Biomarker-driven oncology trials enroll slowly because eligibility depends on a chain of steps — tissue procurement, sample shipment, lab processing, result communication, and site decision — each owned by a different team, with no single owner accountable for end-to-end speed. According to Sitero’s operational experience across 200+ oncology studies, the breakdown most commonly occurs not in the lab itself but in the hand-off between result availability and site awareness — a gap that well-run programs close to same-day through automated notification and pre-negotiated SLAs, and that poorly run programs leave to manual portal checks and ad hoc follow-up.
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Why Do Biomarker-Driven Trials Enroll Slowly?
Biomarker-driven eligibility has transformed oncology drug development. It has also made enrollment harder. When a patient’s eligibility depends on a molecular test result — whether MSI status, KRAS mutation, PD-L1 expression, or a more novel genomic alteration — every step between tissue collection and enrollment decision is a compressible delay. In a competitive enrollment environment where eligible patients often have access to multiple trials, those delays are not neutral. They cost you patients.
Understanding exactly where delays accumulate, and what operationally distinguishes a high-performing site from a low-performing one, is one of the most practical problems a sponsor can address before a single site is activated.
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Where Does the Delay Actually Come From?
The intuitive assumption is that lab turnaround time is the primary variable. It is not — or at least not always. The delay chain looks like this: tissue procurement (biopsy scheduling, pathology processing), sample shipment to central lab, lab processing and reporting, result communication to the site, site review of eligibility against inclusion/exclusion criteria, and enrollment decision. Each step involves a different team, often with no single owner responsible for the end-to-end timeline.
The delay chain is rarely where sponsors assume it is. The intuitive target is lab turnaround time — but in poorly coordinated programs, the larger share of delay occurs after the result is available. The hand-off between central lab and site — result transmission, coordinator awareness, eligibility review — is where days are lost when no one owns that step end-to-end. In well-coordinated programs, that gap is closed to same-day. In poorly coordinated ones, it can stretch to multiple days while the result sits in a portal no one has checked.
Kyle Hanson, Director of Clinical Operations, Sitero:
“At a well-run site with streamlined central lab logistics and a pre-negotiated courier schedule, you’re typically looking at seven to ten business days from tissue collection to eligibility confirmation. Some high-performing academic sites with on-site pathology support can compress that to five days for fresh biopsies. A poorly run site? Realistically two to three weeks — and that’s if the sample doesn’t fail QC. The breakdown points are almost always the same: delays in pathology sign-off before specimen release, couriers not scheduled in advance, incorrect ambient temperature shipping for certain tissue types, and sites that don’t understand the difference between sample collection and sample release dates. That gap between collection and release — where the sample just sits — is where most of the time is lost.”
Well-Run vs. Poorly-Run Biomarker Screening Programs
| Operational Factor | Well-Run Program | Poorly-Run Program |
|---|---|---|
| Result notification | Automated alert to site coordinator | Manual portal check by site staff |
| Median result-to-site gap | Same day | Days (unmonitored, portal-dependent) |
| SLA with central lab | Contractual, site-level result availability | Based on lab processing time only |
| Escalation path for delayed results | Defined and documented | Ad hoc or absent |
| Screening failure tracking | Reported per site, per period | Aggregated or unreported |
| Site initiation training | Includes biomarker workflow procedures | Generic GCP training only |
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Why Does Site Selection Determine Screening Performance?
Not all oncology sites are equivalent for biomarker-driven trials. A site with high throughput in the relevant tumor type but without an established central lab relationship — or without a dedicated coordinator for screening logistics — will underperform a lower-volume site with tighter operational infrastructure.
Site selection for biomarker-driven programs must explicitly evaluate central lab logistics, biopsy scheduling capacity, and site-level experience with biomarker eligibility workflows before activation commitment. Volume alone is not a proxy for screening efficiency. A site that has enrolled 50 patients in a conventional NSCLC study may not have the coordinator bandwidth or lab relationships to run a PD-L1-stratified enrollment program at pace.
Kyle Hanson, Director of Clinical Operations, Sitero:
“They underestimate the operational complexity of the re-biopsy and sample adequacy loop. It’s not a linear process, and sponsors plan for it as if it is. They account for the first biopsy, the turnaround, and the result. What they don’t plan for is the 25–40% of cases — depending on tumor type — where the initial sample is inadequate for NGS: insufficient tumor cellularity, too few cells, degraded DNA. The re-biopsy decision requires a treating physician conversation, potential re-scheduling of interventional radiology, a new consent touchpoint in some protocols, and another round of courier and lab coordination. Central labs will flag the failure, but they won’t manage the site follow-through. Sponsors need a dedicated process — often a CRA or central coordinator function — specifically for managing sample failure escalation.”
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What Does Good Biomarker Screening Workflow Design Look Like?
The operational standard for biomarker screening workflows should include four non-negotiable elements:
- Pre-negotiated turnaround time SLAs with the central lab — commitments based on result availability at the site, not result availability at the lab (see B2 for the distinction)
- Automated result notification to the site coordinator — not reliant on manual portal checks
- A defined escalation path when results are delayed beyond the SLA window
- Clear protocol language specifying what action the site must take within 24 hours of result availability
These are not complicated requirements. They are routinely absent from poorly run programs. Building these workflows into study startup — rather than treating them as operational details to resolve post-activation — is the difference between a program that enrolls to plan and one that spends its first six months managing screening failures.
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5 Questions to Ask Your CRO About Biomarker Screening Readiness
Before selecting a CRO for a biomarker-driven oncology trial, ask specifically:
- How do you coordinate central lab result notification at the site level — is it active notification or portal-based?
- Can you provide screening failure rate data from prior biomarker-driven programs in our tumor type?
- How is biomarker eligibility workflow documented in your site initiation training?
- How do you assess sites for biomarker screening capability during feasibility — what do you look for beyond investigator experience?
- What contractual commitments do you hold central labs to, and how are deviations tracked and escalated?
The answers will tell you whether the CRO treats biomarker screening as a core operational competency or an afterthought.
Related Resources
Biomarker-Driven Oncology Trial Design
Oncology CRO Services & Technology
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Frequently Asked Questions
Q: Does switching to liquid biopsy eliminate biomarker screening delays?
Liquid biopsy (e.g., ctDNA-based eligibility) can reduce the tissue procurement and biopsy scheduling steps, which are often the longest delays in the chain. However, it introduces new workflow requirements for blood sample logistics, assay performance monitoring, and RTSM integration at enrollment. Delays shift rather than disappear unless the new workflow is designed with the same rigor as tissue-based programs.
Q: How do screening failure rates in biomarker-driven trials compare to conventional oncology trials?
Biomarker-driven trials have structurally higher screening failure rates because eligibility requires a passing result on a specific molecular test, and not all screened patients will have the alteration. The operational question is not whether screening failures occur but whether the program is sized, paced, and site-selected to account for the expected failure rate — and whether failures are tracked per site in real time so underperforming sites can be identified and supported.
Q: What is the sponsor’s responsibility vs. the CRO’s responsibility in managing biomarker screening timelines?
The sponsor is responsible for the central lab selection, the assay specification, and the protocol language governing eligibility decisions. The CRO is responsible for site-level workflow design, result notification infrastructure, and screening failure monitoring. The overlap — and the most common failure point — is in the contractual definition of turnaround time commitments and the governance of deviations from those commitments.
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Planning an oncology trial with biomarker-driven eligibility screening?
Sitero has supported 200+ oncology studies across 67+ countries. Talk to an oncology trial expert to discuss your protocol.
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References
- Sitero. Oncology Program Operational Data. Internal dataset. 200+ oncology studies across 67+ countries. sitero.com/oncology/
- Hanson K. Director of Clinical Operations, Sitero. Expert interview conducted for this article. April 2026.
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