Valeant Pharmaceuticals International, responding to investors' queries, says executive vice-president Deb Jorn had not been asked to leave, reiterating that she had resigned for personal reasons.

Ms Jorn oversaw the Canadian drugmaker’s US dermatology business, which had ties with Philidor Rx Services, a specialty pharmacy that came under fire for using aggressive tactics to increase insurer reimbursement.

Valeant in October severed its ties with Philidor, which has since shut shop. The company’s relationship with Philidor is the focus of an investigation by the US Securities and Exchange Commission.

A Valeant board committee is also investigating the company’s ties with Philidor. The drugmaker said Ms Jorn’s departure “is not the result of an action taken by the ad hoc committee of the board of directors”.

The change is effective immediately and comes after three tumultuous days following the return of chief executive Michael Pearson from a two-month medical leave.

Ms Jorn was in charge of all major US product launches and was also general manager of the US dermatology business, according to the company’s website.

“She’s a leader for two of their most important segments, so at a minimum, the optics of the resignation certainly do not look good,” said David Amsellem, an analyst at Piper Jaffray, which has a neutral rating on the stock.

The shares fell 3 per cent to $65.44 in early trading in New York on Thursday. – Bloomberg