Richard Rae

Systemic RNA delivery to dendritic cells exploits antiviral defence for cancer immunotherapy

Lymphoid organs, in which antigen presenting cells (APCs) are in close proximity to T cells, are the ideal microenvironment for efficient priming and amplification of T-cell responses. However, the systemic delivery of vaccine antigens into dendritic cells (DCs) is hampered by various technical challenges. Here we show that DCs can be targeted precisely and effectively in vivo using intravenously administered RNA-lipoplexes (RNA-LPX) based on well-known lipid carriers by optimally adjusting net charge, without the need for functionalization of particles with molecular ligands. The LPX protects RNA from extracellular ribonucleases and mediates its efficient uptake and expression of the encoded antigen by DC populations and macrophages in various lymphoid compartments. RNA-LPX triggers interferon-α (IFNα) release by plasmacytoid DCs and macrophages. Consequently, DC maturation in situ and inflammatory immune mechanisms reminiscent of those in the early systemic phase of viral infection are activated. We show that RNA-LPX encoding viral or mutant neo-antigens or endogenous self-antigens induce strong effector and memory T-cell responses, and mediate potent IFNα-dependent rejection of progressive tumours. A phase I dose-escalation trial testing RNA-LPX that encode shared tumour antigens is ongoing. In the first three melanoma patients treated at a low-dose level, IFNα and strong antigen-specific T-cell responses were induced, supporting the identified mode of action and potency. As any polypeptide-based antigen can be encoded as RNA, RNA-LPX represent a universally applicable vaccine class for systemic DC targeting and synchronized induction of both highly potent adaptive as well as type-I-IFN-mediated innate immune mechanisms for cancer immunotherapy.

Personalized RNA mutanome vaccines mobilize poly-specific therapeutic immunity against cancer

T cells directed against mutant neo-epitopes drive cancer immunity. However, spontaneous immune recognition of mutations is inefficient. We recently introduced the concept of individualized mutanome vaccines and implemented an RNA-based poly-neo-epitope approach to mobilize immunity against a spectrum of cancer mutations. Here we report the first-in-human application of this concept in melanoma. We set up a process comprising comprehensive identification of individual mutations, computational prediction of neo-epitopes, and design and manufacturing of a vaccine unique for each patient. All patients developed T cell responses against multiple vaccine neo-epitopes at up to high single-digit percentages. Vaccine-induced T cell infiltration and neo-epitope-specific killing of autologous tumour cells were shown in post-vaccination resected metastases from two patients. The cumulative rate of metastatic events was highly significantly reduced after the start of vaccination, resulting in a sustained progression-free survival. Two of the five patients with metastatic disease experienced vaccine-related objective responses. One of these patients had a late relapse owing to outgrowth of β2-microglobulin-deficient melanoma cells as an acquired resistance mechanism. A third patient developed a complete response to vaccination in combination with PD-1 blockade therapy. Our study demonstrates that individual mutations can be exploited, thereby opening a path to personalized immunotherapy for patients with cancer.

Generation of TCR-Engineered T Cells and Their Use To Control the Performance of T Cell Assays

The systematic assessment of the human immune system bears huge potential to guide rational development of novel immunotherapies and clinical decision making. Multiple assays to monitor the quantity, phenotype, and function of Ag-specific T cells are commonly used to unravel patients’ immune signatures in various disease settings and during therapeutic interventions. When compared with tests measuring soluble analytes, cellular immune assays have a higher variation, which is a major technical factor limiting their broad adoption in clinical immunology. The key solution may arise from continuous control of assay performance using TCR-engineered reference samples. We developed a simple, stable, robust, and scalable technology to generate reference samples that contain defined numbers of functional Ag-specific T cells. First, we show that RNA-engineered lymphocytes, equipped with selected TCRs, can repetitively deliver functional readouts of a controlled size across multiple assay platforms. We further describe a concept for the application of TCR-engineered reference samples to keep assay performance within or across institutions under tight control. Finally, we provide evidence that these novel control reagents can sensitively detect assay variation resulting from typical sources of error, such as low cell quality, loss of reagent stability, suboptimal hardware settings, or inaccurate gating.

Abstract CT202: IVAC MUTANOME: Individualized vaccines for the treatment of cancer

Cancer arises from the accumulation of genomic alterations and epigenetic changes that constitute a hallmark of cancer. Owing to the molecular heterogeneity in cancer, only a minor fraction of patients profit from approved therapies. Available targeted therapies can only address alterations common to a particular type of cancer and induce transient effects due to the generation of resistant sub-clones. In contrast, the IVAC MUTANOME project aims to immunologically target multiple cancer mutations uniquely expressed in a given patient9s tumor. The IVAC MUTANOME approach should be applicable to the majority of patients irrespective of the tumor entity and offers the potential to exploit the whole tumor mutanome of a given patient using a multi-target approach. The IVAC approach is supported by (i) the availability of technologies that allow fast discovery and validation of individual mutations based on sequencing of whole exome and (ii) an innovative vaccine platform based on RNA-technology supporting fast manufacturing and release of patient-specific vaccines targeting multiple immunogenic mutations within weeks. The phase I study to test the individualized cancer immunotherapeutics for the treatment of malignant melanoma was approved and initiated in 2013 (NCT02035956). With that, the IVAC MUTANOME trial is the first trial in Europe that introduces a fully personalized mutanome vaccine for cancer. The objectives of the clinical trial are to study the feasibility, safety, tolerability and immunogenicity of the IVAC MUTANOME approach for malignant melanoma. Feasibility will be shown by the proven ability to provide the fully personalized IVAC MUANOME vaccine to patients. Recruitment of a patient in the trial repetitively triggers the IVAC MUTANOME process covering (i) the receipt of tumor and blood sample specimens, (ii) the identification, prioritization and confirmation of mutations, (iii) testing of pre-existing immunity against private tumor mutations, (iv) the final selection of mutated sequences, (iv) design, production of a DNA lead structure, (v) GMP manufacturing and release of the patient-specific mRNA, (vi) shipment to the clinical trial site, and (vii) the administration of the IMP to patients. The IVAC MUTANOME recruitment status, manufacturing experiences and treatment status of this first-in-class clinical trial as well as novel data on the immune assessment incl. vaccine-induced mutation-specific T cell responses of the first patients treated will be presented. Citation Format: Bjoern-Philipp Kloke, Cedrik M. Britten, Carmen Loquai, Martin Lower, Sebastian Attig, Valesca Bukur, Nicole Bidmon, Evelyna Derhovanessian, Jan Diekmann, Mustafa Diken, Angela Filbry, Stephan Grabbe, Sandra Heesch, Christoph Hoeller, David Langer, Uli Luxemburger, Matthias Miller, Felicitas Mueller, Tina Mueller-Brenne, Inga Ortseifer, Burkhard Otte, Anna Paruzynski, Sebastian Petri, Richard Rae, Christine Seck, Kristina Spies, Arbel D. Tadmor, Jochen Utikal, Klaus Kuehlke, John Castle, Alexandra Kemmer-Brueck, Isabel Vogler, Andreas N. Kuhn, Sebastian Kreiter, Oezlem Tuereci, Ugur Sahin. IVAC MUTANOME: Individualized vaccines for the treatment of cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr CT202. doi:10.1158/1538-7445.AM2015-CT202

Cancer immunotherapy achieves breakthrough status: 12th annual meeting of the association for cancer immunotherapy (CIMT), Mainz, Germany, May 6–8, 2014

In December 2013, the Science magazine has designated cancer immunotherapy (CIMT) as the breakthrough of the year mainly due to clinical success stories in the area of checkpoint inhibitory antibodies and cellular gene therapy. This year’s CIMT 2014 meeting covered these recent success stories as well as additional technologies and therapeutic concepts that may form the base for the next wave of innovation to reach patients in the near future. Reflecting the increasing attention the field is attracting, the annual meeting of the Association for CIMT could observe yet another rise in the number of international participants (n = 950). A total of 85 used the opportunity to give lectures and 321 presented their cutting-edge innovations in poster sessions. CIMT offered a sizable stage for the dissemination and intensive discussion of research and development efforts in the areas of tumor vaccination, combination therapy, tumor microenvironment, immunoguiding, immunoinformatics and genomics, cellular therapies and

Abstract CT034: A first-in-human phase I/II clinical trial assessing novel mRNA-lipoplex nanoparticles for potent melanoma immunotherapy

Therapeutic vaccination with tumor antigen-encoding RNAs by local administration is currently being successfully employed in various clinical trials. Advancing from local to more efficient systemic targeting of antigen-presenting cells (APCs), we have developed pioneering RNA-lipoplex (RNA(LIP)) immunotherapeutics for intravenous application based on the employment of well-known lipid carriers without the need for functionalization of particles with molecular ligands. The novel RNA(LIP) formulation has been engineered to preserve RNA integrity after intravenous injection and physicochemically optimized for efficient uptake and expression of the encoded antigen by APCs in various lymphoid compartments, resulting in the synchronized induction of both potent adaptive as well as type-I-IFN-mediated innate immune responses. The first-in-human phase I/II dose escalation Lipo-MERIT trial (NCT02410733) assesses the safety, tolerability, and biological efficacy of the innovative RNA(LIP) immunotherapy in four study centers in Germany. This is the first example of a clinically applicable and systemic RNA-based cancer vaccine. Following selective antigen stratification on routinely collected tumor samples, eligible patients with malignant melanoma are treated with increasing doses of the tetravalent Lipo-MERIT vaccine - a fixed set of four RNA(LIP) products, each encoding one shared melanoma-associated antigen, i.e. NY-ESO-1, tyrosinase, MAGE-A3, and TPTE, that are administered successively within one treatment cycle. Accompanying correlative biomarker studies and concerted immunological assessments evaluate the pharmacodynamic activity and immunogenicity upon multiple vaccination cycles with the Lipo-MERIT vaccine. As of January 2017, 15 patients have been treated within five dose escalation cohorts thoroughly guided by an independent data safety and monitoring board. Multiple dosing with the Lipo-MERIT vaccine was generally well-tolerated and no dose-limiting toxicities (DLTs) were observed so far. Further patient enrollment is continuing. Detailed information on the ongoing trial, the recruitment and treatment status as well as preliminary data on the assessment of vaccine-induced immune responses from the first patients treated will be presented. Citation Format: Robert A. Jabulowsky, Carmen Loquai, Jochen Utikal, Jessica Hassel, Roland Kaufmann, Evelyna Derhovanessian, Mustafa Diken, Lena M. Kranz, Heinrich Haas, Sebastian Attig, Christine Anft, Janina Buck, Jan Diekmann, Daniel Fritz, Kerstin Hartmann, Alexandra Kemmer-Brueck, Klaus Kuehlcke, Andreas N. Kuhn, Peter Langguth, Ulrich Luxemburger, Martin Meng, Richard Rae, Fatih Sari, Doreen Schwarck-Kokarakis, Malte Stein, Stephan Grabbe, Sebastian Kreiter, Oezlem Tuereci, Christoph Huber, Ugur Sahin. A first-in-human phase I/II clinical trial assessing novel mRNA-lipoplex nanoparticles for potent melanoma immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT034. doi:10.1158/1538-7445.AM2017-CT034

Abstract CT032: A first-in-human phase I/II clinical trial assessing novel mRNA-lipoplex nanoparticles for potent cancer immunotherapy in patients with malignant melanoma

Immunotherapeutic approaches have evolved as promising and valid alternatives to available conventional cancer treatments. Amongst others, vaccination with tumor antigen-encoding RNAs by local administration is currently successfully employed in various clinical trials. To allow for a more efficient targeting of antigen-presenting cells (APCs) and to overcome potential technical challenges associated with local administration, we have developed a novel RNA immunotherapeutic for systemic application based on a fixed set of four liposome complexed RNA drug products (RNA(LIP)), each encoding one shared melanoma-associated antigen. The novel RNA(LIP) formulation was engineered (i) to protect RNA from degradation by plasma RNases and (ii) to enable directed in vivo targeting of APCs in lymphoid compartments, thus (iii) allowing for intravenous administration of multiple RNA products advancing from local to systemic targeting of APCs. Here, RNA(LIP) products trigger a Toll-like receptor (TLR)-mediated Interferon-α (IFN-α) release from plasmacytoid dendritic cells (DCs) and macrophages stimulating DC maturation and hence inducing innate immune mechanisms as well as potent vaccine antigen-specific immune responses. Notably, BioNTech RNA Pharmaceuticals′ RNA(LIP) formulation is a universally applicable potent novel vaccine class for intravenous APC targeting and the induction of potent synchronized adaptive and type-I interferon-mediated innate immune responses for cancer immunotherapy. Similar to other liposomal drugs, the ready-to-use RNA(LIP) products are prepared individually in a straight-forward manner directly prior to use from three components, namely solutions containing RNA drug product, NaCl diluent, and liposome excipient, that are provided as a kit. A multi-center phase I/II trial to clinically validate this pioneering RNA(LIP) formulation for the treatment of malignant melanoma was initiated in 2015 (NCT02410733). The objective of the clinical trial is to study the feasibility, safety, tolerability, immunogenicity and evaluate potential clinical activity of the RNA(LIP) immunotherapy concept. Detailed information on the ongoing trial, the recruitment and treatment status as well as data on the assessment of vaccine-induced immune responses will be presented. Citation Format: Robert A. Jabulowsky, Carmen Loquai, Mustafa Diken, Lena M. Kranz, Heinrich Haas, Sebastian Attig, Nicole Bidmon, Janina Buck, Evelyna Derhovanessian, Jan Diekmann, Daniel Fritz, Veronika Jahndel, Alexandra Kemmer-Brueck, Klaus Kuehlcke, Andreas N. Kuhn, Peter Langguth, Ulrich Luxemburger, Martin Meng, Felicitas Mueller, Richard Rae, Fatih Sari, Doreen Schwarck-Kokarakis, Christine Seck, Kristina Spies, Meike Witt, Jessica C. Hassel, Jochen Utikal, Roland Kaufmann, Sebastian Kreiter, Christoph Huber, Oezlem Tuereci, Ugur Sahin. A first-in-human phase I/II clinical trial assessing novel mRNA-lipoplex nanoparticles for potent cancer immunotherapy in patients with malignant melanoma. [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 CT032.

Toward next-generation cancer immunotherapy: 10th Annual Meeting of the Association for Cancer Immunotherapy (CIMT), Mainz, Germany, May 23–25, 2012

With 620 international participants, more than 70 speakers and 216 abstracts, the 2012 Annual Meeting of the Association for Cancer Immunotherapy (CIMT) celebrated its 10th anniversary as the premier European meeting dedicated to research and development of cancer immunotherapy. The latest advances of the field were discussed in sessions on cellular therapies, immunomonitoring, new targets and leads, therapeutic vaccination, tumor biology and immune interaction. Here, we summarize the highlights of the meeting which were representative of the newest advances and trends in the field of cancer immunotherapy. Personalized medicine

Development of an RNA-based kit for easy generation of TCR-engineered lymphocytes to control T-cell assay performance

Cell-based assays to monitor antigen-specific T-cell responses are characterized by their high complexity and should be conducted under controlled conditions to lower multiple possible sources of assay variation. However, the lack of standard reagents makes it difficult to directly compare results generated in one lab over time and across institutions. Therefore TCR-engineered reference samples (TERS) that contain a defined number of antigen-specific T cells and continuously deliver stable results are urgently needed. We successfully established a simple and robust TERS technology that constitutes a useful tool to overcome this issue for commonly used T-cell immuno-assays. To enable users to generate large-scale TERS, on-site using the most commonly used electroporation (EP) devices, an RNA-based kit approach, providing stable TCR mRNA and an optimized manufacturing protocol were established. In preparation for the release of this immuno-control kit, we established optimal EP conditions on six devices and initiated an extended RNA stability study. Furthermore, we coordinated on-site production of TERS with 4 participants. Finally, a proficiency panel was organized to test the unsupervised production of TERS at different laboratories using the kit approach. The results obtained show the feasibility and robustness of the kit approach for versatile in-house production of cellular control samples.

Abstract A004: Systemic RNA vaccines: Connecting effective cancer immunotherapy with antiviral defense mechanisms

Mechanisms of antiviral host defense are important for survival and evolutionarily optimized for high sensitivity and potency. Intending to harvest the multitude of highly specialized and intertwined pathogen immune defense programs for cancer immunotherapy, we simulated a systemic pathogen intrusion into the blood stream by intravenous injection of lipid-formulated, tumor antigen-encoding mRNA nanoparticles. These RNA-lipoplexes (RNA-LPX) were directed to various lymphoid tissues, including the spleen, lymph nodes and bone marrow, which provide the ideal microenvironment for efficient priming and amplification of T cell responses. Solely the RNA-to-lipid ratio was discovered to determine the biodistribution of RNA-LPX, irrespective of the types of lipids used, and a slightly negative particle net charge was able to specifically transfect lymphoid-resident antigen presenting cells (APCs). Following uptake by CD11c+ DCs, pDCs and macrophages in the marginal zone of the spleen and in other lymphoid organs, predominantly by macropinocytosis, RNA recognition via TLR7 triggered two transient waves of type I IFN production by pDCs (early response) and macrophages (delayed response), which established an inflammatory, lymphocyte-activating milieu reminiscent of that initiated during the early systemic phase of viral infection. These IFNα receptor (IFNAR)-dependent immune mechanisms were required for DCs to mature, migrate into the T cell zones and express RNA-encoded tumor antigens. Presentation on MHC class I and II in the context of upregulated CD40, CD69 and CD86 elicited strong effector and memory CD8 and CD4 T cell immunity against viral, mutant neo-antigens or self-antigens, which was able to reject progressive tumors in therapeutic mouse models of melanoma, colon carcinoma and human papilloma virus (HPV)-associated cancer. In an ongoing phase I dose escalation study, the first cohort of three patients with advanced melanoma received RNA-LPX encoding four shared tumor antigens at doses lower than those used in the mouse studies. All patients showed a dose-dependent IFNα- and IP-10-dominated cytokine response, developed de novo CD4 and CD8 T cell responses or enhanced pre-existing immunity against the encoded self-antigens NY-ESO-I, Tyrosinase and MAGE-A3, and have stable disease to date. These results support the preclinically identified mode of action and strong potency of this approach in the clinical setting. Our study presents a novel class of systemically administered nanoparticulate RNA vaccines acting by body-wide delivery of encoded antigens to APCs and simultaneous initiation of a strong type I IFN-driven immunostimulatory program. Precise DC targeting in lymphoid compartments is accomplished using well-known lipid carriers and only by manipulating the net charge of the nanoparticles. RNA-LPX vaccines appear to mimic infectious non-self and thus mobilize both adaptive and innate immune mechanisms, connecting effective cancer immunotherapy with host pathogen-defense mechanisms. The simple but highly versatile design allows vaccine preparation with any type of RNA-encoded antigen and may thus be regarded as a universally applicable, first-in-class vaccine platform for cancer immunotherapy. Citation Format: Lena M. Kranz, Mustafa Diken, Heinrich Haas, Sebastian Kreiter, Carmen Loquai, Kerstin C. Reuter, Martin Meng, Daniel Fritz, Fulvia Vascotto, Hossam Hefesha, Christian Grunwitz, Mathias Vormehr, Yves Husemann, Abderraouf Selmi, Andreas N. Kuhn, Janina Buck, Evelyna Derhovanessian, Richard Rae, Sebastian Attig, Jan Diekmann, Robert A. Jabulowsky, Sandra Heesch, Jessica Hassel, Peter Langguth, Stephan Grabbe, Christoph Huber, Ozlem Tureci, Ugur Sahin. Systemic RNA vaccines: Connecting effective cancer immunotherapy with antiviral defense mechanisms [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr A004.