By Tom Corrigan 

A bankruptcy judge Friday approved the sale of the assets of Dendreon Corp., a troubled cancer drug maker, to Valeant Pharmaceuticals International Inc. for $495 million.

The sale underwent significant modifications as recently as Thursday night, adding an extra $95 million to the purchase price.

In addition to Dendreon's flagship drug, Provenge, the deal now also includes $80 million in cash held by Dendreon as well as another product known as D-3263.

"Our judgment is that this is the better alternative," Kenneth Ziman, a lawyer for Dendreon, said during a hearing Friday. "These changes all are for the better."

Valeant has also offered to hire the company's employees and take over the supply contracts for the acquired business, a component of the offer that stabilizes Dendreon's operations.

A string of objections to the sale were all resolved consensually, some just hours before Friday's hearing began. Unsecured creditors also threw their weight behind the revised deal.

"There is no question that a sale should be approved," Judge Laurie Silverstein of the U.S. Bankruptcy Court in Wilmington, Del., said as she made her ruling Friday.

The sale is scheduled to close on Monday, and Mr. Ziman said he expects the company to exit Chapter 11 protection as soon as June.

Originally, Valeant offered $296 million for Dendreon assets, including Provenge. That offer was increased to $400 million when Valeant was approved to serve as the stalking horse, or lead bidder, at a bankruptcy auction that was ultimately canceled when no rival bidders emerged to challenge Valeant.

The deal is Valeant's first big move since its failed hostile takeover of Botox maker Allergan Inc. Actavis PLC ended up buying Allergan in November for $66 billion. After losing out on Allergan, Valeant indicated it would focus on expanding its own business. But Dendreon appears to have been too tempting a target.

Dendreon filed for Chapter 11 protection in September after Provenge failed to prove a hit with doctors. Its cost, $93,000 for a standard course of treatment, and results that showed only a four-month improvement in median survival rate made the drug a tough sell.

Provenge had about $300 million in 2014 revenue, Valeant said.

Peg Brickley contributed to this article.

Write to Tom Corrigan at tom.corrigan@wsj.com

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