Auxilium Pharmaceuticals of Chesterbrook says its merger with Canadian biotechnology firm QLT stands firm and it is rejecting Endo International’s proposal to acquire all of its shares.

In a statement issued Monday morning, Endo says its offer of $28.10 in a cash and stock transaction valued at $2.2 billion is compelling.  However, Auxilium says Endo’s proposal significantly undervalues Auxilium.  Auxilium did say it maintains the right to engage in discussions with Endo and other third parties.

Both Auxilium and Endo have ambitions to grow their pharmaceutical businesses.

Auxilium’s ambitions took wing Sept. 18 when the U.S. Food and Drug Administration approved a supplemental new drug application (sNDA) by Auxilium and its partner Vivus of Mountain View, Ca. for STENDRA® (avanafil). STENDRA is now the only FDA-approved erectile dysfunction (ED) medication indicated to be taken as early as approximately 15 minutes before sexual activity.

“STENDRA is the first FDA-approved ED drug in nearly a decade and offers men and their partners an exciting new option,” said Adrian Adams, Auxilium CEO and president.

“We believe this label expansion helps position STENDRA as an exciting ‘on demand’ ED treatment and assists with the very important aspect of spontaneity for men and their partners in real world use. We believe this provides a meaningful benefit for men with ED and further underscores Auxilium’s commitment to being an innovative leader in men’s healthcare.”

More information about the drug is here.

Whether STENDRA will return jobs to local laid-off workers remains to be seen.  Chesco Business Today reported last week that Auxilium has cut 30 percent of its staff (about 200 jobs) and consolidated its three sales forces into two. Auxilium said it hoped to save $75 million a year, so it can speed development of therapies for other medical conditions. The company expected to pay $20 million in severance and other layoff costs.

Auxilium employed 639 at the end of last year, according to Philly.com, and hoped to move its legal base to Canada.

Auxilium’s plans call for a wholly-owned subsidiary of QLT to merge with and into Auxulim.  QLT is to remain incorporated in Vancouver, British Columbia, Canada, and will be renamed “New Auxilium.”