The bad news keeps getting worse for embattled drug company Valeant Pharmaceuticals: William A. Ackman’s influential hedge fund is shedding much of its shares of Valeant despite Ackman being one of the company’s staunchest defenders.

Pershing Square Capital Management said in a regulatory filing that its stake in Valeant had been reduced to just 8.5 percent. The announcements comes less than two months after Pershing said it would increase its stake to 9.9 percent from 5.7 percent, according to a New York Times report.

In the Thursday sale, Pershing disposed of about five million shares, which was done to generate a tax loss for investors.

It’s a sign that Pershing has lost a lot of confidence in the stock, as selling those shares is a short-term bid that loses any opportunity for future gains on them.

Valeant’s stock has been absolutely hammered this past year, falling 61 percent after peaking in the summer. The company has shown some gains since hitting the deepest lows in November.

The main problems facing Valeant concern its business model, which some have alleged involves greatly raising the prices on old drugs and using a mail-order pharmacy to dispense of some of its expensive dermatology drugs.

Valeant Chairman J. Michael Pearson is on medical leave with pneumonia, leaving his team of executives to run the company in the time being.

The allegations against Valeant have gotten so bad that the company has seen the need to post regular rebuttals against bad press on its website, www.valeantnow.com.

This one on Nov. 25 defends its relationship with mail-order pharmacy Philidor: “Short sellers have been making false, unsubstantiated claims about Valeant for months in an attempt to drive down our stock price, and today’s allegations also contain significant inaccuracies. Valeant has already disclosed that 7.2% of our sales this year through the third quarter went through specialty pharmaceutical channels, and that has not changed. As we have said, in October we decided it was appropriate to sever our relationship with Philidor after allegations about their business practices came to light. The entities mentioned today appear to have been formed on or prior to 8/18/2015, based on public records. Furthermore, our board of directors has appointed an ad hoc committee to review allegations related to Valeant’s business relationship with Philidor and related matters.”