Pozen (Nasdaq: POZN) investors don’t like the latest news from the company.

Shares plunged 15 percent, or 64 cents, to a new 52-week low of $4.26 early Wednesday.

POZN did regain some value later, rallying to $4.56, or a 7 percent decline, just before noon.

Company executives were scheduled to brief analysts at 11 a.m. in a conference call.

The drop came after the Chapel Hill-based company said partnership talks “continue to progress” for two potential pain relievers. But the bigger news involved its current partner. 

Pozen disclosed that its global drug partner, AstraZeneca, has decided to cut back on sales of the pain reliever Vimovo. That product is Pozen’s biggest revenue producer.

Among the markets affected are the U.S. and Europe outside of Spain and Portugal.

The sales cutback will hit countries representing 47 percent of Vimovo sales, Pozen said.

The company also noted that it is “unsure” what the decision means for future revenue and it is seeking “greater clarity.”

About the AstraZeneca news, Pozen stated: 

“On May 3, 2013, AstraZeneca informed Pozen that it will focus its future promotional efforts for Vimovo in specific markets where AstraZeneca feels sufficient future potential can be realized,” Pozen said.

“By the end of third quarter of this year, AstraZeneca will continue to make available, but plans to cease promotion of Vimovo in certain countries, including the U.S. and in Europe, with the exception of Spain and Portugal, due to existing contractual arrangements with third parties.

“For the remaining countries where Vimovo is on the market, which accounted for 47% of sales in Q1, promotion will continue.

“Decisions to launch in new countries will be made by AstraZeneca on a case-by-case basis.

“We are unsure, at this point, of the impact on our future revenue from this change in strategy, however, we will update investors when we have greater clarity.”

In March, Pozen also reported that a migraine drug it is seeking approval to sell in Europe has stalled.

Vimovo Sales Improve

Pozen did report that Vimovo royalties of $1.4 million in the first quarter, up 10 percent from a year ago.

The company also said overall Vimovo sales increased 24 percent from a year earlier.

For the quarter, Pozen reported a net loss of $5.8 million, or 19 cents per share. That missed Wall Street estimates by 2 cents a share, adding further pressure on Pozen shares.

Pozen also said it has yet to find a commercial development partner for two new compounds under development. 

“While there can be no assurances, the Company continues to expect to close a partnership deal in 2013,” Pozen said.

Pozen has submitted a New Drug Application to the FDA seeking marketing approval for two compounds identified as PA32540 and PA8140.

Pozen shares closed at $4.90 on Tuesday. Their 52-week high is $7.55, their low had been $4.55.