Robyn Denise Gartrell

Talimogene laherparepvec (T-Vec) for the treatment of melanoma and other cancers

Talimogene laherparepvec (T-Vec) is the first live virus to be approved by the US Food and Drug Administration for the treatment of cancer. This engineered version of herpes simplex virus type 1 (HSV-1) is the product of decades of preclinical work aimed at identifying and modifying aspects of the viral genome involved in virulence and immunogenicity. T-Vec preferentially infects and lyses tumor cells and, in some cases, induces a systemic immune response against the tumor. These properties have translated into significant and durable clinical responses, particularly in advanced melanoma. Many unanswered questions remain, including how to augment these clinical responses and which other tumor types may respond to oncolytic therapy. Here, we review the development of T-Vec, our current understanding of its impact on the tumor immune micro-environment, and its safety and efficacy in clinical trials for melanoma and other cancers.

Timing of Adjuvant Radiotherapy in Glioblastoma Patients: A Single-Institution Experience With More Than 400 Patients.

BACKGROUND The standard of care for patients with newly diagnosed glioblastoma (GBM) is maximal safe resection followed by adjuvant radiation therapy (RT) and temozolomide (TMZ). OBJECTIVE To investigate whether the timing of adjuvant RT after surgery affected outcome in patients with GBM. METHODS We retrospectively reviewed all patients with a diagnosis of GBM at our institution. A total of 447 patients were included in our analysis. Patients were divided into 3 equal groups based on the interval between surgery and RT. The primary outcome was overall survival (OS). RESULTS Patients who began RT less than 21 days after surgery tended to be older, have a lower a Karnofsky Performance Status score, and higher recursive partitioning analysis class. These patients were more likely to have undergone biopsy only and received 3-dimensional conformal RT or 2-dimensional RT. The median OS for patients who started RT less than 21 days after surgery, between 21 and 32 days after surgery, and more than 32 days after surgery was 374, 465, and 478 days, respectively (P = .004). On multivariate Cox regression analysis, Karnofsky Performance Status score lower than 70, undergoing biopsy only, recursive partitioning analysis classes IV and V/VI, use of less than 36 Gy RT, and lack of TMZ chemotherapy were predictors of worse OS. The interval between surgery and RT was not significantly associated with OS on multivariate analysis. CONCLUSION Patients who begin RT less than 21 days after surgery tend to have worse prognostic factors than those who begin RT later. When accounting for significant covariates, the effect of timing between surgery and RT is not significant.

Hypofractionated radiation therapy versus standard fractionated radiation therapy with concurrent temozolomide in elderly patients with newly diagnosed glioblastoma

PURPOSE Adjuvant hypofractionated radiation therapy (HRT) for elderly patients with newly diagnosed glioblastoma (GBM) is a reasonable option compared with standard fractionation radiation therapy (SFRT). Outcomes in patients receiving HRT in the presence of temozolomide (TMZ) compared with SFRT with TMZ are unclear. We examined HRT for GBM with TMZ in comparison to SFRT with TMZ. METHODS AND MATERIALS We conducted a retrospective analysis of patients ≥60 years of age with newly diagnosed GBM who received SFRT or HRT from 1994 to 2014 in the postoperative setting. Inclusion criteria included SFRT (60 Gy/30 fractions or 59.4 Gy/33 fractions) versus HRT (40 Gy/15 fractions). RESULTS In this cohort, 158 patients were treated with SFRT versus 26 with HRT. Median survival in patients receiving SFRT compared with HRT was 430 and 475 days (P = .550), respectively. Ninety-five percent of the SFRT patients received TMZ versus 100% of those treated with HRT. Patients receiving HRT were older (median, 72 vs 66 years). All HRT patients were treated with the intensity modulated radiation therapy (IMRT) technique versus SFRT, in which 57% had IMRT. Multivariate Cox regression showed decreased overall survival (OS) associated with patient age >70 (hazard ratio [HR], 1.84), lower Karnofsky performance status (HR, 5.25), biopsy versus surgical resection (HR, 4.18), radiation therapy planning technique 3- or 2-dimensional planning versus IMRT (HR, 1.91; HR, 3.40, respectively). Analysis restricted to patients receiving IMRT-based planning showed no difference in OS between HRT and SFRT. For patients receiving TMZ, there was no survival difference between those treated with HRT and those treated with SFRT. CONCLUSIONS Elderly GBM patients receiving HRT and those receiving SFRT had similar OS. Subset analysis patients receiving concurrent TMZ showed no difference in OS between the HRT and SFRT groups.

A Modern Radiotherapy Series of Survival in Hispanic Patients with Glioblastoma

BACKGROUND Studies have shown racial differences in cancer outcomes. We investigate whether survival differences existed in Hispanic patients with glioblastoma (GBM) compared with other ethnicities from our modern radiotherapy series, because no study to date has focused on outcomes in this group after radiation therapy. METHODS We retrospectively evaluated 428 patients diagnosed with GBM from 1996 to 2014 at our institution, divided into 4 groups based on self-report: white, black, Hispanic, and Asian/Indian. The primary outcome was overall survival. We analyzed differences in prognostic factors among the whole cohort compared with the Hispanic cohort alone. RESULTS Baseline characteristics of the 4 racial groups were comparable. With a median follow-up of 387 days, no survival differences were seen by Kaplan-Meier analysis. Median overall survival for Hispanic patients was 355 days versus 450 days for the entire cohort. Factors significant for patient outcomes in the entire cohort differed slightly from those specific to Hispanic patients. Low Karnofsky Performance Status was significant on multivariate analysis in the whole population, but not in Hispanic patients. Extent of resection, recursive partitioning analysis class, and radiation therapy total dose were significant on multivariate analysis in both the whole population and Hispanic patients. CONCLUSIONS We found that Hispanic patients with GBM had no difference in survival compared with other ethnicities in our cohort. Differences exist in factors associated with outcomes on single and multivariate analysis for Hispanic patients with GBM compared with the entire cohort. Additional studies focusing on Hispanic patients will aid in more personalized treatment approaches in this group.

Complete intracranial response to talimogene laherparepvec (T-Vec), pembrolizumab and whole brain radiotherapy in a patient with melanoma brain metastases refractory to dual checkpoint-inhibition

BackgroundImmunotherapy, in particular checkpoint blockade, has changed the clinical landscape of metastatic melanoma. Nonetheless, the majority of patients will either be primary refractory or progress over follow up. Management of patients progressing on first-line immunotherapy remains challenging. Expanded treatment options with combination immunotherapy has demonstrated efficacy in patients previously unresponsive to single agent or alternative combination therapy.Case presentationWe describe the case of a patient with diffusely metastatic melanoma, including brain metastases, who, despite being treated with stereotactic radiosurgery and dual CTLA-4/PD-1 blockade (ipilimumab/nivolumab), developed systemic disease progression and innumerable brain metastases. This patient achieved a complete CNS response and partial systemic response with standard whole brain radiation therapy (WBRT) combined with Talimogene laherparepvec (T-Vec) and pembrolizumab.ConclusionPatients who do not respond to one immunotherapy combination may respond during treatment with an alternate combination, even in the presence of multiple brain metastases. Biomarkers are needed to assist clinicians in evidence based clinical decision making after progression on first line immunotherapy to determine whether response can be achieved with second line immunotherapy.

The Role of Oncolytic Viruses in the Treatment of Melanoma

Purpose of ReviewOncolytic virotherapy is a new approach to the treatment of cancer and its success in the treatment of melanoma represents a breakthrough in cancer therapeutics. This paper provides a review of the current literature on the use of oncolytic viruses (OVs) in the treatment of melanoma.Recent FindingsTalimogene laherparepvec (T-VEC) is the first OV approved for the treatment of melanoma and presents new challenges as it enters the clinical setting. Several other OVs are at various stages of clinical and pre-clinical development for the treatment of melanoma. Reports from phase Ib-III clinical trials combining T-VEC with checkpoint blockade are encouraging and demonstrate potential added benefit of combination immunotherapy.SummaryOVs have recently emerged as a standard treatment option for patients with advanced melanoma. Several OVs and therapeutic combinations are in development. Immunooncolytic virotherapy combined with immune checkpoint inhibitors is promising for the treatment of advanced melanoma.

Quantitative Analysis of Immune Infiltrates in Primary Melanoma

Quantitative multiplex immunofluorescence and quantitative spatial analysis were used to evaluate the tumor microenvironment and allowed for the identification of a biomarker that correlated with survival in melanoma—the cytotoxic T lymphocyte-to-macrophage ratio. Novel methods to analyze the tumor microenvironment (TME) are urgently needed to stratify melanoma patients for adjuvant immunotherapy. Tumor-infiltrating lymphocyte (TIL) analysis, by conventional pathologic methods, is predictive but is insufficiently precise for clinical application. Quantitative multiplex immunofluorescence (qmIF) allows for evaluation of the TME using multiparameter phenotyping, tissue segmentation, and quantitative spatial analysis (qSA). Given that CD3+CD8+ cytotoxic lymphocytes (CTLs) promote antitumor immunity, whereas CD68+ macrophages impair immunity, we hypothesized that quantification and spatial analysis of macrophages and CTLs would correlate with clinical outcome. We applied qmIF to 104 primary stage II to III melanoma tumors and found that CTLs were closer in proximity to activated (CD68+HLA-DR+) macrophages than nonactivated (CD68+HLA-DR−) macrophages (P < 0.0001). CTLs were further in proximity from proliferating SOX10+ melanoma cells than nonproliferating ones (P < 0.0001). In 64 patients with known cause of death, we found that high CTL and low macrophage density in the stroma (P = 0.0038 and P = 0.0006, respectively) correlated with disease-specific survival (DSS), but the correlation was less significant for CTL and macrophage density in the tumor (P = 0.0147 and P = 0.0426, respectively). DSS correlation was strongest for stromal HLA-DR+ CTLs (P = 0.0005). CTL distance to HLA-DR− macrophages associated with poor DSS (P = 0.0016), whereas distance to Ki67− tumor cells associated inversely with DSS (P = 0.0006). A low CTL/macrophage ratio in the stroma conferred a hazard ratio (HR) of 3.719 for death from melanoma and correlated with shortened overall survival (OS) in the complete 104 patient cohort by Cox analysis (P = 0.009) and merits further development as a biomarker for clinical application. Cancer Immunol Res; 6(4); 481–93. ©2018 AACR.

Abstract P5-03-03: Cytotoxic t-lymphocyte density increased within the tumor immune microenvironment of patients with breast cancer following treatment with Akt inhibitor MK-2206

Background: The PAM (PI3K/Akt/mTOR) signaling pathway has been implicated in the oncogenesis of multiple solid malignancies, including breast cancer (BC). Tumor infiltrating lymphocytes (TILs) found within the tumor immune microenvironment (TME) are both prognostic of overall survival as well as predictive of response to neoadjuvant chemotherapy in BC. Our aim is to characterize the TME in a series of patients with operable stage I-III BC treated with MK-2206, an allosteric Akt inhibitor as part of a presurgical, window of opportunity, trial. In our presurgical trial (clinicaltrials.gov #: NCT01319539), patients received 2 doses of MK-2206 with first dose at day -9 and second at day -2 from surgery. Methods: Quantitative multiplex immunofluorescence (qmIF) was performed using immune biomarkers (DAPI, CD3, CD8, CD4, FOXP3, CD68, Pancytokeratin) on full section (4uM) tissue slides from core biopsy specimens and postsurgical specimens of 10 patients - 5 patient treated with MK-2206, and 5 prospectively collected untreated controls. Images were taken using Vectra, a novel pathology workstation and analyzed using inForm software to perform cell classification and phenotyping. Student T- test was used to compare biomarker changes before and after MK-2206. Results: Preliminary analysis demonstrates that patients treated with MK-2206 exhibited a significantly increased median cytotoxic T-cells (CD3CD8+) density, as compared to the matched control cohort (87% vs.0.2%, p Citation Format: Marks DK, Gartrell RD, Asmar ME, Hart TD, Lu Y, Esancy CL, Hibshoosh H, Connolly EP, Kalinsky KM, Saenger YM. Cytotoxic t-lymphocyte density increased within the tumor immune microenvironment of patients with breast cancer following treatment with Akt inhibitor MK-2206 [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-03-03.

Abstract A41: Combination immunotherapy leads to decreased tumor growth

Introduction/Background: Talimogene Laherparepvec (T-Vec) is the first oncolytic virus to be FDA approved for the treatment of cancer. T-Vec, a modified Herpes Simplex Type I virus (HSV I), has two mechanisms of action: direct cell lysis and immune activation. Combination immunotherapy using T-Vec and check-point blockade has shown promise in clinical trials.1 In preliminary work, our lab has shown that T-Vec causes up-regulation of programmed cell death protein 1 (PD-1) on infiltrating T cells in mice, suggesting potential synergy of T-Vec and anti-PD1 (α-PD1). The purpose of our study is to evaluate the effectiveness of combination immunotherapy to treat melanoma tumors in a transgenic BRAF melanoma model and study the immune microenvironment of these tumors post treatment. Materials and Methods: In a temporally and spatially regulated murine model of BRAFCA PTEN-/- spontaneous melanoma2, tumors are induced on the shaved right flank of mice. When tumors reach ≥5mm in diameter, mice are randomized into 6 treatment groups comparing combinations of BRAF inhibition (BRAFi) or control chow, intraperitoneal injections of α-PD1 or control (2A3), and intratumoral injections of T-Vec or control (PBS) by intratumoral injection. Treatment Groups: 1: Control + 2A3 + PBS 2: BRAFi + 2A3 + PBS 3: BRAFi + α-PD1 + PBS 4: BRAFi + 2A3 + T-Vec 5: BRAFi + α-PD1 + T-Vec 6: Control + α-PD1 + T-Vec Tumor growth is measured biweekly until end of study. Flow cytometry is performed on tumor, lymph node, and spleen to assess immune microenvironment. Multiplex immunohistochemistry will also be performed and analyzed with Mantra, using 6 immune biomarkers. Results: Mean tumor volume and survival was plotted to compare groups. Mice treated with combination T-Vec + BRAFi with or without α-PD1 have decreased tumor growth and longer survival compared to mice treated with control or single drug arms. Flow cytometry shows an increase in percent CD3+ cells in tumors of mice treated with combination α-PD1 + T-Vec compared to the control and single drug arms. Further analysis revealed very few CD45+ cells in tumors of the control group whilst mice receiving combination immunotherapy without BRAFi have higher CD45+ cells in tumor. Percent CD8+/CD3+ cells in tumors treated with immunotherapy appears to be increased compared to the control and BRAFi only group. Additionally, percent of CD4+/FOXP3+ cells in tumors appears to be decreased in groups receiving T-Vec while no change in CD4+/FOXP3+ populations was observed in draining lymph node or spleen. Conclusions: Initial findings show that combination therapy of BRAFi + α-PD1 + T-Vec is more effective than any single treatment. Combination immunotherapy increases infiltration of T cells into tumor. Furthermore, oncolytic virus appears to decrease CD4+/FOXP3+ (regulatory T cells) infiltrating tumor. This study is ongoing and further analysis will continue as we further evaluate the immune microenvironment using flow cytometry and immunohistochemistry. Acknowledgements: The study was funded by the Melanoma Research Alliance and Amgen (Amgen-CUMC-MRA Established Investigator Academic-Industry Partnership Award). References: 1. Andtbacka, R.H.I., et al. OPTiM: A randomized phase III trial of talimogene laherparepvec (T-VEC) versus subcutaneous (SC) granulocyte-macrophage colony-stimulating factor (GM-CSF) for the treatment (tx) of unresected stage IIIB/C and IV melanoma. ASCO Meeting Abstracts 31, LBA9008 (2013). 2. Dankort, D., et al. Braf(V600E) cooperates with Pten loss to induce metastatic melanoma. Nature genetics 41, 544-552 (2009). Citation Format: Robyn Gartrell, Zoe Blake, Ines Simoes, Yichun Fu, Takuro Sato, Yingzhi Qian, James Zhang, Yan Lu, Yvonne Saenger. Combination immunotherapy leads to decreased tumor growth. [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2016 Oct 20-23; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2017;5(3 Suppl):Abstract nr A41.