A former regulatory employee at Merial says she was fired after refusing to destroy a document questioning the effectiveness of Heartgard Plus, a top-selling heartworm preventative.   

Kari Blaho-Owens, Ph.D., makes that claim and others in a lawsuit against Merial LLC, the animal drug division of Sanofi Aventis. The case was filed last month in U.S. District Court for the Northern District of Georgia, Atlanta Division. 

Blaho-Owens, hired in 2006 as Merial's head of global pharmacovigilance, contends that Merial executives deliberately suppressed studies showing that Heartgard Plus is losing efficacy and fired her when she refused to destroy documents questioning the drug’s effectiveness.   

Heartgard Plus is primarily marketed to prevent heartworm infestation in dogs. It contains ivermectin and pyrantel, two broad-spectrum antiparasitic agents. The meat-flavored chewable tablets are given monthly to dogs to control hookworms and roundworms, in addition to preventing heartworms.   

In a statement to the VIN News Service, Merial officials promised to "vigorously defend the case."

"At Merial, we stand by the effectiveness of our products," the statement says. "Merial is confident that the Heartgard (ivermectin) brands are highly effective when used in accordance with their FDA-approved labels. Heartgard Plus is the number-one choice of veterinarians for the prevention of heartworm disease — a serious threat to dogs."

By contrast, the 29-page lawsuit alleges active disregard by Merial executives to the possibility that Heartgard might not be 100-percent effective — even after the U.S. Food and Drug Administration's Center for Veterinary Medicine (FDA CVM) repeatedly asked Merial to change the product’s label and notify veterinarians that in some cases, Heartgard Plus had not worked as advertised.  

The drug's eroding efficacy wasn't news to the company, the lawsuit contends, insinuating that Merial executives had known of mounting troubles with the effectiveness of Heartgard Plus since at least 2000. The FDA approved the drug in October 1996, noting, as part of the agency's review process, "100-percent efficacy demonstrated in the dose confirmation studies" and "100-percent efficacy in the clinical field trials."

The lawsuit states that Dr. Felipe Dolz, then-director of Merial's regulatory affairs, believed that acknowledging that Heartgard Plus is less than 100-percent effective on the label would put Merial at a marketing disadvantage unless the CVM posed an industry-wide policy that would equally affect competitors.  

The FDA spent four years pressuring Merial to lose the 100-percent effectiveness claim in reference to Heartgard Plus until the company complied in 2006. But another CVM-issued warning letter came in 2007, this time alleging false advertising. The CVM challenged Merial's promotional verbiage that claimed using Heartgard in pets would control the spread of zoonotic diseases to humans, though there was no scientific evidence to support that claim.   

Behind closed doors, Merial officials blamed the appearance of efficacy troubles with Heartgard Plus on a surge in product sales and lack of compliance on the part of owners — not a product failure, the lawsuit says. But Blaho-Owens found the statistical analysis and methodology of an internal investigation that allowed Merial to come to those conclusions to be steeped in flawed science. Among her criticisms, Blaho-Owens noted that Merial's study was not blinded and evaluated just 7 percent of all Heartgard Plus-related adverse event cases. Her own cursory investigation demonstrated that Heartgard Plus had an approximate 20-percent failure rate, the lawsuit says. 

Upon pushing higher ups to conduct more sound analysis of the drug's efficacy, the lawsuit says Blaho-Owens was shut down. Additionally, the lawsuit alleges that Merial improperly filed adverse event reports with the CVM, effectively burying the ones that showed efficacy troubles with Heartgard.   

A query to the CVM seeking insight into the legitimacy of the lawsuit’s claims was not immediately returned. The CVM lists more than 26,000 adverse event reports involving oral ivermectin and pyrantel — active ingredients in Heartgard Plus — but regulators do not tie brand names to the events, and several other manufacturers make pet parasiticides with formulas containing those chemicals. Furthermore, though ineffectiveness is named as an impetus for some of the adverse event reports, a variety of other reactions are listed. 

In September 2009, Blaho-Owens was notified of a class-action suit against Merial regarding Heartgard. Dolz instructed her to destroy a document in her possession that likely was relevant to the pending lawsuit and to stop generating any new analysis on the efficacy of Heartgard Plus, the lawsuit says.

Rather than destroying the document (the contents of which are not detailed in the lawsuit), Blaho-Owens reported the request to Merial's legal counsel, Adam Bassing. It was then that she learned that the class-action lawsuit related to Merial's refusal to change its labeling as initially ordered by the FDA in 2002.  

She also learned of another Merial whistleblower who had accused the company of falsifying sales data — figures that Blaho-Owens relied on to perform her own safety and efficacy analysis for the FDA and international regulatory authorities. The lawsuit states that she complained to Merial officials that the company's doses sold/distributed data changed randomly, were inconsistent and no controls existed to assure the accuracy of the figures. 

"Dr. Blaho-Owens was told by Dr. Dolz to ignore the problems and just use the data that her department retrieved from the finance databases to prepare her reports, and she did so," the lawsuit says. 

On Nov. 11, 2009, the scientist was placed on a performance improvement plan, which cited a "lack of understanding the differences in levels of priorities" between Blaho-Owens and Merial's management. Dolz, the lawsuit says, then started implementing a workload designed to force Blaho-Owens out of the company.  

On Jan. 29, 2010, Blaho-Owens filed a claim for retaliation against the company with the U.S. Department of Labor, Occupational Safety and Health Administration. Two months later, the plaintiffs for the class action filed for a temporary restraining order against Merial and its employees to cease and desist in the further destruction of documents.  

It is unclear in the lawsuit what contact, if any, Blaho-Owens had with the class action plaintiffs. Blaho-Owens and her attorney, Christopher Vaughn, could not be reached immediately. The temporary restraining order filed by the class action plaintiffs referenced Blaho-Owens' complaint with the labor department.  

Blaho-Owens says in her legal complaint that on April 6, 2010, Dolz told her that "Merial was done with her." She was terminated three months later. She is suing for an unspecified amount of relief that includes back pay, front pay, lost benefits and attorney's fees as well as damages for emotional distress and loss of professional reputation. 

She also wants Merial officials to write her a letter of apology. 

Editor's note: This article was altered from its original, which incorrectly identified Kari Blaho-Owens as a veterinarian.