This Phase l/ll clinical trial employs the unique, new, anti-CD22 monoclonal antibody (mAb), humanized- HB22.7 (hHB22.7). The development of hHB22.7 was supported by the NCI's RAID program because of the antibody's ability to target a specific epitope on CD22 that leads to apoptosis in non-Hodgkin's lymphoma (NHL) cells. HHB22.7 has great potential to become a new therapy for patients with NHL. Our approach to developing anti-NHL mAbs is to examine therapeutic targets by focusing on fundamental aspects of the signaling pathways activated by engagement of lineage-specific cell surface receptors. The rationale is that identifying the ultimate physiologic consequences of receptor engagement sets the stage for receptor manipulation and development of novel, effective drugs. The excellent pre-clinical results using mHB22.7 motivated us to proceed with a clinical trial of hHB22.7. Humanized HB22.7 will allow recruitment of immune functions such as antibody and complement dependent cytotoxicity. After targeting its distinct CD22 epitope, hHB22.7 will stimulate apoptotic pathways making it a multifunctional agent against NHL. The safety, toxicity, and pharmacokinetics of 125, 250, 500 or 1000 mg/m2 of the hHB22.7 anti-CD22 mAb will be evaluated in cohorts of follicular NHL patients. Patients will receive 4 doses of hHB22.7. This study will generate the first clinical data for hHB22.7. Initial efficacy data for immunotherapy with hHB22.7 will be obtained and the dose of hHB22.7 to use in future studies will be determined. This Phase l/ll clinical study will pave the way for future clinical studies and development of hHB22.7. Lay Language Statement: Lymphoma is the sixth most common cause of cancer-related death in the United States, and one of the few malignancies that is increasing in frequency. New therapies are needed to combat this disease. HHB22.7 is an antibody that can specifically target lymphoma. We have shown that hHB22.7 can kill lymphoma cells in studies using mice, and have determined how hHB22.7 works. Antibody therapy has the potential for efficacy without much toxicity because the antibody specifically targets lymphoma. This clinical study is designed to see if hHB22.7 is safe, and promising enough to proceed to additional clinical trials. [unreadable] [unreadable] [unreadable]