Propecia clinical trials
To prove that Propecia does really work for men with MPHL, two 1-year clinical trials were conducted on 1553 men with mild to moderately severe male pattern hair loss on top of the head. The trials were conducted in 16 countries around the world. 1215 men elected to continue in double-blind, placebo-controlled, crossover, 12-month extension studies.
The men in the trial
The men enrolled for the trials were aged 18 to 41 years. They all had hair loss, ranging from mild to moderately severe – stage II to V on the Norwood-Hamilton scale.
Norwood Hamilton Scale
Placebo-controlled – men in the trial were divided into two groups. One group received genuine Propecia, the other received dummy pills (placebo) that looked identical to Propecia.
Double-blind – the packets of pills were coded but otherwise unmarked, so neither the patient nor the doctor knew whether the pills they were using were Propecia or placebo.
Randomised – the doctors and men in the study did not know whether they were going to receive Propecia or placebo. This was randomly assigned at the start.
Multicentre – the trials were carried out in different centres around the world.
The trial process
Once in the trial, patients were not allowed to alter their hairstyle, or dye their hair. At the start, all patients were given placebo pills for a two week run-in. This helped them get into the habit of taking pills once a day.
All patients used the same shampoo throughout the trials (Neutrogena® T/Gel®). Once started on a course of pills, patients visited the clinic every three months, where they were assessed.
Patients were evaluated using the following assessments:
Hair Counts
Researchers counted the number of hairs men gained or lost from a small area of clipped hair (cut to 1mm in length) at the front of their head. This was done using microphotographs (extreme close-ups) of the area taken with a specialised camera system, preset for focus, distance (primary magnification 1:1.7) and exposure. A dot tattoo placed in the middle of the clipped area was used to centre the photographs. Photographs from the start, at 6 months and at 12 months were converted in to dot maps of each visible hair, and hair counts were made using scanners and imaging software.
Patient Self Assessment
Patients completed questionnaires consisting of 4 questions about their treatment’s effectiveness, and three questions about their satisfaction with their own appearance.
Investigator Assessment
The doctors conducting the trials (investigators) assessed patients using a standardised rating for hair growth: from –3 (greatly decreased) to +3 (greatly increased).
Global photographic assessment
3 dermatologists experienced in photographic assessment of scalp hair growth reviewed standardised colour photographs from test centres around the world.
View Photos...
The dermatologists did not know which patients had received Propecia and which had received placebo (they were ‘blinded’). They graded each photograph using the same rating as the investigators (see previous screen).
Safety Measurements
These included adverse event reports and clinical and laboratory evaluations.
