Shares of Crossroads Systems Inc. (CRDS) fell as much as 54% after the Patent Trial and Appeal Board ruled in a final written decision that the claims of the company’s patent 6,425,035 B2 patent were unpatentable.

Crossroads shares fell 55 cents, or 59%, to 38 cents in trading after the PTAB decisions in the inter partes review of the patent filed by Cisco Systems, Quantum Corp., Oracle Corp. and Dot Hill Systems Corp.

The shares have traded between 36 cents and $3.05 over the past year.

Another final ruling in a related IPR petition filed by NetApp, Oracle and Dot Hill found the claims of the patent not unpatentable.

The company is expecting other final decisions by PTAB on March 17.

The ruling may end the Austin, Texas-based company’s enforcement campaign against those companies.

The ruling is a blow to Crossroads CEO Richard Coleman Jr. and Techquity Capital Partners, which in November gave Crossroads $10 million in litigation financing. The financing enabled Crossroads to pay off financing from Fortress Investment Group that had been on more onerous terms.

Crossroads said the while the decision in IPR 2014-01197 confirmed the validity of all patent claims subject to that IPR, the decision in IPR 2014-01226 stated such claims are unpatentable.

"IPR 2014-01207, IPR 2014-01209 and IPR 2014-01544 challenged the validity of the ‘147 patent in response to Crossroads’ lawsuits alleging patent infringement, and the decisions each stated that all patent claims subject to each respective IPR are unpatentable."

The company said it is reviewing these decisions and will consider future actions accordingly.

Techquity officials also couldn’t be reached for comment.

-—To reach the reporter responsible for this story please contact Dan Lonkevich at 707 318-7899 or