Recruitment shortfalls, repeated operational delays and limited site capacity can all put clinical trial timelines at risk.
According to UK Government figures, 22% of commercial contract studies included in the UK Clinical Research Delivery dataset were not recruiting to time and target in July 2026. When recruitment difficulties and other operational challenges persist, sponsors may need to consider whether a study rescue strategy could be the best way forward.
Recognising the warning signs early is important, particularly when delays begin to affect key study milestones.
Recruitment Falling Behind Target
One of the clearest warning signs is recruitment consistently falling short of expectations.
If sites are struggling to identify eligible participants, screening numbers remain low or enrolment deadlines are repeatedly extended, sponsors need to assess whether the existing recruitment strategy can realistically deliver the required numbers.
Where recruitment efforts have failed to improve performance, introducing additional sites or transferring recruitment activities may be worth considering.
Operational Bottlenecks
Delays in site activation, monitoring, data management or communication can have a knock-on effect across a study.
While individual issues may be manageable, recurring problems can suggest that a site or CRO is struggling to meet the study’s operational requirements.
Sponsors should pay particular attention when agreed recovery actions aren’t delivering improvements or when delays in one area begin affecting other study activities.
Limited Site Capacity
Site capacity can change considerably over the course of a clinical trial. Staffing shortages, competing studies, limited facilities or changes in priorities can all affect a site’s ability to meet its original commitments.
When a site no longer has the resources to meet agreed recruitment targets or study timelines, sponsors may need to consider transferring recruitment activities or introducing additional sites to maintain progress.
When is it Time to Consider Study Rescue?
Moving an ongoing clinical trial to different sites or transferring responsibilities to another CRO can be a major decision that requires careful consideration. Beyond the additional time and costs involved, these changes may require regulatory modifications, contractual updates, the transfer of study data and essential records, and arrangements to ensure participant safety and continuity of care.
For this reason, sponsors need to establish whether the problems can be resolved before committing to a transfer. However, when recovery plans repeatedly fail to deliver improvements, continuing with the existing arrangements can carry its own risks.
Importantly, study rescue doesn’t always require a complete transfer to another CRO. Depending on the circumstances, bringing in additional sites, specialist recruitment support or transferring specific study activities may be enough to get the trial back on track.
How MAC Can Help
MAC Clinical Research has extensive experience supporting rescue studies, particularly where recruitment delays or site performance issues have affected study delivery.
Through our network of wholly owned UK research sites and specialist in-house recruitment services, MAC can help sponsors address recruitment shortfalls and get studies back on track.
MAC has previously supported a post-traumatic stress disorder (PTSD) study where recruitment was falling behind schedule. Following the introduction of MAC sites, recruitment exceeded expectations, with 23 participants randomised within 21 weeks. The sponsor subsequently increased MAC’s recruitment target due to the strong enrolment performance.
Whether a study requires additional research sites or specialist recruitment support, MAC can work with sponsors to identify the most appropriate approach to improving study delivery.
Is your clinical trial falling behind schedule? Click here to speak to MAC about your study rescue options.
