Cancer knows no boundaries. Low- and middle-income countries share the greatest burden of cancer mortality globally. But these countries can’t afford to conduct high-level clinical trials. A solution? Collaborations with high-income countries. This might be difficult, but with clear criteria of feasibility and post-trial utility there might be a window of opportunity for trial development.

• Clinical trials should address a question of important clinical need in the society of the country.
• The unmet clinical need should be backed by good evidence.
• They should assess interventions that could be cost-effective and straightforward to apply if found to be efficacious.
• They should be easy to conduct within the settings of standard care.

One of the emerging concepts that meets all of these criteria is drug repurposing: the use of existing drugs for an indication different from the original. A good example is the Add-Aspirin trial, started by UK-based leaders who opened it up to India. This trial is assessing the effect of aspirin as an adjuvant treatment in four cancer types, and the rationale for this expansion was to increase the global impact of the results, to ensure adequate patient recruitment and to help with the development of a research infrastructure for this trial and future trials.

This paper was published in NatureCancer.