The former Pfizer marketing exec, who more recently turned to blogging and mystery writing after big pharma refused to hire him, has scored a legal victory. You may recall that he filed a qui tam, or whistleblower lawsuit against Pfizer, alleging the drugmaker illegally marketed the Genotropin human growth hormone. Rost charges he first uncovered this activity while working as a vp at Pharmacia, which Pfizer later purchased.

As Rost notes, the info in his lawsuit wound up forcing Pfizer to pay a $34.7 million fine last April, but the US District Court in Boston ultimately decided that Rost “failed to plead his fraud claims with sufficient specificity,” and his civil suit was dismissed. Yesterday, however, the US Court of Appeals for the First Circuit overruled and concluded that “the dismissal of the action is vacated. The case is remanded to the district court for further proceedings consistent with this opinion.”

According to Rost, who wrote about this on BrandWeekNRx, this means he gets an opportunity to amend his original complaint with additional information requested by the court. In other words, he’s back in the game and may, ultimately, win a slice of the Pfizer fine. Moreover, the drugmaker may be open to additional fines.

At the time Pfizer reached its deal, the drugmaker acknowledged Pharmacia, “improperly promoted Genotropin between January 2000 and March 2003 for anti-aging purposes, improved athletic performance, and enhanced appearance.” There were also allegations that a unit of the company made kickbacks to “an outside vendor” in order to increase its sales.

UPDATE: A Pfizer spokesman sends us this statement: “We are pleased that the Court of Appeals has recognized that Mr. Rost failed to allege that any false claims were submitted relating to Genotropin, and that neither Pfizer nor Pharmacia submitted any false claims. We are confident that we will prevail once the matter returns to the District Court. As the Court of Appeals noted, Pfizer moved quickly to voluntarily and fully self-disclose the Genotropin promotional issues, which arose at Pharmacia before its acquisition by Pfizer.”