Right after reading the news of the success of leukemia drugs in reversing type 1 diabetes in mice, I emailed the lead researcher, Dr. Jeffrey Bluestone at UCSF, to find out more about his study. He wrote back the following important caveat, which I thought people might find interesting:
Thank you for your e-mail. Unfortunately, the news account was misleading and did not accurately reflect the substance of the study that we have performed. Please read the information below to get a better sense of what was done in the study and the current prospects
· The results published in PNAS journal are data from a mouse model of type 1 diabetes, and did not include any human research. The results in mouse models are very important, as they help researchers decide which treatments are most promising and therefore should be tested in humans. However, positive results in a mouse model does not mean that the drug will necessarily work in humans. Extensive testing in human clinical trials is required to prove that the drugs are safe and effective in people. It is important to understand that it generally takes years to test these drugs in humans.
· Imatinib and sunitinib are believed to work by halting the autoimmune response that destroys the insulin-producing beta cells located in the pancreas. Therefore, human clinical trials must focus on patients who are in the early stages of type 1 diabetes – in other words, patients who still have some functioning beta cells left in their pancreas. It is important to note that in people who have had diabetes for a number of years and who have no functional beta cells left, imatinib and sunitinib would not be expected to have any effect.
· While it is promising indeed that two drugs used against cancer could be of benefit in type 1 diabetes, it does not necessarily mean that they will be as safe if used against type 1 diabetes. These are very powerful drugs so the safety of the drugs, specifically for type 1 diabetes, will need to be tested in human clinical trials.
· Human clinical trials of these drugs are currently being planned, but it may be sometime before they begin as the companies, funding agencies and food and Drug Administration will all have to be involved. Even once started, as is typical in the development of any drug, it will be several years before definitive results of imatinib and sunitinib in type 1 diabetes will be known.
It’s disappointing to find out it’s not as dramatic a discovery as the news has made it seem. But combined with recent research showing potential for beta cell regeneration, I still think it’s exciting.