Transfusable neutrophil progenitors as cellular therapy for the prevention of invasive fungal infections.

The use of mature neutrophil (granulocyte) transfusions for the treatment of neutropenic patients with invasive fungal infections (IFIs) has been the focus of multiple clinical trials. Despite these efforts, the transfusion of mature neutrophils has resulted in limited clinical benefit, likely owing to problems of insufficient numbers and the very short lifespan of these donor cells. In this report, we employed a system of conditionally immortalized murine neutrophil progenitors that are capable of continuous expansion, allowing for the generation of unlimited numbers of homogenous granulocyte-macrophage progenitors (GMPs). These GMPs were assayed in vivo to demonstrate their effect on survival in 2 models of IFI: candidemia and pulmonary aspergillosis. Mature neutrophils derived from GMPs executed all cardinal functions of neutrophils. Transfused GMPs homed to the bone marrow and spleen, where they completed normal differentiation to mature neutrophils. These neutrophils were capable of homing and extravasation in response to inflammatory stimuli using a sterile peritoneal challenge model. Furthermore, conditionally immortalized GMP transfusions significantly improved survival in models of candidemia and pulmonary aspergillosis. These data confirm the therapeutic benefit of prophylactic GMP transfusions in the setting of neutropenia and encourage development of progenitor cellular therapies for the management of fungal disease in high-risk patients.

Carfilzomib in Combination With Bendamustine and Rituximab in Patients With Relapsed or Refractory Non-Hodgkin Lymphoma: A Phase I Trial.

INTRODUCTION: We designed a multicenter, phase Ib dose-escalation trial of carfilzomib with bendamustine and rituximab in patients with relapsed/refractory non-Hodgkin lymphoma (NCT02187133) in order to improve the response rates of this difficult-to-treat population. Chemoimmunotherapy with bendamustine and rituximab has shown activity in a variety of lymphomas, and proteasome inhibitors have demonstrated pre-clinical synergy and early clinical activity in this population. The objectives were to determine the maximum tolerated dose of carfilzomib and the preliminary efficacy of this combination. PATIENTS AND METHODS: The protocol followed a 3+3 design of carfilzomib dose escalation combined with standard doses of bendamustine and rituximab. Patients were treated for up to 6 cycles with an interim positron emission tomography/computed tomography after cycle 3. RESULTS: Ten patients were treated on the dose-escalation phase. The study was terminated at a carfilzomib dose of 56 mg/m2, and the maximum tolerated dose was not reached. The most common grade 3/4 adverse event was thrombocytopenia. There was 1 dose-limiting toxicity observed, grade 3 febrile neutropenia, and there were no treatment-related deaths. The overall response rate was 40% (complete response rate, 30%), with a median duration of response of 12 months and a median progression-free survival of 2.1 months. CONCLUSION: Carfilzomib in combination with bendamustine and rituximab is a safe and well-tolerated treatment for patients with relapsed/refractory non-Hodgkin lymphoma. Preliminary data indicate that this combination may have efficacy with an acceptable side effect profile in this heavily pre-treated patient population with limited treatment options.