Trials Terminated Due To Poor Enrollment Are Four Times More Likely To Involve A Marketed Therapy Versus A Novel Drug

Trial termination is a natural consequence of clinical development, with the largest numbers of trial terminations occuring at Phase II. In the November issue of GCPj, Citeline authors Christine Blazynski and Tracy DeGregorio analyzed terminated Phase II trials in oncology - with specific attention to trials involving solid tumors - to assess the reasons and strategies behind companies' no-go decisions and found that the majority of terminations due to poor enrollment are trials investigating a marketed therapy.

"We looked at the reasons Phase II industry-sponsored trials in solid tumors were terminated," says author, Christine Blazynski. "By doing so, we were able to dilineate two major driver types: company-controlled and trial-related. For example, companies can choose to terminate trials due to internal drug strategy shifts or pipeline reprioritization. Looking specifically at these two company-controlled reasons, it is striking that they are cited much more frequently for trials involving novel compounds compared to already marketed therapies. Companies also control the decision to terminate a trial when enrollment lags, but in this instance it's predominantly label expansion studies that were terminated, a finding that we didn't necessarily expect."

Says DeGregorio, "It's a reasonable assumption that patient enrollment for a trial involving a marketed therapy may be better than one for a novel therapy, as there is a greater level of patient comfort in trying a marketed drug for a new disease versus trying an unapproved drug. But, in fact, we saw the opposite in terminated Phase II solid tumor trials, indicating that companies may be quicker to pull the plug on a poorly enrolling trial of a marketed drug, as it isn't dependent upon the trial for time to market."

The analysis also examined the overall trend in terminated drug candidates, which mirrors that of terminated trials, with the majority of attrition occurring in Phase II. An examination by company indicates that some are making their decisions sooner than others. Notably, sanofi-aventis, Roche and UCB had no oncology candidates terminated after Phase II, while GlaxoSmithKline had 87% of their terminations occurring at or before Phase II, followed by Novartis (75%), Genzyme (67%) and Pfizer (65%).

In addition to an analysis of the reasons for terminations, this report also investigates Phase II solid tumor trial terminations by company and by tumor type.

SOURCE: Informa Healthcare