Pfizer's Mylotarg gets a second shot at market
- Pfizer Inc. has garnered a Food and Drug Administration OK to bring Mylotarg back to market nearly two decades since the drug's original approval.
- The agency announced late Friday morning it has approved Mylotarg for the treatment of adults with newly diagnosed acute myeloid leukemia (AML) whose tumors express the CD33 antigen, as well as for treatment in the second-line setting for patients over two years old with CD33-positive AML.
- Pfizer has priced the drug at $24,600 for one cycle of treatment. This is higher than the drugs list price of $15,522 in 2010 when it was pulled from the market. Pfizer said in an email to BioPharma Dive that it expects few patients to have out-of-pocket costs, noting Mylotarg is priced below other recently approved AML treatments.
Mylotarg (gemtuzumab ozogamicin) was first approved by the FDA in 2000 under the regulator's accelerated approval program, which is meant to speed promising drugs to market. It was the first new treatment for AML to be approved in nearly 15 years and was touted as a potential miracle drug.
The original approval was for patients 60 and older with CD33-positive AML who had experienced a relapse.
Accelerated approvals are often based on very strong mid-stage data and require the drugmaker to prove those results again in a post-marketing study. For Mylotarg, this confirmatory study didn't go as planned, failing to show the drug improved survival.
Pfizer voluntarily withdrew the drug, making Mylotarg the first drug OK'd under accelerated approval to be taken off the market. Adding to Pfizer's woes, there was a much higher incidence of patient deaths in the Mylotarg arm of the study due to treatment-related toxicities.
Mylotarg became a bit of a black mark for the big pharma. Yet, after going through a new Phase 3 study (dubbed ALFA-0701) that enrolled 271 newly diagnosed AML patients, as well as another analysis of nearly 3,000 patients across five other Phase 3 studies, Mylotarg is ready for prime time again.
Patients in the ALFA-0701 study who received Mylotarg plus chemotherapy experienced better results than those on chemo alone, showing an event-free survival of 17.3 months compared with 9.5 months for the chemo-only patients.
The cancer drug’s label will include a boxed warning for hepatotoxicity, including severe or fatal hepatic veno-occlusive disease (VOD), which has been seen in patients taking the drug alone and as a combination therapy.
There are some differences between this approval and the last one. Three things in particular stand out: a lower recommended dose, a different dosing schedule and a slightly different patient population.
"We are approving Mylotarg after a careful review of the new dosing regimen, which has shown that the benefits of this treatment outweigh the risk," said Richard Pazdur, director of the FDA’s Oncology Center of Excellence and acting director of the Office of Hematology and Oncology Products. "Mylotarg’s history underscores the importance of examining alternative dosing, scheduling, and administration of therapies for patients with cancer, especially in those who may be most vulnerable to the side effects of treatment."
Mylotarg is an antibody drug conjugate (ADC), indicating an antibody hooked to a cytotoxic payload by a chemical linker. ADCs are often reformulations of older cancer drugs that have been linked to a payload. The technology has been in development for decades and typically allows these drugs to be much more targeted.
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