Across 237 leukemia Phase II and Phase III CTIS trials authorised in 2024–2026, CROs or CRO-like outsourced providers appear in 96 trials, or 40.5%. The strongest activity signal is trial complexity: CRO use reaches 35/43 trials (81.4%) once a leukemia trial spans 7 or more European countries, while Phase III trials show 43/76 CRO use (56.6%). IQVIA is the most active named provider, appearing in 31 trials, followed by ICON/PRA and Parexel/Perceptive with 25 trials each.
The leading named CRO/provider is IQVIA, listed in 31/237 trials (13.1%). ICON/PRA and Parexel/Perceptive each appear in 25/237 trials (10.5%), while PPD/Thermo Fisher appears in 21/237 trials (8.9%). CRO/provider counting is trial-level: a provider is counted once per trial even if listed more than once in the CTIS sponsor record.
Leukemia outsourcing is not dominated by one full-service CRO alone. The CTIS sponsor records show a layered model: IQVIA, ICON/PRA, Parexel/Perceptive, and PPD/Thermo Fisher lead broad operational coverage, while Almac, Signant/ERT, Labcorp, Medidata, 4G Clinical, and similar providers cover specialised EU submission, data, IRT, lab, and trial-technology functions.
CRO use is materially higher in Phase III leukemia trials: 43/76 Phase III trials (56.6%) list a CRO, compared with 49/152 Phase II trials (32.2%). By authorisation year, CRO use rises from 58/158 trials in 2024 (36.7%) to 27/58 in 2025 (46.6%) and 11/21 in 2026 (52.4%).
The CRO trigger is not simply “leukemia”; it is late-stage execution complexity. Phase III leukemia trials require more country coordination, monitoring, vendor governance, data systems, lab support, and CTIS Part II country execution, which explains the higher CRO intensity.
Country count is the clearest outsourcing threshold in the leukemia dataset. CRO use is only 15/115 trials (13.0%) in single-country trials, but rises to 24/37 trials (64.9%) at 4–6 countries and 35/43 trials (81.4%) at 7 or more CTIS countries.
For leukemia trial managers, 7 or more European countries is the strongest practical CRO-buying signal. At that point, CTIS/EU submission coordination, Part II country responses, local contracts, site activation, translations, and vendor oversight become difficult to manage with sponsor-only infrastructure.
CRO use rises with the number of European sites. It is 6/34 trials (17.6%) in 1–3 site trials, 19/51 (37.3%) in 4–10 site trials, 29/76 (38.2%) in 11–25 site trials, and 33/61 (54.1%) once a trial reaches 26 or more sites.
The operational inflection point appears around 26 sites. Below that level, many academic and hospital-network leukemia studies remain sponsor-run; above it, monitoring, site payment, contracting, data cleaning, central lab, and IRT demands increasingly require outsourced infrastructure.
Participant volume shows a more moderate relationship than country count. The highest CRO-use rate is in the 151–300 participant stratum, where 18/38 trials (47.4%) list CRO support. The largest absolute CRO-backed volume is in 51–150 participant trials, with 33 CRO-supported trials out of 77 (42.9%).
For leukemia, participant count alone is not the strongest CRO trigger. A 200-patient, 3-country trial may be easier to manage than a 100-patient, 10-country trial; the CTIS data points to geographic spread and site count as the more actionable outsourcing thresholds.
CRO use is highest in chronic lymphocytic leukemia/small lymphocytic lymphoma/Richter transformation trials, where 35/60 trials (58.3%) list CRO support. AML trials have the highest absolute disease volume after CLL/SLL, with 21/58 CRO-supported trials (36.2%), while AML/MDS overlap trials show 12/30 CRO use (40.0%).
CLL/SLL and Richter transformation appear to be the most CRO-intensive leukemia niche in this CTIS cohort. These trials often include multi-country mature haematology networks, biomarker/lab vendors, IRT systems, and commercial sponsors, making them stronger outsourcing candidates than many smaller academic AML or ALL studies.
The largest CRO-backed trial-country footprints are Spain with 64 CRO-backed trial-country entries, Italy with 61, France with 55, Germany with 52, and Poland with 42. In CRO-backed trials, Spain accounts for 406 sites and 2,304 participants, while Italy accounts for 430 sites and 1,479 participants.
CRO-backed leukemia trials concentrate in the major EU haematology markets: Spain, Italy, France, Germany, and Poland. These are the countries where CTIS Part II coordination, site activation, contracting, and patient allocation are most likely to require a centralised operating model.
The most common outsourced function category is clinical operations/full-service CRO support, appearing in 83/237 trials (35.0%). Laboratory, biomarker, diagnostics, and PK support appears in 74/237 trials (31.2%), followed by eClinical, EDC/eCOA, and TMF systems in 48/237 (20.3%) and IRT/randomisation technology in 47/237 (19.8%).
Leukemia trials outsource beyond monitoring. The CTIS records point to a common operating stack: central lab and biomarker vendors, eCOA/EDC/TMF systems, IRT/randomisation, supplies, site payments, patient travel/reimbursement, and imaging. This is especially relevant for AML, ALL, and CLL studies with MRD, PK/PD, central diagnostics, or multi-country EU submission requirements.
Sponsor type is a major outsourcing signal: industry/pharma sponsors use CROs in 79/102 trials (77.5%), compared with 16/124 academic, hospital, or network-sponsored trials (12.9%). Orphan-designated leukemia trials also show higher CRO use at 39/74 trials (52.7%), compared with 57/163 non-orphan trials (35.0%).
The best CRO prospecting filters in leukemia are industry sponsorship, orphan designation, Phase III status, 7+ CTIS countries, and 26+ sites. Academic/hospital studies are common in the dataset but are much less likely to list a CRO unless they carry multinational or paediatric network complexity.
CRO-supported trial: a trial where the CTIS sponsor record lists one or more organisations under cro_present.cros. This can include full-service CROs and specialised outsourced clinical service providers.
CTIS: the Clinical Trials Information System used for EU/EEA clinical trial applications; Part II information is country-specific and covers national/site-level assessment and authorisation details.
Disease shorthand: AML = acute myeloid leukemia; ALL = acute lymphoblastic leukemia; CLL = chronic lymphocytic leukemia; SLL = small lymphocytic lymphoma; CML = chronic myeloid leukemia; MDS = myelodysplastic syndrome.