Showing papers in "Clinical Cancer Research in 2013"

Analysis of Tumor Specimens at the Time of Acquired Resistance to EGFR-TKI Therapy in 155 Patients with EGFR-Mutant Lung Cancers

Abstract: Purpose: All patients with EGF receptor ( EGFR )–mutant lung cancers eventually develop acquired resistance to EGFR tyrosine kinase inhibitors (TKI). Smaller series have identified various mechanisms of resistance, but systematic evaluation of a large number of patients to definitively establish the frequency of various mechanisms has not been conducted. Experimental Design: Patients with lung adenocarcinomas and acquired resistance to erlotinib or gefitinib enrolled onto a prospective biopsy protocol and underwent a rebiopsy after the development of acquired resistance. Histology was reviewed. Samples underwent genotyping for mutations in EGFR, AKT1, BRAF, ERBB2, KRAS, MEK1, NRAS and PIK3CA , and FISH for MET and HER2 . Results: Adequate tumor samples for molecular analysis were obtained in 155 patients. Ninety-eight had second-site EGFR T790M mutations [63%; 95% confidence interval (CI), 55%–70%] and four had small cell transformation (3%, 95% CI, 0%–6%). MET amplification was seen in 4 of 75 (5%; 95% CI, 1%–13%). HER2 amplification was seen in 3 of 24 (13%; 95% CI, 3%–32%). We did not detect any acquired mutations in PIK3CA, AKT1, BRAF, ERBB2, KRAS, MEK1 , or NRAS (0 of 88, 0%; 95% CI, 0%–4%). Overlap among mechanisms of acquired resistance was seen in 4%. Conclusions: This is the largest series reporting mechanisms of acquired resistance to EGFR-TKI therapy. We identified EGFR T790M as the most common mechanism of acquired resistance, whereas MET amplification, HER2 amplification, and small cell histologic transformation occur less frequently. More comprehensive methods to characterize molecular alterations in this setting are needed to improve our understanding of acquired resistance to EGFR-TKIs. Clin Cancer Res; 19(8); 2240–7. ©2013 AACR .

The Definition of Primary and Secondary Glioblastoma

Abstract: Glioblastoma is the most frequent and malignant brain tumor. The vast majority of glioblastomas (~90%) develop rapidly de novo in elderly patients, without clinical or histologic evidence of a less malignant precursor lesion (primary glioblastomas). Secondary glioblastomas progress from low-grade diffuse astrocytoma or anaplastic astrocytoma. They manifest in younger patients, have a lesser degree of necrosis, are preferentially located in the frontal lobe, and carry a significantly better prognosis. Histologically, primary and secondary glioblastomas are largely indistinguishable, but they differ in their genetic and epigenetic profiles. Decisive genetic signposts of secondary glioblastoma are IDH1 mutations, which are absent in primary glioblastomas and which are associated with a hypermethylation phenotype. IDH1 mutations are the earliest detectable genetic alteration in precursor low-grade diffuse astrocytomas and in oligodendrogliomas, indicating that these tumors are derived from neural precursor cells that differ from those of primary glioblastomas. In this review, we summarize epidemiologic, clinical, histopathologic, genetic, and expression features of primary and secondary glioblastomas and the biologic consequences of IDH1 mutations. We conclude that this genetic alteration is a definitive diagnostic molecular marker of secondary glioblastomas and more reliable and objective than clinical criteria. Despite a similar histologic appearance, primary and secondary glioblastomas are distinct tumor entities that originate from different precursor cells and may require different therapeutic approaches.

An Epithelial–Mesenchymal Transition Gene Signature Predicts Resistance to EGFR and PI3K Inhibitors and Identifies Axl as a Therapeutic Target for Overcoming EGFR Inhibitor Resistance

Abstract: Purpose: Epithelial–mesenchymal transition (EMT) has been associated with metastatic spread and EGF receptor (EGFR) inhibitor resistance. We developed and validated a robust 76-gene EMT signature using gene expression profiles from four platforms using non–small cell lung carcinoma (NSCLC) cell lines and patients treated in the Biomarker-Integrated Approaches of Targeted Therapy for Lung Cancer Elimination (BATTLE) study. Experimental Design: We conducted an integrated gene expression, proteomic, and drug response analysis using cell lines and tumors from patients with NSCLC. A 76-gene EMT signature was developed and validated using gene expression profiles from four microarray platforms of NSCLC cell lines and patients treated in the BATTLE study, and potential therapeutic targets associated with EMT were identified. Results: Compared with epithelial cells, mesenchymal cells showed significantly greater resistance to EGFR and PI3K/Akt pathway inhibitors, independent of EGFR mutation status, but more sensitivity to certain chemotherapies. Mesenchymal cells also expressed increased levels of the receptor tyrosine kinase Axl and showed a trend toward greater sensitivity to the Axl inhibitor SGI-7079, whereas the combination of SGI-7079 with erlotinib reversed erlotinib resistance in mesenchymal lines expressing Axl and in a xenograft model of mesenchymal NSCLC. In patients with NSCLC, the EMT signature predicted 8-week disease control in patients receiving erlotinib but not other therapies. Conclusion: We have developed a robust EMT signature that predicts resistance to EGFR and PI3K/Akt inhibitors, highlights different patterns of drug responsiveness for epithelial and mesenchymal cells, and identifies Axl as a potential therapeutic target for overcoming EGFR inhibitor resistance associated with the mesenchymal phenotype. Clin Cancer Res; 19(1); 279–90. ©2012 AACR .

BRAF inhibition is associated with enhanced melanoma antigen expression and a more favorable tumor microenvironment in patients with metastatic melanoma

Abstract: Purpose: To evaluate the effects of BRAF inhibition on the tumor microenvironment in patients with metastatic melanoma. Experimental Design: Thirty-five biopsies were collected from 16 patients with metastatic melanoma pretreatment (day 0) and at 10 to 14 days after initiation of treatment with either BRAF inhibitor alone (vemurafenib) or BRAF + MEK inhibition (dabrafenib + trametinib) and were also taken at time of progression. Biopsies were analyzed for melanoma antigens, T-cell markers, and immunomodulatory cytokines. Results: Treatment with either BRAF inhibitor alone or BRAF + MEK inhibitor was associated with an increased expression of melanoma antigens and an increase in CD8+ T-cell infiltrate. This was also associated with a decrease in immunosuppressive cytokines [interleukin (IL)-6 and IL-8] and an increase in markers of T-cell cytotoxicity. Interestingly, expression of exhaustion markers TIM-3 and PD1 and the immunosuppressive ligand PDL1 was increased on treatment. A decrease in melanoma antigen expression and CD8 T-cell infiltrate was noted at time of progression on BRAF inhibitor alone and was reversed with combined BRAF and MEK inhibition. Conclusions: Together, these data suggest that treatment with BRAF inhibition enhances melanoma antigen expression and facilitates T-cell cytotoxicity and a more favorable tumor microenvironment, providing support for potential synergy of BRAF-targeted therapy and immunotherapy. Interestingly, markers of T-cell exhaustion and the immunosuppressive ligand PDL1 are also increased with BRAF inhibition, further implying that immune checkpoint blockade may be critical in augmenting responses to BRAF-targeted therapy in patients with melanoma. Clin Cancer Res; 19(5); 1225–31. ©2013 AACR .

Pd-l1 expression is characteristic of a subset of aggressive b-cell lymphomas and virus-associated malignancies

Abstract: Purpose: Programmed cell death ligand 1 (PD-L1) is an immunomodulatory molecule expressed by antigen-presenting cells and select tumors that engages receptors on T cells to inhibit T-cell immunity. Immunotherapies targeting the PD-1/PD-L1 pathway have shown durable antitumor effects in a subset of patients with solid tumors. PD-L1 can be expressed by Reed–Sternberg cells comprising classical Hodgkin lymphoma (CHL) and by malignant B cells comprising EBV-positive posttransplant lymphoproliferative disorders (PTLD). We sought to determine whether the expression of PD-L1 represents a general strategy of immune evasion among aggressive B-cell lymphomas and virus- and immunodeficiency-associated tumors. Experimental Design: Using novel antibodies and formalin-fixed, paraffin-embedded (FFPE) tissue biopsies, we examined 237 primary tumors for expression of PD-L1. Results: Robust PD-L1 protein expression was found in the majority of nodular sclerosis and mixed cellularity CHL, primary mediastinal large B-cell lymphoma, T-cell/histiocyte-rich B-cell lymphoma, EBV-positive and -negative PTLD, and EBV-associated diffuse large B-cell lymphoma (DLBCL), plasmablastic lymphoma, extranodal NK/T-cell lymphoma, nasopharyngeal carcinoma, and HHV8-associated primary effusion lymphoma. Within these tumors, PD-L1 was highly expressed by malignant cells and tumor-infiltrating macrophages. In contrast, neither the malignant nor the nonmalignant cells comprising nodular lymphocyte-predominant Hodgkin lymphoma, DLBCL-not otherwise specified, Burkitt lymphoma, and HHV8-associated Kaposi sarcoma expressed detectable PD-L1. Conclusion: Certain aggressive B-cell lymphomas and virus- and immunodeficiency-associated malignancies associated with an ineffective T-cell immune response express PD-L1 on tumor cells and infiltrating macrophages. These results identify a group of neoplasms that should be considered for PD-1/PD-L1-directed therapies, and validate methods to detect PD-L1 in FFPE tissue biopsies. Clin Cancer Res; 19(13); 3462–73. ©2013 AACR .

CTLA-4 and PD-1/PD-L1 Blockade: New Immunotherapeutic Modalities with Durable Clinical Benefit in Melanoma Patients

Abstract: Immune checkpoint blockade with monoclonal antibodies directed at the inhibitory immune receptors CTLA-4, PD-1, and PD-L1 has emerged as a successful treatment approach for patients with advanced melanoma. Ipilimumab is the first agent associated with a documented improved overall survival benefit in this patient population. A striking attribute of CTLA-4 blockade is the durability of objective responses, leading to speculation of a possible cure for some patients. Many tumor responses achieved with PD-1 and PD-L1 inhibition were durable in the phase I trials and were seen in a higher proportion of patients with melanoma than typically observed with ipilimumab. Biomarker development to identify the subset of patients with melanoma who will achieve durable clinical benefit with checkpoint blockade is critical; tumor PD-L1 expression has been promising in early studies. The contrast between unprecedented response rates but limited durability of responses achieved with BRAF and MEK inhibition in BRAF V600 -mutated melanoma and the impressive durability but relatively low rate of response achieved with immune checkpoint blockade is striking. Preclinical data on potential synergies between CTLA-4/PD-1/PD-L1 inhibition and MAPK-targeted therapy is emerging, and combined immune checkpoint blockade and MAPK inhibition are being explored in clinical trials. Other promising approaches to increase the number of patients with melanoma who benefit from durable responses with immune checkpoint blockade include concurrent or sequenced CTLA-4 and PD-1/PD-L1 inhibition and combination with other immunotherapeutic strategies. Clin Cancer Res; 19(19); 5300–9. ©2013 AACR .

Anti-PD-1 Antibody Therapy Potently Enhances the Eradication of Established Tumors By Gene-Modified T Cells

Abstract: Purpose: To determine the antitumor efficacy and toxicity of a novel combination approach involving adoptive T-cell immunotherapy using chimeric antigen receptor (CAR) T cells with an immunomodulatory reagent for blocking immunosuppression. Experimental Design: We examined whether administration of a PD-1 blocking antibody could increase the therapeutic activity of CAR T cells against two different Her-2+ tumors. The use of a self-antigen mouse model enabled investigation into the efficacy, mechanism, and toxicity of this combination approach. Results: In this study, we first showed a significant increase in the level of PD-1 expressed on transduced anti-Her-2 CD8+ T cells following antigen-specific stimulation with PD-L1+ tumor cells and that markers of activation and proliferation were increased in anti-Her-2 T cells in the presence of anti-PD-1 antibody. In adoptive transfer studies in Her-2 transgenic recipient mice, we showed a significant improvement in growth inhibition of two different Her-2+ tumors treated with anti-Her-2 T cells in combination with anti-PD-1 antibody. The therapeutic effects observed correlated with increased function of anti-Her-2 T cells following PD-1 blockade. Strikingly, a significant decrease in the percentage of Gr1+ CD11b+ myeloid-derived suppressor cells (MDSC) was observed in the tumor microenvironment of mice treated with the combination therapy. Importantly, increased antitumor effects were not associated with any autoimmune pathology in normal tissue expressing Her-2 antigen. Conclusion: This study shows that specifically blocking PD-1 immunosuppression can potently enhance CAR T-cell therapy that has significant implications for potentially improving therapeutic outcomes of this approach in patients with cancer. Clin Cancer Res; 19(20); 5636–46. ©2013 AACR . See related article by Morales-Kastresana, et al., [p. 5546][1] This article is featured in Highlights of This Issue, [p. 5543][2] [1]: /lookup/volpage/19/5546?iss=20 [2]: /lookup/volpage/19/5543?iss=20

Differential response to neoadjuvant chemotherapy among 7 triple-negative breast cancer molecular subtypes

Abstract: Purpose: The clinical relevancy of the 7-subtype classification of triple-negative breast cancer (TNBC) reported by Lehmann and colleagues is unknown. We investigated the clinical relevancy of TNBC heterogeneity by determining pathologic complete response (pCR) rates after neoadjuvant chemotherapy, based on TNBC subtypes. Experimental Design: We revalidated the Lehmann and colleagues experiments using Affymetrix CEL files from public datasets. We applied these methods to 146 patients with TNBC with gene expression microarrays obtained from June 2000 to March 2010 at our institution. Of those, 130 had received standard neoadjuvant chemotherapy and had evaluable pathologic response data. We classified the TNBC samples by subtype and then correlated subtype and pCR status using Fisher exact test and a logistic regression model. We also assessed survival and compared the subtypes with PAM50 intrinsic subtypes and residual cancer burden (RCB) index. Results: TNBC subtype and pCR status were significantly associated ( P = 0.04379). The basal-like 1 (BL1) subtype had the highest pCR rate (52%); basal-like 2 (BL2) and luminal androgen receptor had the lowest (0% and 10%, respectively). TNBC subtype was an independent predictor of pCR status ( P = 0.022) by a likelihood ratio test. The subtypes better predicted pCR status than did the PAM50 intrinsic subtypes (basal-like vs. non basal-like). Conclusions: Classifying TNBC by 7 subtypes predicts high versus low pCR rate. We confirm the clinical relevancy of the 7 subtypes of TNBC. We need to prospectively validate whether the pCR rate differences translate into long-term outcome differences. The 7-subtype classification may spur innovative personalized medicine strategies for patients with TNBC. Clin Cancer Res; 19(19); 5533–40. ©2013 AACR .

Antagonist Antibodies to PD-1 and B7-H1 (PD-L1) in the Treatment of Advanced Human Cancer—Response

Abstract: The immune suppressive molecule programmed death-1 (PD-1) is upregulated in activated T lymphocytes and inhibits T-cell function upon binding to its ligands B7-H1 (PD-L1, CD274) and B7-DC (PD-L2, CD273). Substantial experimental data from in vitro cell culture systems and animal models, and more recently from clinical trials, indicate that PD-1/PD-1-ligand interactions are a major mechanism of immune suppression within the tumor microenvironment. Initial clinical studies of antibodies directed against PD-1 and B7-H1 showed both an encouraging safety profile and remarkable antitumor activity in subsets of patients with metastatic disease, including malignancies--such as lung cancer--which were previously thought to be unresponsive to immunotherapy. Preliminary data have suggested a correlation between tumor membrane B7-H1 expression and clinical response to anti-PD-1 antibodies. Several key challenges remain to optimize development of PD-1/B7-H1 pathway blockade, including defining the biologic significance of all potential ligand-receptor interactions in the tumor microenvironment, developing more accurate predictive biomarkers of response, determining the breadth of activity in human malignancies, and developing rational combinations of therapy that address key mechanisms involved in positive and negative regulation of antitumor immune responses.

Phase II Trial of Bicalutamide in Patients with Androgen Receptor–Positive, Estrogen Receptor–Negative Metastatic Breast Cancer

Abstract: Purpose: Patients with hormone receptor–negative breast cancer generally do not benefit from endocrine-targeted therapies. However, a subset with androgen receptor (AR) expression is predicted to respond to antiandrogen therapies. This phase II study explored bicalutamide in AR-positive, estrogen receptor (ER), and progesterone receptor (PgR)-negative metastatic breast cancer. Experimental Design: Tumors from patients with ER/PgR-negative advanced breast cancer were tested centrally for AR [immunohistochemistry (IHC) > 10% nuclear staining considered positive]. If either the primary or a metastatic site was positive, patients were eligible to receive the AR antagonist bicalutamide at a dose of 150 mg daily. Clinical benefit rate (CBR), the primary endpoint, was defined as the total number of patients who show a complete response (CR), partial response (PR), or stable disease (SD) > 6 months; secondary endpoints included progression-free survival (PFS) and toxicity. Correlative studies included measurement of circulating endocrine markers and IHC surrogates for basal-like breast cancer. Results: Of 424 patients with ER/PgR-negative breast cancer, 12% tested AR-positive. The 6-month CBR was 19% [95% confidence interval (CI), 7%–39%] for bicalutamide. The median PFS was 12 weeks (95% CI, 11–22 weeks). Bicalutamide was well-tolerated with no grade 4/5 treatment-related adverse events observed. Conclusion: AR was expressed in 12% of patients with ER/PgR-negative breast cancer screened for this trial. The CBR of 19% observed with bicalutamide shows proof of principle for the efficacy of minimally toxic androgen blockade in a select group of patients with ER/PgR-negative, AR-positive breast cancer. Clin Cancer Res; 19(19); 5505–12. ©2013 AACR.

B-cell Maturation Antigen Is a Promising Target for Adoptive T-cell Therapy of Multiple Myeloma

Abstract: Purpose: Multiple myeloma is a usually incurable malignancy of plasma cells. New therapies are urgently needed for multiple myeloma. Adoptive transfer of chimeric antigen receptor (CAR)–expressing T cells is a promising new therapy for hematologic malignancies, but an ideal target antigen for CAR-expressing T-cell therapies for multiple myeloma has not been identified. B-cell maturation antigen (BCMA) is a protein that has been reported to be selectively expressed by B-lineage cells including multiple myeloma cells. Our goal was to determine if BCMA is a suitable target for CAR-expressing T cells. Experimental Design: We conducted an assessment of BCMA expression in normal human tissues and multiple myeloma cells by flow cytometry, quantitative PCR, and immunohistochemistry. We designed and tested novel anti-BCMA CARs. Results: BCMA had a restricted RNA expression pattern. Except for expression in plasma cells, BCMA protein was not detected in normal human tissues. BCMA was not detected on primary human CD34 + hematopoietic cells. We detected uniform BCMA cell-surface expression on primary multiple myeloma cells from five of five patients. We designed the first anti-BCMA CARs to be reported and we transduced T cells with lentiviral vectors encoding these CARs. The CARs gave T cells the ability to specifically recognize BCMA. The anti-BCMA-CAR–transduced T cells exhibited BCMA-specific functions including cytokine production, proliferation, cytotoxicity, and in vivo tumor eradication. Importantly, anti-BCMA-CAR–transduced T cells recognized and killed primary multiple myeloma cells. Conclusions: BCMA is a suitable target for CAR-expressing T cells, and adoptive transfer of anti-BCMA-CAR–expressing T cells is a promising new strategy for treating multiple myeloma. Clin Cancer Res; 19(8); 2048–60. ©2013 AACR .

Durable Cancer Regression Off-Treatment and Effective Reinduction Therapy with an Anti-PD-1 Antibody

Abstract: Purpose: Results from the first-in-human phase I trial of the anti–programmed death-1 (PD-1) antibody BMS-936558 in patients with treatment-refractory solid tumors, including safety, tolerability, pharmacodynamics, and immunologic correlates, have been previously reported. Here, we provide long-term follow-up on three patients from that trial who sustained objective tumor regressions off therapy, and test the hypothesis that reinduction therapy for late tumor recurrence can be effective. Experimental Design: Three patients with colorectal cancer, renal cell cancer, and melanoma achieved objective responses on an intermittent dosing regimen of BMS-936558. Following cessation of therapy, patients were followed for more than 3 years. A patient with melanoma who experienced a prolonged partial regression followed by tumor recurrence received reinduction therapy. Results: A patient with colorectal cancer experienced a complete response, which is ongoing after 3 years. A patient with renal cell cancer experienced a partial response lasting 3 years off therapy, which converted to a complete response, which is ongoing at 12 months. A patient with melanoma achieved a partial response that was stable for 16 months off therapy; recurrent disease was successfully treated with reinduction anti-PD-1 therapy. Conclusion: These data represent the most prolonged observation to date of patients with solid tumors responding to anti-PD-1 immunotherapy and the first report of successful reinduction therapy following delayed tumor progression. They underscore the potential for immune checkpoint blockade with anti-PD-1 to reset the equilibrium between tumor and the host immune system. Clin Cancer Res; 19(2); 462–8. ©2012 AACR .

ALK Rearrangements Are Mutually Exclusive with Mutations in EGFR or KRAS: An Analysis of 1,683 Patients with Non–Small Cell Lung Cancer

Abstract: Purpose: Anaplastic lymphoma kinase ( ALK ) gene rearrangements define a distinct molecular subset of non–small cell lung cancer (NSCLC). Recently, several case reports and small series have reported that ALK rearrangements can overlap with other oncogenic drivers in NSCLC in crizotinib-naive and crizotinib-resistant cancers. Experimental Design: We reviewed clinical genotyping data from 1,683 patients with NSCLC and investigated the prevalence of concomitant EGFR or KRAS mutations among patients with ALK-positive NSCLC. We also examined biopsy specimens from 34 patients with ALK-positive NSCLC after the development of resistance to crizotinib. Results: Screening identified 301 (17.8%) EGFR mutations, 465 (27.6%) KRAS mutations, and 75 (4.4%) ALK rearrangements. EGFR mutations and ALK rearrangements were mutually exclusive. Four patients with KRAS mutations were found to have abnormal ALK FISH patterns, most commonly involving isolated 5′ green probes. Sufficient tissue was available for confirmatory ALK immunohistochemistry in 3 cases, all of which were negative for ALK expression. Among patients with ALK-positive NSCLC who acquired resistance to crizotinib, repeat biopsy specimens were ALK FISH positive in 29 of 29 (100%) cases. Secondary mutations in the ALK kinase domain and ALK gene amplification were observed in 7 of 34 (20.6%) and 3 of 29 (10.3%) cases, respectively. No EGFR or KRAS mutations were identified among any of the 25 crizotinib-resistant, ALK-positive patients with sufficient tissue for testing. Conclusions: Functional ALK rearrangements were mutually exclusive with EGFR and KRAS mutations in a large Western patient population. This lack of overlap was also observed in ALK-positive cancers with acquired resistance to crizotinib. Clin Cancer Res; 19(15); 4273–81. ©2013 AACR .

Receptor Affinity and Extracellular Domain Modifications Affect Tumor Recognition by ROR1-Specific Chimeric Antigen Receptor T Cells

Abstract: Purpose: The adoptive transfer of T cells modified to express a chimeric antigen receptor (CAR) comprised of an extracellular single-chain antibody (scFV) fragment specific for a tumor cell surface molecule, and linked to an intracellular signaling module, has activity in advanced malignancies. The receptor tyrosine kinase–like orphan receptor 1 (ROR1) is a tumor-associated molecule expressed in prevalent B-lymphoid and epithelial cancers and is absent on normal mature B cells and vital tissues, making it a candidate for CAR T-cell therapy. Experimental Design: We constructed ROR1-CARs from scFVs with different affinities and containing extracellular IgG4-Fc spacer domains of different lengths, and evaluated the ability of T cells expressing each CAR to recognize ROR1 + hematopoietic and epithelial tumors in vitro , and to eliminate human mantle cell lymphoma (MCL) engrafted into immunodeficient mice. Results: ROR1-CARs containing a short “Hinge-only” extracellular spacer conferred superior lysis of ROR1 + tumor cells and induction of T-cell effector functions compared with CARs with long “Hinge-CH2-CH3” spacers. CARs derived from a higher affinity scFV conferred maximum T-cell effector function against primary CLL and ROR1 + epithelial cancer lines in vitro without inducing activation-induced T-cell death. T cells modified with an optimal ROR1-CAR were equivalently effective as CD19-CAR–modified T cells in mediating regression of JeKo-1 MCL in immunodeficient mice. Conclusions: Our results show that customizing spacer design and increasing affinity of ROR1-CARs enhances T-cell effector function and recognition of ROR1 + tumors. T cells modified with an optimized ROR1-CAR have significant antitumor efficacy in a preclinical model in vivo , suggesting they may be useful to treat ROR1 + tumors in clinical applications. Clin Cancer Res; 19(12); 3153–64. ©2013 AACR .

Inflammatory Monocyte Mobilization Decreases Patient Survival in Pancreatic Cancer: A Role for Targeting the CCL2/CCR2 Axis

Abstract: Purpose: To determine the role of the CCL2/CCR2 axis and inflammatory monocytes (CCR2 + /CD14 + ) as immunotherapeutic targets in the treatment of pancreatic cancer. Experimental Design: Survival analysis was conducted to determine if the prevalence of preoperative blood monocytes correlates with survival in patients with pancreatic cancer following tumor resection. Inflammatory monocyte prevalence in the blood and bone marrow of patients with pancreatic cancer and controls was compared. The immunosuppressive properties of inflammatory monocytes and macrophages in the blood and tumors, respectively, of patients with pancreatic cancer were assessed. CCL2 expression by human pancreatic cancer tumors was compared with normal pancreas. A novel CCR2 inhibitor (PF-04136309) was tested in an orthotopic model of murine pancreatic cancer. Results: Monocyte prevalence in the peripheral blood correlates inversely with survival, and low monocyte prevalence is an independent predictor of increased survival in patients with pancreatic cancer with resected tumors. Inflammatory monocytes are increased in the blood and decreased in the bone marrow of patients with pancreatic cancer compared with controls. An increased ratio of inflammatory monocytes in the blood versus the bone marrow is a novel predictor of decreased patient survival following tumor resection. Human pancreatic cancer produces CCL2, and immunosuppressive CCR2 + macrophages infiltrate these tumors. Patients with tumors that exhibit high CCL2 expression/low CD8 T-cell infiltrate have significantly decreased survival. In mice, CCR2 blockade depletes inflammatory monocytes and macrophages from the primary tumor and premetastatic liver resulting in enhanced antitumor immunity, decreased tumor growth, and reduced metastasis. Conclusions: Inflammatory monocyte recruitment is critical to pancreatic cancer progression, and targeting CCR2 may be an effective immunotherapeutic strategy in this disease. Clin Cancer Res; 19(13); 3404–15. ©2013 AACR .

Developing a Common Language for Tumor Response to Immunotherapy: Immune-Related Response Criteria Using Unidimensional Measurements

Abstract: Purpose: Immune-related response criteria (irRC) was developed to adequately assess tumor response to immunotherapy. The irRC are based on bidimensional measurements, as opposed to unidimensional measurements defined by Response Evaluation Criteria in Solid Tumors, which has been widely used in solid tumors. We aimed to compare response assessment by bidimensional versus unidimensional irRC in patients with advanced melanoma treated with ipilimumab. Experimental Design: Fifty-seven patients with advanced melanoma treated with ipilimumab in a phase II, expanded access trial were studied. Bidimensional tumor measurement records prospectively conducted during the trial were reviewed to generate a second set of measurements using unidimensional, longest diameter measurements. The percent changes of measurements at follow-up, best overall response, and time-to-progression (TTP) were compared between bidimensional and unidimensional irRC. Interobserver variability for bidimensional and unidimensional measurements was assessed in 25 randomly selected patients. Results: The percent changes at follow-up scans were highly concordant between the 2 criteria (Spearman r : 0.953–0.965, first to fourth follow-up). The best immune-related response was highly concordant between the 2 criteria ( κ w = 0.881). TTP was similar between the bidimensional and unidimensional assessments (progression-free at 6 months: 70% vs. 81%, respectively). The unidimensional measurements were more reproducible than bidimensional measurements, with the 95% limits of agreement of (−16.1%, 5.8%) versus (−31.3%, 19.7%), respectively. Conclusion: irRC using the unidimensional measurements provided highly concordant response assessment compared with the bidimensional irRC, with less measurement variability. The use of unidimensional irRC is proposed to assess response to immunotherapy in solid tumors, given its simplicity, higher reproducibility, and high concordance with the bidimensional irRC. Clin Cancer Res; 19(14); 3936–43. ©2013 AACR .

Molecular Pathways: Reactive Oxygen Species Homeostasis in Cancer Cells and Implications for Cancer Therapy

Abstract: Reactive oxygen species (ROS) are important in regulating normal cellular processes, but deregulated ROS contribute to the development of various human diseases, including cancers. Cancer cells have increased ROS levels compared with normal cells, because of their accelerated metabolism. The high ROS levels in cancer cells, which distinguish them from normal cells, could be protumorigenic, but are also their Achilles' heel. The high ROS content in cancer cells renders them more susceptible to oxidative stress-induced cell death, and can be exploited for selective cancer therapy. In this review, we describe several potential therapeutic strategies that take advantage of ROS imbalance in cancer cells by further increasing oxidative stress, either alone or in combination with drugs that modulate certain signaling pathways.

The Activation of MAPK in Melanoma Cells Resistant to BRAF Inhibition Promotes PD-L1 Expression That Is Reversible by MEK and PI3K Inhibition

Abstract: Purpose: Selective BRAF inhibition (BRAFi) provides a paradigm shift for melanoma treatment. The duration of benefit is typically limited before resistance develops. Interest remains in combining targeted and immune therapies to overcome resistance and improve durability of clinical benefit. One mechanism of evading immune destruction is programmed death-1-ligand 1 (PD-L1) expression by tumors that results in potent antitumor immune suppression. Experimental Design: BRAFi-resistant melanoma cells were examined for changes in PD-L1 expression by immunoblot and flow cytometry. Signaling pathways involved in altering PD-L1 expression were examined. Strategies to maximize the effect of the BRAFi therapy were studied including MEKi, MEKi combinations, and additional pathways including phosphoinositide-3 kinase (PI3K). Results: Melanoma cells resistant to BRAFi exhibit increased MAPK signaling and promotion of PD-L1 expression. PD-L1 expression is transcriptionally modulated by c-Jun and augmented by STAT3. MEK inhibition (MEKi) regains downregulation of MAPK signaling and suppresses the production of PD-L1. MEKi in melanoma cells shows dual therapeutic effects with simultaneous suppression of PD-L1 expression and induction of apoptosis. By combining MEKi with BRAFi, an additive effect on the inhibition of PD-L1 expression results. Conclusions: We report a novel mechanism that suppresses preexisting immune responses in patients with melanoma receiving BRAFi therapy. BRAFi resistance leads to increased expression of PD-L1 in melanoma cells, mediated by c-Jun and STAT3. MEKi may be feasible to counteract BRAFi resistance of MAPK reactivation and also for the additive effect of PD-L1 suppression. Potential therapeutic benefits of combining targeted inhibitors and immune modulation to improve patient outcomes should be investigated. Clin Cancer Res; 19(3); 598–609. ©2012 AACR .

Targeting CD73 Enhances the Antitumor Activity of Anti-PD-1 and Anti-CTLA-4 mAbs

Abstract: Purpose: Monoclonal antibodies (mAb) that block programmed death (PD)-1 or cytotoxic T lymphocyte antigen (CTLA-4) receptors have been associated with durable clinical responses against a variety of cancer types and hold great potential as novel cancer therapeutics. Recent evidence suggest that targeted blockade of multiple immunosuppressive pathways can induce synergistic antitumor responses. Experimental Design: In this study, we investigated whether targeted blockade of CD73, an ectonucleotidase that catabolizes the hydrolysis of extracellular adenosine monophosphate (AMP) to adenosine, can enhance the antitumor activity of anti-CTLA-4 and anti-PD-1 mAbs against transplanted and chemically induced mouse tumors. Results: Anti-CD73 mAb significantly enhanced the activity of both anti-CTLA-4 and anti-PD-1 mAbs against MC38-OVA (colon) and RM-1 (prostate) subcutaneous tumors, and established metastatic 4T1.2 breast cancer. Anti-CD73 mAb also significantly enhanced the activity of anti-PD-1 mAb against 3-methylcholanthrene (MCA)-induced fibrosarcomas. Gene-targeted mice revealed that single-agent therapies and combinatorial treatments were dependent on host IFN-γ and CD8 + T cells, but independent of perforin. Interestingly, anti-CD73 mAb preferentially synergized with anti-PD-1 mAb. We investigated the effect of extracellular adenosine on tumor-infiltrating T cells and showed that activation of A2A adenosine receptor enhances PD-1 expression, but not CTLA-4 expression, on tumor-specific CD8+ T cells and CD4+ Foxp3+ T regulatory cells. Conclusions: Taken together, our study revealed that targeted blockade of CD73 can enhance the therapeutic activity of anti-PD-1 and anti-CTLA-4 mAbs and may thus potentiate therapeutic strategies targeting immune checkpoint inhibitors in general. Clin Cancer Res; 19(20); 5626–35. ©2013 AACR .

HMGB1 in cancer: good, bad, or both?

Abstract: Forty years ago, high mobility group box 1 (HMGB1) was discovered in calf thymus and named according to its electrophoretic mobility in polyacrylamide gels. Now, we know that HMGB1 performs dual functions. Inside the cell, HMGB1 is a highly conserved chromosomal protein acting as a DNA chaperone. Outside of the cell, HMGB1 is a prototypical damage-associated molecular pattern, acting with cytokines, chemokines, and growth factors. During tumor development and in cancer therapy, HMGB1 has been reported to play paradoxical roles in promoting both cell survival and death by regulating multiple signaling pathways, including inflammation, immunity, genome stability, proliferation, metastasis, metabolism, apoptosis, and autophagy. Here, we review the current knowledge of both HMGB1's oncogenic and tumor-suppressive roles and the potential strategies that target HMGB1 for the prevention and treatment of cancer.

BMN 673, a Novel and Highly Potent PARP1/2 Inhibitor for the Treatment of Human Cancers with DNA Repair Deficiency

Abstract: Purpose: PARP1/2 inhibitors are a class of anticancer agents that target tumor-specific defects in DNA repair. Here, we describe BMN 673, a novel, highly potent PARP1/2 inhibitor with favorable metabolic stability, oral bioavailability, and pharmacokinetic properties. Experimental Design: Potency and selectivity of BMN 673 was determined by biochemical assays. Anticancer activity either as a single-agent or in combination with other antitumor agents was evaluated both in vitro and in xenograft cancer models. Results: BMN 673 is a potent PARP1/2 inhibitor (PARP1 IC50 = 0.57 nmol/L), but it does not inhibit other enzymes that we have tested. BMN 673 exhibits selective antitumor cytotoxicity and elicits DNA repair biomarkers at much lower concentrations than earlier generation PARP1/2 inhibitors (such as olaparib, rucaparib, and veliparib). In vitro , BMN 673 selectively targeted tumor cells with BRCA1 , BRCA2 , or PTEN gene defects with 20- to more than 200-fold greater potency than existing PARP1/2 inhibitors. BMN 673 is readily orally bioavailable, with more than 40% absolute oral bioavailability in rats when dosed in carboxylmethyl cellulose. Oral administration of BMN 673 elicited remarkable antitumor activity in vivo ; xenografted tumors that carry defects in DNA repair due to BRCA mutations or PTEN deficiency were profoundly sensitive to oral BMN 673 treatment at well-tolerated doses in mice. Synergistic or additive antitumor effects were also found when BMN 673 was combined with temozolomide, SN38, or platinum drugs. Conclusion: BMN 673 is currently in early-phase clinical development and represents a promising PARP1/2 inhibitor with potentially advantageous features in its drug class. Clin Cancer Res; 19(18); 5003–15. ©2013 AACR .

A Phase I Study of an Agonist CD40 Monoclonal Antibody (CP-870,893) in Combination with Gemcitabine in Patients with Advanced Pancreatic Ductal Adenocarcinoma

Abstract: Purpose: This phase I study investigated the maximum-tolerated dose (MTD), safety, pharmacodynamics, immunological correlatives, and anti-tumor activity of CP-870,893, an agonist CD40 antibody, when administered in combination with gemcitabine in patients with advanced pancreatic ductal adenocarcinoma (PDA). Experimental Design: Twenty-two patients with chemotherapy-naive advanced PDA were treated with 1000 mg/m2 gemcitabine once weekly for 3 weeks with infusion of CP-870,893 at 0.1 mg/kg or 0.2 mg/kg on day 3 of each 28 day cycle. Results: CP-870,893 was well-tolerated; one dose-limiting toxicity (grade 4 cerebrovascular accident) occurred at the 0.2 mg/kg dose level, which was estimated as MTD. The most common adverse event was cytokine release syndrome (grade 1 to 2). CP-870,893 infusion triggered immune activation marked by an increase in inflammatory cytokines, an increase in B cell expression of co-stimulatory molecules, and a transient depletion of B cells. Four patients achieved a partial response (PR). [18F]-fluorodeoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) demonstrated >25% decrease in FDG uptake within primary pancreatic lesions in 6 of 8 patients; however, responses observed in metastatic lesions were heterogeneous with some lesions responding with complete loss of FDG uptake while other lesions in the same patient failed to respond. Improved overall survival correlated with a decrease in FDG uptake in hepatic lesions (R = -0.929; p = 0.007). Conclusions: CP-870,893 in combination with gemcitabine was well-tolerated and associated with anti-tumor activity in patients with PDA. Changes in FDG uptake detected on PET/CT imaging provide insight into therapeutic benefit. Phase II studies are warranted.

Gliomas Promote Immunosuppression through Induction of B7-H1 Expression in Tumor-Associated Macrophages

Abstract: Purpose: Gliomas are known to induce local and systemic immunosuppression, inhibiting T-cell–mediated cytotoxic responses to tumor growth. Tumor-associated macrophages are a significant component of the immune infiltrate in gliomas and may express immunosuppressive surface ligands, such as B7-H1. Experimental Design: Tumor and peripheral blood samples from patients with glioblastoma (GBM) were analyzed by flow cytometry to evaluate the expression of B7-H1 in circulating and tumor-infiltrating macrophages. Human monocytes from healthy patients were stimulated with conditioned media from glioma cells to evaluate B7-H1 expression. Production of interleukin (IL)-10 by stimulated monocytes was measured by ELISA, and stimulation with IL-10 alone was evaluated for the ability to induce B7-H1 expression. The effect of inhibiting IL-10 and its receptor on glioma-induced B7-H1 expression in monocytes was evaluated. Results: Circulating monocytes in patients with GBM had significantly increased expression of B7-H1 compared with healthy control patients. Tumor-associated macrophages from matched GBM tissue had even greater B7-H1 expression. Treatment of normal monocytes with glioma-conditioned media could significantly increase B7-H1 expression. Stimulation of monocytes with conditioned media resulted in substantial production of IL-10 and upregulation of the IL-10 receptor. Stimulation of monocytes with IL-10 alone could significantly increase B7-H1 expression, sufficient to induce T-cell apoptosis when cocultured with stimulated monocytes. Inhibition of IL-10 and the IL-10 receptor could knock down the effect of glioma media on B7-H1 by more than 50%. Conclusions: Gliomas can upregulate B7-H1 expression in circulating monocytes and tumor-infiltrative macrophages through modulation of autocrine/paracrine IL-10 signaling, resulting in an immunosuppressive phenotype. Clin Cancer Res; 19(12); 3165–75. ©2013 AACR .

Phase II study of Lutetium-177-labeled anti-prostate-specific membrane antigen monoclonal antibody J591 for metastatic castration-resistant prostate cancer

Abstract: Purpose: To assess the efficacy of a single infusion of radiolabeled anti-prostate-specific membrane antigen (PSMA) monoclonal antibody J591 (lutetium-177; 177 Lu) by prostate-specific antigen (PSA) decline, measurable disease response, and survival. Experimental Design: In this dual-center phase II study, two cohorts with progressive metastatic castration-resistant prostate cancer received one dose of 177 Lu-J591 (15 patients at 65 mCi/m 2 , 17 at 70 mCi/m 2 ) with radionuclide imaging. Expansion cohort ( n = 15) received 70 mCi/m 2 to verify response rate and examine biomarkers. Results: Forty-seven patients who progressed after hormonal therapies (55.3% also received prior chemotherapy) received 177 Lu-J591. A total of 10.6% experienced ≥50% decline in PSA, 36.2% experienced ≥30% decline, and 59.6% experienced any PSA decline following their single treatment. One of 12 with measurable disease experienced a partial radiographic response (8 with stable disease). Sites of prostate cancer metastases were targeted in 44 of 47 (93.6%) as determined by planar imaging. All experienced reversible hematologic toxicity, with grade 4 thrombocytopenia occurring in 46.8% (29.8% received platelet transfusions) without significant hemorrhage. A total of 25.5% experienced grade 4 neutropenia, with one episode of febrile neutropenia. The phase I maximum tolerated dose (70 mCi/m 2 ) resulted in more 30% PSA declines (46.9% vs. 13.3%, P = 0.048) and longer survival (21.8 vs. 11.9 months, P = 0.03), but also more grade 4 hematologic toxicity and platelet transfusions. No serious nonhematologic toxicity occurred. Those with poor PSMA imaging were less likely to respond. Conclusion: A single dose of 177 Lu-J591 was well tolerated with reversible myelosuppression. Accurate tumor targeting and PSA responses were seen with evidence of dose response. Imaging biomarkers seem promising. Clin Cancer Res; 19(18); 5182–91. ©2013 AACR .

Agonistic CD40 Antibodies and Cancer Therapy

Abstract: Recent success in cancer immunotherapy has reinvigorated the hypothesis that the immune system can control many if not most cancers, in some cases producing durable responses in a way not seen with many small-molecule drugs. Agonistic CD40 monoclonal antibodies (mAb) offer a new therapeutic option which has the potential to generate anticancer immunity by various mechanisms. CD40 is a TNF receptor superfamily member expressed broadly on antigen-presenting cells (APC) such as dendritic cells, B cells, and monocytes as well as many nonimmune cells and a range of tumors. Agonistic CD40 mAb have been shown to activate APC and promote antitumor T-cell responses and to foster cytotoxic myeloid cells with the potential to control cancer in the absence of T-cell immunity. Thus, agonistic CD40 mAb are fundamentally different from mAb which block negative immune checkpoint such as anti-CTLA-4 or anti-PD-1. Initial clinical trials of agonistic CD40 mAb have shown highly promising results in the absence of disabling toxicity, both in single-agent studies and in combination with chemotherapy; however, numerous questions remain about dose, schedule, route of administration, and formulation. Recent findings about the role played by the IgG isotype and the Fc gamma receptor (FcγR) in mAb cross-linking, together with insights into mechanisms of action, particularly with regard to the role of myeloid cells, are predicted to help design next-generation CD40 agonistic reagents with greater efficacy. Here, we will review the preclinical and clinical data and discuss the major issues facing the field.

Platinum-Based Chemotherapy for Variant Castrate-Resistant Prostate Cancer

Abstract: Purpose: Clinical features characteristic of small-cell prostate carcinoma (SCPC), “anaplastic,” often emerge during the progression of prostate cancer. We sought to determine the efficacy of platinum-based chemotherapy in patients meeting at least one of seven prospectively defined “anaplastic” clinical criteria, including exclusive visceral or predominantly lytic bone metastases, bulky tumor masses, low prostate-specific antigen levels relative to tumor burden, or short response to androgen deprivation therapy. Experimental Design: A 120-patient phase II trial of first-line carboplatin and docetaxel (CD) and second-line etoposide and cisplatin (EP) was designed to provide reliable clinical response estimates under a Bayesian probability model with early stopping rules in place for futility and toxicity. Results: Seventy-four of 113 (65.4%) and 24 of 71 (33.8%) were progression free after four cycles of CD and EP, respectively. Median overall survival (OS) was 16 months [95% confidence interval (CI), 13.6–19.0 months]. Of the seven “anaplastic” criteria, bulky tumor mass was significantly associated with poor outcome. Lactic acid dehydrogenase strongly predicted for OS and rapid progression. Serum carcinoembryonic antigen (CEA) concentration strongly predicted OS but not rapid progression. Neuroendocrine markers did not predict outcome or response to therapy. Conclusion: Our findings support the hypothesis that patients with “anaplastic” prostate cancer are a recognizable subset characterized by a high response rate of short duration to platinum-containing chemotherapies, similar to SCPC. Our results suggest that CEA is useful for selecting therapy in men with castration-resistant prostate cancer and consolidative therapies to bulky high-grade tumor masses should be considered in this patient population. Clin Cancer Res; 19(13); 3621–30. ©2013 AACR .

BRAF inhibition increases tumor infiltration by T cells and enhances the antitumor activity of adoptive immunotherapy in mice.

Abstract: Purpose: Treatment of melanoma patients with selective BRAF inhibitors results in objective clinical responses in the majority of patients with BRAF -mutant tumors. However, resistance to these inhibitors develops within a few months. In this study, we test the hypothesis that BRAF inhibition in combination with adoptive T-cell transfer (ACT) will be more effective at inducing long-term clinical regressions of BRAF -mutant tumors. Experimental Design: BRAF -mutated human melanoma tumor cell lines transduced to express gp100 and H-2D b to allow recognition by gp100-specific pmel-1 T cells were used as xenograft models to assess melanocyte differentiation antigen–independent enhancement of immune responses by BRAF inhibitor PLX4720. Luciferase-expressing pmel-1 T cells were generated to monitor T-cell migration in vivo . The expression of VEGF was determined by ELISA, protein array, and immunohistochemistry. Importantly, VEGF expression after BRAF inhibition was tested in a set of patient samples. Results: We found that administration of PLX4720 significantly increased tumor infiltration of adoptively transferred T cells in vivo and enhanced the antitumor activity of ACT. This increased T-cell infiltration was primarily mediated by the ability of PLX4720 to inhibit melanoma tumor cell production of VEGF by reducing the binding of c-myc to the VEGF promoter. Furthermore, analysis of human melanoma patient tumor biopsies before and during BRAF inhibitor treatment showed downregulation of VEGF consistent with the preclinical murine model. Conclusion: These findings provide a strong rationale to evaluate the potential clinical application of combining BRAF inhibition with T-cell–based immunotherapy for the treatment of patients with melanoma. Clin Cancer Res; 19(2); 393–403. ©2012 AACR .

Dual CDK4/CDK6 inhibition induces cell-cycle arrest and senescence in neuroblastoma

Abstract: Purpose: Neuroblastoma is a pediatric cancer that continues to exact significant morbidity and mortality. Recently, a number of cell-cycle proteins, particularly those within the Cyclin D/CDK4/CDK6/RB network, have been shown to exert oncogenic roles in neuroblastoma, suggesting that their therapeutic exploitation might improve patient outcomes. Experimental Procedures: We evaluated the effect of dual CDK4/CDK6 inhibition on neuroblastoma viability using LEE011 (Novartis Oncology), a highly specific CDK4/6 inhibitor. Results: Treatment with LEE011 significantly reduced proliferation in 12 of 17 human neuroblastoma-derived cell lines by inducing cytostasis at nanomolar concentrations (mean IC 50 = 307 ± 68 nmol/L in sensitive lines). LEE011 caused cell-cycle arrest and cellular senescence that was attributed to dose-dependent decreases in phosphorylated RB and FOXM1, respectively. In addition, responsiveness of neuroblastoma xenografts to LEE011 translated to the in vivo setting in that there was a direct correlation of in vitro IC 50 values with degree of subcutaneous xenograft growth delay. Although our data indicate that neuroblastomas sensitive to LEE011 were more likely to contain genomic amplification of MYCN ( P = 0.01), the identification of additional clinically accessible biomarkers is of high importance. Conclusions: Taken together, our data show that LEE011 is active in a large subset of neuroblastoma cell line and xenograft models, and supports the clinical development of this CDK4/6 inhibitor as a therapy for patients with this disease. Clin Cancer Res; 19(22); 6173–82. ©2013 AACR .

Adoptive Transfer of Tumor-Infiltrating Lymphocytes in Patients with Metastatic Melanoma: Intent-to-Treat Analysis and Efficacy after Failure to Prior Immunotherapies

Abstract: Purpose: Adoptive cell transfer (ACT) using autologous tumor-infiltrating lymphocytes (TIL) was reported to yield objective responses in about 50% of metastatic patients with melanoma. Here, we present the intent-to-treat analysis of TIL ACT and analyze parameters predictive to response as well as the impact of other immunotherapies. Experimental Design: Eighty patients with stage IV melanoma were enrolled, of which 57 were treated with unselected/young TIL and high-dose interleukin-2 (IL-2) following nonmyeloablative lymphodepleting conditioning. Results: TIL cultures were established from 72 of 80 enrolled patients. Altogether 23 patients were withdrawn from the study mainly due to clinical deterioration during TIL preparation. The overall response rate and median survival was 29% and 9.8 months for enrolled patients and 40% and 15.2 months for treated patients. Five patients achieved complete and 18 partial remission. All complete responders are on unmaintained remission after a median follow-up of 28 months and the 3-year survival of responding patients was 78%. Multivariate analysis revealed blood lactate-dehydrogenase levels, gender, days of TIL in culture, and the total number of infused CD8 + cells as independent predictive markers for clinical outcome. Thirty-two patients received the CTLA-4-blocking antibody ipilimumab prior or post TIL infusion. Retrospective analysis revealed that nonresponders to ipilimumab or IL-2 based therapy had the same overall response rate to ACT as other patients receiving TIL. No additional toxicities to TIL therapy occurred following ipilimumab treatment. Conclusion: Adoptive transfer of TIL can yield durable and complete responses in patients with refractory melanoma, even when other immunotherapies have failed. Clin Cancer Res; 19(17); 4792–800. ©2013 AACR .

Clinical, pathologic, and biologic features associated with BRAF mutations in non-small cell lung cancer.

Abstract: Purpose: BRAF mutations are found in a subset of non–small cell lung cancers (NSCLC). We examined the clinical characteristics and treatment outcomes of patients with NSCLC harboring BRAF mutations. Experimental Design: Using DNA sequencing, we successfully screened 883 patients with NSCLC for BRAF mutations between July 1, 2009 and July 16, 2012. Baseline characteristics and treatment outcomes were compared between patients with and without BRAF mutations. Wild-type controls consisted of patients with NSCLC without a somatic alteration in BRAF , KRAS , EGFR , and ALK . In vitro studies assessed the biologic properties of selected non-V600E BRAF mutations identified from patients with NSCLC. Results: Of 883 tumors screened, 36 (4%) harbored BRAF mutations (V600E, 18; non-V600E, 18) and 257 were wild-type for BRAF , EGFR , KRAS , and ALK negative. Twenty-nine of 36 patients with BRAF mutations were smokers. There were no distinguishing clinical features between BRAF -mutant and wild-type patients. Patients with advanced NSCLC with BRAF mutations and wild-type tumors showed similar response rates and progression-free survival (PFS) to platinum-based combination chemotherapy and no difference in overall survival. Within the BRAF cohort, patients with V600E-mutated tumors had a shorter PFS to platinum-based chemotherapy compared with those with non-V600E mutations, although this did not reach statistical significance (4.1 vs. 8.9 months; P = 0.297). We identified five BRAF mutations not previously reported in NSCLC; two of five were associated with increased BRAF kinase activity. Conclusions: BRAF mutations occur in 4% of NSCLCs and half are non-V600E. Prospective trials are ongoing to validate BRAF as a therapeutic target in NSCLC. Clin Cancer Res; 19(16); 4532–40. ©2013 AACR .