The research, published in the May edition of Nature Reviews Drug Discovery, looked at the 108 reported drug candidates that failed in Phase II clinical trials between 2008 and 2010 to try and establish the key trends.
The observations that emerged are alarming. Of the 87 studies that gave reasons for the failure: 17 were halted on safety concerns; 44 on a lack of efficacy; and, perhaps most worryingly of all for precious drug industry R&D budgets, 25 were been pulled for ‘strategic reasons.’
Sixteen of the strategic failures involved validated targets which, author John Arrowsmith, scientific director at Thomson Reuters, said may indicate inadequate differentiation from more advanced drugs in the same class or from drugs in similar indications in another mechanistic class.
Arrowsmith told Outsourcing-pharma.com that: “Strategic failures result from…too many companies chasing the same targets…or because the drug was a long shot [and] wishful thinking.”
This idea is further supported by the data from the 21 Phase II trial failures for which reasons were not given, 17 of which involved fully validated disease targets.
“Again,” Arrowsmith continued “it would seem reasonable to conclude that some of these failures were due to insufficient evidence of an efficacy advantage over a more advanced drug.
“However, it is important not to rule out that failure could be due to a change in the benefit-risk balance of a known target in a new patient population” he added.
Market dynamics and hope
Arrowsmith also told Outsourcing-pharma.com that “The increased losses from Phase II have probably been catalysed by recent M&A activity and the need to manage R&D costs.”
But while this is a concern, Arrowsmith predicted that the industry’s interest in developing products for niche indications and desire for risk sharing through partnerships will, at least in part, help address the higher rate of failures.
“The increase in focus on rare disease and patient stratification will open up the opportunity space but as change is driven by the emerging science then the problem will not go away completely.
“There will also be an increase in consortia and partnering so this should also temper the strategic failures.
“Will attractive areas always be attractive? Of course, but those who adapt to the new way of working, focus on quality and form external partnerships will be better positioned to win.”
Focus on quality and recruitment
Beyond this, Arrowsmith believes the pharmaceutical sector should concentrate on improving the quality of new drugs it develops to help reduce attrition rates and increase return on R&D investment.
He explained that companies should use the best science to select targets that have a strong correlation with disease states and ensure that candidates are fully evaluated in detailed trials.
Arrowsmith also cautioned against “rushing to make up numbers” during patient recruitment and instead called for a renewed focus on patient stratification and rigorous exclusion criteria.