-label, combination and CRO-supported assessments also showed higher delay rates.

Selected Part II delay factors
Factor comparisonMedian days≥60 days≥90 days
Systemic intravenous vs other local or mixed430 vs 3090.2% vs 28.6%87.8% vs 19.0%
Orphan vs non-orphan448 vs 8189.7% vs 54.7%87.2% vs 45.3%
Open label vs blinded242 vs 5475.3% vs 45.5%69.1% vs 36.4%
Combination vs single treatment276 vs 9880.0% vs 60.8%77.1% vs 51.9%
CRO present vs no CRO280 vs 84.573.6% vs 54.8%68.1% vs 45.2%
Randomised vs non-randomised31 vs 25621.7% vs 78.0%13.0% vs 71.4%
Associations are descriptive and may reflect correlated choices of disease, country, route and trial design rather than independent causal effects.
Interpretation

The largest delay signals clustered around systemic delivery, orphan development, open-label designs and operationally complex submissions. Randomised studies were an exception, with substantially shorter Part II medians in this cohort.

Part II submission month showed a strong timing pattern

For months with at least six country assessments, March submissions had a median of 27 days and November submissions 50 days. April submissions had a median of 614.5 days and May submissions 445 days. The 90-day delay rate ranged from 11.1% in November to 91.7% in April.

CTIS Part II timing by submission month
MonthnMedian days≤60 days≥90 days
March827 87.5%12.5%
November950 77.8%11.1%
July15149 40.0%53.3%
October11154 36.4%63.6%
June12215 16.7%66.7%
August14210.5 35.7%64.3%
May11445 9.1%81.8%
April12614.5 8.3%91.7%
Months with fewer than six assessments are excluded from this comparison. Calendar year is not used as an analytical factor.
Interpretation

Submission month was more informative for country Part II timing than the number of countries or sites. March and November formed the fastest clusters, while April and May carried the highest long-delay rates.

More countries and sites did not explain the delay

The number of countries had almost no monotonic relationship with first authorization (Spearman ρ=0.07) or Part II duration (ρ=−0.06). Total site count was similarly weak (ρ=0.07 for first authorization and ρ=−0.12 for Part II). In contrast, recruitment-window length correlated moderately with Part II duration (ρ=0.37), and primary-endpoint count correlated at ρ=0.30.

Country countρ=0.07 end to end
ρ=−0.06 Part II
Total site countρ=0.07 end to end
ρ=−0.12 Part II
Recruitment windowρ=−0.55 end to end
ρ=0.37 Part II
Endpoint complexityPrimary endpoints ρ=0.30 Part II
Secondary endpoints ρ=0.26 end to end
Interpretation

Geographic scale alone was not the main source of review variation. Submission timing, country mix, route and design characteristics provided stronger descriptive signals than simply adding countries or sites.

Planning implications for EU Phase II gene therapy submissions

First authorization
Use 120 days as the central planning case
A 120-day window covered 46/63 trials (73.0%); 180 days covered 60/63 (95.2%).
Country completion
Maintain a one-year tail scenario
34/114 assessments (29.8%) exceeded 365 days, despite 34.2% concluding within 60 days.
Country strategy
Do not extrapolate the first decision
The Part II median was 97.5 days longer and SD was 4.2× higher than the first-authorization metric.
Complex submissions
Add contingency for orphan systemic programs
Orphan Part II assessments had an 87.2% 90-day delay rate; systemic intravenous assessments had an 87.8% rate.

Definitions

EU end to endCalendar days from initial CTIS submission to the first CTIS authorization for the trial.
CTIS Part IICalendar days from the earliest country Part II submission to the latest recorded country decision or authorization.
MedianThe middle observed duration; preferred over the mean for the highly skewed Part II distribution.
SDPopulation standard deviation, reported in days. It describes dispersion around the mean, not around the median.