In any repurposing project, the status of the candidate and the route to delivering a treatment to the patient make a huge impact on your strategy for selecting a drug. As described in the “What is drug repurposing?” section of this course, it is possible to target existing generic drugs for repurposing (those that are no longer under patent and widely available), current branded compounds (sold under licence and protected by intellectual property) or shelved compounds.There are a number of benefits and challenges associated with both generic drugs and those under patent/benefiting from marketing exclusivity, which should be carefully considered when selecting a candidate drug:
Under patent
Pros:
- Patented drugs have an obvious route to approaching the patent-holding industry partner to develop a drug for your condition, with a clear business benefit for the patent holder to repurpose.
Cons:
- Robust clinical evidence is required to convince the patent holder to work on the repurposing project.
- There is likely to be limited understanding of safety in a wider range of patients.
Generic
Pros:
- These drugs are likely to have lots of data available on human use and are usually at a low cost.
- This means that they are readily producible and have good access for off-label use.
- They are therefore ideal for an academic-led clinical trial.
Cons:
- Due to an absence of a patent, a repurposed generic drug is likely to have less options for its intellectual property to be defended.
- Consequently, there will be a less obvious business opportunity for industry partners to repurpose this drug.
- The drug’s current formulation/delivery method may not be appropriate for the patient population in question.
- It is possible that the drug could be taken by patients outside of clinical trials if they hear about potential benefits of the treatment. This would make recruitment for the clinical trials more challenging, and may put patients at risk since they are not being monitored in the context of the trial.