The Real World vs The Trial Patient: Bridging the Gap
Expert Perspectives · Keira Smith · 2026-05-07
Every oncologist knows the moment well: you're reviewing treatment options with a patient, guidelines in hand, when you realize the person sitting across from you wouldn't have qualified for the pivotal trial that established your recommended therapy. In this episode of Oncology Unfiltered, Melissa Cutrona, Co-Founder and General Manager of i3 Health and Oncology Data Advisor, speaks with Dr. Matthew Hadfield, Oncology Data Advisor Editor in Chief, about one of oncology's most persistent challenges—the widening gap between carefully curated trial populations and the complex, real-world patients who enter clinics daily.
The Trial Patient: Healthy by Design
Clinical trial eligibility criteria exist for logical reasons: patient safety, data integrity, and regulatory compliance. But these safeguards create a paradox. "Clinical trial patients are oftentimes the healthiest of oncology patients because we have protocols that run trials with specific eligibility criteria," Dr. Hadfield explains. From hemoglobin thresholds to stringent performance status requirements, these criteria are intended to help mitigate toxicities and ensure that patients are healthy enough to participate in a trial.
However, exclusion criteria often reflect outdated paradigms. Many requirements were established during the era of cytotoxic chemotherapy, when bone marrow suppression and severe toxicities were expected. "Some of the eligibility criteria now don't necessarily match the toxicity profiles of drugs that are being developed," Dr. Hadfield notes. A hemoglobin cutoff that made sense for traditional chemotherapies may be unnecessarily restrictive for immunotherapies that rarely cause anemia.
When Guidelines Meet Reality
National Comprehensive Cancer Network (NCCN) and American Society of Clinical Oncology (ASCO) guidelines provide evidence-based roadmaps built primarily on randomized controlled trial data. Yet clinicians must navigate beyond these boundaries daily. "Guidelines are kind of the median of the curve,” Dr. Hadfield explains. “You have to operate within the guidelines, but also look at the patient in front of you."
Consider the patient with a solid organ transplant who develops cancer. Historically excluded from checkpoint inhibitor trials due to organ rejection risk, these patients nonetheless require treatment. "In the absence of clinical trial data, which we would consider gold standard data, you have to keep in mind that they exclude many patient populations that are being seen by us in clinic and need to be treated, and we have to do our best to treat them safely" Dr. Hadfield emphasizes. Clinicians must rely on retrospective case series, institutional experience, and carefully calibrated risk-benefit discussions.
The Evolving Trial Landscape
An encouraging shift is away from the outdated notion that clinical trials are only for patients who have exhausted all standard options. "The idea that you have to exhaust every line of therapy before you can be considered for a clinical trial has somewhat fallen out of favor," Dr. Hadfield explains. Modern antibody-drug conjugates and T-cell–engaging therapies have dramatically higher success rates than experimental agents from two decades ago, making early-line trial enrollment increasingly attractive—when patients qualify.
Phase 1 trials themselves have evolved. No longer purely dose-escalation safety studies, they now incorporate biomarker enrichment and histology-specific cohorts, seeking early efficacy signals alongside safety data. This strategic approach makes trial participation more clinically meaningful, provided that patients can access these opportunities.
The Disparity Dimension
Trial enrollment remains disappointingly homogenous. "We know unequivocally that trial enrollment is very homogenous, and patients coming from lower socioeconomic areas have less representation in clinical trials," Dr. Hadfield states. Geographic barriers, logistical demands, and support system requirements compound the problem. Academic centers where trials cluster may be inaccessible to rural or underserved communities. The result: treatments are approved based on populations that poorly represent the diversity of American cancer patients.
Supplementing the Evidence Base
Can real-world evidence bridge this gap? While acknowledging that "there's no way a well-designed phase 3 randomized clinical trial is the gold standard for data," Dr. Hadfield recognizes the critical role of retrospective studies. Much of what we know about managing immune-related adverse events—steroid-refractory toxicity, rechallenge protocols—comes from case series and institutional experiences published after drugs reach the market.
The key is integration, not replacement. Trial data provides the foundation; real-world evidence fills the gaps. For community oncologists managing patients who wouldn't have qualified for registration trials, Dr. Hadfield's advice is straightforward: "First try to identify, is this patient someone who would have been included in this trial population? And then try to use retrospective data, where it's available, to supplement those decisions."
Key Takeaways
Trial populations are systematically healthier than real-world oncology patients due to strict eligibility criteria that exclude common comorbidities and limit enrollment based on performance status and laboratory parameters.
Many exclusion criteria are outdated, carried forward from the chemotherapy era and not reflective of modern immunotherapy and targeted therapy toxicity profiles.
Clinical trials should be considered earlier in treatment, not reserved as a last resort after exhausting all standard options, as modern experimental therapies have substantially higher efficacy potential.
Retrospective data and real-world evidence are essential supplements to randomized trial data, particularly for patient populations systematically excluded from trials, such as those with solid organ transplants or HIV.
Trial enrollment disparities persist, with lower socioeconomic and minority populations underrepresented, limiting the generalizability of trial results to diverse real-world patient populations.
Guidelines provide a median approach that must be individualized based on patient-specific factors, requiring clinicians to balance gold-standard trial data with clinical judgment and available real-world evidence.