UPDATED: Warning letter details contamination of Alexion's Soliris API

Late last month, Alexion Pharmaceuticals ($ALXN) gave a heads up to the markets that the FDA had issued it a warning letter detailing "bacterial contamination of certain batches" of its pricey rare-disease drug Soliris. Alexion assured investors it was on top of the issues. But the FDA today posted the report, and it indicates Alexion has had trouble figuring out the source of the contamination and so adequately attacking it.

Alexion last month said that it is hard at work fixing the problems and does not expect any interruptions in supplies of Soliris, a biologic that can cost patients up to $400,000 a year. Soliris is approved to treat a rare kidney disorder, atypical hemolytic uremic syndrome, and the blood disorder paroxysmal nocturnal hemoglobinuria.

The company said it continues to manufacture Soliris at the plant and had inventory on hand. It said in a filing with the Securities and Exchange Commission (SEC) that it also has a contract manufacturer, Lonza, approved to manufacture the drug. It let shareholders know that on top of all of that, it also expects to get a second contractor approved for manufacturing later this year. 

The FDA warning letter sounds less confident about Alexion's abilities. It said, "It appears that you have not implemented a robust quality system at your firm" and pointed out that some of the CGMP violations were repeats. The warning letter said that between April 2011 and August 2012, 6 lots of its API manufactured at the plant in Rhode Island "were found to be contaminated with too numerous to count (TNTC)/10 mL Bacillus thuringiensis." Additionally, Acinetobacter radioresistens was identified in one lot of Soliris. Inspectors said Alexion attacked the problem by using more of a "sporicidal agent" in clean rooms but never got to the "root cause" of the problem. It also failed to verify whether using extra cleanser helped before moving on with production.

Inspectors also saw "residues in already-cleaned equipment." And they were interested in the fact that Alexion had "repeated bioreactor cleaning at least several times" in an 18-month period. The agency asked for assurances that Alexion's cleaning cycle was "functioning appropriately."  

A spokesperson for Alexion pointed out that no finished product was contaminated. In an emailed statement the company said: "It is important to note that all of our released lots have met our rigorous release specifications, including testing for non-eculizumab protein and that these specifications have been approved by the FDA as well as other regulatory agencies. To emphasize, the final product is sterile."

Alexion said that it believes its inventory and back-up manufacturing will keep plenty of supply available. In the SEC filing, however, it said it intends to notify international regulators that "it is possible that the letter may impact our ability to supply Soliris manufactured at our Rhode Island facility outside the United States."

- here's the warning letter

Editor's Note: The story was updated to include a comment from the company that the contamination noted by the FDA did not include any finished product.