FDA Approval Process for PAH Drugs
The past decade has seen many new drugs approved to treat PAH. The development of a new drug is a long and expensive process. Candidate new drugs are identified and then enter the clinical research pathway. Before a medication is ever tested in humans, the medication is tested in a variety of laboratory settings and then in animal models. Potential toxicity is carefully evaluated before the drug is first given to people.
Next the medication is given to healthy normal people in what is termed a PHASE 1 Trial. Various doses are tested and blood tests are done to evaluate how the drug is metabolized and looking for any side effects or problems.
The drug then moves into PHASE 2 trials. These involve patients with PAH. These studies usually involve 30-100 patients and a couple different doses are tested and compared to placebo (sugar pill). Effectiveness is measured usually either by looking at pulmonary vascular resistance or six minute walk distance.
If the medication continues to show promise (signals of efficacy and no problems with toxicity or side effects) then the drug moves to PHASE 3 clinical trials. One or two PHASE 3 trials are required for approval. These studies usually involve many hundreds of patients and are conducted at many different locations often in many countries. One or two doses are usually tested and compared to placebo. The primary outcome measure in the past has been six-minute walk distance and more recently has been rate of clinical worsening (hospitalization, need for more treatments, death or lung transplantation).
Who Can Participate in a Clinical Trial?
Each clinical trial has specific inclusion and exclusion criteria. The research team looks very carefully at your history and data to make sure that a prospective study patient fits into the study. Some studies are looking for patients with milder disease and others are looking for sicker patients. Most PAH studies exclude patients with active cancer, advanced left heart disease or an inability to perform the study procedures.
Participation is always voluntary. You should never be pressured to participate. You will never be asked to pay anything to participate in a real clinical research study. All clinical trials involving new treatments are registered with the FDA and can be found on clinicaltrials.gov.
Why Participate in a Clinical Trial?
There are many reasons to participate in a clinical trial. First, participating in clinical trials is good for you. The outcomes of patients who choose to participate in clinical trials are better than for similar patients who choose not to participate. This may relate to very close monitoring of patients who participate in clinical trials.
Second, by participating in a clinical trial you gain access to medications often years before the drug gets approved.
Third, study medications are given free of charge for most clinical trials. Lastly, you are helping to advance the care of all PAH patients by participating.
Where Do You Find Pulmonary Hypertension Clinical Trials?
PAH centers of excellence (Comprehensive Care Centers) all participate in clinical trials. If you have PAH and are not part of a center of excellence program then you can find the closest comprehensive care center and call and inquire about clinical trials. You can also visit the FDA website (clinicaltrials.gov).
Upcoming Clinical Trials for PAH
We are very excited about a large number of new phase 2 and 3 clinical trials that will be starting soon. We will continue to update this site with new opportunities.