Psoriasis is an autoimmune disease that usually
affects the skin and sometimes the joints. It has been suggested that
interleukin-17, a mediator of inflammation, is involved in causing the symptoms
of psoriasis. Levels of interleukin-17 have been found to be increased in the
skin lesions and blood of patients with psoriasis.
The interleukin-17 group consists of 6 cytokines
from A to F. These act on 5 receptors, interleukins 17RA to 17RE, to bring
about their effect.
Brodalumab is
a monoclonal antibody that inhibits the interleukin-17 pathway. It blocks the action of
17A, 17F, 17A/F heterodimer, and 17E. A recently published study assessed the
short-term efficacy and safety of brodalumab in patients with
moderate-to-severe plaque psoriasis.
The study was an international study in which
patients received either placebo or brodalumab at a dose of 70 mg, 140 mg, or
210 mg, subcutaneously on day 1 and at weeks 1, 2, 4, 6, 8, and 10, or at a
dose of 280 mg subcutaneously on day 1 and at weeks 4 and 8.
A total of 188 patients completed the study. Patients taking brodalumab showed significant
improvement in psoriasis as compared to those who did not receive the
medication. The improvement was observed as early as 2 weeks after starting
treatment. The improvement in psoriasis was significantly better in
patients taking 140 mg, 210mg and 280 mg brodalumab as compared to 70 mg.
The quality of life was less affected in people
taking brodalumab as compared to those not taking the drug. The physical
component of well being was increased significantly in the 140 mg group whereas
the mental component was significantly better in the 140mg and 210 mg groups
compared to those not taking the medication.
Improvements were also observed in biopsy specimens from patients
undergoing treatment with brodalumab.
At week 16, which was 6 to 8 weeks after the last
dose of brodalumab, some improvement was maintained though it was less than
that seen at 12 weeks.
Common adverse effects observed in the study
included nose and throat inflammation, upper respiratory tract infection, joint
aches, and redness at the injection site. Serious adverse effects included
renal colic in 1 patient, an ectopic pregnancy (pregnancy outside the uterus)
in 1 case and asymptomatic neutropenia (decrease in white blood cell count) in
2 cases.
The study
suggests that brodalumab is likely to be useful for the treatment of
moderate-to-severe psoriasis with a quick onset of action. The effect is likely
to be better at higher dosages as compared to 70 mg dosage. Further clinical trials in
larger populations are necessary before the drug can be approved by the FDA and
introduced in the market.
Reference:
1. Brodalumab, an Anti-Interleukin-17-Receptor Antibody for Psoriasis;
Kim Papp et al; N Engl J Med 2012; 366:1181-1189March 29, 2012
Source-Medindia