Fluzoparib is an oral potent, selective PARP-1 and PARP-2 inhibitor; Apatinib is an oral selective VEGFR inhibitor. This open-label, dose finding phase I trial studies the tolerability and the best dose of Fluzoparib in combination with apatinib and paclitaxel and to see how well this three drugs work together in the treatment of patients with recurrent and metastatic gastric cancer who progress following first-line therapy. The safety and efficacy of fluzoparib in combination with apatinib and paclitaxel will be explored.

Inclusion Criteria:

• ECOG performance status of 0 to 1.
• Life expectancy of more than 12 weeks.
• Histologically or cytologically confirmed gastric adenocarcinoma( adenocarcinoma of the gastroesophageal junction included).
• Recurrent or metastatic gastric cancer that has progressed following first line-therapy.
• At least one lesion (measurable and/or non-measurable) that can be accurately assessed by imaging (CT/MRI) at baseline
• Subjects who have overall good overall general condition.
• Signed informed consent.

Exclusion Criteria:

• Subjects who received any previous treatment with any PARP inhibitors.
• Subjects who received any previous treatment with any taxanes.
• More than one prior chemotherapy regimen for the treatment of gastric cancer in the metastatic or recurrent setting.
• Less than 4 weeks from the last clinical trial.
• Less than 2 weeks from the last radiotherapy, chemotherapy, surgery, hormone treatment and target therapy.
• Unstable hypertension.
• Subjects that are unable to swallow, or dysfunction of gastrointestinal absorption.
• Subjects with brain metastases.
• Subjects with uncontrolled hypokalemia and hypomagnesemia before study entry.
• Subjects with a known hypersensitivity to fluzoparib, apatinib, paclitaxel or any of the excipients of the product.
• Ongoing infection (determined by investigator).
• History of immunodeficiency, including HIV-positive, suffering from other acquired, congenital immunodeficiency disease, or history of organ transplantation.
• Subjects who can not interrupt the using of the drugs that may cause QT prolongation during study.
• Pregnant or breast-feeding women.