Phase II trials published in 2002: a cross-specialty comparison showing significant design differences between...

Phase II trials play an essential role in drug development pathway, and their conclusions often impact the decision to embark on large, pivotal trials. However, the determination of agent activity is highly dependent on trial design. Formal comparisons of phase II trial designs across medical specialties are uncommon. We hypothesized that there are significant differences in the design of trials conducted by oncologists and those conducted by other medical and surgical specialties.

We screened MEDLINE for the abstracts of phase II trials published in 2002. All abstracts were analyzed and classified by a priori defined variables, including study type, intervention, subspecialty, journal impact factor, method of control, and study conclusions.

Our search yielded 703 abstracts of phase II trials published in 2002. A total of 586/703 (83%) were trials on antineoplastic agents. Twenty percent (143/703) of the trials included explicit control subjects. Oncology trials, as compared with all trials done by other specialties, were significantly less likely to use control subjects (13% versus 56%, P < 0.001) and were less likely to conclude that the investigational intervention was safe and efficacious and/or worthy of additional investigation (76% versus 89%, P < 0.01).

There are significant differences in the phase II trials published in oncology compared with those conducted by other medical and surgical specialties. The impact that such differences have on the efficiency of drug development should be investigated.