AUBURN, Wash., March 30 /PRNewswire/ -- Researchers from Syntrix
Biosystems, Inc. and The University of Medicine and Dentistry of New Jersey
(UMDNJ) announced today that there was no evidence of Aminopterin in the
tissues of animals who had died from consuming food from Menu Foods, the
manufacturer of the many brands of dog and cat food that are currently the
subject of a nationwide recall.
"We became concerned when Aminopterin was implicated as the toxin in
the recent pet food recall. The clinical pattern did not fit the known
toxicology of Aminopterin," said John A. Zebala, M.D., Ph.D. President and
CEO of Syntrix Biosystems. "We immediately reached out and offered our
expertise to other investigators in the field who had reported finding the
compound in food samples."
Using a highly specific and sensitive test for Aminopterin,
investigators at UMDNJ documented that there was no evidence of Aminopterin
in the tissues of affected animals. "Aminopterin persists in the liver of
animals for months at levels that are readily detected," said Barton A.
Kamen, M.D., Ph.D. Professor of Pediatric Oncology at UMDNJ. "Whatever is
causing the renal failure, it is not Aminopterin." These results are
completely consistent with the findings of the FDA, who announced today
that they found no evidence of Aminopterin in food samples.
The reference to the use of Aminopterin as a rodenticide (i.e. rat
poison) dates back to a 1951 patent issued to the American Cyanamid Company
that is commonly cited by a variety of reference textbooks including the
Merck Manual.(1) "To our knowledge, Aminopterin is not, and has never been,
actually used as a rodenticide. The preparation of the molecule is complex
and expensive. It is also unstable in the environment due to degradation by
light and heat," said Dr. Zebala.
The FDA Office of Orphan Products Development has supported Dr. Kamen
with grants for the clinical testing of Aminopterin in pediatric leukemia.
"We have found that Aminopterin has unique properties relative to other
drugs in its class that hold significant clinical promise and which we are
very excited about," said Dr. Kamen. "Since our clinical development
program began, we have safely treated over 100 patients with Aminopterin in
Phase 1 and Phase 2 clinical trials. Many patients have been treated for
over 2 years with Aminopterin and are disease free after 5 years."
Syntrix Biosystems, Inc. acquired the exclusive rights to Aminopterin
from UMDNJ in February 2003. The company aims to market Aminopterin for the
treatment of inflammatory and oncology disorders in both veterinary and
human markets. "We see Aminopterin as the next blockbuster drug in clinical
development with a market potential of over 4 million prescriptions per
year," said Dr. Zebala.
Aminopterin was first used by Dr. Sydney Farber of the Harvard Medical
School to induce temporary remissions in patients with acute leukemia as
reported in the New England Journal of Medicine.(2) It was later marketed
by Lederle Laboratories in the United States from 1953 to 1964 for the
indication of pediatric leukemia. The drug was discontinued by the company
due to manufacturing difficulties before its advantages could be
appreciated by scientists.
During the period Aminopterin was marketed, the agent was used
off-label to safely treat over 4,000 patients with psoriasis in the United
States, producing dramatic clearing of lesions.(3) The National Institutes
of Health (NIH) has recently awarded Syntrix Biosystems $800,000 to support
the clinical testing of Aminopterin in psoriasis.
Dr. Zebala said, "the exciting and unique clinical properties of
Aminopterin promise to make this the first-line agent for treating
psoriasis, as well as a variety of other human autoimmune diseases
including rheumatoid arthritis, systemic lupus erythematosus, polymyositis,
multiple sclerosis, ulcerative colitis and Crohn's disease to name a few."
Syntrix Biosystems has also conducted a clinical trial of Aminopterin
in canine atopic dermatitis, a common inflammatory disease affecting up to
15% of dogs. "There was dramatic improvement in disease scores in dogs
treated with a single weekly dose of Aminopterin for up to 40 weeks with no
evidence of toxicity," said Dr. Zebala. "This is a devastating disease for
both dogs and pet owners, and having a convenient, highly effective and
well tolerated treatment will be a major improvement in its management."
Dr. Zebala emphasized by saying, "Aminopterin is one of the most
promising new therapeutic drugs in investigational clinical development for
both humans and animals. In order for animals affected by contaminated pet
food to be properly and accurately treated, it is critical that
veterinarians know as soon as possible that Aminopterin is not the
Syntrix Biosystems is a privately held pharmaceutical company located
in Auburn, WA. The Syntrix Biosystems website is located at
(1) Alfred L. Franklin. United States Patent Number 2,575,168.
"Rodenticide comprising 4-amino-pteroylglutamic acid." American Cyanamid
Company, New York, NY. November 13, 1951.
(2) Farber, S., L. K. Diamond, et al. "Temporary remissions in acute
leukemia in children produced by folic acid antagonist, 4-aminopteroyl-
glutamic acid (aminopterin)" The New England Journal Of Medicine. Volume
238, page 787, Jun 3, 1948.
(3) Rees, R. B., J. H. Bennett, et al. "Aminopterin for psoriasis: A
decade's observation." The Archives of Dermatology. Volume 90, page 544,
SOURCE Syntrix Biosystems, Inc.