JMP Securities analyst Jason Butler says Arena Pharmaceuticals' (ARNA) amended agreement with Eisai (ESALY) reduces resource and capital constraints on the company while maintaining "attractive" long-term upside from Belviq success. The analyst notes that Eisai will now have full global development and marketing rights to Belviq in exchange for lowering Arena's royalties and cost contributions, which he views "favorably" as the commercial potential for it remains limited. Furthermore, the new agreement allows Arena to further focus its energies and resources in its Phase 2 pipeline assets, Butler adds. He reiterates a Market Perform on Arena Pharmaceuticals' shares.