Tykerb Warning Letter Says Glaxo Misled Doctors on Benefits, Side EffectsNov 28, 2007 | Parker Waichman LLP Tykerb promotional letters sent to doctors by GlaxoSmithKline have drawn the ire of regulators at the Food & Drug Administration (FDA). The Tykerb promotional materials led the FDA to issue Glaxo a warning letter that criticized the company for hyping the breast cancer drugs’ benefits while failing to mention its harmful side effects.
Approved by the FDA in March 2007, Tykerb is a once daily pill taken in conjunction with chemotherapy to treat advanced, metastasized breast cancer. Tykerb is indicated for women with HER2-positive breast cancer that does not respond to standard treatment, including the other HER2-specific drug, Herceptin.
Signed by Paolo Paoletti, MD, Senior Vice President of Glaxo's Oncology Medicine Development Center, the letters advise healthcare practitioners of the Tykerb's availability, and present efficacy and adverse events data. The Glaxo letters also promote the company’s Tykerb Cares access program. But the Nov. 21 FDA warning said the three letters – two to doctors and one to oncology nurses – “omit and minimize the most serious and important risk information for Tykerb and selectively present efficacy information.”
In the warning letter, the FDA criticized Glaxo for exaggerating the effectiveness of Tykerb. The drug was approved based on two studies: one that showed a 43 percent decrease in patients' risk of tumor growth and another that showed a 28 percent decrease. However, the Tykerb promotional letter from Glaxo only mentions the study with the 43 percent reduction.
The FDA warning letter also chastises Glaxo for omitting information on Tykerb’s side effects, including precautions pertaining to pregnancy, patients with hepatic impairment and QT prolongation. The FDA also said that although the Tykerb promotional information did mention diarrhea as a possible side effect, the letters downplayed the seriousness of this problem. Finally, the FDA letter said that the agency was especially concerned that Glaxo had omitted information regarding the risk that Tykerb could reduce pumping action of the heart's lower left chamber. The drug's label instructs doctors to monitor patients' heart strength before and after starting treatment with Tykerb, but the FDA says that information was left out of Glaxo's marketing letters to doctors.
The FDA letter states that the agency was particularly disturbed that the Tykerb promotional letters were sent to doctors during the product’s launch earlier this year. The FDA said that it was concerned that the letters would form healthcare providers’ first impression of Tykerb, and undermine their awareness of the drug’s side effects. The FDA has asked Glaxo to stop distributing the letters and to outline a plan for correcting its marketing message by Dec. 6. FDA warning letters are not legally binding, but the agency can take companies and individuals to court if the warnings are ignored.