Byetta Thyroid Cancer Risk Not Seen According to Amylin
According to Amylin Pharmaceuticals, Inc., the new long-acting version of their diabetes drug Byetta does not have the same link to thyroid cancer recently associated with Novo Nordisk’s Liraglutide, a similar diabetes drug in the same class of medications that the FDA is also considering for approval.
Concerns about potential Byetta thyroid cancer side effects emerged last week after an FDA advisory panel revealed that there is a link between Liraglutide and thyroid cancer in animals. Since Byetta (exenatide) belongs to the same class of diabetes drugs, known as GLP-1 agonists, it was suggested that the thyroid tumor risk may be a class effect.
The FDA panel arrived at a split vote on the question of whether to recommend that permission to market Liraglutide be approved for Novo Nordisk. Analysts have speculated that this may delay approval for the new once-daily version of exenatide (which will be marketed as Byetta LAR) or that the FDA may place substantial restrictions on the use of both drugs.
This week Amylin has jumped to the defense of their drug, which is critical to the future of the relatively small pharmaceutical company. Although the drugs are in the same class, Amylin points out that exenatide and liraglutide are different molecules.
Amylin says that their data from a two-year study of the potential cancer side effects of Byetta LAR in rodents did not find the same tyroid tumor risk demonstrated with Liraglutide. While Liraglutide was found to cause tumors in both female and male rats at multiple doses, Byetta LAR was only found to produce an abnormal number of thyroid cancers in female rats that were given high doses of the drug.
Of the approximately 1 million diabetes patients who have used the current version of Byetta, which is injected multiple times a day, Amylin indicates that only 9 reports of spontaneous thyroid cancer have been reported. However, none of these cases were fatal or similar to the tumors associated with Liraglutide.
The FDA’s review of Byetta LAR has already been delayed several times due to requests for additional safety data and concerns that Byetta side effects may increase the risk of pancreatitis.
In October 2007, the FDA released a statement indicating that about 30 cases of acute pancreatitis with Byetta use had been reported. This alert was updated in August 2008, to notify doctors that at least six additional cases had been reported involving severe forms of pancreatitis, known a hemorrhagic and necrotizing pancreatitis. At that time, the FDA indicated that two of the six severe cases had resulted in death.
Although Amylin and Eli Lilly & Co, who co-market Byetta, denied that there is any causal connection between Byetta and pancreatitis, the FDA has reportedly been considering a stronger warning about the potential side effect, which may include a “black box” Byetta warning, which is the strongest warning that can be placed on a prescription medication.
Amylin and Eli Lilly currently face a number of Byetta pancreatitis lawsuits filed on behalf of users of the current version of the drug, which allege that the drug makers failed to adequately test and monitor the side effects of their drug and failed to issue sufficient warnings about the potential pancreatitis risk.
5 comments
I disagree. I think the drug Byetta does have side effect of getting Thyroid cancer. Last year my wife was diagnosed with Thyroid cancer, even when none of the causes applied to her. There is no family history of thyroid cancer. Also when she started taking Byetta, her body started to behave very strange. She suddenly had no energy. Her immune system seemed to slow down to fight any diseases. She used to work out everyday for 1 hour, which she no longer could do. I think Byetta has serious side effects, and the FDA needs to put this medication under more clinical trials.
Rakesh, I have been taking Byetta for past 3 years with excellent results, a1c under control and weight loss. I suggest you look at other issues too. Wish you luck and quick recovery for your wife.
My mother has recently been diagnosed with stage IV cancer with thyroid primary, lungs and liver involved. She has been labeled terminal and the doctors don’t expect her to last long. She was on Byetta last year and then again for a bit this year. It started leaving bruises and making her feel funny this time. She had clean x-rays just 11 months ago when she had back surgery. I think there is a VERY strong possibility Byetta is responsible. I took it for a month, and hope this isn’t true. But it should be investigated.
I had thyroid cancer beginning in 1993, In 2003 my cat scan was clear. I went on Byetta in 2006. By 2009 my cancer had spread to my lungs. II developed endometrial cancer. In preparation for surgery I went off the Byetta in June of 2009 and stayed off it through November. A cat scan in July 2009 showed innumerable nodules in the lungs. I went off the Byetta in June 2009 and took another cat scan at the end of November. There had been no progression between July 2009 and November 2009. I don’t know if Byetta causes or enhances the growth of thyroid cancer but there is certainly a suspicion in my mind that going off it, stopped the growth.
I went on Byetta in 2009 after attempting to control my type II diabetes with oral medications. I continued use of the drug with many of the symptoms described in other comments: chronic fatigue, concentration and neorological interruptions, weight gain, suppressed immune system.
I was diagnosed with a very aggressive thyroid cancer in 2007 when my entire thyroid was removed. I also underwent radioactive iodine treatment and 3 years of subsequent scans. Although I am in remission, I continue to suffer many of the longterm side effects of this drug and was forced to retire early and go on full permanent disability.