OPAXIO^™ in Lung Cancer

Studies in Women with Lung Cancer

Lung cancer is the leading cause of cancer death worldwide. Among females, the incidence of lung cancer continues to rise, killing more women than breast, ovarian, and cervical cancers combined.

Recent in vivo studies indicate that OPAXIO (formerly known as XYOTAX) metabolism by some cancer cells is enhanced in the presence of estrogen, which leads to increased levels of paclitaxel in tumor tissue and greater anti-tumor effects.

The efficacy of OPAXIO as a first-line treatment in advanced non-small cell lung cancer (NSCLC) was evaluated in our STELLAR 3 and 4 trials. The composite analysis showed a statistically significant survival benefit for women receiving OPAXIO (198 patients) compared to the control arms, where men treated with OPAXIO did similarly to men treated with comparator agents.

The largest improvement in survival with OPAXIO was seen in women under age 55 and in women with premenopausal estrogen levels, regardless of age (51 patients). Estrogen has an adverse effect on prognosis in advanced NSCLC. Studies show that premenopausal women and women receiving hormone replacement therapy have a poor outcome compared to postmenopausal women. Retrospective analysis of clinical data from STELLAR 3 and STELLAR 4 suggest that OPAXIO’s anti-tumor activity may be modulated by estrogen levels.

Clinical Trials for Women with NSCLC

We believe the lack of safe and effective treatment for women with advanced first-line NSCLC who have premenopausal estrogen levels represents an unmet medical need.

A phase III clinical trial, known as PGT307, is currently recruiting women in the United States with advanced NSCLC who have premenopausal estrogen levels (> 25pg/mL). Survival of this group is significantly shorter than postmenopausal women. We received Special Protocol Assessment (SPA) approval from the FDA on the design of the trial.

The PGT307 phase III trial is expected to enroll 450 patients. Each study arm of approximately 225 patients will be randomized to receive either OPAXIO plus carboplatin or paclitaxel plus carboplatin once every three weeks. Patients will be treated for up to six cycles. The primary endpoint is superior overall survival with several secondary endpoints, including progression-free survival, disease control, clinical benefit, response rate, quality of life, and the safety and tolerability of the treatment arms.