Regulatory policy and pharmaceutical innovation in the United Kingdom after Brexit: Initial insights.

Brexit was presented as an opportunity to promote innovation by breaking free from the European Union regulatory framework. Since the beginning of 2021 the Medicines and Healthcare products Regulatory Agency (MHRA) has operated as the independent regulatory agency for the United Kingdom. The MHRA's regulatory activity in 2021 was analyzed and compared to that of other international regulatory bodies. The MHRA remained reliant on EU regulatory decision-making for novel medicines and there were significant regulatory delays for a small number of novel medicines in the UK, the reasons being so far unclear. In addition, the MHRA introduced innovation initiatives, which show early promise for quicker authorization of innovative medicines for cancer and other areas of unmet need. Longer-term observation and analysis is needed to show the full impact of post-Brexit pharmaceutical regulatory policy.

Nonclinical data supporting orphan medicinal product designations in the area of rare infectious diseases.

This review provides an overview of nonclinical in vivo models that can be used to support orphan designation in selected rare infectious diseases in Europe, with the aim to inform and stimulate the planning of nonclinical development in this area of often neglected diseases.

Marketing authorisation of orphan medicines in Europe from 2000 to 2013.

An analysis was performed on a data set of 157 orphan designated medicines with an outcome for marketing authorisation application (MAA) between 2000 and 2013. The intention was to understand the factors associated with marketing authorisation success, the challenges developers face regarding orphan medicine development, and how scientific advice (SA) is used during development. The results demonstrated that orphan medicines have a lower success rate compared with non-orphan medicines and that determinants for marketing authorisation success were company size and compliance with SA. Compliance with SA could help orphan medicine developers overcome clinical development challenges.

Nonclinical data supporting orphan medicinal product designations: lessons from rare neurological conditions.

Here, we provide an in-depth literature and experience-based review of nonclinical models and data used to support orphan medicinal product designations (OMPDs) in rare neurodegenerative conditions. The Committee for Orphan Medicinal Products (COMP) of the European Medicines Agency updates its assessment processes based on scientific progress and aims to provide transparent criteria required in support of OMPDs. Thus, we also provide an updated analysis of existing nonclinical models in selected conditions and identify key features of nonclinical studies that are crucial for the support of OMPDs. This could not only inform future drug development in rare neurological conditions, but also indicate areas where the use of nonclinical models can be made more efficient.

Tamoxifen accelerates the repair of demyelinated lesions in the central nervous system.

Enhancing central nervous system (CNS) myelin regeneration is recognized as an important strategy to ameliorate the devastating consequences of demyelinating diseases such as multiple sclerosis. Previous findings have indicated that myelin proteins, which accumulate following demyelination, inhibit remyelination by blocking the differentiation of rat oligodendrocyte progenitor cells (OPCs) via modulation of PKCα. We therefore screened drugs for their potential to overcome this differentiation block. From our screening, tamoxifen emerges as a potent inducer of OPC differentiation in vitro. We show that the effects of tamoxifen rely on modulation of the estrogen receptors ERα, ERß, and GPR30. Furthermore, we demonstrate that administration of tamoxifen to demyelinated rats in vivo accelerates remyelination. Tamoxifen is a well-established drug and is thus a promising candidate for a drug to regenerate myelin, as it will not require extensive safety testing. In addition, Tamoxifen plays an important role in biomedical research as an activator of inducible genetic models. Our results highlight the importance of appropriate controls when using such models.

Inhibition of phosphodiesterase-4 promotes oligodendrocyte precursor cell differentiation and enhances CNS remyelination.

The increasing effectiveness of new disease-modifying drugs that suppress disease activity in multiple sclerosis has opened up opportunities for regenerative medicines that enhance remyelination and potentially slow disease progression. Although several new targets for therapeutic enhancement of remyelination have emerged, few lend themselves readily to conventional drug development. Here, we used transcription profiling to identify mitogen-activated protein kinase (Mapk) signalling as an important regulator involved in the differentiation of oligodendrocyte progenitor cells (OPCs) into oligodendrocytes. We show in tissue culture that activation of Mapk signalling by elevation of intracellular levels of cyclic adenosine monophosphate (cAMP) using administration of either dibutyryl-cAMP or inhibitors of the cAMP-hydrolysing enzyme phosphodiesterase-4 (Pde4) enhances OPC differentiation. Finally, we demonstrate that systemic delivery of a Pde4 inhibitor leads to enhanced differentiation of OPCs within focal areas of toxin-induced demyelination and a consequent acceleration of remyelination. These data reveal a novel approach to therapeutic enhancement of remyelination amenable to pharmacological intervention and hence with significant potential for translation.