At Last, FDA Approval of SYMLIN Pen-Injector Devices

Well, it has been promised for nearly 3 years now, but today, the company revealed that they were in receipt of an approval from the U.S. Food and Drug Administration (FDA) for the SymlinPen 60 and the SymlinPen 120 pen-injector devices for administering SYMLIN (or pramlintide acetate) injection. According to the news release, the pens are expected to be available to patients by December 2007.

Patients have long complained that SYMLIN is cumbersome to use, in part, because there are no pen injection devices for the use with SYMLIN, therefore its not portable. As a result, dosing SYMLIN on the run is more cumbersome and less convenient, and may have slowed doctor and patient uptake of this insulin-adjunctive treatment approved for all forms of diabetes. The Amylin/Lilly partnership have promised a pen for several years, but bringing one (or in this case, two) to market received a lower priority as the company struggled to market a pen for the type 2 medicine Byetta instead amid production problems and surging product demand for Byetta.

However, Amylin also stated that FDA had issued a "Not Approvable" letter for SYMLIN use with basal insulin in patients with type 2 diabetes who have not achieved desired glucose control. SYMLIN is currently only approved in the U.S. for patients with either type 1 or type 2 diabetes who use mealtime insulin and need improved glucose control. In other words, SYMLIN cannot be used by type 2 patients who are using only long-acting insulins like Lantus or Levemir. It's no secret that the Amylin/Lilly partnership had hoped to promote the use of SYMLIN as a kind of weight-loss drug for the type 2 market, but this FDA action will limit this to patients who are using a full basal/bolus combination and may therefore exclude many type 2 patients who use only basal insulin. Not that this is the final word on this.

For example, Daniel M. Bradbury, President and CEO of Amylin
Pharmaceuticals did say "We will initiate discussions with the FDA to clarify their response for its use with basal insulin alone." Of course, "not approvable" does not necessarily mean it is not approvable, only that the FDA needs more information before they will approve it for that use. I suspect the reason for this application was to make SYMLIN marketable to the large number of type 2s who use only basal insulin. But basal insulin-only is not necessarily the optimal insulin therapy for most type 2 patients, so this may therefore limit the ability to market SYMLIN in the fashion the partnership had hoped. Regulators will no doubt seek to limit "off-label" marketing of this medicine, especially given Lilly's recent problems in off-label marketing of its schizophrenia/bipolar disorder medicine Zyprexa which received public notice following an exposé published in The New York Times last year, and more recently, the FDA notice that Lilly failed to disclose adverse effects of Cymbalta, which is being marketed as a treatment for diabetic neuropathy in addition to depression.

It is worth noting that the FDA approved two different sized SYMLIN pens, the SymlinPen 60 is targeted at the type 1 market, while the SymlinPen 120 is targeted at the type 2 market, reflecting the different dosage requirements applicable to both groups.