Valeant Pharmaceuticals announced plans to extend its growing list of acquisitions, saying it would buy the largest U.S. dermatology company, Medicis Pharmaceutical, for $2.6 billion. The deal will allow Valeant to leapfrog Galderma as the leading prescription skincare company in terms of sales.

The transaction, in which Valeant will acquire all outstanding Medicis shares for $44 per share in cash, represents a 39 percent premium to Medicis’ closing share price on August 31, the last trading day prior to the announcement. The boards of directors of both companies unanimously approved the deal. The companies expect the transaction to close in the first half of 2013.

Medicis’ portfolio includes the oral acne treatment Solodyn, and the injectable wrinkle remedies Restylane, Perlane, and Dysport, a competitor to Botox. Medicis will maintain its brand and headquarters in Scottsdale, Arizona.

“We have a great deal of respect for Medicis,” says Valeant’s chairman and CEO, J. Michael Pearson. “And given the complementary nature of our portfolios, and our aspirations in dermatology, we have been looking at Medicis for some time.” The acquisition represents a “significant next step” in Valeant’s plan to strengthening its products for acne, actinic keratosis, aesthetic injectables, and antivirals, he says.

Valeant sees a lot to like in the U.S. dermatology market, which it sees as fragmented among several small players all scrambling for a slice of an estimated $12 billion-plus opportunity with very little Big Pharma competition. “With a focused target list of prescribers, it is a relationship-oriented and industry-friendly environment,” Pearson told analysts on a call explaining the company’s rationale. “In terms of coverage, there is fairly low government reimbursement for these products, and a growing self-pay component.”

Valeant expects the transaction, once completed, to be immediately accretive its earnings while, within six months of closing, yielding a savings of at least $225 million annually.

Canada’s biggest public pharmaceutical company, Biovail, merged in 2010 with the California-based Valeant in a $3.2 billion deal to create a specialty pharmaceutical group with a global presence and portfolio. Since then, the company has pursued a string of strategic acquisitions, looking for advantages in niche markets, areas with little Big Pharma competition, and an emphasis on producs for which patients foot the bill rather than relying on reimbursement from government or other payers.

The Medicis deal adds to a string of 2012 deals the Canadian company has struck this year, including the acquisition of the specialty pharmaceutical companies Pedinol Pharmacal and Natur Produkt as well as branded generic drugs from Mexican and Austrian drugmakers. It also bought Brazil’s Probiotica Laboratorios and took a stake in a Brazilian biotech, Pele Nova Biotecnologia.