Fast Track Program Approaches 500 Mark Multiple sclerosis drug Tysabri® probably isn’t the poster child for the US fast track program. In February Biogen Idec got the green light to resume a clinical trial of the agent. A year earlier the company had voluntarily suspended sales of the drug based on two reports of serious neurological adverse events that occurred in patients with multiple sclerosis treated with Tysabri. Biogen and its partner Elan have submitted a supplemental application seeking to convince regulators of the drug’s safety and allow the drug to return to market. The US FDA is expected to announce a decision regarding that application in late March. Fast track drug development, introduced in the US in 1997, has become an important element of the drug development landscape, according to an analysis by the Tufts Center for the Study of Drug Development. For the period 1998–2005, the FDA has granted nearly 500 fast track designations, accounting for approximately 20% of all active investigational compounds in clinical development programs worldwide during that time. The fast track program was introduced to expedite development and approval of new prescription medicines that address unmet medical needs for serious or life-threatening conditions. While a formal fast track program currently exists only in the US, international interest in similar fast track mechanisms is growing in Europe, Japan and China. The Tufts CSDD analysis also found that cancer-related programs currently account for 40% of all fast track designations. While HIV/AIDS accounted for about 20% of all fast track designations in 2001, today such programs account for 8%. The analysis also showed that total development time for fast track products is about the same as for non-fast track standard and priority review drugs – 8 years on average – and varies considerably by therapeutic area. Currently, approximately one-third of all fast track programs are struggling, with efficacy issues in late-stage trials being the major source of problems.