The development of a new medicine takes in average ten years and costs more than 2 billion US dollars. The process starts with the discovery of a new compound aimed at the cure of a certain condition in the laboratory. Then the potential medicine will be tested for safety on animals. If these previous stages have been successful, the sponsor (usually a pharma company) will ask for authorisations to start clinical development. When a green light is obtained the drug can be tested on humans. The first phase is an administration to 10 to 100 healthy volunteers, mainly to evaluate safety and the absorption and elimination of the drug in the body: this will take at least one year. The following steps will be phases II and III which are basically a succession of Randomised Clinical Trials comparing the outcome of patients treated by the new drug with others receiving an existing treatment or a placebo. Both efficacy and safety are evaluated. This will involve in average of up to 3000 patients and take several years. If the efficacy is confirmed and the side effects moderate and acceptable, the company will present a request to the FDA in the US or the EMA in Europe for a marketing authorisation. This will take at least a year; Then the drug can be manufactured and marketed. Two other important issues will be discussed at the national level: price and conditions for reimbursement by the health insurances.
This long process can be shortened for innovative medicines like in orphan diseases (diseases with no available treatment), life threatening conditions (it has been done for AIDS, cancers, etc) or in crisis like the Covid-19 pandemic.
The classical randomised Clinical Trials may for example be replaced by adaptive trials in which the comparison between the groups is rendered faster. There are also trials which permit to compare several potential treatments in parallel, permitting an important gain of time.
The EMA has put in place a “fast track “development specially for Covid19 treatments and vaccines. Every step of the process development is accelerated thanks to a collaboration between the sponsor and the EMA. There is a similar plan in the US. A considerable amount of money has been invested in research by companies or given by governmental national and international organisations. Scientific and medical journals are giving immediate and free access to papers dedicated to Covid-19: this never happened before.
An existing medicine may be considered as potentially effective after observation of a possible better outcome of patients receiving it. This was the case with hydroxychloroquine (Plaquenil) combined or not with an antibiotic (azithromycin) in Covid-19 infected persons. In this situation there is no need to remake the whole process of drug development to evaluate safety, which should not be different from what is already known. But the efficacy remains to be confirmed by a comparative trial.
What happened during the last months is that under the pressure of the crisis and the lack of alternative many organisations have given a provisory authorisation to hydroxychloroquine. But today, as no evidence of benefit of has been produced and side effects are not uncommon, the authorities are withdrawing their authorisation. It must be noted that the enthusiasm produced by the promotors of treatment by hydroxychloroquine has delayed the realisation of controlled studies because patients were reluctant to accept the risk of receiving a placebo.
Several new antivirals are presently tested, alone or in combination, as well as anti-inflammatory medicines, antibodies or other immunotherapies. Besides, numerous other treatments aimed at treating the numerous complications of the infection are put in clinical research. There are currently in the world more than one thousand clinical trials dedicated to research on treatments or vaccines against Covid-19.