Oncology Products in the European Union: An Analysis of Regulatory Approvals with a CHMP Oral Explanation

BACKGROUND

The oral explanation (OE) is a critical event during new marketing authorisation procedures in the European Union (EU). The primary objective of the present study was to investigate how many procedures, having an OE in front of the Committee for Medicinal Products for Human Use (CHMP), resulted in a regulatory approval for oncology products.

METHODS

Procedures for new marketing authorisation applications (MAAs) and Type II variations (new indication) for oncology products with at least one OE (with or without a Scientific Advisory Group (SAG) meeting) and for which the outcome took place between 31 January 2016 to 31 January 2020 were included in the analysis. Publicly available agendas/meeting minutes and assessment reports were used to obtain information on the products.

RESULTS

An OE occurred in about 20% of procedures (n = 28/150) for oncology products during the review period. The majority of procedures having an OE (61%), with or without any SAG meeting, led to MAA/Type II variation approval in the Centralised Procedure. It was also observed that in 41% of the cases a successful outcome was contingent upon willingness of the applicant to restrict the indication.

CONCLUSION

A majority of oncology procedures that had an OE resulted in a positive outcome suggesting that such agency interaction is an important opportunity for the applicant to have a last chance to resolve any outstanding issues at the final stage of the procedure.

CDK1 controls CHMP7-dependent nuclear envelope reformation

Through membrane sealing and disassembly of spindle microtubules, the Endosomal Sorting Complex Required for Transport-III (ESCRT-III) machinery has emerged as a key player in the regeneration of a sealed nuclear envelope (NE) during mitotic exit, and in the repair of this organelle during interphase rupture. ESCRT-III assembly at the NE occurs transiently during mitotic (M) exit and is initiated when CHMP7, an ER-localised ESCRT-II/ESCRT-III hybrid protein, interacts with the Inner Nuclear Membrane (INM) protein LEM2. Whilst classical nucleocytoplasmic transport mechanisms have been proposed to separate LEM2 and CHMP7 during interphase, it is unclear how CHMP7 assembly is suppressed in mitosis when NE and ER identities are mixed. Here, we use live cell imaging and protein biochemistry to examine the biology of these proteins during M-exit. Firstly, we show that CHMP7 plays an important role in the dissolution of LEM2 clusters that form at the NE during M-exit. Secondly, we show that CDK1 phosphorylates CHMP7 upon M-entry at Ser3 and Ser441 and that this phosphorylation reduces CHMP7's interaction with LEM2, limiting its assembly during M-phase. We show that spatiotemporal differences in the dephosphorylation of CHMP7 license its assembly at the NE during telophase, but restrict its assembly on the ER at this time. Without CDK1 phosphorylation, CHMP7 undergoes inappropriate assembly in the peripheral ER during M-exit, capturing LEM2 and downstream ESCRT-III components. Lastly, we establish that a microtubule network is dispensable for ESCRT-III assembly at the reforming nuclear envelope. These data identify a key cell-cycle control programme allowing ESCRT-III-dependent nuclear regeneration.

EMA Review of Axicabtagene Ciloleucel (Yescarta) for the Treatment of Diffuse Large B-Cell Lymphoma

On June 28, 2018, the Committee for Advanced Therapies and the Committee for Medicinal Products for Human Use adopted a positive opinion, recommending the granting of a marketing authorization for the medicinal product Yescarta for the treatment of adult patients with relapsed or refractory diffuse large B-cell lymphoma and primary mediastinal large B-cell lymphoma, after two or more lines of systemic therapy. Yescarta, which was designated as an orphan medicinal product and included in the European Medicines Agency's Priority Medicines scheme, was granted an accelerated review timetable. The active substance of Yescarta is axicabtagene ciloleucel, an engineered autologous T-cell immunotherapy product whereby a patient's own T cells are harvested and genetically modified ex vivo by retroviral transduction using a retroviral vector to express a chimeric antigen receptor (CAR) comprising an anti-CD19 single chain variable fragment linked to CD28 costimulatory domain and CD3-zeta signaling domain. The transduced anti-CD19 CAR T cells are expanded ex vivo and infused back into the patient, where they can recognize and eliminate CD19-expressing cells. The benefits of Yescarta as studied in ZUMA-1 phase II (NCT02348216) were an overall response rate per central review of 66% (95% confidence interval, 56%-75%) at a median follow-up of 15.1 months in the intention to treat population and a complete response rate of 47% with a significant duration. The most common adverse events were cytokine release syndrome, neurological adverse events, infections, pyrexia, diarrhea, nausea, hypotension, and fatigue. IMPLICATIONS FOR PRACTICE: Yescarta (axicabtagene ciloleucel) was the first chimeric antigen receptor T-cell therapy to be submitted for evaluation to the European Medicines Agency and admitted into the "priority medicine" scheme; it was granted accelerated assessment on the basis of anticipated clinical benefit in relapsed/refractory diffuse large B-cell lymphoma, a condition of unmet medical need. Indeed, Yescarta showed an overall response rate of 66% and a complete response rate of 47% with a significant duration and a manageable toxicity that compared very favorably with historical controls. Here the analysis of benefits and risks is presented, and specific challenges with this important novel product are highlighted, providing further insights and reflections for future medical research.

Blinatumomab for Acute Lymphoblastic Leukemia: The First Bispecific T-Cell Engager Antibody to Be Approved by the EMA for Minimal Residual Disease

On November 15, 2018, the Committee for Medicinal Products for Human Use (CHMP) recommended the extension of indication for blinatumomab to include the treatment of adults with minimal residual disease (MRD) positive B-cell precursor acute lymphoblastic leukemia (ALL). Blinatumomab was authorized to treat relapsed or refractory B-precursor ALL, and the change concerned an extension of use. On March 29, 2018, the U.S. Food and Drug Administration (FDA) granted accelerated approval to blinatumomab to treat both adults and children with B-cell precursor ALL who are in remission but still have MRD. On July 26, 2018, the CHMP had originally adopted a negative opinion on the extension. The reason for the initial refusal was that although blinatumomab helped to reduce the amount of residual cancer cells in many patients, there was no strong evidence that it led to improved survival. During the re-examination, the CHMP consulted the scientific advisory group. The CHMP agreed with the expert group's conclusion that, although there was no strong evidence of patients living longer, the available data from the main study (MT103-203) indicated a good durable response to blinatumomab, with an overall complete response rate for the primary endpoint full analysis set (defined as all subjects with an Ig or T-cell receptor polymerase chain reaction MRD assay with the minimum required sensitivity of 1 × 10^-4 at central lab established at baseline [n = 113]) as 79.6% (90/113; 95% confidence interval, 71.0-86.6), with a median time to complete MRD response of 29.0 days (range, 5-71). Therefore, the CHMP concluded that the benefits of blinatumomab outweigh its risks and recommended granting the change to the marketing authorization. The Committee for Orphan Medicinal Products, following reassessment, considered that significant benefit continued to be met and recommended maintaining the orphan designation and thus 10 years market exclusivity (the Orphan Designation is a legal procedure that allows for the designation of a medicinal substance with therapeutic potential for a rare disease, before its first administration in humans or during its clinical development). The marketing authorization holder for this medicinal product is Amgen Europe B.V. IMPLICATIONS FOR PRACTICE: Immunotherapy with blinatumomab has excellent and sustainable results, offering new hope for patients with minimal residual disease-positive acute lymphoblastic leukemia, a disease with poor prognosis. New recommendations and change of practice for treatment of this patient group are detailed.

Comprehensive analysis of yeast ESCRT-III composition in single ESCRT-III deletion mutants

The endosomal sorting complex required for transport (ESCRT)-III is associated with a multitude of cellular processes involving membrane remodeling and abscission. The exact composition of ESCRT-III and the contribution of individual ESCRT-III family members to these diverse functions is unclear. Most of the currently available information about ESCRT-III was obtained with tagged, largely non-functional proteins, which may not correctly reflect the in vivo situation. Here, we performed a comprehensive biochemical analysis of ESCRT-III localization and composition in yeast under purely native conditions. Most of our findings are in line with the current concepts about ESCRT-III, but some findings are unexpected and call for adjustments to the model. In particular, our data suggest that the distinction between bona fide ESCRT-III components and ESCRT-III associated proteins is not justified. We detected a single complex containing all ESCRT-III members (except of Chm7) with Did2 as its main component. The classical core components were present in equimolar amounts. Our analysis of the impact of single deletions on the composition of ESCRT-III confirmed the central role of Snf7 for ESCRT-III assembly. For the other ESCRT-III family members predictions could be made about their role in ESCRT-III assembly. Furthermore, our cell fractionation points to a role of Vps20 at the endoplasmic reticulum.

Dynamic and Sequential Protein Reconstitution on Negatively Curved Membranes by Giant Vesicles Fusion

In vitro investigation of the interaction between proteins and positively curved membranes can be performed using a classic nanotube pulling method. However, characterizing protein interaction with negatively curved membranes still represents a formidable challenge. Here, we describe our recently developed approach based on laser-triggered Giant Unilamellar Vesicles (GUVs) fusion. Our protocol allows sequential addition of proteins to a negatively curved membrane, while at the same time controlling the buffer composition, lipid composition and membrane tension. Moreover, this method does not require a step of protein detachment, greatly simplifying the process of protein encapsulation over existing methods.

ESCRT Mutant Analysis and Imaging of ESCRT Components in the Model Fungus Ustilago maydis

The ESCRT machinery (endosomal sorting complex required for transport) is an evolutionarily highly conserved multiprotein complex involved in numerous cellular processes like endocytosis, membrane repair, or endosomal long-distance transport. In fungal hyphae, endocytosis and long-distance mRNA transport are tightly linked, as endocytotic vesicles are also the key carrier vehicles for mRNAs. Studying the regulatory component Did2 (CHMP1) in the plant pathogen Ustilago maydis revealed that loss of Did2 resulted in disturbed endosomal maturation, thereby causing defects in microtubule-dependent transport of early endosomes. Here, we describe methods and protocols that allow studying the role of ESCRT components during endosomal transport. We present experimental strategies to analyze U. maydis ESCRT mutant phenotypes and test complementation with heterologous components, such as ESCRT regulators from Drosophila melanogaster.

Nonenvelopment Role for the ESCRT-III Complex during Human Cytomegalovirus Infection

Secondary envelopment of human cytomegalovirus (HCMV) occurs through a mechanism that is poorly understood. Many enveloped viruses utilize the endosomal sorting complexes required for transport (ESCRTs) for viral budding and envelopment. Although there are conflicting reports on the role of the ESCRT AAA ATPase protein VPS4 in HCMV infection, VPS4 may act in an envelopment role similar to its function during other viral infections. Because VPS4 is normally recruited by the ESCRT-III complex, we hypothesized that ESCRT-III subunits would also be required for HCMV infection. We investigated the role of ESCRT-III, the core ESCRT scission complex, during the late stages of infection. We show that inducible expression of dominant negative ESCRT-III subunits during infection blocks endogenous ESCRT function but does not inhibit virus production. We also show that HCMV forms enveloped intracellular and extracellular virions in the presence of dominant negative ESCRT-III subunits, suggesting that ESCRT-III is not involved in the envelopment of HCMV. We also found that as with ESCRT-III, inducible expression of a dominant negative form of VPS4A did not inhibit the envelopment of virions or reduce virus titers. Thus, HCMV does not require the ESCRTs for secondary envelopment. However, we found that ESCRT-III subunits are required for efficient virus spread. This suggests a role for ESCRT-III during the spread of HCMV that is independent of viral envelopment.IMPORTANCE Human cytomegalovirus (HCMV) is a prevalent opportunistic pathogen in the human population. For neonatal and immunocompromised patients, HCMV infection can cause severe and possibly life-threatening complications. It is important to define the mechanisms of the viral replication cycle in order to identify potential targets for new therapies. Secondary envelopment, or acquisition of the membrane envelope, of HCMV is a mechanism that needs further study. Using an inducible fibroblast system to carefully control for the toxicity associated with blocking ESCRT-III function, this study determines that the ESCRT proteins are not required for viral envelopment. However, the study does discover a nonenvelopment role for the ESCRT-III complex in the efficient spread of the virus. Thus, this study advances our understanding of an important process essential for the replication of HCMV.

The role of ESCRT during development and functioning of the nervous system

The endosomal sorting complex required for transport (ESCRT) is made of subcomplexes (ESCRT 0-III), crucial to membrane remodelling at endosomes, nuclear envelope and cell surface. ESCRT-III shapes membranes and in most cases cooperates with the ATPase VPS4 to mediate fission of membrane necks from the inside. The first ESCRT complexes mainly serve to catalyse the formation of ESCRT-III but can be bypassed by accessory proteins like the Alg-2 interacting protein-X (ALIX). In the nervous system, ALIX/ESCRT controls the survival of embryonic neural progenitors and later on the outgrowth and pruning of axons and dendrites, all necessary steps to establish a functional brain. In the adult brain, ESCRTs allow the endosomal turn over of synaptic vesicle proteins while stable ESCRT complexes might serve as scaffolds for the postsynaptic parts. The necessity of ESCRT for the harmonious function of the brain has its pathological counterpart, the mutations in CHMP2B of ESCRT-III giving rise to several neurodegenerative diseases.

Cytokinetic abscission is an acute G1 event

Animal cell division ends with the cutting of the microtubule and membrane intercellular bridge connecting the 2 daughter cells. This process, known as cytokinetic abscission (abscission), is widely regarded as the last step of cytokinesis, i.e., the last step of the cell cycle. Major breakthroughs have been recently achieved, illuminating mechanistic aspects of abscission; however, the timing of abscission with respect to the mammalian cell cycle remains unclear. In this study, we carefully measured the onset and progression of abscission in dividing cells expressing a G1 reporter. We conclude that abscission commences long after cells enter the G1 phase. Affiliating abscission with G1 is beyond semantics since it essentially postulates that the last step of the cell cycle is regulated in, and probably by, the following cycle.

Elimination pathways of cyclosarin (GF) mediated by β-cyclodextrin in vitro: pharmacokinetic and toxicokinetic aspects

Cyclodextrins (CD) are promising small molecular scavengers showing favourable degradation of extremely toxic organophosphorus compounds (OP) such as tabun (GA), soman (GD) or cyclosarin (GF). For β-CD derivatives as potential OP antidotes with low intrinsic toxicity it is of great interest to completely understand the modes of interaction of both compounds in terms of OP detoxification. The mechanisms of CD action are not completely understood which prompted us to investigate the interactions of GF and β-cyclodextrin (β-CD) as model compounds. Using positive electrospray ionization mass spectrometry (ESI/MS), the formation of covalent conjugates of β-CD with O-cyclohexylmethylphosphonate (CHMP) residue was detected for the first time and was examined in vitro. With a newly developed LC-MS method the formation of O-cyclohexylmethylphosphonic acid (CHMPA) (i.e. GF hydrolysis) and covalent CHMP-β-CD conjugates was analyzed. Compared to water, tris(hydroxymethyl)aminomethane (TRIS) reduced the formation of covalent conjugates but amplified formation of CHMPA. Depending on experimental conditions the degradation of GF by β-CD may be preferably catalytic or stoichiometric. For illustrating different possible reaction pathways a scheme was established that could support the idea of β-CD acting as an artificial enzyme. These results provide an important insight into the β-CD mediated detoxification pathways of GF.

Long-term immunogenicity of an AS03-adjuvanted influenza A(H1N1)pdm09 vaccine in young and elderly adults: an observer-blind, randomized trial

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We assessed the immunogenicity of A(H1N1)pdm09 vaccine (1 dose) with/without adjuvant.

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Four thousands and forty-eight adults received one dose of either the adjuvanted or non-adjuvanted vaccine.

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Both vaccines induced protective HI antibody levels at Day 21.

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At Month 6 immunogenicity guidance criteria were met in subjects 18–64 years of age.

Background

This study (NCT00979602) evaluated the immunogenicity and relative protective efficacy of one dose of influenza A(H1N1)pdm09 vaccine with or without AS03 (an α-tocopherol oil-in-water emulsion based Adjuvant System).

Methods

Four thousands and forty-eight healthy adults aged ≥18 years were randomized (1:1) to receive one dose of either the adjuvanted split virion (3.75 μg hemagglutinin antigen [HA]/AS03) or non-adjuvanted (15 μg HA) vaccine. Hemagglutination inhibition [HI] antibody response was evaluated before vaccination and at Days 21, 42 and 182 (Month 6). Safety of the study vaccines was evaluated during the entire study duration.

Results

At Day 21, both study vaccines induced HI immune responses meeting the US regulatory criteria in subjects 18–64 years (seroprotection rate [SPR]: 98.0% [97.1–98.6]; seroconversion rate [SCR]: 89.7% [88.0–91.2] in the AS03-adjuvanted group; SPR: 91.4% [89.9–92.8]; SCR: 74.6% [72.3–76.9] in the non-adjuvanted group) and >64 years of age (SPR: 86.0% [82.5–89.0]; SCR: 75.3% [71.1–79.2] in the AS03-adjuvanted group; SPR: 69.1% [64.6–73.3]; SCR: 56.7% [52.0–61.3] in the non-adjuvanted group). The AS03-adjuvanted vaccine induced higher HI geometric mean titers than the non-adjuvanted vaccine at all time points. At Month 6, only subjects 18–64 years of age from both vaccine groups still met the US regulatory criteria (SPR: 82.1% [80.0–84.1]; SCR: 62.3% [59.6–64.8] in the AS03-adjuvanted group; SPR: 75.3% [72.9–77.5]; SCR: 53.7% [51.0–56.4] in the non-adjuvanted group). Protective efficacy was not evaluated due to low number of RT-qPCR-confirmed A(H1N1)pdm09 influenza cases. Through Month 12, 216 serious adverse events (in 157 subjects: 84 in the AS03-adjuvanted and 73 in the non-adjuvanted group) and 12 potentially immune mediated diseases (5 in the AS03-adjuvanted and 7 in the non-adjuvanted group) were reported.

Conclusion

A single dose of either adjuvanted or non-adjuvanted influenza A(H1N1)pdm09 vaccine induced protective HI antibody levels against the A/California/7/2009 strain that persisted through Month 6 in the 18–64 years population.

History of gene therapy

Two decades after the initial gene therapy trials and more than 1700 approved clinical trials worldwide we not only have gained much new information and knowledge regarding gene therapy in general, but also learned to understand the concern that has persisted in society. Despite the setbacks gene therapy has faced, success stories have increasingly emerged. Examples for these are the positive recommendation for a gene therapy product (Glybera) by the EMA for approval in the European Union and the positive trials for the treatment of ADA deficiency, SCID-X1 and adrenoleukodystrophy. Nevertheless, our knowledge continues to grow and during the course of time more safety data has become available that helps us to develop better gene therapy approaches. Also, with the increased understanding of molecular medicine, we have been able to develop more specific and efficient gene transfer vectors which are now producing clinical results. In this review, we will take a historical view and highlight some of the milestones that had an important impact on the development of gene therapy. We will also discuss briefly the safety and ethical aspects of gene therapy and address some concerns that have been connected with gene therapy as an important therapeutic modality.