Pfizer, on Monday, announced that it would cease offering the leukemia treatment Mylotarg (gemtuzumab ozogamicin for Injection) after it was found to increase the death rate in patients in Phase III trials.
Mylotarg, a Wyeth drug inherited by Pfizer during the megamerger, was shrouded with hope and optimism after FDA gave Mylotarg fast-track approval in 2000 to help patients with acute myeloid leukemia (AML)—a devastating form of leukemia that attacks the bone marrow.
“ACL is a horrible disease, and treatment is limited,” said Craig Eagle, vice president of oncology at Pfizer. “One of the biggest challenges we face is that we always like to have a good buildup of information to suggest that our drug is going to work, but it’s not until you do the big Phase III trials that you know for certain.”
Eagle said that Pfizeris not yet sure why the drug didn’t work, and the company won’t speculate as to the problem.
Mylotarg went through two Phase III trials before it was sidelined. It was first given to patients as a single agent, and it was determined that the treatment helped put the disease in remission. However, the second trial—a combination of Mylotarg and chemotherapy—was stopped last year when more patients died while taking the medication than those taking the placebo.
“This is the nature of the fight against cancer,” Eagle said. “You win some, you lose some. But it’s not going to be over until we come out with treatments that benefit people.”
The original purpose of the accelerated approval program was to get potentially life saving drugs to people who need them as early as possible. However, as in the case of Mylotarg, there is always the chance that the treatment might not work as planned.
Eagle explains that if the drug was not fast-tracked and it had worked, it would have taken years to get it to market costing many patients their lives.
“ACL is a very serious disease, and it’s a real shame to recognize that Mylotarg was promising, and then realize that it wasn’t successful,” Eagle said. “But the reality is that it’s a drug that needed more research, and needs to come back to the research realm and be followed through again on a different path. Therefore, we are completely in alignment with the FDA.”