poziotinib and Stomach-Neoplasms

Poziotinib (HM781-36B) is an irreversible pan-HER tyrosine kinase inhibitor which targets EGFR, HER2, and HER4. This prospective, multicenter, open-label, phase I/II study determined the maximum tolerated dose (MTD) and evaluated the safety and efficacy of poziotinib combined with paclitaxel and trastuzumab in patients with HER2-positive advanced gastric cancer (GC).. In the phase I part, 12 patients were enrolled (7 at dose level 1, 5 at dose level 2). One patient receiving poziotinib 8 mg and 2 receiving poziotinib 12 mg had dose-limiting toxicities (DLTs); all DLTs were grade 4 neutropenia, one with fever. The most common poziotinib-related adverse events were diarrhea, rash, stomatitis, pruritus and loss of appetite. The MTD of poziotinib was determined to be 8 mg/day and this was used in the phase II part which enrolled 32 patients. Two patients (6.3%) had complete responses and 5 (15.6%) had partial responses (objective response rate 21.9%). Median progression-free survival and overall survival were 13.0 weeks (95% CI 9.8-21.9) and 29.5 weeks (95% CI 17.9-59.2), respectively.. The MTD of poziotinib combined with paclitaxel and trastuzumab was 8 mg/day. This combination yielded promising anti-tumor efficacy with manageable toxicity in previously treated patients with HER2-positive GC.

Topics: Adult; Aged; Antineoplastic Combined Chemotherapy Protocols; Disease-Free Survival; Dose-Response Relationship, Drug; Female; Humans; Male; Maximum Tolerated Dose; Middle Aged; Paclitaxel; Prospective Studies; Quinazolines; Receptor, ErbB-2; Stomach Neoplasms; Survival Rate; Trastuzumab

Trastuzumab, a HER2 directed treatment has shown clinical benefit in HER2 amplified gastric cancer. This study demonstrated the potent antitumor activity of HM781-36B, a quinazoline-based irreversible pan-HER inhibitor, in HER2 amplified gastric cancer cells (SNU216 and N87) in vitro and in vivo. HM781-36B inhibited phosphorylation of HER family and downstream signaling molecules, and induced apoptosis and G1 arrest. Furthermore, HM781-36B exerted synergistic effects with chemotherapeutic agents in both HER2 amplified and HER2 non-amplified gastric cancer cells. Therefore, HM781-36B may be useful for the treatment of HER2 amplified gastric cancer alone or in combination with chemotherapeutic agents.

Topics: Animals; Antineoplastic Agents; Apoptosis; Cell Cycle; Cell Line, Tumor; Cisplatin; Drug Synergism; ErbB Receptors; Female; Gene Expression Regulation, Neoplastic; Humans; Inhibitory Concentration 50; Mice; Phosphorylation; Quinazolines; Receptor, ErbB-2; Stomach Neoplasms