“Repurposing” Off-patent Drugs offers big hopes of New Treatments
Reporter: Irina Robu, PhD
Given the substantial costs and the slow pace of drug discovery and development, repurposing old drugs has become a practice, partly because it involves the use of already developed compounds. Yet, there is lack of clinical interest in repurposing off patent drugs.
However, the scale of the opportunity for drug repurposing is huge. Initially approved for one disease, these drugs went off-patent and now show potential in other diseases. Even so, many non-profit groups see promise in supporting trials into drug repurposing. There is a huge untapped medicine chest of generic drugs with unexploited uses. These generic drugs are often cheap, already approved, off-patent and relatively quick to develop, whereas new drugs can cost millions of dollars to develop, test and 45% of the drugs fail in clinical trials.
However, numerous non-profit groups see potential in supporting trials into drug repurposing. Epidemiological data can offer enticing leads. Yet, clinical trials for these drugs are costly, but the benefits can be huge. The Drugs for Neglected Diseases Initiative, a Swiss non-profit research group, supported research into fexinidazole, which was abandoned by a pharma at an early stage. The drug showed to have antiparasitic qualities. However, after years of work in January 2020, it was approved for sleeping sickness in the Democratic Republic of Congo. It is the first oral medicine for the disease, and works for all stages of it.
Up till now, when it comes to cancer the most promising generic pills are known. Cancer Research, a UK based charity is testing aspirin to see if can stop cancer from recurring; metformin in a large prostate-cancer trial; and an anti-fungal medication to treat bowel cancer. At the same time, the Anticancer Fund in Brussels hopes that propranolol in treating cancers of the inner lining of blood vessels and pancreatic cancer. Propranolol is a generic 1960s beta-blocker used for a wide range of ailments such as hypertension, anxiety and migraine. If approved for cancer, its cost would be negligible in comparison the tens of thousands of dollars a month usually charged for cancer medicines.
Money seems the crucial constraint with these drugs, in addition to the clinical trials needed to have these drugs updated and relabeled. Only the makers or original developers of a drug are permitted to adjust its label. Sanofi, based in Paris, was the firm that requested regulatory review of fexinidazole for sleeping sickness, while the research was a charitable effort. But drug firms are not forced to support non-commercial efforts to repurpose drugs. And outside the industry it is tough to find the legal expertise to be able to do the necessary paperwork.
As non-profits make progress in repurposing, corporate interest may be rising. In terms of achieving new treatment options, this is good news. But it will not bring cheaper medicines in areas traditionally neglected by the drug industry. Firms will focus on finding ways to patent the new uses and charge high prices for the finished product.
If governments need cheaper drugs, non-profits will need financial incentives and a cooperative regulatory framework. They include making regulators give free advice and waive approval fees, and a public fund to support repurposing. Yet, when drugs are approved, investors are paid back by the public health service, which makes savings by using the newly approved generic drugs.
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Other related articles published in this Online Scientific Open Access Journal include:
The Castleman Disease Research Network publishes Phase 1 Results of Drug Repurposing Database for COVID-19
Reporter: Stephen J. Williams, PhD
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