Purpose: Expansion and activation of natural killer (NK) cells with interleukin-2 (IL-2) may enhance antibodydependent cellular cytotoxicity (ADCC), an important mechanism of rituximab activity. Two parallel Phase I studies evaluated combination therapy with rituximab and IL-2 in relapsed or refractory B-cell non-Hodgkin's lymphoma (NHL).Experimental Design: Thirty-four patients with advanced NHL received rituximab (375 mg/m 2 i.v. weekly, weeks 1-4) and escalating doses of s.c. IL-2 [2-7.5 MIU daily (n ‫؍‬ 19) or 4.5-14 million international units three times weekly (n ‫؍‬ 15), weeks 2-5]. Safety, tolerability, clinical responses, NK cell counts, and ADCC activity were evaluated.Results: Maximally tolerated doses (MTD) of IL-2 were 6 MIU daily and 14 million international units thrice weekly. The most common adverse events were fever, chills, and injection site reactions. Dose-limiting toxicities were fatigue and reversible liver enzyme test elevations. Of the 9 patients enrolled at the daily schedule MTD, 5 showed clinical response. On the thrice-weekly schedule at the MTD, 4 of 5 patients responded. Responders showed median time to progression of 14.9 and 16.1 months, respectively, for the two studies. For the same total weekly dose, thrice-weekly IL-2 administration induced greater increases in NK cell counts than daily dosing, and NK cells correlated with clinical response on the thrice-weekly regimen. ADCC activity was increased and maintained after IL-2 therapy in responding and stable disease patients.Conclusions: Addition of IL-2 to rituximab therapy is safe and, using thrice-weekly IL-2 dosing, results in NK cell expansion that correlates with response. This combination treatment regimen merits additional evaluation in a randomized clinical trial.

Objectives Cytokine release syndrome (CRS) is a potentially severe complication of COVID-19 most commonly resulting in respiratory failure. This ten-patient study was designed to determine the efficacy of therapeutic plasma exchange (TPE) in improving oxygenation and in reducing the cytokine load in a critically ill subset of patients. Methods Five single volume plasma exchanges over eight days within a 14-day study period. In mechanically ventilated patients, oxygenation was measured via the PaO2/FiO2 (P/F) ratio and the oxygenation index (OI) daily for 14 days. Supplemental oxygen requirements were tracked daily for non-ventilated patients. Results Non-ventilated patients were liberated from supplemental oxygen after TPE. The response was rapid with an 87% average reduction in oxygenation requirements following and average time to return to room air of 5.25 days. All mechanically ventilated patients demonstrated improvement in oxygenation with a 78% average improvement in the P/F ratio and a 43% improvement in OI. C-reactive protein (CRP) and serum levels of IL-6, IL-8, IL-10, TNFα, IFNγ and GM-CSF, were measured daily with immediate post TPE levels drawn on days 1, 2, 4, 6 and 8. All patients demonstrated significant reductions in CRP, IL-6, IL-10 and TNFα. Conclusions In the majority of patients with Penn class 3 and 4 CRS complicating COVID-19, TPE demonstrated a prompt improvement in oxygenation and reduction in cytokine load without compromising patient safety. As this pilot study was envisioned to be hypothesis generating, expanded trials using TPE alone and in conjunction with novel pharmacologic agents are warranted. Registration ClinicalTrials.gov NCT04374149 .

Background This open-label, first-inhuman , phase 1 study evaluated AMG 232, an oral selective MDM2 inhibitor in patients with TP53 wild-type (P53WT), advanced solid tumors or multiple myeloma (MM). Methods In the dose escalation (n = 39), patients with P53WT refractory solid tumors enrolled to receive once-daily AMG 232 (15, 30, 60, 120, 240, 480, and 960 mg) for seven days every 3 weeks (Q3W). In the dose expansion (n = 68), patients with MDM2-amplified (well-differentiated and dedifferentiated liposarcomas [WDLPS and DDLPS], glioblastoma multiforme [GBM], or other solid tumors [OST]), MDM2overexpressing ER+ breast cancer (BC), or MM received AMG 232 at the maximum tolerated dose (MTD). Safety, pharmacokinetics, pharmacodynamics, and efficacy were assessed. Results AMG 232 had acceptable safety up to up to 240 mg. Three patients had dose-limiting toxicities of thrombocytopenia (n = 2) and neutropenia (n = 1). Due to these and other delayed cytopenias, AMG 232 240 mg Q3W was determined as the highest tolerable dose assessed in the dose expansion. Adverse events were typically mild/moderate and included diarrhea, nausea, vomiting, fatigue, decreased appetite, and anemia. AMG 232 plasma concentrations increased dose proportionally. Increases in serum macrophage inhibitor cytokine-1 from baseline were generally dose dependent, indicating p53 pathway activation. Per local review, there were no responses. Stable disease (durability in months) was observed in patients with WDLPS (3.9), OST (3.3), DDLPS (2.0), GBM (1.8), and BC (1.4-2.0). Conclusions In patients with P53WT advanced solid tumors or MM, AMG 232 showed acceptable safety and dose-proportional pharmacokinetics, and stable disease was observed.

A 57-year-old woman presented with L3 acute lymphoblastic leukemia demonstrating typical Burkitt's type morphology. Cytogenetic analysis revealed one of the variant translocations seen in Burkitt's lymphoma [t(8;22)] and a 14;18 translocation. Surface marker data at presentation and at autopsy demonstrated several B-cell markers, but absent surface immunoglobulins. The case presented here reveals a possible cytogenetic link between Burkitt's lymphoma and follicular center-cell lymphoma, and illustrates a variant surface marker profile for Burkitt's lymphoma.

278 Background: Tarextumab (TRXT), fully human IgG2 antibody, inhibits signaling Notch 2, 3 receptors. Tumor regression seen in Notch 3 patient-derived PC xenografts when TRXT added to Nab-P+Gem. The maximum tolerated dose (MTD) of single agent TRXT was 7.5mg/kg every other week (Smith, EORTC 2012); the main dose limiting toxicity (DLT) was Grade 3 diarrhea. This study evaluates MTD, pharmacokinetics (PK), pharmacodynamics (PD) and early efficacy of TRXT + Nab-P+Gem in mPC. Methods: Cohorts of 3-6 pts treated at 6 dose levels of TRXT. TRXT IV Days 1 + 15 with GEM 1000mg/m2 alone (first two cohorts) or nab-P 125 mg/m2 and GEM 1000mg/m2on Days 1, 8, 15 of every 28-day cycle. Biomarker analysis of surrogate tissue and tumor undertaken. Results: By 08/22/14, N= 40 treated. TRXT 15 mg/kg selected as Phase 2 dose. 1 DLT Grade 3 diarrhea in 15 mg/kg cohort. Frequently reported (≥15%) TRXT adverse events(AEs) were: diarrhea(60%), fatigue(43%), anemia(28%), decreased appetite (18%) and nausea(15%); most grade 1 or 2 and managed supportively. Other AEs (≥ 30%) were: cytopenia, alopecia, vomitng and peripheral edema. GEM or Nab-P+Gem did not alter PK of TRXT. Notch pathway-related genes, HEYL, HES2, NOTCH2 and cancer stem cell markers were altered in hair follicles at TRXT > 7.5 mg/kg combined with Nab-P+Gem. Plasma, blood RNA biomarkers were also modulated by TRXT + Nab-P+Gem. Conclusions: TRXT + Nab-P+ Gem is well tolerated. 15 mg/kg is the selected Phase 2 dose of TRXT. Encouraging anti-tumor activity was observed. Final safety, efficacy, PK and PD results in surrogate and serial tumor tissues will be presented. The Phase 2 randomized, placebo-controlled ALPINE study is underway. Clinical trial information: NCT01647828. [Table: see text]