Multicenter Analysis of Genomically Targeted Single Patient Use Requests for Pediatric Neoplasms.

PURPOSE: The US Food and Drug Administration-expanded access program (EAP) uses a single patient use (SPU) mechanism to provide patient access to investigational agents in situations where no satisfactory or comparable therapy is available. Genomic profiling of de novo and relapsed or refractory childhood cancer has led to increased identification of new drug targets in the last decade. The aim of this study is to examine the SPU experience for genomically targeted therapies in patients with pediatric cancer. PATIENTS AND METHODS: All genomically targeted therapeutic SPUs obtained over a 5-year period were evaluated at four large pediatric cancer programs. Data were collected on the type of neoplasm, agents requested, corresponding molecularly informed targets, and clinical outcomes. RESULTS: A total of 45 SPUs in 44 patients were identified. Requests were predominantly made for CNS and solid tumors (84.4%) compared with hematologic malignancies (15.6%). Lack of an available clinical trial was the main reason for SPU initiation (64.4%). The median time from US Food and Drug Administration submission to approval was 3 days (range, 0-12 days) and from Institutional Review Board submission to approval was 5 days (range, 0-50 days). Objective tumor response was seen in 39.5% (15 of 38) of all evaluable SPUs. Disease progression was the primary reason for discontinuation of drug (66.7%) followed by toxicity (13.3%). CONCLUSION: SPU requests remain an important mechanism for pediatric access to genomically targeted agents given the limited availability of targeted clinical trials for children with high-risk neoplasms. Furthermore, this subset of SPUs resulted in a substantial number of objective tumor responses. The development of a multi-institutional data registry of SPUs may enable systematic review of toxicity and clinical outcomes and provide evidence-based access to new drugs in rare pediatric cancers.

CD244 represents a new therapeutic target in head and neck squamous cell carcinoma.

BACKGROUND: Developing novel strategies to overcome the immunosuppressive tumor microenvironment is a critically important area of cancer therapy research. Here, we assess the therapeutic potential of CD244 (2B4/signaling lymphocyte activation molecule family 4), an immunoregulatory receptor found on a variety of immune cells, including exhausted CD8+ T cells, dendritic cells (DCs), and myeloid-derived suppressor cells (MDSCs). METHODS: Using de-identified human tumor and blood samples from patients with head and neck squamous cell carcinoma (HNSCC) and HNSCC models in WT and CD244-/- mice, we assessed the therapeutic potential of CD244 using flow cytometry, RT-PCR, Luminex immunoassays and histopathological analyses. RESULTS: Compared with healthy tissues, tumor infiltrating CD8+ T cells from HNSCC patients and a HNSCC mouse model showed significant increased expression of CD244 expression that correlated with PD1 expression. Moreover, CD244 was increased on intratumoral DC and MDSC and high CD244 expression correlated with PD-L1 expression and increased spontaneous expression of immune-suppressive mediators. In addition, CD244 activation inhibited production of proinflammatory cytokines in human DC in vitro. Importantly, CD244-/- mice showed significantly impaired tumor growth of HNSCC and interventional treatment of WT mice with anti-CD244 monoclonal antibody significantly impaired the growth of established HNSCC tumors and increased tumor-infiltrating CD8+ T cells. CONCLUSIONS: Together these data suggest that CD244 contributes to the overall immune-suppressive environment and therefore has potential as a new immunotherapy target in the treatment of malignancies.

Malignant peripheral nerve sheath tumor: Transformation in a patient with neurofibromatosis type 2.

Malignant peripheral nerve sheath tumor (MPNST) is a rare soft-tissue sarcoma with an unfavorable prognosis and limited therapeutic options. MPNSTs can be sporadic, but are often associated with neurofibromatosis (NF) 1 and usually arise from preexisting neurofibromas. MPNSTs in patients with NF2 have been reported in only exceedingly rare cases, and the mechanisms underlying transformation into an MPNST have not been fully elucidated. Here, we describe the clinicopathological and genomic features of a peripheral nerve sheath tumor (PNST), with a primary diagnosis of a neurofibroma, as it transforms into a high-grade MPNST in the context of NF2.

The Emerging Role of CD244 Signaling in Immune Cells of the Tumor Microenvironment.

In cancer, immune exhaustion contributes to the immunosuppressive tumor microenvironment. Exhausted immune cells demonstrate poor effector function and sustained expression of certain immunomodulatory receptors, which can be therapeutically targeted. CD244 is a Signaling Lymphocyte Activation Molecule (SLAM) family immunoregulatory receptor found on many immune cell types-including NK cells, a subset of T cells, DCs, and MDSCs-that represents a potential therapeutic target. Here, we discuss the role of CD244 in tumor-mediated immune cell regulation.

Pazopanib therapy for desmoid tumors in adolescent and young adult patients.

BACKGROUND: Desmoid tumors/aggressive fibromatosis (DT/AF) lack a reliably effective medical therapy. Surgical resection may be morbid and does not preclude recurrence. Radiation may carry severe late effects, particularly detrimental in young patients. At our institution, we recently observed promising results with pazopanib therapy for DT/AF in adolescent and young adult (AYA) patients. PROCEDURE: Retrospective single-institution chart review. RESULTS: Six DT/AF patients of 3-21 years with previously treated DT/AF received pazopanib; 31 DT/AF patients received established therapies only. In both groups, median age at diagnosis was 16 years, female patients comprised 50%, and most common DT/AF site was extremity. Established therapies showed few objective responses and most patients therefore received multiple therapies. Surgical resection had a 68% recurrence rate. Of eight patients who received vinblastine/methotrexate, only one had a partial response (PR) by RECIST 1.1 and five had stable disease (SD); 62.5% required additional therapy. Of seven patients who received sulindac/tamoxifen, none showed objective improvement. In contrast, pazopanib demonstrated best responses by RECIST of PR in two of seven and SD in six of seven tumors. A PR of 66% was observed in a patient who had failed multiple prior therapies. The mesenteric DT/AF also showed PR. Maximum volumetric decrease by T2-weighted magnetic resonance imaging (MRI) was 97%. Dramatically increased fibrosis was seen on T2-weighted MRI. Patients reported pain relief and improvement in function within 1 month. Except for one case of edema, all other toxicities responded to dose reduction without sacrificing objective treatment response. CONCLUSION: Pazopanib provides a promising, well-tolerated therapy for DT/AF in the AYA population and warrants further study.

The TRPV1 receptor is associated with preferential stress in large dorsal root ganglion neurons in early diabetic sensory neuropathy.

Chronic diabetic neuropathy is associated with peripheral demyelination and degeneration of nerve fibers. The mechanism(s) underlying neuronal injury in diabetic sensory neuropathy remain poorly understood. Recently, we reported increased expression and function of transient receptor potential vanilloid 1 (TRPV1) in large dorsal root ganglion (DRG) neurons in diabetic sensory neuropathy. In this study, we examined the effects of TRPV1 activation on cell injury pathways in this subpopulation of neurons in the streptozotocin-induced diabetic rat model. Large DRG neurons from diabetic (6-8 weeks) rats displayed increased oxidative stress and activation of cell injury markers compared with healthy controls. Capsaicin (CAP) treatment induced decreased labeling of MitoTracker Red and increased cytosolic cytochrome c and activation of caspase 3 in large neurons isolated from diabetic rats. CAP treatment also induced oxidative stress in large diabetic DRG neurons, which was blocked by pre-treatment with caspase or calpain inhibitor. In addition, both mu-calpain expression and calpain activity were significantly increased in DRG neurons from diabetic rats after CAP treatment. Treatment with capsazepine, a competitive TRPV1 antagonist, markedly reduced these abnormalities in vitro and prevented activation of cell injury in large DRG neurons in diabetic rats in vivo. These results suggest that activation of the TRPV1 receptor activates pathways associated with caspase-dependent and calpain-dependent stress in large DRG neurons in STZ-diabetic rats. Activation of the TRPV1 receptor may contribute to preferential neuronal stress in large DRG neurons relatively early in diabetic sensory neuropathy.