Study of APG-1252 Plus Paclitaxel in Patients With Relapsed/Refractory Small Cell Lung Cancer

Upon enrollment, patients will undergo a comprehensive history and physical exam, along with baseline laboratory assessment. Baseline CT imaging will be required within 4 weeks prior to study entry. Archival tissue is mandatory; a fresh biopsy of the primary tumor or a metastatic lesion prior to initiation of therapy is optional and post-treatment tumor biopsy is strongly encouraged. In the phase Ib portion, eligible patients will receive APG-1252 at the assigned dose-level on days 1, 8 and 15 plus a fixed-dose of paclitaxel 80 mg/m˄2 on days 1 and 8 of a 21-day cycle. There will be three dose-levels of APG-1252 (-1, 80 mg; 1, 160 mg; 2, 240 mg) with the first patient starting at dose-level 1 and subsequent patients at dose-levels determined by the TITE-CRM methodology. There will be no intra-patient dose-escalation. Patients will be continuously assessed for adverse events, including DLTs which are defined in the protocol. Response assessment by CT imaging will occur every 2 cycles and treatment will continue until progression of disease, unacceptable toxicity, patient preference to stop treatment, withdrawal of consent, or administrative discontinuation. In the phase II portion, eligible patients will receive APG-1252 at the RP2D determined in the phase Ib portion on days 1, 8 and 15 plus paclitaxel 80 mg/m˄2 on days 1 and 8 of a 21-day cycle. Response assessment by CT imaging will occur every 2 cycles and treatment will continue until progression of disease, unacceptable toxicity, patient preference to stop treatment, withdrawal of consent, or administrative discontinuation.