Drew Pratt

Tremelimumab in combination with ablation in patients with advanced hepatocellular carcinoma

BACKGROUND & AIMS Tremelimumab is a fully human monoclonal antibody that binds to cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) on the surface of activated T lymphocytes. Ablative therapies induce a peripheral immune response which may enhance the effect of anti-CTLA4 treatment in patients with advanced hepatocellular carcinoma (HCC). This study aimed to demonstrate whether tremelimumab could be combined safely and feasibly with ablation. METHODS Thirty-two patients with HCC were enrolled: male:female: 28:4; median age: 62 (range 36-76). Patients were given tremelimumab at two dose levels (3.5 and 10mg/kg i.v.) every 4weeks for 6 doses, followed by 3-monthly infusions until off-treatment criteria were met. On day 36, patients underwent subtotal radiofrequency ablation or chemoablation. Staging was performed by contrast-enhanced CT or MRI scan every 8weeks. RESULTS No dose-limiting toxicities were encountered. The most common toxicity was pruritus. Of the 19 evaluable patients, five (26.3%; 95% CI: 9.1-51.2%) achieved a confirmed partial response. Twelve of 14 patients with quantifiable HCV experienced a marked reduction in viral load. Six-week tumor biopsies showed a clear increase in CD8+ T cells in patients showing a clinical benefit only. Six and 12-month probabilities of tumor progression free survival for this refractory HCC population were 57.1% and 33.1% respectively, with median time to tumor progression of 7.4months (95% CI 4.7 to 19.4months). Median overall survival was 12.3months (95% CI 9.3 to 15.4months). CONCLUSIONS Tremelimumab in combination with tumor ablation is a potential new treatment for patients with advanced HCC, and leads to the accumulation of intratumoral CD8+ T cells. Positive clinical activity was seen, with a possible surrogate reduction in HCV viral load. LAY SUMMARY Studies have shown that the killing of tumors by direct methods (known as ablation) can result in the immune system being activated or switched on. The immune system could potentially also recognize and kill the cancer that is left behind. There are new drugs available known as immune checkpoint inhibitors which could enhance this effect. Here, we test one of these drugs (tremelimumab) together with ablation. CLINICAL TRIAL NUMBER ClinicalTrials.gov: NCT01853618.

Combined Small Cell Carcinoma of the Lung: Is It a Single Entity?

Background: SCLC accounts for 15% and 20% of all lung cancers, with combined SCLC (CSCLC) comprising 2% to 5%. Little is known about the clinical characteristics and molecular changes associated with the various histologic components. Methods: A total of 205 SCLC cases were resected between 2005 and 2015. Clinical and pathologic features were analyzed. All CSCLC cases were confirmed by histologic examination and immunohistochemistry. The individual components were microdissected using a novel automated dissection system, and DNA was extracted and subjected to targeted exome sequencing. Results: A total of 10 cases of CSCLC were identified out of 170 cases with adequate histologic material; squamous cell carcinoma comprised the second component in half of these (n = 5). There were no significant differences between CSCLC and pure SCLC with respect to clinical features. The median follow‐up time was 36 months. The median survival times of patients with pure SCLC and CSCLC were 58 months and 26 months, respectively (p = 0.030). The different components of three cases of CSCLC were deemed adequate for microdissection and sequencing. Approximately 75% of the identified somatic mutations were present in both components. There were also 15 gene mutations or six amplifications unique to only one of the components. Conclusions: We identified no significant clinical or pathologic differences between pure SCLC and CSCLC; CSCLC was associated with decreased overall survival compared with pure SCLC. The histologic components of CSCLC had high genetic concordance but also showed divergent genotypes. These findings may suggest a common precursor with subsequent acquisition of oncogenic changes in CSCLC.

Expression of CD70 (CD27L) Is Associated With Epithelioid and Sarcomatous Features in IDH-Wild-Type Glioblastoma.

Glioblastoma is an aggressive, often recalcitrant disease. In the majority of cases, prognosis is dismal and current therapies only moderately prolong survival. Immunotherapy is increasingly being recognized as an effective treatment modality. CD70 is a transmembrane protein that shows restricted expression in tissue but has been described in various malignancies. Therapeutic targeting of CD70 has demonstrated antitumor efficacy and is in clinical trials. Here, we sought to characterize CD70 expression in a large cohort of gliomas (n = 205) using tissue microarrays. We identified a subset of tumors (n = 18, 8.8% of high-grade gliomas) exhibiting moderate-to-strong immunoreactivity that enriched for the IDH-wild-type glioblastoma variants gliosarcoma (n = 10) and the newly described epithelioid glioblastoma (n = 4). CD70 expression was associated with prolonged survival in gliosarcoma. Analysis of TCGA datasets showed significantly increased CD70 expression in mesenchymal tumors and prolonged survival in recurrent non-G-CIMP high-expressing tumors. In CD70+ gliomas, there was a significant increase in CD68/CD163/HLA-DR+ tumor-associated macrophages, but not CD27+ TIL. These results confirm prior in vitro studies and demonstrate expression in a clinical cohort. The absence of CD70 expression in the post-treatment setting may portend more clinically aggressive disease in gliosarcoma. However, larger-scale studies will be needed to characterize and validate this relationship.

Diagnosis of Giant Cell Arteritis in an Asymptomatic Patient

Identification of an immunodominant type-II collagen peptide recognized by T cells in H-2q mice: self tolerance at the level of determinant selection. Eur J Immunol 1992;22: 1819–25. 50. Backlund J, Carlsen S, Hoger T, Holm B, Fugger L, Kihlberg J, et al. Predominant selection of T cells specific for the glycosylated collagen type II epitope (263-270) in humanized transgenic mice and in rheumatoid arthritis. Proc Natl Acad Sci U S A 2002;99:9960–5. 51. Snir O, Widhe M, Hermansson M, von Spee C, Lindberg J, Hensen S, et al. Antibodies to several citrullinated antigens are enriched in the joints of rheumatoid arthritis patients. Arthritis Rheum 2010;62:44–52. 52. Van Steenbergen HW, Raychaudhuri S, Rodriguez-Rodriguez L, Rantapaa-Dahlqvist S, Berglin E, Toes RE, et al. Association of valine and leucine at HLA–DRB1 position 11 with radiographic progression in rheumatoid arthritis, independent of the shared epitope alleles but not independent of anti–citrullinated protein antibodies. Arthritis Rheumatol 2015;67:877–86.

Type II (adult onset) Alexander disease in a paraplegic male with a rare D128N mutation in the GFAP gene.

Abstract not available.

Pulmonary tumor thrombotic microangiopathy and pulmonary veno-occlusive disease in a woman with cervical cancer treated with cediranib and durvalumab

BackgroundPulmonary tumor thrombotic microangiopathy (PTTM) is a rare cause of pulmonary hypertension that is associated with malignancies and is marked by the presence of non-occlusive tumor emboli and fibrocellular intimal proliferation of small pulmonary arteries leading to increased pulmonary vascular resistance and right heart failure. The diagnosis of PTTM is challenging to make pre-mortem and guidelines on treatment are lacking.Case presentationA 45-year-old woman with advanced squamous cell carcinoma of the cervix developed symptoms of dyspnea and evidence of right heart failure during a phase I clinical trial with cediranib and durvalumab. After an extensive evaluation, pre-capillary pulmonary hypertension was confirmed by right heart catheterization. Vasodilator therapy was initiated but resulted in the development of symptomatic hypoxemia and was discontinued. Despite continued supportive care, she continued to decline and was transitioned to hospice care. At autopsy, the cause of her right heart failure was found to be due to PTTM with features of pulmonary veno-occlusive disease (PVOD).ConclusionPTTM and PVOD are important diagnoses to consider in patients with a malignancy and the development of right heart failure and may be manifestations of a spectrum of similar disease processes.

A 47-year old female with a destructive sellar mass

A 47-year old woman from Honduras presented with severe headache and left eye pain. Imaging revealed a sellar mass. Cabergoline side-effects limited treatment and she subsequently developed left eye exophthalmos, ptosis and ophthalmoplegia. CT scans showed increased size and involvement of the cavernous sinus and left orbital apex. Presurgical MR imaging of the brain and dedicated pituitary scan revealed a 2.6 3 3.9 3 3.2 cm heterogeneously enhancing mass on T1-weighted images in the sella turcica with erosion of the surrounding bone and extension into the cavernous sinuses bilaterally (Figure 1a–c). Complete encasement of the left internal carotid artery and superior extension abutting the optic chiasm were also noted. The patient underwent a transsphenoidal approach for resection of the intrasellar component of the mass. Postoperative course was complicated by a right sixth nerve palsy that responded to radiation. MICROSCOPIC PATHOLOGY

Diagnosis of a growing radiation-induced skull lesion in a patient: an unusual scar

New lesions arising from within an area of previous irradiation often present a diagnostic dilemma, with new malignancy or metastasis of particular concern. The authors report a case of reactive fibroblast proliferation emerging from a previous radiation field and presenting as a growing lesion of the frontal and parietal skull. Following complete gross resection of the skull lesion and histopathological analysis, it was discovered that this lesion consisted of dense fibroblast proliferation with areas of osteonecrosis. This unusual reactive phenomenon offers a novel differential diagnosis for a new contrast-enhancing lesion in a region of previous radiation.

Abstract A195: Tremelimimab activates CD4 and CD8+ T cells in patients with hepatocellular carcinoma

Introduction: Tremelimumab is a fully human monoclonal antibody that binds to CTLA-4 expressed on the surface of activated T lymphocytes and results in inhibition of B7-CTLA-4-mediated downregulation of T-cell activation. Patients with advanced hepatocellular carcinoma, who progressed on standard of care, were treated with tremelimumab and tumor ablation (radiofrequency ablation and transcatheter arterial chemoembolization) to augment anti-tumor immunity. Treatment was safe and feasible. Encouraging clinical activity has been seen with objective confirmed partial responses in 4/12 (33%) evaluable patients and a time to progression of 7.4 months. Here we report first results from immunoanalysis evaluating tumor biopsies, immune cell subsets in peripheral blood and serum viral loads in patients with chronic HBV or HCV infection. Methods: 20 Patients with HCC were treated with tremelimumab and tumor ablation on clinical trial NCT01853618. Tumor biopsies were taken at the time of ablation and peripheral blood mononuclear cells (PBMC) were collected before and during treatment in a subset of patients. Serum samples were tested for viral load (quantitative HCV RNA). Serum HBsAg titers were measured by chemiluminescent microparticle immunoassay (CMIA) using the ARCHITECT platform (Abbott Laboratories, Chicago, IL), as per the manufacturer9s instructions. Tumor biopsies with analyzed by immunohistochemistry for CD3, CD4, CD8, CD20 and Granzyme B. Eleven-color flow cytometry was performed to study PBMC using the following antibodies: CD4, CD3, CD4, CD8, CD11c, CD14, CD19, CD20, CD25, CD38, CD45RA, CD56, CD123, CD127, CCR7, CCR4, CXCR3, PD-1, 4-1BB, TIM3, CTLA4, PD-L1, ICOS, HLA-DR. Statistical analysis was done using the Wilcoxon signed rank test. Results presented are preliminary and update data will be presented at meeting. Results: Immunohistochemical analysis of tumor biopsies demonstrated an increase in the CD3+CD8+ T cell population in tumors. CD8+ T cells stained positive for Granzyme A. No changes in the number of CD68+ macrophages were seen. Multi-color flow cytotometry PBMC revealed statistically significant changes after the 1st cycle of activated CD4+ and CD8+ T cells. There was a trend towards a reduction in CD4+ Tregs. Activated CD8+ T cells remained elevated for more than three months. Eight of 9 patients with quantifiable HCV experienced a marked reduction in viral load. Four of 4 HBV patients experienced a reduction in quantitative HepBsAg. Analysis of immune cell phenotype and more in depth analysis of tumor samples is ongoing and will be reported. Conclusions: Tremelimumab in combination with subtotal TACE or RFA leads to an accumulation of intratumoral CD8+ T cells, an activation of CD4+ and CD8+ T cells in peripheral blood and reductions in HCV viral load and HBsAg. Citation Format: Firouzeh Korangy, Mei ElGindi, Drew Pratt, David Venzon, Austin Duffy, Oxana Makarova-Rusher, Sid Kerkar, David Kleiner, Bradford Wood, Tim Greten. Tremelimimab activates CD4 and CD8+ T cells in patients with hepatocellular carcinoma. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A195.

Abstract 2653: Tremelimimab plus tumor ablation for patients with hepatocellular carcinoma: Clinical results, immunomonitoring analysis of peripheral T cells and tumor biopsies

Introduction: Ipilimumab, an anti-CTLA4 mAb, is the first immune-checkpoint inhibitor, to be approved by the FDA for the treatment of patients with melanoma. We performed a phase I/II clinical trial in patients with advanced hepatocellular carcinoma, who progressed on standard of care. Patients were treated with tremelimumab, another anti-CTLA4 mAb, and tumor ablation (radiofrequency ablation, cryoablation, and transcatheter arterial chemoembolization) to augment anti-tumor immunity. Peripheral blood mononuclear cells, viral load (HBV/HCV) and tumor biopsies were studied and clinical efficacy was correlated with immune monitoring results. Methods: Patients with HCC were enrolled in a study of tremelimumab combined with tumor ablation performed on week 6. Tumor biopsies were performed at baseline and at time of RFA/TACE and analyzed by immunohistochemistry. Gene expression analysis was performed using Nanostring technology and QIAGEN9s Ingenuity Pathway Analysis (IPA) software. Eleven-color flow cytometry was performed to study peripheral blood mononuclear cells obtained at baseline, after 4 and 8 weeks using the following antibodies: CD4, CD3, CD4, CD8, CD11c, CD14, CD19, CD20, CD25, CD38, CD45RA, CD56, CD123, CD127, CCR7, CCR4, CXCR3, PD-1, 4-1BB, TIM3, CTLA4, PD-L1, ICOS, HLA-DR, AFP- and survivin-HLA-A2 tetramer. HCV and HBV viral load was determined in serum samples. Results: 27 patients were enrolled. 12 patients received TACE and 13 underwent tumor ablation during week 6 of tremelimumab therapy. Of N = 10 patients evaluable for response outside of TACE/RFA-treated lesion, 4 (40%) achieved confirmed partial responses. 6-week tumor biopsies showed clear increase in the number of CD3+ and CD8+ T cells in patients showing a clinical response only. Multi-color flow cytometry of PBMC revealed statistically significant changes after the 1st cycle in activated CD4+ and CD8+ T cells. The CD4/Treg and CD8/Treg ratio increased only in patients showing a clinical response. Both AFP and survivin specific CD8+ T cells were detected in HLA-A2+ patients, but there was no change in the frequency of these cells upon treatment. However PD1 expression increased over time both on AFP and survivin specific T cells. Finally, eight of 9 patients with quantifiable HCV experienced a marked reduction in viral load. 100% (N = 4) of HBV patients experienced a reduction in quantitative HBsAg. Pathway analysis conducted through IPA revealed that the top canonical pathways upregulated by treatment were T-cell receptor, Ephrin-A, IL-1, G-coupled protein, and IL-6 signaling. Conclusions: Tremelimumab in combination with subtotal TACE or RFA leads to an accumulation of intratumoral CD8+ T cells, activation of CD4+ and CD8+ T cells in peripheral blood and reduction in HCV viral load and HBsAg in patients showing clinical response to therapy. Citation Format: Ashish Uppala, Mei ElGindi, Firouzeh Korangy, Drew Pratt, David Venzon, Austin Duffy, Oxana Rusher, David Kleiner, Elliot Levy, Bradford Wood, Tim Greten. Tremelimimab plus tumor ablation for patients with hepatocellular carcinoma: Clinical results, immunomonitoring analysis of peripheral T cells and tumor biopsies. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2653.