Veerabhadran Baladandayuthapani

Safety and Activity of PD1 Blockade by Pidilizumab in Combination with Rituximab in Patients with Relapsed Follicular Lymphoma: a Single Group, Open-label, Phase 2 Trial

BACKGROUND Endogenous or iatrogenic antitumour immune responses can improve the course of follicular lymphoma, but might be diminished by immune checkpoints in the tumour microenvironment. These checkpoints might include effects of programmed cell death 1 (PD1), a co-inhibitory receptor that impairs T-cell function and is highly expressed on intratumoral T cells. We did this phase 2 trial to investigate the activity of pidilizumab, a humanised anti-PD1 monoclonal antibody, with rituximab in patients with relapsed follicular lymphoma. METHODS We did this open-label, non-randomised trial at the University of Texas MD Anderson Cancer Center (Houston, TX, USA). Adult (≥18 years) patients with rituximab-sensitive follicular lymphoma relapsing after one to four previous therapies were eligible. Pidilizumab was administered at 3 mg/kg intravenously every 4 weeks for four infusions, plus eight optional infusions every 4 weeks for patients with stable disease or better. Starting 17 days after the first infusion of pidilizumab, rituximab was given at 375 mg/m(2) intravenously weekly for 4 weeks. The primary endpoint was the proportion of patients who achieved an objective response (complete response plus partial response according to Revised Response Criteria for Malignant Lymphoma). Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00904722. FINDINGS We enrolled 32 patients between Jan 13, 2010, and Jan 20, 2012. Median follow-up was 15.4 months (IQR 10.1-21.0). The combination of pidilizumab and rituximab was well tolerated, with no autoimmune or treatment-related adverse events of grade 3 or 4. The most common adverse events of grade 1 were anaemia (14 patients) and fatigue (13 patients), and the most common adverse event of grade 2 was respiratory infection (five patients). Of the 29 patients evaluable for activity, 19 (66%) achieved an objective response: complete responses were noted in 15 (52%) patients and partial responses in four (14%). INTERPRETATION The combination of pidilizumab plus rituximab is well tolerated and active in patients with relapsed follicular lymphoma. Our results suggest that immune checkpoint blockade is worthy of further study in follicular lymphoma. FUNDING National Institutes of Health, Leukemia and Lymphoma Society, Cure Tech, and University of Texas MD Anderson Cancer Center.

Safety and activity of lenalidomide and rituximab in untreated indolent lymphoma: an open-label, phase 2 trial

BACKGROUND Standard treatments for indolent non-Hodgkin lymphomas are often toxic, and most patients ultimately relapse. Lenalidomide, an immunomodulatory agent, is effective as monotherapy for relapsed indolent non-Hodgkin lymphoma. We assessed the efficacy and safety of lenalidomide plus rituximab in patients with untreated, advanced stage indolent non-Hodgkin lymphoma. METHODS In this phase 2 trial, undertaken at one instution, patients with follicular lymphoma and marginal zone lymphoma were given lenalidomide, orally, at 20 mg/day on days 1-21 of each 28-day cycle. For patients with small lymphocytic lymphoma, dosing began at 10 mg/day to avoid tumour flare, with an escalation of 5 mg/month to 20 mg/day. Rituximab was given at 375 mg/m(2) as an intravenous infusion on day 1 of each cycle. Patients responding after six cycles could continue therapy for up to 12 cycles. The primary endpoint was overall response, defined as the proportion of patients who achieved a partial or complete response; patients were assessed for response if they had any post-baseline tumour assessment. This trial is registered with ClinicalTrials.gov, number NCT00695786. FINDINGS 110 patients with follicular lymphoma (n=50), marginal zone lymphoma (n=30), and small lymphocytic lymphoma (n=30) were enrolled from June 30, 2008, until Aug 12, 2011. 93 of 103 evaluable patients had an overall response (90%, 95% CI 83-95). Complete responses occurred in 65 (63%, 95% CI 53-72) and partial responses in 28 patients (27%, 19-37). Of 46 evaluable patients with follicular lymphoma, 40 (87%) patients had a complete response and five (11%) had a partial response. Of 27 evaluable patients with marginal zone lymphoma, 18 (67%) had a complete response and six (22%) had a partial response. Of 30 evaluable patients with small lymphocytic lymphoma, seven (23%) had a complete response and 17 (57%) had a partial response. The most common grade 3 or 4 adverse events were neutropenia (38 [35%] of 110 patients), muscle pain (ten [9%]), rash (eight [7%]), cough, dyspnoea, or other pulmonary symptoms (five [5%]), fatigue (five [5%]), thrombosis (five [5%]), and thrombocytopenia (four [4%]). INTERPRETATION Lenalidomide plus rituximab is well tolerated and highly active as initial treatment for indolent non-Hodgkin lymphoma. An international phase 3 study (NCT01476787) to compare this regimen with chemotherapy in patients with untreated follicular lymphoma is in progress. FUNDING Celgene Corporation and Richard Spencer Lewis Memorial Foundation and Cancer Center Support Grant.

Overexpression of Separase induces aneuploidy and mammary tumorigenesis

Separase is an endopeptidase that separates sister chromatids by cleaving cohesin Rad21 during the metaphase-to-anaphase transition. Conditional expression of Separase in tetracycline-inducible diploid FSK3 mouse mammary epithelial cells with both p53 WT and mutant (Ser-233-234) alleles of unknown physiological significance develops aneuploidy within 5 days of Separase induction in vitro. Overexpression of Separase induces premature separation of chromatids, lagging chromosomes, and anaphase bridges. In an in vivo mouse mammary transplant model, induction of Separase expression in the transplanted FSK3 cells for 3–4 weeks results in the formation of aneuploid tumors in the mammary gland. Xenograft studies combined with histological and cytogenetic analysis reveal that Separase-induced tumors are clonal in their genomic complements and have a mesenchymal phenotype suggestive of an epithelial–mesenchymal transition. Induction of Separase resulted in trisomies for chromosomes 8, 15, and 17; monosomy for chromosome 10; and amplification of the distal region of chromosomes 8 and 11. Separase protein is found to be significantly overexpressed in human breast tumors compared with matched normal tissue. These results collectively suggest that Separase is an oncogene, whose overexpression alone in mammary epithelial cells is sufficient to induce aneuploidy and tumorigenesis in a p53 mutant background.

Targeting the insulin-like growth factor-1 receptor to overcome bortezomib resistance in preclinical models of multiple myeloma

Proteasome inhibition with bortezomib is a validated approach to the treatment of multiple myeloma, but drug resistance often emerges and limits its utility in the retreatment setting. To begin to identify some of the mechanisms involved, we developed bortezomib-resistant myeloma cell lines that, unlike previously reported models, showed no β5 subunit mutations. Instead, up-regulation of the insulin-like growth factor (IGF)-1 axis was identified, with increased autocrine and paracrine secretion of IGF-1, leading to increased activation of the IGF-1 receptor (IGF-1R). Exogenous IGF-1 reduced cellular sensitivity to bortezomib, whereas pharmacologic or small hairpin RNA-mediated IGF-1R suppression enhanced bortezomib sensitivity in cell lines and patient samples. In vitro studies with OSI-906, a clinically relevant dual IGF-1R and insulin receptor inhibitor, showed it acted synergistically with bortezomib, and potently resensitized bortezomib-resistant cell lines and patient samples to bortezomib. Importantly, OSI-906 in combination with bortezomib also overcame bortezomib resistance in an in vivo model of myeloma. Taken together, these data support the hypothesis that signaling through the IGF-1/IGF-1R axis contributes to acquired bortezomib resistance, and provide a rationale for combining bortezomib with IGF-1R inhibitors like OSI-906 to overcome or possibly prevent the emergence of bortezomib-refractory disease in the clinic.

Survival advantage observed with the use of metformin in patients with type II diabetes and colorectal cancer

Background:Patients with type II diabetes mellitus (DM) have an increased risk of adenomatous colorectal (CRC) polyps and CRC cancer. The use of the anti-hyperglycemic agent metformin is associated with a reduced incidence of cancer-related deaths.Methods:We retrospectively evaluated the medical records of 4758 patients seen at a single institution and determined that 424 patients were identified by their physicians as having type II DM and CRC cancer. Data were subsequently acquired determining the subjects age, body mass index (BMI), and disease date of diagnosis, stage, site of cancer, treatment, and survival.Results:Patients with type II DM and CRC cancer treated with metformin as one of their diabetic medications had a survival of 76.9 months (95% CI=61.4–102.4) as compared with 56.9 months in those patients not treated with metformin (95% CI=44.8–68.8), P=0.048. By using a multivariable Cox regression model adjusted for age, sex, race, BMI, and initial stage of disease, we demonstrated that type II diabetic patients treated with metformin had a 30% improvement in overall survival (OS) when compared with diabetic patients treated with other diabetic agents.Conclusion:Colorectal cancer patients with DM treated with metformin as part of their diabetic therapy appear to have a superior OS.

Phase I Clinical Trial of Systemically Administered TUSC2(FUS1)-Nanoparticles Mediating Functional Gene Transfer in Humans

Background Tumor suppressor gene TUSC2/FUS1 (TUSC2) is frequently inactivated early in lung cancer development. TUSC2 mediates apoptosis in cancer cells but not normal cells by upregulation of the intrinsic apoptotic pathway. No drug strategies currently exist targeting loss-of–function genetic abnormalities. We report the first in-human systemic gene therapy clinical trial of tumor suppressor gene TUSC2. Methods Patients with recurrent and/or metastatic lung cancer previously treated with platinum-based chemotherapy were treated with escalating doses of intravenous N-[1-(2,3-dioleoyloxy)propyl]-N,N,N-trimethylammonium chloride (DOTAP):cholesterol nanoparticles encapsulating a TUSC2 expression plasmid (DOTAP:chol-TUSC2) every 3 weeks. Results Thirty-one patients were treated at 6 dose levels (range 0.01 to 0.09 milligrams per kilogram). The MTD was determined to be 0.06 mg/kg. Five patients achieved stable disease (2.6–10.8 months, including 2 minor responses). One patient had a metabolic response on positron emission tomography (PET) imaging. RT-PCR analysis detected TUSC2 plasmid expression in 7 of 8 post-treatment tumor specimens but not in pretreatment specimens and peripheral blood lymphocyte controls. Proximity ligation assay, performed on paired biopsies from 3 patients, demonstrated low background TUSC2 protein staining in pretreatment tissues compared with intense (10–25 fold increase) TUSC2 protein staining in post-treatment tissues. RT-PCR gene expression profiling analysis of apoptotic pathway genes in two patients with high post-treatment levels of TUSC2 mRNA and protein showed significant post-treatment changes in the intrinsic apoptotic pathway. Twenty-nine genes of the 82 tested in the apoptosis array were identified by Igenuity Pathway Analysis to be significantly altered post-treatment in both patients (Pearson correlation coefficient 0.519; p<0.01). Conclusions DOTAP:chol-TUSC2 can be safely administered intravenously in lung cancer patients and results in uptake of the gene by human primary and metastatic tumors, transgene and gene product expression, specific alterations in TUSC2-regulated pathways, and anti-tumor effects (to our knowledge for the first time for systemic DOTAP:cholesterol nanoparticle gene therapy). Trial Registration ClinicalTrials.gov NCT00059605

Ursolic Acid Inhibits Growth and Metastasis of Human Colorectal Cancer in an Orthotopic Nude Mouse Model by Targeting Multiple Cell Signaling Pathways: Chemosensitization with Capecitabine

Purpose: Development of chemoresistance, poor prognosis, and metastasis often renders the current treatments for colorectal cancer (CRC) ineffective. Whether ursolic acid, a component of numerous medicinal plants, either alone or in combination with capecitabine, can inhibit the growth and metastasis of human CRC was investigated. Experimental design: The effect of ursolic acid on proliferation of CRC cell lines was examined by mitochondrial dye uptake assay, apoptosis by esterase staining, NF-κB activation by DNA-binding assay, and protein expression by Western blot. The effect of ursolic acid on the growth and chemosensitization was also examined in orthotopically implanted CRC in nude mice. Results: We found that ursolic acid inhibited the proliferation of different colon cancer cell lines. This is correlated with inhibition of constitutive NF-κB activation and downregulation of cell survival (Bcl-xL, Bcl-2, cFLIP, and survivin), proliferative (cyclin D1), and metastatic (MMP-9, VEGF, and ICAM-1) proteins. When examined in an orthotopic nude mouse model, ursolic acid significantly inhibited tumor volume, ascites formation, and distant organ metastasis, and this effect was enhanced with capecitabine. Immunohistochemistry of tumor tissue indicated that ursolic acid downregulated biomarkers of proliferation (Ki-67) and microvessel density (CD31). This effect was accompanied by suppression of NF-κB, STAT3, and β-catenin. In addition, ursolic acid suppressed EGF receptor (EGFR) and induced p53 and p21 expression. We also observed bioavailability of ursolic acid in the serum and tissue of animals. Conclusion: Overall, our results show that ursolic acid can inhibit the growth and metastasis of CRC and further enhance the therapeutic effects of capecitabine through the suppression of multiple biomarkers linked to inflammation, proliferation, invasion, angiogenesis, and metastasis. Clin Cancer Res; 18(18); 4942–53. ©2012 AACR.

Spatially Adaptive Bayesian Penalized Regression Splines (P-splines)

In this article we study penalized regression splines (P-splines), which are low-order basis splines with a penalty to avoid undersmoothing. Such P-splines are typically not spatially adaptive, and hence can have trouble when functions are varying rapidly. Our approach is to model the penalty parameter inherent in the P-spline method as a heteroscedastic regression function. We develop a full Bayesian hierarchical structure to do this and use Markov chain Monte Carlo techniques for drawing random samples from the posterior for inference. The advantage of using a Bayesian approach to P-splines is that it allows for simultaneous estimation of the smooth functions and the underlying penalty curve in addition to providing uncertainty intervals of the estimated curve. The Bayesian credible intervals obtained for the estimated curve are shown to have pointwise coverage probabilities close to nominal. The method is extended to additive models with simultaneous spline-based penalty functions for the unknown functions. In simulations, the approach achieves very competitive performance with the current best frequentist P-spline method in terms of frequentist mean squared error and coverage probabilities of the credible intervals, and performs better than some of the other Bayesian methods.

Evidence of a role for CD44 and cell adhesion in mediating resistance to lenalidomide in multiple myeloma: Therapeutic implications

Resistance of myeloma to lenalidomide is an emerging clinical problem, and though it has been associated in part with activation of Wnt/β-catenin signaling, the mediators of this phenotype remained undefined. Lenalidomide-resistant models were found to overexpress the hyaluronan (HA)-binding protein CD44, a downstream Wnt/β-catenin transcriptional target. Consistent with a role of CD44 in cell adhesion-mediated drug resistance (CAM-DR), lenalidomide-resistant myeloma cells were more adhesive to bone marrow stroma and HA-coated plates. Blockade of CD44 with monoclonal antibodies, free HA or CD44 knockdown reduced adhesion and sensitized to lenalidomide. Wnt/β-catenin suppression by FH535 enhanced the activity of lenalidomide, as did interleukin-6 neutralization with siltuximab. Notably, all-trans retinoic acid (ATRA) downregulated total β-catenin, cell-surface and total CD44, reduced adhesion of lenalidomide-resistant myeloma cells and enhanced the activity of lenalidomide in a lenalidomide-resistant in vivo murine xenograft model. Finally, ATRA sensitized primary myeloma samples from patients that had relapsed and/or refractory disease after lenalidomide therapy to this immunomodulatory agent ex vivo. Taken together, our findings support the hypotheses that CD44 and CAM-DR contribute to lenalidomide resistance in multiple myeloma, that CD44 should be evaluated as a putative biomarker of sensitivity to lenalidomide, and that ATRA or other approaches that target CD44 may overcome clinical lenalidomide resistance.

IBAG: Integrative Bayesian analysis of high-dimensional multiplatform genomics data

Motivation: Analyzing data from multi-platform genomics experiments combined with patients’ clinical outcomes helps us understand the complex biological processes that characterize a disease, as well as how these processes relate to the development of the disease. Current data integration approaches are limited in that they do not consider the fundamental biological relationships that exist among the data obtained from different platforms. Statistical Model: We propose an integrative Bayesian analysis of genomics data (iBAG) framework for identifying important genes/biomarkers that are associated with clinical outcome. This framework uses hierarchical modeling to combine the data obtained from multiple platforms into one model. Results: We assess the performance of our methods using several synthetic and real examples. Simulations show our integrative methods to have higher power to detect disease-related genes than non-integrative methods. Using the Cancer Genome Atlas glioblastoma dataset, we apply the iBAG model to integrate gene expression and methylation data to study their associations with patient survival. Our proposed method discovers multiple methylation-regulated genes that are related to patient survival, most of which have important biological functions in other diseases but have not been previously studied in glioblastoma. Availability: http://odin.mdacc.tmc.edu/∼vbaladan/. Contact: veera@mdanderson.org Supplementary information: Supplementary data are available at Bioinformatics online.