By Mary Welch

Staff Writer

Maxygen Inc., which went public in December, already has gone back to the financial market, filing to sell another 1.5 million shares of stock currently valued at about $252 million.

Maxygen, which will use the proceeds to fund research and development activities, will have 32.3 million shares outstanding after the offering. The underwriters have an option on an additional 225,000 shares to cover any overallotments. The offering is being made through an underwriter group managed by Goldman, Sachs & Co., Robertson Stephens, Credit Suisse First Boston and Invemed Associates Inc., all of New York.

The company is in a SEC-imposed "quiet period."

In December, the Redwood City, Calif.-based company sold 6.9 million shares at $16 per share, grossing $110.4 million in its initial offering. The shares shot up immediately, and have continued to rise since. (See BioWorld Today, Dec. 20, 1999, p. 1.)

Maxygen's stock (NASDAQ:MAXY) closed Friday at $169.75, down $4.

Maxygen's focus is in the field of directed molecular evolution, the process by which genes are modified for specific commercial uses. Its proprietary technology, known as MolecularBreeding, consists of DNAShuffling recombination technologies and MaxyScan screening systems. DNAShuffling is the process of recombining single genes or gene families to generate a library of new modified genes. MaxyScan is a series of specialized screening systems designed to efficiently and rapidly select those gene products and enzymes best suited for specific commercial purposes.

Currently the company is conducting research on more than 40 product candidates for the chemical, agricultural and pharmaceutical industries. Products include those to increase crop yield and quality, as well as to treat cancer, infectious diseases and autoimmune diseases.

Among the company's collaborators are Zeneca Agrochemicals, of London; Pioneer Hi-Bred International Inc., of Des Moines, Iowa; and Novo Nordisk AS, of Bagsvaerd, Denmark.

For 1999 the company posted a net loss of $11.3 million with total revenues of $14 million. The company had $136.3 million in cash as of Dec. 31.