SDX-105 Demonstrates a High Response Rate as a Single-Agent with Acceptable Safety in Rituximab-Refractory, Relpased Indolent or Transformed Non-Hodgkin’s Lymphoma (NHL).

SDX-105 (Treanda™, Bendamustine HCl) is an alkylating agent that may exert its anti-tumor activity via mitotic catastrophe, an apoptosis-independent cell-death pathway, as well as, through apoptosis. Its cytotoxic potency is unattenuated in chemotherapy-resistant lymphoma cell lines. We initiated a multi-center Phase II trial to investigate the safety and efficacy of SDX-105 in patients with rituximab-refractory, relapsed indolent or transformed B cell NHL. Patients must have pathologically-confirmed disease that has been demonstrated to be rituximab-refractory (no response or progression within 6 months) or must be intolerant of rituximab. Other requirements include measurable disease, adequate renal, hepatic and bone marrow function (ANC ≥1K/mm³, platelet ≥ 100K/mm³, except in cases of >50% NHL in bone marrow), up to 3 prior chemotherapies, and no prior allogeneic transplant. Patients receive SDX-105, 120 mg/m² IV over 30–60 min, days 1 and 2, every 21 days. Grade 4 hematologic toxicity during a cycle results in dose reduction for subsequent cycles (to 90 mg/m² and then to 60 mg/m²). Patients achieving stable disease or better after 6 cycles may receive up to 6 more cycles. 49 patients have been accrued to date with data available on the first 15 patients. The median age is 69 yrs (range 47–84), 47% male, median 6 yrs since diagnosis with NHL. Histologies: 10 follicular (6 Grade 1, 3 Grade 2, 1 Grade 3), 2 SLL, 1 marginal zone and 2 transformed NHL. Other features include: 93% Stage III/IV, 20% with B symptoms, 87% with extranodal disease, median 2 prior chemotherapies with 40% not responding to last chemotherapy. 4 patients have required dose reduction to 90 mg/m² and 2 patients have withdrawn prior to completing 6 cycles due to treatment-associated toxicity. The current overall response rate (ORR) based upon best response in the intent-to-treat population is 80% (CR/CRu 20%, PR 60%). Overall 73% of patients experienced a related non-hematologic adverse event (AE), of which 20% were Grade 3 and 0% Grade 4. The most frequent AEs were nausea (40%), vomiting (27%), fatigue (33%), anorexia (20%), and constipation (20%). Alopecia was not observed. Grade 3 or 4 hematologic toxicity was seen in 53% (neutropenia), 20% (thrombocytopenia), and 13% (anemia) of patients. 4 patients experienced serious AEs, including 1 patient with baseline renal insufficiency who died on study from renal failure and pulmonary edema; other events include admissions for fever and anemia, urinary tract infection, and dehydration. Based upon these preliminary findings, SDX-105 demonstrates a high overall response rate with acceptable hematologic toxicity and modest non-hematologic toxicity in a relapsed lymphoma patient population, many of whom are refractory to rituximab-chemotherapy combinations. An additional study evaluating the combination of SDX-105 and rituximab in patients with relapsed indolent NHL who are rituximab-sensitive is also ongoing.