Equipoise in the Enhanced Supression of the Platelet IIb/IIIa Receptor with Integrilin Trial (ESPRIT): a critical appraisal

Bypassing phase 2 in cancer drug development erodes the risk/benefit balance in phase 3 trials

OBJECTIVES

Drug developers sometimes launch phase 3 (P3) trials without supporting evidence from phase 2 (P2) trials. We call this practice "P2 bypass." The aims of this study were to estimate the prevalence of P2 bypass and to compare the safety and efficacy results for P3 trials that bypassed with those that did not.

STUDY DESIGN AND SETTING

We created a sample of P3 solid tumor trials registered on ClinicalTrials.gov with primary completion dates between 2013 and 2019. We then attempted to match each with a supporting P2 trial using strict and broad criteria. P3 outcomes were meta-analyzed using a random effects model with subgroup contrast between trials that bypassed and those that did not.

RESULTS

129 P3 trial arms met eligibility and nearly half involved P2 bypass. P3 trials involving P2 bypass produced significantly and nonsignificantly worse pooled efficacy estimates using broad and strict matching criteria, respectively. We did not observe significant differences in safety outcomes between P3 trials that bypassed P2 and those that did not.

CONCLUSION

The risk/benefit balance of P3 trials that bypassed P2 is less favourable than for trials supported by P2.

Issues in assessing products for the treatment of hemophilia - the intersection between efficacy, economics, and ethics

Following the obviation of the pathogen safety threats posed by previous generations of clotting factor concentrates for the treatment of hemophilia, the principal issue facing the patient community is timely access to adequate supplies of continuously improving therapies. The application of evidence-based medicine has enhanced the basis of hemophilia therapy, while resulting in some challenges to patient care. Increasingly, the criteria used for the approval and payment of treatment products by regulatory and reimbursement agencies, respectively, are becoming inflexible and unrealistic. This is occurring particularly in the requirements for demonstrating product efficacy. Concurrently, emerging evidence of the interpatient variability in the clinical response to therapy has led to the proposed personalization of therapeutic regimens. Possible impediments to optimal care include competitive tensions among suppliers who seek to gain label claims for reimbursement purposes, which result in clinical trial designs of, arguably, unethical design, carried out in poor countries. We synthesize these converging developments to suggest some changes to the current hemophilia treatment paradigm, which should make it more patient-centric and enable speedier access to new therapies.

Considering usual medical care in clinical trial design

Liza Dawson and colleagues discuss the scientific and ethical issues associated with choosing clinical trial designs when there is no consensus on what constitutes usual care.