The Last Mile Problem in Clinical Supply
A clinical trial can have the most rigorous bioanalytical programme and the most carefully designed protocol in the world, but if the investigational medicinal product (IMP) does not arrive at the investigator site in the right condition, at the right time, and with the right documentation, none of that matters. Global clinical distribution is the operational backbone of a clinical trial, and it is one of the most underestimated sources of risk in early-phase programmes.
For a Phase I trial running at a handful of sites in Western Europe, the logistical challenges are manageable. As a programme grows and extends to sites in multiple continents, the complexity of customs requirements, depot management, cold chain maintenance, and country-specific regulatory documentation multiplies quickly.
The Regulatory Dimension of IMP Distribution
Investigational medicinal products are not commercial pharmaceutical products, and they are not treated as such by customs authorities. They require specific import licences, certificates of analysis, manufacturing authorisation documentation, and, in many countries, additional country-specific approvals before they can legally be imported for clinical use. The EU Clinical Trials Regulation (EU) 536/2014 and its associated guidance on IMP manufacturing and supply set the framework for European clinical supply, while individual non-EU markets each have their own import requirements that must be navigated separately.
The consequences of getting this wrong are not minor. IMP held in customs clearance for two weeks because of a documentation error means two weeks of delay to site activation, which means two weeks of delay to first patient dosing, which in a competitive therapeutic area can have real consequences for programme timelines and funding milestones.
Clinical Supply Distribution Models
| Distribution Model | How It Works | Best Suited For | Key Consideration |
| Direct to site | IMP shipped from manufacturer directly to each investigator site | Simple programmes; small number of sites; stable ambient products | High volume of individual shipments; complex for multi-country programmes |
| Central depot | IMP shipped to a single central depot, then distributed to sites as needed | Multi-site, multi-country trials; products requiring controlled storage | Depot must hold appropriate storage authorisations; adds handling step |
| Regional depots | Multiple regional depots covering different geographic zones | Phase III trials with large numbers of sites across multiple continents | Higher cost; requires coordination between depots; preferred for cold chain products |
| Investigator site as depot | Sites hold small buffer stock and request resupply as needed | Adaptive trials; variable dosing schedules | Requires on-site storage capability and electronic IMP tracking |
Cold Chain Management in Global Distribution
Many investigational products require storage and transport at controlled temperatures, ranging from standard refrigerated conditions at 2 to 8 degrees Celsius through to deep frozen at minus 20 degrees Celsius or minus 80 degrees Celsius for cell therapies and some biologic products. Maintaining the cold chain across an international distribution network, through multiple handling steps, customs inspections, and last-mile delivery, requires validated packaging, temperature monitoring, and documented procedures for managing excursions.
Temperature excursion management is an area where clear decision trees and pre-defined acceptance criteria save significant time during a trial. When a temperature excursion is recorded, the sponsor needs to be able to determine quickly, using validated stability data, whether the product is still fit for use or needs to be quarantined. Having this process documented and tested before the trial starts prevents ad hoc decisions under time pressure.
Country-Specific Challenges Worth Planning For
Named Patient and Compassionate Use Requirements
In some markets, investigational products can only be imported on a named patient basis, which requires individual import licences linked to specific patient identifiers. This creates significant administrative overhead for trials with large numbers of sites in those markets and requires close coordination between the clinical operations team, the regulatory team, and the clinical supply partner.
Labelling Requirements
Clinical trial labelling requirements vary by jurisdiction. In the EU, Annex 13 of the EU GMP guidelines sets out the labelling requirements for IMPs, including the mandatory elements and the language requirements for each member state. Markets outside the EU may require additional information on the label or translated labels. Designing a master label that can be adapted for all required markets, while remaining within the physical dimensions of the packaging, is a practical challenge that benefits from early planning.
Controlled Substance Scheduling
Clinical programmes involving controlled substances, including psychedelics, opioids, or other scheduled compounds, face additional requirements at every border crossing. Import licences, permits, and sometimes individual authorisations from national regulatory authorities are required. The lead times for obtaining these permits can be significant and must be built into the programme timeline.
How Ardena Manages Global Clinical Supply
Ardena’s clinical supply team, based at the Assen facility in the Netherlands and coordinated across the wider European network, provides IMP packaging, labelling, storage, and distribution services for clinical trials across Europe and to international markets. The team manages customs documentation, depot coordination, and cold chain logistics for programmes ranging from single-site Phase I studies to multi-country Phase II trials.
