12-YEAR-OLD PROCEEDS WITH REVOLUTIONARY MD THERAPY

JACKSON -- Twelve-year-old Chad Birk loves to swim, play Nintendo and is "kind of" looking forward to going back to school, this year in the seventh grade at R.O. Hawkins Jr. High School.

Another thing Chad has to look forward to is the third phase of a revolutionary treatment for Duchenne Muscular Dystrophy, with which he was diagnosed in February 1988.

The Cell Therapy Research Foundation in Memphis, Tenn., has been given the go ahead by the federal Food and Drug Administration to proceed with the next phase of the treatment.

The procedure, termed Myoblast Transfer Therapy, involves injecting healthy, myoblast-producing cells into the muscles of boys stricken with the muscle-degenerative disease.

Last week, a 15-year-old DMD boy under general anesthesia received 12.5 billion myoblasts via 188 injections into 28 muscles in his shoulders, arms and back. He will return in three months to receive an additional 12.5 billion myoblasts in 36 muscles in his lower body.

The concept behind the procedure is relatively straightforward. The muscle cells of boys with DMD cannot produce dystrophin, a chemical which causes cells to regenerate and muscles to develop with bone growth. Dystrophin-producing cells are taken from healthy donors, grown in a controlled environment and then injected into the patient.

"This is a logical extension of the first human gene therapy that we initiated on Feb. 15, 1990," said Dr. Peter Law, chairman of CTRF. "Through cell fusion, the missing gene is incorporated into the dystrophic muscle cells to repair them."

The truth about Chad's worrisome condition remained a mystery to the Birks until he was 7 years old.

"It was probably the most frustrating part of all of this," said Donna Birk, Chad's mother. "We knew there was something wrong, but the doctors kept telling us to `Wait it out,' that he would grow out of it or that he was just developing slowly."

After Donna and Terry Birk requested their son see a neurologist, they finally were referred to a specialist who recognized Chad's symptoms as those of DMD. The family then traveled to St. Louis, where a biopsy was performed to confirm the neurologist's beliefs.

"We were devastated," Donna Birk said. "We wanted to know as much and find out as much as we could about Chad's condition to find a way to combat it."

The Birks were referred to the Muscular Dystrophy Association by the St. Louis hospital. Several different drugs and therapies were used to combat their son's degenerative condition, all with little effect.

DMD affects one in 3,500 male children and is the most common and most severe form of human MD. Progressive muscle degeneration becomes apparent by age 6. There is no effective treatment or known cure.

The CTRF is a publicly-supported not-for-profit organization and is not associated with the Muscular Dystrophy Association. The foundation does not charge any fees for participation in clinical trials and is funded by direct public donations.

At the time, Law worked for the MDA. When federal funding ran out for his genetic research projects then being performed on animals Law left the agency and began the CTRF. The Birks, who had never met the doctor but had heard of his research, followed.

The first phase of Law's research on humans involved the injection of healthy cells into the big toe of 13 boys with DMD. Law monitored the body's reaction to the new cells, and monitored the effect on the boys' condition.

Chad Birk became involved in the second phase of Law's program in late 1991. He was one of 32 boys whose legs were injected with healthy, dystrophin-producing cells.

Chad's cell donor was his 11-year-old brother Josh.

"I just wanted to do it for him," Josh said.

The donors need not be genetically compatible because the boys are placed on anti-rejection medication for six months after the procedure is completed.

Terry Birk explained that the doctors had to insert flexible needles in Josh's leg several times to "traumatize the muscle," or cause it to bruise and produce an inordinate amount of dystrophin. Then an inch-deep incision was made in Josh's leg, allowing the doctors to extract one gram of muscle tissue.

"It really hurt," Josh said.

Over the next two months, the tissue was "grown" in a controlled environment until doctors had a sample of about 5 billion cells.

The cells then were injected into Chad's legs.

"It took about 20 minutes," Terry Birk said. "Two doctors made 22 injections in each of Chad's legs scattered along the muscles."

Chad then spent the night in a Memphis, Tenn., hospital so doctors could monitor his recovery.

"We were becoming discouraged with some of the other treatments Chad was getting," said Terry Birk. "With this one, we saw some positive results; some increase in strength in his legs."

For six months following the treatment, Chad took anti-rejection medication. His blood was drawn regularly in Cape Girardeau and sent to Memphis for testing. None of the 32 boys has experienced ill effects, Birk said.

In the months after the procedure was performed, the positive effects gradually began to wear off.

Almost a year ago, Chad had to undergo surgery to relieve the pressure on the tendons in his legs. They were atrophying, causing his feet to curl backward. Doctors made 18 incisions in the tendons to straighten them.

The FDA has the necessary paperwork to allow Chad and the other boys receiving treatment from Law to undergo the same treatment as the five already approved. The Birks are patiently waiting their son's turn.

"It is so experimental, we don't know what the future holds," said Terry Birk.

Meanwhile, Chad exercises with braces and a walker daily for therapy, but otherwise rides in an electric wheelchair his family purchased last month. He also swims every other day in the indoor pool his family built for his therapy.

"He really loves to swim," said Donna Birk.