The US Patent and Trademark Office (USPTO) has issued a notice of allowance for a patent application with claims covering a pharmaceutical composition of tamibarotene in capsule form to CytRx Corporation, a biopharmaceutical company specializing in oncology.

Tamibarotene is an orally available, rationally designed, synthetic retinoid compound that was designed to be more potent than the chemotherapeutic agent all-trans retinoic acid (ATRA), while avoiding several of ATRA’s toxic side effects by selectively binding to specific molecular receptors. The US patent issuing from this application on the tamibarotene capsule formulation will have a term that expires in 2028.

CytRx is currently conducting a phase II b global clinical trial with tamibarotene as a first-line treatment for non-small-cell lung cancer (NSCLC) and a phase II clinical trial with tamibarotene as a treatment for acute promyelocytic leukaemia (APL). CytRx holds the North American and European rights to certain tamibarotene intellectual property for the treatment of NSCLC and APL, and retains an option to expand its licenses for the use of tamibarotene in other fields in oncology.

“We are highly optimistic about tamibarotene’s prospects for improving the treatment of certain cancers, and strengthening the intellectual property position for this oncology asset is clearly in our best interest,” said CytRx CEO Steven A Kriegsman. “Last month we announced a major milestone in our late-stage clinical trial with tamibarotene in NSCLC. An approval to market tamibarotene for this indication alone could represent a blockbuster opportunity for CytRx.”

In late June the Data Safety Monitoring Board recommended moving forward with CytRx’s phase II b clinical trial with tamibarotene as a first-line treatment for NSCLC. This recommendation indicated that no significant safety issues had been seen at that time with tamibarotene even in trial patients with advanced disease. CytRx expects to report clinical data from the phase II b trial in 2013.