Clinical benefit of idiotype vaccines: too many trials for a clever demonstration?

The most accepted and least biased manner to demonstrate clinical benefit for any new treatment is to show that it conveys a survival advantage in a well-designed phase III, randomized clinical trial. However, in selected cases, an exception can be made to this sound rule. This review aims at elucidating one such example. In particular, I intend to show that when an individualized form of immunotherapy like idiotypic vaccination, which by definition is completely inactive against any tumor cells, is applied to cancer patients with indolent follicular lymphoma, a carefully crafted phase II clinical trial may be able to demonstrate clinical benefit better and more rapidly than a phase III alternative. This consideration might be rather important over the next two to three years, since the results of as many as three ongoing phase III clinical trials on idiotype vaccines are expected to be unveiled within this time frame, following the release of conclusive data of our phase II clinical trial, which is imminent.