Biopharmaceutical research and development company CytRx has completed patient enrolment in a Phase IIb clinical study of its oral retinoid compound, tamibarotene in combination with chemotherapeutic agents, as a first-line treatment for patients with advanced non-small-cell lung cancer (NSCLC).
CytRx decided to pursue the NSCLC treatment indication based on the results from a single-centre Phase II 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.
CytRx executive vice president and chief medical officer Dr 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."
Tamibarotene was designed to be superior to ATRA, an approved retinoid, by binding to the molecular target more selectively, according to the company.
During the company's preclinical studies, tamibarotene proved to be 10 times more potent than ATRA, with milder side effects.
The Phase IIb study has enrolled 140 patients with stage IIIB or IV squamous or adenocarcinoma NSCLC who had not received prior non-adjuvant chemotherapy from the US, Bulgaria, India, Mexico, Russia and Ukraine.
Patients will be randomised to receive treatment with paclitaxel plus carboplatin, with half receiving tamibarotene and half receiving placebo for up to six cycles.
Progression-free survival is the primary endpoint of the study, while response rate, overall survival and RAR beta expression, a potential biomarker for responders, form part of secondary endpoints.
The company, which holds the North American and European rights to certain tamibarotene intellectual property for the treatment of NSCLC, is expecting to present Phase IIb study results in the second half of 2013.
Tamibarotene is currently being commercialised in Japan for a rare form of leukemia.
Image: Micrograph of a squamous carcinoma, a type of non-small-cell lung carcinoma. Photo: Courtesy of Nephron.