Interview with Giselle Singer and Shelbi Jim On, PXE Clinical Trial

Icahn School of Medicine at Mt. Sinai logoMay 30, 2013
By Terry Mac Dermaid, Executive Director, PXE International
This interview first appeared in the May 2013 PXE International eNewsletter

Shelbi Jim On, MD, is a Dermatopharmacology Fellow at The Mount Sinai School of Medicine Department of Dermatology
Giselle Singer is the Director of Clinical Trials at The Mount Sinai School of Medicine Department of Dermatology

Terry Mac Dermaid: Thank you, Giselle and Dr. Jim On, for taking time to answer a few questions about the clinical trial. What is your role in the clinical trial of magnesium supplementation for treatment of PXE?
Giselle Singer: My role is project manager, that means I handle all the logistics of the study.
Shelbi Jim On: My role in this clinical trial is a sub-investigator. As a sub-investigator, I am responsible for conducting and implementing all trial-related procedures under the supervision of Dr. Mark Lebwohl.

Terry: Why is the PXE magnesium trial important? What excites you about this clinical trial?
Giselle: This study is important because it is looking for a treatment for a rare disease, PXE. It is exciting because we were able to get federal funding to support this research project and it is only the second of its kind. Of course the first one was our study 10 years ago. It is exciting that we have an active part in trying to help patients with this condition.
Dr. Jim On: Currently there are no effective treatments for patients with pseudoxanthoma elasticum (PXE). Guidelines recommend early detection and regular follow-up to manage PXE’s complications. This trial is particularly exciting and important because it highlights the therapeutic potential of magnesium supplementation in the reversal of elastic fiber calcification. Discovering a potential mode of treatment for this multisystem disease would be a substantial contribution to its clinical management.

Terry: Why is the trial two years long?
Giselle and Dr. Jim On: The clinical trial consists of two parts. The first year is a double-blind, placebo-controlled study in which qualified subjects will be randomized to receive either magnesium oxide supplements or placebo in a 1:1 ratio. The second year is an open-label extension in which all subjects will be administered magnesium oxide supplements. In order to run a clean clinical trial you need to compare an active treatment to a placebo to see if there is a significant difference in improvement between the two groups. In PXE, skin changes are subtle and need more time to become apparent. The second year is an incentive for subjects to complete the first year of the study and to collect additional safety and efficacy data. 

Terry: Why do participants need this suite of tests done (MRI, bone density, EKG, etc.)?  
Giselle and Dr. Jim On: PXE is a multisystem disease affecting the cutaneous, ocular and cardiovascular systems. During the course of two years, qualified subjects undergo a variety of tests such as a non-contrast CT of the carotid and coronary arteries, ophthalmologic exam, bone densitometry, etc. to monitor changes, if any, of calcification in the elastic fibers and bone mineralization. Subjects need a wide range of testing in order to show safety of the study drug. It also enables us to see changes in other areas of the body affected by PXE besides the skin. 

Terry: In your opinion, what motivates PXEers to participate in this trial?
Giselle and Dr. Jim On: What motivates PXE patients to participate in this clinical trial is the ability to better understand their disease and the opportunity to contribute to the advancement of clinical management of this disease. They really are doing it for the greater good.

Terry: If this trial does show that magnesium is an effective treatment for PXE, what happens next? 
Giselle and Dr. Jim On: If this trial does show a significant reversal of calcification levels and clinical scores of PXE, then further clinical studies should be conducted to support these results. Eventually, if the magnesium is shown to work, then doctors will be able to recommend it to their patients without a prescription. This is also the reason for all our thorough testing. Since it will be a nonprescription drug we want to make sure we capture all the safety issues surrounding the product. 

Terry: What brought you to medicine, and where do you see your career in medicine leading you to?
Giselle: I originally wanted to do psychology related research, but ended up interviewing with Dr. Lebwohl just for "practice" since I was a recent college grad, and 22 years later I'm still here.  I really enjoy what I do and I love working for Dr. Lebwohl, so I think I'll be doing this for a while longer. Eventually I may end up working for the FDA or one of the pharmaceutical companies.
Dr. Jim On: My love of working with people and my desire to positively impact their lives through medicine.  I see myself working at a University affiliated practice where I can continue to pursue dermatological clinical research while also practicing medical dermatology.

Terry: Thank you Giselle and Dr. Jim On!