FDA approves unique leukemia drug for elderly patients

Thursday, May 18th 2000, 12:00 am
By: News On 6

WASHINGTON (AP) -- Elderly Americans with a particularly deadly leukemia won a new treatment Thursday that doctors hope could be less traumatic for their patients.

A drug called Mylotarg was approved by the Food and Drug Administration for use only by patients over age 60 whose acute myeloid leukemia has relapsed and cannot tolerate standard therapy.

Mylotarg is a two-part drug that pairs chemotherapy with genetic engineering in a unique way.

One is a "monoclonal antibody," a biotherapy that seeks out and binds to leukemia cells.

The other is a chemotherapy along for the ride. Mylotarg is the first anti-cancer monoclonal antibody that can bind a chemotherapy directly to cancer cells.

Acute myeloid leukemia strikes over 9,000 Americans a year, most over age 60. Most eventually relapse.

But standard treatment for this type of leukemia causes so many serious side effects in older patients who relapse -- and is less
effective in them -- that many doctors do not even offer it, FDA oncology chief Dr. Richard Pazdur said.

The hope is that Mylotarg will offer these elderly patients a viable option. "That's the real need, and why we approved it," he said.

But Pazdur cautioned that the drug's effects are not yet proved.

The FDA approved Mylotarg under a special rule that lets promising drugs for certain lifethreatening diseases to sell before studies
prove just how well they work.

In studies where 80 patients over age 60 were given Mylotarg, 26 percent went into remission, Pazdur said.

That is very little research, and Mylotarg was not compared with traditional therapy. But the median survival was 6.8 months, about what doctors would expect from such patients who could try conventional treatment, Pazdur said.

But Mylotarg is given in two outpatient infusions, while standard chemotherapy for these patients requires a week's
hospitalization, he said.

Mylotarg did cause typical chemotherapy side effects, including infections, immune suppression and a need for blood transfusions,
Pazdur said. But oncologists hope these side effects will prove fewer than those caused by conventional chemotherapy.

To win FDA approval, manufacturer Wyeth-Ayerst had to pledge to continue studying Mylotarg's effect. Studies in younger patients
continue, too.

Wyeth-Ayerst said Mylotarg will be available within two weeks, but refused to disclose the price.