Original Publication Date: 12 January, 2017
Publication / Source: Oncology Central
Authors: Pan Pantziarka
Drug repurposing, also known as drug repositioning, is a strategy that seeks to re-use existing, licensed medications for new indications. Repurposing is not a new approach, and medicine is replete with many well-known examples of drugs being licensed for illnesses very different from those they were originally developed to treat.
Perhaps the best known example is sildenafil (Viagra), famously developed for angina and then successfully repurposed as a treatment for erectile dysfunction and then again as a treatment for pulmonary hypertension.
In the case of oncology, there are examples of chemotherapy drugs being repurposed for non-oncological diseases, for example methotrexate or cyclophosphamide re-used for rheumatoid arthritis. Examples of non-oncological drugs repurposed to treat cancers are far fewer in number, most notable being thalidomide as a treatment for multiple myeloma and all-trans retinoic acid for acute promyelocytic leukemia (APL).
However, there is a growing level of interest in repurposing noncancer drugs for use in oncology . The advantages of repurposing are intuitively obvious – we have the benefit of well-characterized, widely prescribed and often very cheap drugs. This means that there is a wealth of data regarding pharmacokinetics, pharmacodynamics, safety, mechanisms of action and so on.
In some cases we also have extensive epidemiological data that may indicate that the drug has some impact on cancer incidence or outcomes. Good examples include aspirin, metformin and statins – all drugs that are used daily by millions of patients and are now subject to intense scrutiny for their potential anticancer effects.