Do Early Phase Oncology Trials Predict Clinical Efficacy in Subsequent Biomarker-Enriched Phase III Randomized Trials?

BACKGROUND: Promising early phase trial results of biomarker-targeted therapies have occasionally led to regulatory approval. OBJECTIVE: We examined if early phase trials were predictive of efficacy in randomized controlled trials (RCTs) with matching treatment settings. PATIENTS AND METHODS: Cancer drug RCTs conducted between January 2006 and March 2021 were identified through Clinicaltrials.gov. Biomarker-enriched RCTs and associated matching early phase trials were included. Trial pairs were compared using objective response rate (ORR) and progression-free survival (PFS). We examined whether early phase trials results were associated with RCT results using logistic regression. RESULTS: The search yielded 2157 unique RCTs and 27 RCTs pairing with early phase trials were included. Based on average difference of trial pairs, ORR was similar (1.6%; 95% confidence interval (CI) - 2.5 to 5.6, p = 0.50) and median PFS was higher in early phase trials (2.0 months; 95% CI 0.9-3.0, p < 0.05). On an individual pair basis, there was large variability in difference for ORR (range - 23.9 to 20.2%) and median PFS (range - 0.8 to 7.4 months). The probability of the RCT meeting its primary endpoint is 95% (95% prediction interval (PI) 72.8-99.3%) when the early phase trial ORR is 77.7%. CONCLUSIONS: Overall, in early phase trials, ORR has minimal bias and median PFS appears to be slightly overestimated. Substantial variability between trials suggests early phase trial results may be inconsistent with subsequent RCT. Early phase trial results may be associated with RCTs meeting their primary endpoint when ORR is very high; however, caution must be exercised when using early phase trials as representative of RCTs.

Pembrolizumab alone or with chemotherapy for metastatic non-small-cell lung cancer: A systematic review and network meta-analysis.

Pembrolizumab monotherapy has replaced chemotherapy as first-line treatment for patients with metastatic non-small-cell lung cancer with tumor programmed death-ligand 1 expression ≥ 50%. The benefit of chemotherapy combined with pembrolizumab, as compared to pembrolizumab monotherapy, remains uncertain. This systematic review and network meta-analysis aimed to compare these therapies through a network of randomized controlled trials. Endpoints evaluated were progression-free survival (PFS) and overall survival (OS) expressed as hazard ratio (HR) and restricted mean survival time (RMST) through reconstruction of individual patient data from Kaplan-Meier curves, and objective response rate and adverse events. Four trials were included. Through HR and RMST, combination therapy demonstrated longer PFS and similar OS as compared to pembrolizumab monotherapy. Combination therapy was associated with an increase in response rate and adverse events. Thus, combination therapy can be considered when rapid response or prevention of rapid progression is needed. Further evidence to directly compare these therapies is required.

Cancer treatment-related financial toxicity experienced by patients in low- and middle-income countries: a scoping review.

PURPOSE: In the past decade, literature has called attention to financial toxicities experienced by cancer patients. Though studies have addressed research questions in high-income countries, there remains a paucity of in-depth reviews regarding low- and middle-income countries (LMICs). Our scoping review provides an overview of treatment-related financial toxicities experienced by cancer patients in LMICs. METHODS: A systematic search was conducted in MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials. English peer-reviewed articles that (a) explored patients' experience with financial toxicity due to cancer treatment (b) were specific to LMICs as defined by the World Bank and (c) focused on qualitative data were included. Details regarding participants and main findings were extracted and synthesized. RESULTS: The search yielded 6290 citations, and 42 studies across 3 low-income, 9 lower-middle-income and 8 upper-middle-income countries. Main themes identified included cancer patients encountered various material hardships, managed costs with different coping behaviours and experienced negative psychological responses to their financial burden. Higher levels of financial toxicities were associated with patient characteristics such as lower socio-economic status and lack of insurance, as well as patient outcomes such as lower quality of life. CONCLUSION: Cancer patients in LMIC experience deleterious financial toxicities as a result of treatment. This comprehensive characterization of financial toxicities will better allow health systems to adopt evidence-based mitigation strategies to reduce the financial burden on patients.

The Past, Present, and Future of Economic Evaluations of Precision Medicine at the Committee for Economic Analyses of the Canadian Cancer Trials Group.

Precision medicine in oncology poses unique challenges to the generation of clinical and economic evidence used for cost-effectiveness analyses that can inform health technology assessment. The conduct of randomized controlled trials for biomarker-specific therapies targeted towards small populations has limitations in regard to feasibility, timeliness, and cost. These limitations result in associated challenges for groups involved in the generation of economic evidence to inform treatment-related decision making, including the Committee of Economic Analysis (CEA) at the Canadian Cancer Trials Group (CCTG). We provide a high-level description and vision about the new paradigm of clinical trial design, generation of economic evidence, and novel approaches to economic evaluations necessary in the space of precision medicine in oncology in Canada. The CEA's previous approach to precision medicine, including master protocol designs and single-arm studies, is reviewed. Methods and approaches currently under consideration by the CEA and national collaborators, such as the role of real-world and clinical trial evidence in enabling life-cycle assessment of therapies, are explored. Finally, future initiatives being planned in the space of precision medicine at CCTG, such as the incorporation of correlative studies to identify and test high-performing biomarkers in trials, are discussed.

Assessing the benefit of cancer drugs approved by the European Medicines Agency using the European Society for Medical Oncology Magnitude of Clinical Benefit Scale over time.

BACKGROUND: Increasingly, cancer drugs are being approved based on surrogate measurements of efficacy. Clinically meaningful data, such as overall survival (OS) and quality of life, are often only presented in subsequent publications. We examined if the clinical benefit of cancer drugs, as measured by the European Society for Medical Oncology Magnitude of Clinical Benefit Scale (ESMO-MCBS), improves post-European Medicines Agency (EMA) approval as more data emerges. METHODS: Cancer drug indications approved by the EMA from January 2006 to December 2016 were reviewed and trials cited for efficacy were identified. Primary and subsequent publications (up to December 2019) of scorable trials were included. Changes in benefit over time were measured using ESMO-MCBS thresholds for non-curative (≥4 for substantial, =3 for intermediate and ≤2 for low benefit) and curative intent (A or B for major benefit) scoring. RESULTS: Fifty-five non-curative and two curative intent trials were included. At approval, 29.1% of non-curative trials were substantial, 45.5% intermediate and 25.5% low benefit. For curative intent trials, one displayed major benefit and one displayed no major benefit. We identified 82 subsequent publications for reassessment. A change in ESMO-MCBS classification was seen in 34.5% of non-curative trials (11 raised and 8 lowered). At 3-year reassessment, 36.4% of non-curative trials were substantial, 34.5% intermediate and 29.1% low benefit. Both curative trials showed no major benefit at reassessment. CONCLUSION: As over a third of trials changed classification, in either direction, reassessing the ESMO-MCBS score of approved cancer drugs may help to inform patients and ensure ongoing relevance of regulatory and reimbursement decisions.