Sometimes drugs are tested in clinical trials and don’t meet their goals. In many situations this is the end of development for these drugs. Notably, given the amount of science that has gone into development of many agents it is not inconceivable that they could be repurposed to treat difference problems. Sildenafil (Viagra) is a case in point – it started as a treatment for hypertension and ended up being used for erectile dysfunction. This was a chance development and in reality most companies aren’t interested in pursuing further trials in other conditions given the cost of drug development.
In some circumstances there is a superimposed ethical problem. Some trials are stopped for overall lack of benefit but some participants may well have benefited. This often happens for orphan indications. This is actually probably true for most medications – they only work in some of the people that take them, in much the same way that they only cause adverse effects in some of the people that take them. The case of arbaclofen for treating Fragile X syndrome and autism is a recent example http://www.nytimes.com/2013/06/07/business/an-experimental-drugs-bitter-end.html?smid=pl-share
There are however potential ways to overcome the problem of withdrawing a ‘possibly effective therapy’. Regulators are now partnering with industry to deliberately encourage research into discarded medications. Medications which incidentally have been shown to be safe through previous clinical research but ineffective in their original target research. The NIH funds such a program http://www.ncats.nih.gov/research/reengineering/rescue-repurpose/therapeutic-uses/therapeutic-uses.html
A potential pathway in the case of arbaclofen to continue studies in these patients, and also supply of drug, would be crowdsourcing. The owner of the intellectual property – having decided that the product is worthless – could agree to either write-down its’ ownership and make the IP public domain or alternately allow public development with minimal claim on any patent royalties if the product is successfully developed or alternately to retroactively cover costs of development undertaken in the public domain through a limited buy-back of rights – all of these approached would be significantly less expensive than the traditional methods of developing the drug and financing that development. The drug manufacture could no doubt be cheaply outsourced to an Indian manufacturer and study data collection could move to open source models with independent review.
Developing novel methods to pursue drug development both of old and new drugs is important to ensure new treatments are developed and to ensure to viability of an industry which is increasingly poor at developing successful new drugs and increasingly unlikely to have them paid for by cash-strapped healthcare systems.