Codexis shares were up 84% in after-hours trading at $2.60.
The license lets Glaxo use Codexis' platform technology to develop enzymes for use in pharmaceutical and health-care products.
Codexis said it is eligible to receive up to $25 million over a period of about two years, $6 million of which will be paid upfront and $19 million that is subject to completion of technology transfer milestones.
The company could receive additional milestone payments of $5.75 million to $38.5 million per project, depending on successful application of the technology.
Codexis said in May that first-quarter revenue fell 38% to $7.1 million, reflecting a loss of biocatalyst and intermediate sales in the hepatitis C drug marketplace. The company's net loss narrowed to $6.4 million, or 17 cents a share, from $9.6 million, or 25 cents a share. At the time, Codexis also reaffirmed 2014 revenue guidance of $33 million to $35 million.
On June 30, Codexis announced the resignation of Chief Financial Officer David O'Toole. On July 9, diagnostic devices company Capnia Inc. said it hired Mr. O'Toole as its CFO.