Transplant drug monitoring: a tiered site network
Immunosuppressant drug-level assays · transplant specimen collection · 244 subjects, 7 sites
The challenge the client gave us
The client makes assays for the immunosuppressant drug levels that transplant patients manage for life (tacrolimus, cyclosporine, sirolimus, everolimus, and mycophenolic acid). They needed specimens spanning five drugs across heart, liver, and kidney recipients — with tacrolimus split further into peak and trough draws.
The catch: it's a matrix of drug × organ sub-cohorts, each behaving like its own sub-study, and the samples demand draw-time precision, the right tube type per drug, and cold chain held from the moment of collection.
At a glance
| Subjects enrolled | 244 (by 1 May 2026) |
| Sites active | 7 U.S. transplant centers |
| IRB submission → clearance | 15 days |
| Collection I close | 218 subjects (Mar 2026) |
| Collection II target added | +350 subjects (Apr 2026) |
Timeline
- 15 Jul 2025 IRB filed
- 30 Jul 2025 IRB cleared (15 days)
- Aug 2025 First site initiations (+18)
- Nov 2025 192 enrolled
- Mar 2026 Collection I closes (218)
- 3 Apr 2026 Collection II opens
- Apr 2026 EDC goes live
- May 2026 Two more sites (H and I) initiated
- 1 May 2026 244 enrolled
What we did as a CRO
| CRO responsibility | What RDI did on this study |
|---|---|
| Regulatory & study start-up | Filed and cleared IRB in 15 days; added Collection II scope in April 2026 |
| Site selection & feasibility | Built a tiered network: academic transplant centers to carry volume, community sites to fill the specific drug/organ cohorts the academics couldn't reach |
| Site activation & training | Phased SIVs from Aug 2025; two additional sites (H, I) initiated May 2026 |
| Recruitment & enrollment | Enrolled against a drug × organ matrix, with peak/trough draw timing for tacrolimus treated as distinct sub-cohorts |
| Kits, samples & lab | Enforced tube-type discipline per drug (whole blood for cyclosporine/tacrolimus, serum for mycophenolic acid) and cold chain held from draw for assay-grade integrity |
| Monitoring & data | Migrated the study onto an EDC (live Apr 2026); central monitoring |
| Project management & close-out | Closed Collection I at 218 and opened Collection II (+350 target) without a gap in the site network |
What made it hard
- It's a matrix, not a cohort. Five drugs × three organ groups (plus peak/trough for tacrolimus) means each combination is effectively its own sub-study, with its own target and its own eligible patients.
- Sites aren't interchangeable. A center strong in kidney tacrolimus may have no liver everolimus patients — so no single network covers the whole matrix.
- The samples are unforgiving. These assays need exact draw timing, the correct tube per drug, and cold chain from the moment of collection.
How we solved it
- We built a tiered site network: academic transplant centers to drive volume, plus community sites deliberately added to fill the drug/organ cohorts the academics couldn't supply.
- We treated each drug × organ combination as its own sub-study with its own target, rather than one big enrollment number.
- We standardized specimen discipline (tube type per drug, draw timing, cold chain) and moved the study onto an EDC to keep data clean as scope grew.
The result
244 subjects across seven transplant centers; Collection I closed at 218, and Collection II opened immediately with a +350-subject target — the client expanded the program rather than pausing it.
Source: Diagnostica™ and sponsor project updates at 1 May 2026. Sponsor identity withheld; site labels anonymized. Operations report, not a clinical-results publication.