CytRx completes patient enrollment in tamibarotene Phase 2b study

Oral retinoid compound tamibarotene, which was designed to be superior to all trans-retinoic acid (ATRA) by binding to the molecular target more selectively, proved to be 10 times more potent than ATRA with milder side effects during the preclinical studies.

The Phase 2b study has enrolled 140 patients with stage IIIB or IV squamous or adenocarcinoma NSCLC who had not received prior non-adjuvant chemotherapy and randomized them to receive treatment with either paclitaxel plus carboplatin, with half receiving tamibarotene and half receiving placebo for up to six cycles.

Primary endpoint of the study is progression-free survival, while secondary endpoints include response rate, overall survival and RAR beta expression, a potential biomarker for responders.

The NSCLC treatment indication for the drug was based on the results from a single-center Phase 2 clinical trial, which showed that all trans-retinoic acid (ATRA) when added to a regimen of paclitaxel plus cisplatin produced superior results in late-stage NSCLC patients than a regimen of paclitaxel plus cisplatin alone, claims CytRx.

CytRx executive vice president and chief medical officer Daniel Levitt said, "In fact, response rates for patients receiving ATRA in this trial increased two-fold, progression-free survival increased by three months and median overall survival increased 14 months. Those results were published in the July 2010 issue of the peer-reviewed Journal of Clinical Oncology."

Holding North American and European rights to certain tamibarotene intellectual property for the treatment of NSCLC, the company is expecting to present Phase 2b study results in the second half of 2013.

Tamibarotene is currently being marketed in Japan for a rare form of leukemia.