Drug discovery is a laborious process.
From initial discovery of a promising target to the final medication becoming available, is an expensive, and lengthy process. At present, the costs of bringing a single new drug to market is around $1.2 billion, an amount that doubles every five years.
Aside from the cost, it takes, on average, 12 years for an experimental drug to progress from bench through FDA approval to market.
Annually, North American and European pharmaceutical industries invest more than $40 billion to identify and develop new drugs. Even so, for every 5,000 compounds that enter pre-clinical testing, only five, on average, are tested in human trials, and only one of these five receives approval for therapeutic use.
So, it’s hardly surprising that many pharmaceutical companies are choosing to take a closer look at old drugs. Last week, SRxA’s Word on Health brought you news of a host of potential new uses for aspirin.
And aspirin is not alone. Old drugs often get a surprising second shot at life. In the past few weeks, the news has buzzed about the skin cancer drug – bexarotene – that may cure Alzheimer’s; a common antimalarial drug – hydroxychloroquine – that may help to destroy cancer; and, a leukemia drug that inhibits the Ebola virus.
Then, of course, there’s the personal favorite of many women – Latisse. Originally developed as a glaucoma treatment , it was found to have the desirable side effect of making eyelashes fuller and longer and is now FDA approved for this purpose.
Testing drugs already approved for one use to see if they can treat other conditions, can reduce time and money. Since these known drugs have already undergone toxicology and safety testing, the clinical development program can be streamlined.
Sometimes it’s pure serendipity.
Take Viagra for example. Although these days it’s the stuff of pharmaceutical industry legend , in the early 1990s, it was just a chest pain drug that wasn’t performing very well in clinical trials. So how did the little blue pill go from heart to crotch? Pfizer was ready to call it quits when they decided to look into one unexpected but common side effect: long-lasting erections. Then came the drug patent and the rest is history.
The discovery that lithium could be used to treat manic episodes in bipolar patients was equally fortuitous. In 1949, Australian psychiatrist John Cade was injecting guinea pigs with urine extracts from schizophrenia patients to try and isolate a compound that caused mental illness. By accident he happened to use a compound with lithium – which at the time was used as a treatment for gout, as the control. Although he didn’t find the compound that caused mental illness, he did find one that treated it!
Back in 2010 we reported on the repurposing of thalidomide. Although the drug caused serious birth defects when it was launched in the 1960’s as a morning sickness pill it has since been found to be useful in reducing severe and frequent bleeding in patients with hemorrhagic telangiectasia (HHT); in the treatment of patients with newly diagnosed multiple myeloma when taken in combination with dexamethasone; and for the acute treatment of the cutaneous manifestations of moderate to severe erythema nodosum leprosum
The National Institutes of Health (NIH) recently established The Learning Collaborative (TLC) to study how to more easily repurpose known drugs to treat rare forms of blood cancers.
TLC is a dedicated collaboration between the NIH Chemical Genomics Center (NCGC) and its Therapeutics for Rare and Neglected Diseases (TRND) program, The Leukemia & Lymphoma Society (LLS), and Kansas University Cancer Center (KUCC) to discover and develop new drug therapies for rare blood cancers. TLC is creating a pipeline of new therapies to treat leukemia from both the discovery of new treatments as well as identifying new uses for approved and abandoned drugs. For example, Auranofin, a drug originally used for rheumatoid arthritis, is now in clinical trials for treating chronic lymphocytic leukemia.
Word on Health will continue to follow the drug recycling trend and bring you news as it breaks. In the meantime if you have noticed any beneficial side effects from the medicines you’re taking, we’d love to know.