Arthritis & Rheumatism, Volume 62,
November 2010 Abstract Supplement

Abstracts of the American College of
Rheumatology/Association of Rheumatology Health Professionals
Annual Scientific Meeting
Atlanta, Georgia November 6-11, 2010.


Fulvestrant (Faslodex) an Estrogen Selective Receptor Down Regulator in the Therapy of Female SLE Patients, One to Two Year Following Faslodex Study Termination Revealed Mild Reactivation of the Serologic Parameters and Disease Activity.

Abdou1,  Nabih I., Rider3,  Virginia, Greenwell2,  Cindy A.

Center for Rheumatic Disease Allergy & Immunology, Kansas City, MO
Center for Rheumatic Disease Allery & Immunology, Kansas City, MO
University of Pittsburg, Pittsburg, KS

Background:

Estrogen plays a role in upregulation of intracellular signals by binding to estrogen receptors. In SLE, the disease predominantly affects females. Faslodex (fulvestrant) competes for receptor binding in vitro and inhibits estrogen action in immune cells. This study investigated the role of the estrogen receptor blocker (Faslodex) given in a double blind protocol, monthly in vivo for one year with clinical and serological parameters. The bone density was measured pre-study and at the end of study. There was an observational visit one to two years after the completion of study.

Objective:

We would like to examine the clinical status and immunologic parameters of female SLE patients at the end of the one-year study compared to the one-to-two year follow-up observation period after study completion.

Methods:

Sixteen female SLE patients with moderate disease activity (SLEDAI 7.87+/- 3.7) were entered into the one-year double-blind placebo controlled Faslodex study. Eight patients received Faslodex IM monthly and eight received placebo IM monthly. Parameters checked pre-study and monthly as well as 3 months post study were SLEDAI, ANA, C3, C4, CH50, urinalysis, anti-dsDNA, liver enzymes, creatinine, serum estrogen and Faslodex levels, and the bone density was done pre-study and at end-of-study. Two of these sixteen were lost to follow-up. At one to two years post study, 12 patients had SLEDAI, ANA, anti-dsDNA, C3 and C4 or CH50, UA, liver enzymes, and creatinine measured.

Results:

During the one-year study there was a significant drop in SLEDAI in the Faslodex group. SLEDAI pre-study of 8.25 dropped to 3.75 one to two years post Faslodex (p <0.02). Antids-DNA in the same group dropped from 9.25 to 5.75 IU/ml (p <0.01). The drop of anti-dsDNA persisted for one to two years after the study. There were no significant changes in any other parameter, including the estrogen levels and bone density.

Conclusion:

Blocking estrogen receptors in vivo by an estrogen selective receptor down-regulator could be considered as a new therapeutic approach for moderately active female SLE. No untoward effects were seen in the patients studied by blocking the estrogen receptor without changes in estrogen levels or drop in the bone density. Only the anti-dsDNA was significantly decreased, but the complement leverls, ANA, and other measured parameters did not change. Faslodex is safe and could be a good alternative for the treatment of moderately active female SLE patients. We would like to extend this study for a longer duration and larger doses of Faslodex.

To cite this abstract, please use the following information:
Abdou, Nabih I., Rider, Virginia, Greenwell, Cindy A.; Fulvestrant (Faslodex) an Estrogen Selective Receptor Down Regulator in the Therapy of Female SLE Patients, One to Two Year Following Faslodex Study Termination Revealed Mild Reactivation of the Serologic Parameters and Disease Activity. [abstract]. Arthritis Rheum 2010;62 Suppl 10 :462
DOI: 10.1002/art.28231

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