Pharmaceutical manufacturer Kadmon Pharmaceuticals has been issued a Warning Letter by the US Food and Drug Administration's (FDA) Office of Prescription Drug Promotion (OPDP), with regulators saying that one of the company's promotional materials promotes an indication beyond that which has been approved by FDA while making unsubstantiated claims and omitting facts.
The letter, posted online 20 November 2013, references a letter submitted under Form 2253 and intended to support Ribasphere RibaPak (ribavirin, USP) Tablets. The drug, used to treat hepatitis C, is a twice-per day combination therapy drug that is specifically contraindicated for monotherapy use.
The company's website touts the drug as being advantageous because of its unique packaging design. "Each package provides 7 days of treatment divided into morning and evening doses," it says. "This packaging is designed to simplify treatment, make it easier to remember to take your medication, and also help you keep track of how many pills you've taken."
The drug is also associated with some serious risks-enough so that it is paired with a medication guide (MedGuide) and a voluntary pregnancy registry to avoid the risk of birth defects.
But according to FDA's Warning Letter to Kadmon, the company reportedly downplayed these risks in its two-page promotional letter to healthcare providers. The letter makes "numerous claims regarding the benefits of Ribasphere, but fails to include any risk information associated with the drug in the body of the letter," FDA wrote. While the back of the letter included the full prescribing information, its inclusion did not serve to "mitigate the misleading representations within the body of the letter."
Regulators also claim the company's claims serve to expand its approved indication by implying that the drug could be used by itself. Regulators called this an "overwhelmingly misleading impression," even despite a brief mention of the drug's use with peginterferon injections.
In addition to omitting risks, Kadmon was also charged with omitting material facts, such as information that would ordinarily be found under the "Indications and Usage" section of the prescribing information (PI). Specifically, FDA said the omission of information about the trial used to support approval and its limitations was impermissible.
Regulators also flagged what they called "unsubstantiated efficacy claims" that use of the drug would result in improved rates of sustained viral response (SVR) and patient adherence. Those outcomes have not been borne out through substantial evidence, FDA noted.
Altogether, the claims made against Kadmon are substantial, especially considering the length of the text in the letter. All of FDA's complaints came from text that is not even 200 words in length and spans just part of a single page.
Second Letter Since 2011
Alone, the problems may well have been enough to warrant a Warning Letter instead of the Untitled Letters most often sent by OPDP for alleged advertising violations. However, the company also had what FDA called a "particularly troubling" history with FDA going back to March 2011, when FDA sent it a similar Warning Letter regarding Infergen (interferon alfacon-1), an injectable drug also used in the treatment of hepatitis C.
"OPDP is concerned that Kadmon is continuing to promote its prescription products in a violative manner," FDA wrote.
As of the time of this article's publication, the company had taken down its website for Ribapak, but a version was still up on the company's main website making claims similar to the ones noted in the Warning Letter.