Here’s a disturbing finding: fewer than one in eight Phase II cancer clinical trials with encouraging results move on to Phase III. But in many cases, researchers conducting the trials knew beforehand that, due to financial or other constraints, a Phase III trial was unlikely, HealthDay News reports.

Why, then, would that happen? Two possible explanations - Pressure on younger academics to publish and the interest drugmakers have in using promising Phase II results to encourage off-label use of existing drugs without having to spend lots of money on Phase III trials, according to a few wags.

“Given the scarcity of both money and willing volunteers for cancer research, “a Phase II trial shouldn’t even be started unless there is an intention - if the Phase II results look promising - to take it forward,” the study’s lead author, Ian Tannock, professor of medical oncology at Princess Margaret Hospital and the University of Toronto, Canada, tells HealthDay. He presented the study findings in June at the American Society of Clinical Oncology annual meeting.

Many of the trials reached a dead end, because the researchers couldn’t get financial backing or enough patients for a phase III look at the treatment. However, the study also found that “many of these limitations are known (to the researchers) when planning the phase II study, implying that many phase II trials are not planned as precursors of phase III trials.”

“If all of this effort in supporting phase II trials doesn’t go anywhere, it means that the patients included - and the efforts of their doctors - could have been spent in finishing potentially practice-changing phase III studies,” Tannock tells HealthDay.

They reviewed the post-presentation histories of 200 phase II trials with “encouraging results” for breast, lung, gastrointestinal, genitourinary, and gynecological cancers, HealthDay writes. Half were presented at ASCO’s 1995 and 1996 annual meetings, and the other half were presented at the society’s 2006 conference. They found that just 13 percent of the trials went to Phase III, despite results that had shown a positive response of the therapy against the targeted tumor.

“There’s a lot of young oncologists out there, and they are encouraged to publish,” he explains to HealthDay. “Their promotion at academic centers is dependent on publication. So, many of them may be encouraged to put together a protocol in which they take new drugs and treat a small number of patients with a certain disease in a phase II trial.”

Because the teams that conduct phase II trials are smaller, a young researcher is more likely to be listed as the prestigious “lead researcher.” This gains researchers more recognition than if their name is buried among the much-longer list of authors that typically accompanies phase III studies, Tannock says.

In some cases, Bruce Hillner, a professor of medicine at Virginia Commonwealth University, tells HealthDay that drugmakers use promising results from small Phase II trials to encourage docs to use an already FDA-approved drug ‘off-label’ for another purpose. In this way, drug sales are boosted without undertaking the expense of a multimillion-dollar Phase III trial required for FDA approvals.

“The public should also be very cautious about ‘exciting’ results from phase II trials,” Tannock says. “The literature is replete with things that looked very good in phase II but did not prove to be any better than standard treatment in phase III. You have to be careful.”