Barely a week after securing private funding, Momenta Pharmaceuticals Inc. laid out plans to go public.

The Cambridge, Mass.-based company, which is applying the chemistry and biology of complex sugars to drug development, registered for an estimated $86.25 million initial public offering. Momenta filed for listing on the Nasdaq National Market under the symbol "MNTA," though it has yet to specify the number of shares it plans to offer or a share price range.

The company joins a lengthening line of biotech companies looking for IPOs. Since late last summer, more than a dozen biotech businesses have gone public. Several others remain registered, waiting to price.

Momenta said in its prospectus that it intends to use the proceeds to fund product development and for working capital, capital expenditures and other general corporate purposes. While the latter are loosely defined for various spending needs, the company's drug development plans take center stage for investors.

And in Momenta's case, its programs remain at earlier stages of development than most other biotech companies seeking IPOs. The company's programs all center on its knowledge of sugars and applying that to cardiovascular diseases, cancer and the improvement of therapeutic proteins.

Its most advanced product candidate, M-Enoxaparin, is designed to be a technology-enabled generic version of Lovenox, a low-molecular-weight heparin from Aventis SA, of Strasbourg, France. Scheduled to enter clinical trials later this year, M-Enoxaparin is the subject of a collaborative development program with Sandoz Inc., of Princeton, N.J.

Momenta is aiming for similar development of an improved, generic version of Fragmin, another low-molecular-weight heparin, this one from Johnson & Johnson, of New Brunswick, N.J. The 33-employee company also is exploring other potential therapeutic applications of other chemical structures found in heparin.

For cancer, Momenta is exploring the use of complex polysaccharides to treat and diagnose cancer. The company also is using its technology to improve protein therapeutics by characterizing and modifying their sugars for better efficacy and dosing regimens, while reducing side effects.

Its programs have been supported in large part by venture capital investment.

At the beginning of the month, Momenta raised $20.5 million in its third round of financing, about 10 months after receiving $19 million through a Series B placement. The company has raised more than $45.5 million since its founding in 2001. (See BioWorld Today, May 23, 2003, and March 3, 2004.)

Momenta's primary institutional shareholders include Waltham, Mass.-based Polaris Venture Partners, with 25.5 percent; fellow Waltham firm Atlas Venture, with 19.2 percent; London-based MVM International Life Sciences, with 14.1 percent; Princeton, N.J.-based CHP II, with 10.9 percent; and Boston-based Mithra Ventures, with 5.9 percent.

Its founders include Ganesh Venkataraman, Robert Langer, Ram Sasisekharan and Christoph Westphal.

The IPO's lead underwriters include Banc of America Securities LLC and SG Cowen Securities Corp., both of New York. Additional underwriters include CIBC World Markets Corp. and ThinkEquity Partners LLC, both of New York.