Cancer in the headlines, June 25: old, new and potential cancer drugs

OUT WITH THE OLD

FDA: Pfizer Voluntarily Withdraws Cancer Treatment Mylotarg from U.S. Market
The cancer drug Mylotarg (gemtuzumab ozogamicin) was voluntarily withdrawn from the US market by its manufacturer Pfizer earlier this week, the US FDA reports. The drug is indicated for the treatment of acute myeloid leukemia (AML), a type of bone marrow cancer. Mylotarg was approved for this indication way back in May 2000 under the US FDA accelerated approval program. The program allows fast approval of drugs for serious and life-threatening diseases with the requirement of performance of additional clinical trials to demonstrate the drug’s efficacy and safety. Data from postapproval trials of Mylotarg as add-on to chemotherapy failed to show additional clinical benefit and indicated increased mortality compared to chemotherapy alone. These disappointing results led to the withdrawal. According to Dr. Richard Pazdur, director of FDA’s Office of Oncology Drug Products:

“Mylotarg was granted an accelerated approval to allow patient access to what was believed to be a promising new treatment for a devastating form of cancer. However, a confirmatory clinical trial and years of postmarketing experience with the product have not shown evidence of clinical benefit in patients with AML.”

IN WITH THE NEW

Potential cancer drug derived from Australian rainforest
The Queensland-based biotech firm QBiotics Ltd reports a promising drug cancer candidate that is now ready for human testing. The drug EBC-46 is made from seed extracts of a shrub native to the Australian rainforest. The drug has been tested on more than 150 dogs with different types of tumors, with very promising results. The QBiotics researchers believe that the drug can potentially treat skin cancers, head and neck cancer, breast cancer and prostate cancer. A company spokesman stated:

“The world’s rainforests are an amazing biological resource which we need to conserve and cherish. Not only may they hold the secret to many new drugs, they are the home of more than half of all other species with which we share the planet.”

USE EXISTING DRUGS FOR OTHER DISEASES

Turning a painkiller into a cancer killer
The non-steroidal anti-inflammatory drugs (NSAIDs) are popular remedies for pain and fever available over-the-counter. Examples of OTC NSAIDs are aspirin and ibuprofen. There have been reports that people who take NSAIDs regularly have a lower risk for getting certain types of cancer but data have been limited and the mechanisms involved poorly understood. Researchers Sanford-Burnham Medical Research Institute recently published a paper in the journal Cancer Cell which showed how the NSAID Sulindac inhibits tumor growth. The researchers explain:

“…Sulindac shuts down cancer cell growth and initiates cell death by binding to nuclear receptor RXRα, a protein that receives a signal and carries it into the nucleus to turn genes on or off.”