Abstract CT180: Changes in immunologic responses and in the tumor microenvironment in patients with glioblastoma multiforme treated with IFN-a immune cell and gene therapy (TEM-GBM_001 Study)

Genetically modified cell-based therapies are of increasing relevance in immuno-oncology due to their potential for tumor specificity, long term efficacy & limiting off-target effects. We have developed a genetically modified cell-based platform, with ex-vivo transduction of autologous hematopoietic stem & progenitor cells with a lentiviral vector expressing the IFN-α transgene (Temferon) & delivery by autologous stem cell transplantation (ASCT). Specific control mechanisms restrict transgene expression to Tie-2 expressing macrophages (TEMs) thanks to a specific Tie-2 promoter & a post-transcriptional regulation layer represented by miRNA target sequences.

TEM-GBM is an ongoing open-label, Phase I/IIa dose-escalation study evaluating safety & efficacy of Temferon in newly diagnosed patients with glioblastoma & unmethylated MGMT promoter. Part A includes 15 patients to optimize the dose & conditioning regimen (completion expected end of Q2/21), & Part B includes 6 patients.

By 10th Nov 2020, 13 patients had enrolled; 8 received Temferon with a median follow up of 298 days (53-491). One patient died from progressive disease (PD) at D+403. PD occurred in 6 patients after a median 123 days (83-229) from treatment, within expectations for this tumor type. 4 patients underwent second surgery. Temferon was well tolerated, with median neutrophil & platelet engraftment occurring at D+13 & D+12, respectively, post submyeloablative BCNU + Thiotepa conditioning, & without dose-limiting toxicities. SAEs attributed to ASCT, concomitant medications & GBM progression included febrile neutropenia & other infectious complications, venous thromboembolism, poor performance status, liver enzyme elevation, brain abscess & hemiparesis. Temferon-derived differentiated cells, as determined by the presence of vector genomes in peripheral blood & bone marrow, were evident within 14 days from treatment & persisted, albeit at lower levels, in the long term (up to 1 year). The built-in transgene expression control mechanism was effective as suggested by the very low concentrations of IFN-α detected in the plasma & cerebrospinal fluid. The T-cell immune repertoire changed after treatment, with evidence for expansion of tumor-associated clones in peripheral blood. Preliminary data on tumor specimens from second surgery confirmed the presence of TEMs & increased expression of IFN-responsive gene signatures compared to diagnosis indicative of local IFN-α release. Biopsies of a stable as compared to a progressing lesion in 1 patient had a higher proportion of T cells & TEMs within the myeloid infiltrate & a markedly increased IFN-response signature. Comprehensive characterization of the tumor microenvironment by scRNA sequencing is ongoing. The results provide initial evidence of the biological effects of Temferon in patients with GBM.

Citation Format: Bernhard Gentner, Gaetano Finocchiaro, Francesca Farina, Alessia Capotondo, Marica Eoli, Elena Anghileri, Maya Ganzetti, Matteo Carabba, Valeria Cuccarini, Francesco Di Meco, Federico Legnani, Bianca Pollo, Maria Grazia Bruzzone, Marco Saini, Paolo Ferroli, Roberto Pallini, Alessandro Olivi, Rosina Paterra, Mariagrazia Garramone, Stefania Mazzoleni, Valentina Brambilla, Tiziana Magnani, Gabriele Antonarelli, Matteo Naldini, Matteo Barcella, Carlo Russo, Luigi Naldini, Fabio Ciceri. Changes in immunologic responses and in the tumor microenvironment in patients with glioblastoma multiforme treated with IFN-a immune cell and gene therapy (TEM-GBM_001 Study) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr CT180.

CAR T-Cells in Multiple Myeloma: State of the Art and Future Directions

Despite recent therapeutic advances, the prognosis of multiple myeloma (MM) patients remains poor. Thus, new strategies to improve outcomes are imperative. Chimeric antigen receptor (CAR) T-cell therapy has changed the treatment landscape of B-cell malignancies, providing a potentially curative option for patients who are refractory to standard treatment. Long-term remissions achieved in patients with acute lymphoblastic leukemia and Non-Hodgkin Lymphoma encouraged its further development in MM. B-cell maturation antigen (BCMA)-targeted CAR T-cells have established outstanding results in heavily pre-treated patients. However, several other antigens such as SLAMF7 and CD44v6 are currently under investigation with promising results. Idecabtagene vicleucel is expected to be approved soon for clinical use. Unfortunately, relapses after CAR T-cell infusion have been reported. Hence, understanding the underlying mechanisms of resistance is essential to promote prevention strategies and to enhance CAR T-cell efficacy. In this review we provide an update of the most recent clinical and pre-clinical data and we elucidate both, the potential and the challenges of CAR T-cell therapy in the future.

Smoldering multiple myeloma: the role of different scoring systems in identifying high-risk patients in real-life practice

We explore the predictive role of 2014-updated International Myeloma Working Group (IMWG) diagnostic criteria and of some of currently available risk models for progression to symptomatic myeloma when applied in our unselected population of 75 smoldering multiple myeloma (SMM) patients observed between 2000 and 2015. Risk scores including routinely used clinical parameters such as bone marrow plasmacell infiltration rate, immunoparesis, serum monoclonal component (sMC) value, and altered free light chain ratio (FLCr), were clinically useful to identify SMM patients at higher risk of progression. Time to myeloma progression in our ultra-high risk SMM according to IMWG diagnostic update criteria was very short (12.4 months). Our analysis identified as independent reliable predictors of progression altered FLCr as well as increasing plasma cell infiltration which are part of most commonly applied risk models. Waiting for new scoring systems, bone marrow evaluation and complete laboratory screening are still milestones for SMM management.

Can sliding-window correlations reveal dynamic functional connectivity in resting-state fMRI?

During the last several years, the focus of research on resting-state functional magnetic resonance imaging (fMRI) has shifted from the analysis of functional connectivity averaged over the duration of scanning sessions to the analysis of changes of functional connectivity within sessions. Although several studies have reported the presence of dynamic functional connectivity (dFC), statistical assessment of the results is not always carried out in a sound way and, in some studies, is even omitted. In this study, we explain why appropriate statistical tests are needed to detect dFC, we describe how they can be carried out and how to assess the performance of dFC measures, and we illustrate the methodology using spontaneous blood-oxygen level-dependent (BOLD) fMRI recordings of macaque monkeys under general anesthesia and in human subjects under resting-state conditions. We mainly focus on sliding-window correlations since these are most widely used in assessing dFC, but also consider a recently proposed non-linear measure. The simulations and methodology, however, are general and can be applied to any measure. The results are twofold. First, through simulations, we show that in typical resting-state sessions of 10 min, it is almost impossible to detect dFC using sliding-window correlations. This prediction is validated by both the macaque and the human data: in none of the individual recording sessions was evidence for dFC found. Second, detection power can be considerably increased by session- or subject-averaging of the measures. In doing so, we found that most of the functional connections are in fact dynamic. With this study, we hope to raise awareness of the statistical pitfalls in the assessment of dFC and how they can be avoided by using appropriate statistical methods.