CpG-STAT3 siRNA CAS3/SS3 and Localized Radiation Therapy for the Treatment of Relapsed/Refractory B-Cell NHL

PRIMARY OBJECTIVES: I. Determine the recommended phase 2 dose (RP2D) of CAS3/SS3 when given in combination with local fixed-dose radiation therapy (RT). II. Evaluate the safety and feasibility of intratumoral injections of CAS3/SS3 when combined with local fixed-dose RT, by evaluation of toxicities including: type, frequency, severity, attribution, time course and duration. SECONDARY OBJECTIVES: I. Characterize the clinical activity (overall and per dose level) of CAS3/SS3 through the assessment of disease response, and response duration. (Clinical) II. Characterize the biologic activity (overall and per dose level) of CAS3/SS3 when combined with local fixed-dose RT by assessing. (Biologic \[Immunologic Correlative Studies\]) IIa. Silencing of the STAT3 gene and its key downstream genes. IIb. Local and systemic immune responses, including: evidence/extent of immune cell intratumoral infiltration, immune cell activation within the tumor and in the peripheral blood, and changes in proinflammatory mediators in plasma. OUTLINE: Patients undergo radiation therapy on days 1 and 2 tumor-bearing lymph node, and receive CAS3/SS3 intratumorally on days 2, 4, 16, and 18. Patients assigned to dose level 3 also receive CAS3/SS3 intratumorally on days 9, 11, 23, and 25. After completion of study treatment, patients are followed up every 3 months.