Single immunization with genetically attenuated Pf∆mei2 (GA2) parasites by mosquito bite in controlled human malaria infection: a placebo-controlled randomized trial.

Malaria vaccines consisting of metabolically active Plasmodium falciparum (Pf) sporozoites can offer improved protection compared with currently deployed subunit vaccines. In a previous study, we demonstrated the superior protective efficacy of a three-dose regimen of late-arresting genetically attenuated parasites administered by mosquito bite (GA2-MB) compared with early-arresting counterparts (GA1-MB) against a homologous controlled human malaria infection. Encouraged by these results, we explored the potency of a single GA2-MB immunization in a placebo-controlled randomized trial.

Validating human induced pluripotent stem cell-specific quality control tests for the release of an intermediate drug product in a Good Manufacturing Practice quality system.

One of the challenges in Good Manufacturing Practice (GMP)-compliant human induced pluripotent stem cell (hiPSC) production is the validation of quality control (QC) tests specific for hiPSCs, which are required for GMP batch release. This study presents a comprehensive description of the validation process for hiPSC-specific GMP-compliant QC assays; more specifically, the validation of assays to assess the potential presence of residual episomal vectors (REVs), the expression of markers of the undifferentiated state and the directed differentiation potential of hiPSCs. Critical aspects and specific acceptance criteria were formulated in a validation plan prior to assay validation.

EMA commentary on the guideline on quality, nonclinical and clinical aspects of medicinal products containing genetically modified cells.

Great advances have been made in the knowledge of development and regulatory approval of medicinal product containing genetically modified cells. Although a guideline has been available in the EU since 2012, the current updated version provides a useful guide to developers and professionals involved in the regulatory process of these medicines. This article presents the main issues communicated in that guidance, the regulators' insights and a commentary from the academic developers' point of view.

Good Manufacturing Practice-compliant human induced pluripotent stem cells: from bench to putative clinical products.

Background Aims: Few human induced pluripotent stem cell (hiPSC) lines are Good Manufacturing Practice (GMP)-compliant, limiting the clinical use of hiPSC-derived products. Here, we addressed this by establishing and validating an in-house platform to produce GMP-compliant hiPSCs that would be appropriate for producing both allogeneic and autologous hiPSC-derived products.

Methods: Our standard research protocol for hiPSCs production was adapted and translated into a GMP-compliant platform.

Protective efficacy of short-term infection with Necator americanus hookworm larvae in healthy volunteers in the Netherlands: a single-centre, placebo-controlled, randomised, controlled, phase 1 trial.

Background: Vaccine development against hookworm is hampered by the absence of the development of protective immunity in populations repeatedly exposed to hookworm, limiting identification of mechanisms of protective immunity and new vaccine targets. Immunisation with attenuated larvae has proven effective in dogs and partial immunity has been achieved using an irradiated larvae model in healthy volunteers. We aimed to investigate the protective efficacy of immunisation with short-term larval infection against hookworm challenge.

Timed adoptive T cell transfer during chemotherapy in patients with recurrent platinum-sensitive epithelial ovarian cancer.

Background: The presence of T cells and suppressive myeloid cells in epithelial ovarian cancer (EOC) correlate with good and bad clinical outcome, respectively. This suggests that EOC may be sensitive to adoptive cell therapy with autologous tumor-infiltrating lymphocytes (TIL), provided that immunosuppression by myeloid-derived suppressor cells and M2 macrophages is reduced. Platinum-based chemotherapy can alleviate such immunosuppression, potentially creating a window of opportunity for T cell-based immunotherapy.

Controlled Human Infection Studies: Proposals for guidance on how to design, develop and produce a challenge strain.

There is an increasing need to establish quality principles for designing, developing and manufacturing challenge agents as currently these agents are classified differently by various jurisdictions. Indeed, considerations for challenge agent manufacturing vary between countries due to differences in regulatory oversight, the categorization of the challenge agent and incorporation into medicinal/vaccine development processes. To this end, a whitepaper on the guidance has been produced and disseminated for consultation to researchers, regulatory experts and regulatory or advisory bodies.

Phase I/II study protocol to assess safety and efficacy of adoptive cell therapy with anti-PD-1 plus low-dose pegylated-interferon-alpha in patients with metastatic melanoma refractory to standard of care treatments: the ACTME trial.

Introduction: Treatment with anti-PD-1 immunotherapy does not lead to long-lasting clinical responses in approximately 60% of patients with metastatic melanoma. These refractory patients, however, can still respond to treatment with tumour infiltrating lymphocytes (TIL) and interferon-alpha (IFNa). A combination of TIL, pegylated-interferon-alpha (PEG-IFNa) and anti-PD-1 is expected to provide a safe, feasible and effective therapy for patients with metastatic melanoma, who are refractory to standard of care treatment options.

Regulating advanced therapy medicinal products through the Hospital Exemption: an analysis of regulatory approaches in nine EU countries.

To study regulatory approaches for the implementation and utilization of the Hospital Exemption (HE) in nine EU countries. Using public regulatory documentation and interviews with authorities we characterized the national implementation process of the HE, including national implementation characteristics and two outcomes: national licensing provisions and the amount of license holders. National licensing provisions vary substantially among selected countries as a result of different regulatory considerations that relate to unmet medical needs, benefit/risk balance, and innovation.

HA-1H T-Cell Receptor Gene Transfer to Redirect Virus-Specific T Cells for Treatment of Hematological Malignancies After Allogeneic Stem Cell Transplantation: A Phase 1 Clinical Study.

Graft-vs.-leukemia (GVL) reactivity after HLA-matched allogeneic stem cell transplantation (alloSCT) is mainly mediated by donor T cells recognizing minor histocompatibility antigens (MiHA). If MiHA are targeted that are exclusively expressed on hematopoietic cells of recipient origin, selective GVL reactivity without severe graft-vs.

A Randomized Controlled Trial to Investigate Safety and Variability of Egg Excretion After Repeated Controlled Human Hookworm Infection.

Background: Controlled human hookworm infections could significantly contribute to the development of a hookworm vaccine. However, current models are hampered by low and unstable egg output, reducing generalizability and increasing sample sizes. This study aims to investigate the safety, tolerability, and egg output of repeated exposure to hookworm larvae.

Advanced therapy medicinal product manufacturing under the hospital exemption and other exemption pathways in seven European Union countries.

Background Aims: As part of the advanced therapy medicinal product (ATMP) regulation, the hospital exemption (HE) was enacted to accommodate manufacturing of custom-made ATMPs for treatment purposes in the European Union (EU). However, how the HE pathway has been used in practice is largely unknown.

Methods: Using a survey and interviews, we provide the product characteristics, scale and motivation for ATMP manufacturing under HE and other, non-ATMP-specific exemption pathways in seven European countries.

Preclinical Development of Autologous Hematopoietic Stem Cell-Based Gene Therapy for Immune Deficiencies: A Journey from Mouse Cage to Bed Side.

Recent clinical trials using patient's own corrected hematopoietic stem cells (HSCs), such as for primary immunodeficiencies (Adenosine deaminase (ADA) deficiency, X-linked Severe Combined Immunodeficiency (SCID), X-linked chronic granulomatous disease (CGD), Wiskott-Aldrich Syndrome (WAS)), have yielded promising results in the clinic; endorsing gene therapy to become standard therapy for a number of diseases. However, the journey to achieve such a successful therapy is not easy, and several challenges have to be overcome. In this review, we will address several different challenges in the development of gene therapy for immune deficiencies using our own experience with Recombinase-activating gene 1 (RAG1) SCID as an example.

A double-blind, placebo-controlled phase 1/2a trial of the genetically attenuated malaria vaccine PfSPZ-GA1.

Immunization with attenuated sporozoites can induce protection against malaria infection, as shown by (Pf) sporozoites attenuated by radiation in multiple clinical trials. As alternative attenuation strategy with a more homogeneous population of Pf sporozoites (PfSPZ), genetically engineered sporozoites (SPZ) lacking the genes b9 and slarp induced sterile protection against malaria in mice. Consequently, PfSPZ-GA1 Vaccine, a Pf identical double knockout (Pf∆∆), was generated as a genetically attenuated malaria parasite vaccine and tested for safety, immunogenicity, and preliminary efficacy in malaria-naïve Dutch volunteers.

What does cell therapy manufacturing cost? A framework and methodology to facilitate academic and other small-scale cell therapy manufacturing costings.

Background Aims: Recent technical and clinical advances with cell-based therapies (CBTs) hold great promise in the treatment of patients with rare diseases and those with high unmet medical need. Currently the majority of CBTs are developed and manufactured in specialized academic facilities. Due to small scale, unique characteristics and specific supply chain, CBT manufacturing is considered costly compared to more conventional medicinal products.

Successful Preclinical Development of Gene Therapy for Recombinase-Activating Gene-1-Deficient SCID.

Recombinase-activating gene-1 (RAG1)-deficient severe combined immunodeficiency (SCID) patients lack B and T lymphocytes due to the inability to rearrange immunoglobulin and T cell receptor genes. Gene therapy is an alternative for those RAG1-SCID patients who lack a suitable bone marrow donor. We designed lentiviral vectors with different internal promoters driving codon-optimized to ensure optimal expression.

Low-dose interferon-alpha preconditioning and adoptive cell therapy in patients with metastatic melanoma refractory to standard (immune) therapies: a phase I/II study.

Background: Adoptive cell therapy (ACT) with tumor-reactive T cells has shown consistent clinical efficacy. We evaluated the response to ACT in combination with interferon alpha (IFNa) preconditioning in patients with stage IV metastatic melanoma, most of which were progressive on cytotoxic T-lymphocyte-associated protein 4 and/or programmed cell death protein 1 checkpoint blockade therapy.

Methods: Thirty-four patients were treated with ex vivo expanded tumor reactive T cells, derived from mixed lymphocyte autologous tumor cultures, or with autologous tumor-infiltrating lymphocytes and evaluated for clinical response.

A controlled human Schistosoma mansoni infection model to advance novel drugs, vaccines and diagnostics.

Schistosomiasis treatment relies on the use of a single drug, praziquantel, which is insufficient to control transmission in highly endemic areas. Novel medicines and vaccines are urgently needed. An experimental human model for schistosomiasis could accelerate the development of these products.

Generation and infusion of multi-antigen-specific T cells to prevent complications early after T-cell depleted allogeneic stem cell transplantation-a phase I/II study.

Prophylactic infusion of selected donor T cells can be an effective method to restore specific immunity after T-cell-depleted allogeneic stem cell transplantation (TCD-alloSCT). In this phase I/II study, we aimed to reduce the risk of viral complications and disease relapses by administrating donor-derived CD8 T cells directed against cytomegalovirus (CMV), Epstein-Barr virus (EBV) and adenovirus antigens, tumor-associated antigens (TAA) and minor histocompatibility antigens (MiHA). Twenty-seven of thirty-six screened HLA-A*02:01 patients and their CMV and/or EBV donors were included.

New Insights Into the Kinetics and Variability of Egg Excretion in Controlled Human Hookworm Infections.

Four healthy volunteers were infected with 50 Necator americanus infective larvae (L3) in a controlled human hookworm infection trial and followed for 52 weeks. The kinetics of fecal egg counts in volunteers was assessed with Bayesian multilevel analysis, which revealed an increase between weeks 7 and 13, followed by an egg density plateau of about 1000 eggs/g of feces. Variation in egg counts was minimal between same-day measurements but varied considerably between days, particularly during the plateau phase.

Establishing the Production of Male Schistosoma mansoni Cercariae for a Controlled Human Infection Model.

To accelerate the development of novel vaccines for schistosomiasis, we set out to develop a human model for Schistosoma mansoni infection in healthy volunteers. During natural infections, female schistosomes produce eggs that give rise to morbidity. Therefore, we produced single-sex, male Schistosoma mansoni cercariae for human infection without egg production and associated pathology.

Label-Free, Flow-Imaging Methods for Determination of Cell Concentration and Viability.

Purpose: To investigate the potential of two flow imaging microscopy (FIM) techniques (Micro-Flow Imaging (MFI) and FlowCAM) to determine total cell concentration and cell viability.

Methods: B-lineage acute lymphoblastic leukemia (B-ALL) cells of 2 different donors were exposed to ambient conditions. Samples were taken at different days and measured with MFI, FlowCAM, hemocytometry and automated cell counting.