When enrollment falls behind, adding sites can feel like the most direct response. More locations create more opportunities to find participants. But a new location also introduces startup work, training, oversight and a period before the first person can be screened. The relevant question is whether those activities can produce useful enrollment within the time that remains.
For sponsors and CROs evaluating a clinical trial rescue site in Florida, Puerto Rico or another market, the decision should begin with the cause of the shortfall. A site that can solve a referral problem may not solve a restrictive eligibility requirement. A site with strong clinical experience may still face the same scheduling or procedure constraint as the existing network.
Diagnose the enrollment gap before opening another site
Separate the problem into stages. Is the study receiving too few inquiries? Are interested people failing preliminary review? Are records unavailable? Are screening visits being delayed? Are screened participants failing a specific criterion? Is randomization waiting on an assessment or central review?
Each pattern suggests a different response. Low inquiry volume may justify a new referral population. A repeated screening failure may call for a closer look at eligibility assumptions. A scheduling bottleneck may be better addressed by helping an existing site increase capacity. A new site is useful when it changes the limiting factor.
Ask for a short evidence summary from the sponsor and existing sites, using aggregate information appropriate for the discussion. Review the period measured, the denominator at each stage and the main reasons people do not progress. Avoid comparing a count of advertising leads with a count of clinically reviewed candidates as though they describe the same population.
Work backward from the last useful enrollment date
The final date for adding a site is not necessarily the last date on which a site could be activated. Work backward from the last protocol-allowed randomization or enrollment date, including any screening period, required repeat assessments, central confirmation and participant scheduling.
Then identify how much time remains for the candidate site to become ready. Include contracts, regulatory work, translations when needed, training, system access, supplies, required vendors and initiation activities. Some tasks can overlap; others have dependencies that cannot be removed by working faster.
A credible proposal should show a plausible first screening date and the subsequent opportunity to enroll, not merely a projected activation date. Ask which assumptions would move those dates and who can influence them. Sponsor-side turnaround matters when the rescue plan depends on rapid document decisions or vendor setup.
Look for incremental patient access
A large patient population is not automatically an additional population. A prospective rescue site may refer to the same physicians, advertise to the same audience or compete with nearby locations already recruiting for the protocol.
Review the candidate pathway in enough detail to understand what is genuinely additional. Which practices or clinical relationships are relevant? Are the required treatment histories represented? How current is the information? What remains unknown until formal screening? What other studies could compete during the remaining window?
WCR's feasibility and startup approach includes connected records, local competition and team review. Those are useful inputs to a rescue evaluation, but they do not establish an enrollment guarantee or a verified rescue outcome. The proposed protocol still needs a fresh assessment against the actual deadline.
Test throughput against staffing and visit capacity
A potential patient pool can be larger than the site's ability to process it. The team may have enough people to make calls but too few appointments for clinical review, screening or a required specialty procedure. Later visits can also compete with the new screening workload.
Ask the investigator and coordinator to identify the most constrained step. Review the availability of appropriately trained staff, rooms, laboratory processing, outside procedures and the investigator's oversight time. Include coverage for existing studies rather than assuming that a newly selected protocol will receive all available capacity.
FDA's E6(R3) guidance states that investigators should be able to demonstrate potential to recruit eligible participants within the agreed period and have adequate time, staff and facilities. For a rescue decision, the practical application is to test both patient access and the team's ability to deliver within the remaining period.
Compare adding a site with helping existing sites
The choice is not always between doing nothing and opening another location. A sponsor may be able to resolve a shared records delay, clarify a procedure, improve response times or provide operational support to sites that already have interested candidates.
Compare options using the same endpoint: expected contribution before enrollment closes. Include the work required, the assumptions supporting the estimate and the possibility that the same barrier will remain. A new site may be the better option when it offers a distinct patient pathway or relevant capacity that the current network cannot supply.
This comparison should not blame a site for a problem outside its control. It should identify where an additional effort is most likely to help. An operational conversation becomes more useful when each party can distinguish an action it owns from a decision that requires another team.
Set a short, meaningful review cycle
If a rescue site is selected, define the early signals that will show whether the assumptions are holding. Track completed actions and participant progression, not only calls made or names added to a list.
The recruitment and retention workflow should support a review of records readiness, clinical review, scheduled screenings and actual outcomes. Agree in advance on what would prompt a revised forecast or another intervention. This prevents the team from waiting until the enrollment window is nearly closed to discover that a critical assumption was wrong.
Keep the first review proportionate to the amount of activity completed. A new site needs time to establish a meaningful pattern. The purpose is to identify actionable differences from the plan, not to react to every short-term fluctuation.
A rescue-site decision record
Before proceeding, capture the answers to a compact set of questions:
- Problem: Which documented enrollment barrier will this site address?
- Population: What patient access is additional and relevant to the protocol?
- Timing: Can screening and enrollment finish within the remaining window?
- Readiness: Which approvals, contracts, vendors and supplies remain outstanding?
- Capacity: What is the limiting visit or staffing resource?
- Evidence: Which assumptions are supported, and which still require confirmation?
- Review: What early results would change the plan?
Make the decision specific to the study
A rescue label does not replace feasibility. The strongest proposal explains what the added site can contribute, what must happen first and how the sponsor will recognize progress. It also leaves room to decide that a different intervention is more useful.
For a discussion of a protocol with an enrollment shortfall, submit the study details to WCR, including the remaining enrollment window and known barriers. That gives the team the context needed to assess fit without assuming that another site, by itself, will solve the problem.