Savient Pharmaceuticals Inc. said that it is committed to keeping Krystexxa on the market throughout and after its bankruptcy process. The struggling biotech filed Chapter 11 voluntarily in the Bankruptcy Court for the District of Delaware, along with a motion seeking authorization to pursue a sale process.

A “stalking horse bidder,” Sloan Holdings C.V., has stepped up to acquire all of Savient’s assets, including gout drug Krystexxa (pegloticase) for $55 million. The sale will be carried out through a court-supervised auction, to provide the best value for Savient shareholders.

Savient’s stock (NASDAQ:SVNT) lost 87.5 percent of its value Tuesday, closing at a mere 7 cents.

The disappointing Chapter 11 filing follows a two-year battle by the company to launch and market the drug alone, after failing to sell the company concomitantly with approval of Krystexxa.

Savient reported net sales of $6.1 million for Krystexxa for the second quarter of 2013, an increase of 38 percent over the first quarter. But the company overall lost $25.4 million, or 35 cents per share, that quarter on total revenues of $6.7 million, compared to a net loss of $16.4 million, or 23 cents per share, on total revenues of $4.6 million for the same period in 2012.

Savient’s net loss for the first six months of 2013 was $49.9 million, or 69 cents per share, on total revenues of $11.4 million. It ended the second quarter with $51.5 million in cash, cash equivalents and short-term investments.

The company attempted to cut its losses in 2012 by eliminating 35 percent of its work force, reducing the field force for Krystexxa to 35 account managers and three regional business directors. (See BioWorld Today, July 10, 2012.)

Krystexxa was approved in September 2010 as the first treatment available in the U.S. for adults with chronic gout refractory to conventional therapy. (See BioWorld Today, Sept. 16, 2010.)

However, a plan to sell the company fell through shortly after. Savient offered itself to a range of potential buyers, but no sale of the company resulted. That put the burden of launching and marketing Krystexxa on Savient alone.

The drug is a pegylatic uric acid-specific enzyme designed for patients who do not respond to currently marketed therapies such as Zyloprim (allopurinol) and Uloric (febuxostat). Two randomized, double-blind, placebo-controlled trials met a primary efficacy endpoint of lowering plasma uric acid levels to less than 6 mg/dL for at least 80 percent of the time during month three and month six.

The company reported that many patients achieved an immediate lowering of serum uric acid level from a baseline mean of about 10 mg/dL to a mean of 0.7 mg/dL, or five times lower than what could be expected with conventional therapy.

To make ends meet, Savient offered $125 million aggregate principle amount of convertible senior notes due 2018. The funds were intended to be used to commercialize Krystexxa, including recruitment of a sales force, expansion of its marketing organization and establishment of a commercial infrastructure.

Krystexxa’s launch, however, was a disappointment, with sluggish sales that the company attributed in part to a miscellaneous J-code that delayed the drug’s ability to gain traction in the Medicare market.

The company eventually straightened out its J-code, gained European approval and racked up additional positive clinical results. But, while sales of Krystexxa picked up, the increase wasn’t enough to overcome the rapid cash burn. In its court filings, Savient reported about $73 million in assets and more than $260 million in liabilities. The company reported about 73.7 million shares of stock outstanding.

Savient expects normal operations to continue throughout the bankruptcy process. It negotiated with senior secured noteholders to ensure that it has liquidity to carry out its business and meet its obligations such as payment of wages, servicing of distributors and obligations to patients.

The law firms Skadden, Arps, Slate, Meagher and Flom LLP and Cole, Schotz, Meisel, Forman and Leonard P.A. are legal advisors for Savient, with Lazard serving as financial advisor.