Gastric and gastroesophageal junction (GEJ) adenocarcinoma is characterized by poor prognosis. Japan has the highest incidence of gastric and GEJ adenocarcinoma among the markets under study, making that country a commercially attractive and lucrative market for gastric cancer treatment. The disease’s rapid progression, most patients’ poor performance status, and the large number of elderly patients result in lower treatment rates than those of other cancer indications. Therapeutic options for gastric and GEJ adenocarcinoma are limited, with only two targeted agents approved. In the HER2-positive patient segment, Herceptin (Roche/Genentech/Chugai’s trastuzumab) is commonly prescribed, particularly in earlier-line settings. The 2014 approval of the angiogenesis inhibitor, Cyramza (Eli Lilly’s ramucirumab), partially fulfills the need for an effective second-line treatment, particularly for patients who are HER2-negative. However, the gastric and GEJ adenocarcinoma market as a whole is largely untapped, and thus, there is a lucrative opportunity in this disease market. The gastric and GEJ adenocarcinoma late-stage pipeline is buoyant; the eagerly anticipated emergence of multiple therapies belonging to a wide variety of drug classes is expected to diversify treatment options in all population segments during our forecast period.Questions Answered: We forecast that the gastric and GEJ adenocarcinoma therapy markets will grow considerably during the 2015-2025 forecast period. What are the key drivers of gastric and GEJ adenocarcinoma market growth? What will be the major constraints on growth of the gastric and GEJ adenocarcinoma market? What are the drug development activities of note? What challenges and opportunities remain? Four immune checkpoint inhibitors, Opdivo (BMS/Ono Pharmaceutical’s nivolumab), Keytruda (Merck & Co.’s pembrolizumab), avelumab (Merck KGaA/Pfizer), and ipilimumab (BMS/Ono Pharmaceutical’s Yervoy), entered Phase III clinical development for the treatment of gastric and GEJ adenocarcinoma between 2014 and 2016. What is thought-leader opinion of these agents and of this drug class? In which patient populations will these agents be positioned? How will their use change over the next ten years? How will use of these agents affect prescribing of other agents in the gastric and GEJ adenocarcinoma market? The second-generation HER2-targeting agent Perjeta (Genentech/Roche/Chugai’s pertuzumab) is expected to enter the gastric and GEJ adenocarcinoma market in the first-half of the forecast period, for the first-line treatment of HER2-positive disease, in combination with Herceptin and chemotherapy. What are thought-leaders opinion of Perjeta? How will Perjeta use change over the next ten years? How will the dynamics in managing HER2-positive gastric and GEJ adenocarcinoma change over the forecast period? In 2014, Cyramza (Eli Lilly’s ramucirumab) was approved for second- and later-line treatment of advanced gastric and GEJ adenocarcinoma. This agent is also in development as a first-line therapy for HER2-negative patients. How do key opinion leaders perceive this agent? What impact will Cyramza have on the market during the 2015-2025 forecast period? Where will Cyramza show the strongest uptake? Two first-in-class agents—a cancer stemness inhibitor (Boston Biomedical’s napabucasin) and a MMP-9 inhibitor (Gilead Sciences’ GS-5745)—and the cytotoxic agent Lonsurf (Taiho Pharmaceutical’s tipiracil/trifluridine) are in Phase III clinical development for the treatment of metastatic gastric and GEJ adenocarcinoma. What are thought-leader opinion of these agents? If these agents are approved, in which patient populations will these therapies be positioned? How will their use change over the forecast period and how will this affect the dynamics of each patient population?Scope:Markets covered: United States, France, Germany, Italy, Spain, United Kingdom, Japan.Primary research: 21 country-specific interviews with thought leaders.Epidemiology: diagnosed incident cases of gastric and GEJ adenocarcinoma—with AJCC stage IA, IB, II, IIIA-B, IIIC, and IV.Population segments in market forecast: resectable (stage I-IIIB); unresectable locally advanced, HER2-negative; unresectable locally advanced, HER2-positive; first-line metastatic, HER2-negative; first-line metastatic, HER2-positive; second-line metastatic, HER2-negative; second-line metastatic, HER2-positive; third- and fourth-line metastatic, HER2-negative; and third- and fourth-line metastatic, HER2-positive.Emerging therapies: Phase III: 9 drugs; Phase II: 16 drugs. Coverage of 9 select preclinical and Phase I products.