Science Pool

Curing paraplegia

In January 2021, researchers from Ruhr-Universität Bochum made headlines after publishing in Nature Communications that they had succeeded for the first time in enabling formerly paralyzed mice to walk. They had accomplished the feat by using gene therapy to transfer the gene for hyper-interleukin-6, a so-called designer cytokine, which does not occur in nature, to the brain of the animals. The gene was packed into Adeno-Associated Viruses (AAV) and the vector injected into the brain, where motoneurons and associated motion-related nerve cells started to produce this growth factor.

“Thus, gene therapy treatment of only a few cells stimulated the axonal regeneration of various nerve cells in the brain and several motor tracts in the spinal cord simultaneously,” said Dietmar Fischer, Professor at the Department for Cell Physiology at Ruhr-Universität Bochum and lead author of the study. “Ultimately, this enabled the previously paralyzed animals to start walking after two to three weeks. This came as a great surprise to us at the beginning, as it had never been shown to be possible before after full paraplegia.”

The development of gene therapy

This breakthrough, which might end paraplegia in injured humans, is just one of many successes accomplished with gene therapy. The approach has come a long way. Its basic concept – modifying human genes by introducing genetic material – was first proposed in 1972. After premature first attempts in the 1980s failed, the science greatly improved and in 2003 China took the lead by approving Gendicine, a recombinant Ad-p53 gene therapy for the treatment of head and neck squamous cell carcinoma (HNSCC)—a cancer that accounts for about 10% of the 2.5 million annual new cancer patients in China.

It took another 9 years until the EU followed with the approval of Glybera, a treatment for patients who cannot produce enough of an enzyme that is crucial for breaking down fat, and in 2017 the first gene therapies were approved in the U.S.: Luxturna to treat RPE65 mutation-induced blindness and Kymriah, a therapy for the treatment of B-cell acute lymphoblastic leukemia (ALL) which uses genetically engineered T cells of the affected patients. Since then, further gene therapies have been approved, e.g. Zolgensma and Patisiran, and hundreds of clinical trials are under way to test gene therapy as a treatment for genetic disorders, cancer, and HIV/AIDS.

The gene therapy market was valued at approx. $ 500 m in 2018 but is expected to reach > $ 5 bn by 2025 with an impressive CAGR of about 34%.

How does gene therapy work?

Gene therapies can work through several mechanisms, the replacement of a disease-causing gene with a healthy copy, inactivation of a disease-causing gene that is not functioning properly and the introduction of a new or modified gene into the body to help treat a disease. The latter approach was used in the study to heal paraplegic mice.

There are various methods for administering gene therapeutics. The most common approaches are the use of viral vectors (mostly AAVs and lentiviruses) to transfer the genes directly to the patient, or the modification of patient-derived cells in the lab with subsequent transfer of the modified cells back into the patient. Most approaches use performing gene insertions in vivo and ex vivo, respectively, but non-viral delivery systems are also being used.

Evotec´s gene therapy strategy

Evotec entered the gene therapy space in 2020 by establishing an alliance with Takeda, adding a team of 20 specialists by creating Evotec GT in Austria, where Takeda’s gene therapy operation GTCA (Gene Therapy Center Austria) is located.

Evotec GT is now an integral part of Evotec’s integrated drug discovery platform. Its services include

• the design of state-of-the-art viral AAV vectors,
• the generation of AAV material for research and non-clinical studies, 
• in vitroand in vivo proof of concept studies for target validation including screening of drug candidates, as well as
• the design, execution and interpretation of non-clinical gene therapy studies.

The services cover both in vivo and ex vivo gene therapy approaches. With this new unit, Evotec is now able to find the best potential drug candidate agnostic of modality for any given biology.

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COVID-19 related delay of clinical research - a shortage in novel drugs?

Among the many fallouts of the COVID-19 pandemic is a disruption of clinical research. Laboratories are closed, conferences have been cancelled, travel is restricted, supply chains for equipment have been interrupted, and resources have been lost. In particular smaller biotechs have or will incur losses as they have to considerably stretch their financial resources and can’t meet milestones.

The biggest effect has been on planned and already ongoing clinical trials of new drug candidates. Thousands of trials have been stopped or called off altogether (an unprecedented event with long-lasting effects on medicine). According to Michael Lauer, Deputy Director for Extramural Research at the US National Institutes of Health, about 80% of non-COVID trials in the U.S. have been interrupted or stopped. A recent world-wide research report by Informa Pharma Intelligence and Oracle Health Sciences revealed that the COVID-19 pandemic has led to longer enrolment timelines (49%), amended protocols (45%), and paused protocols (41%). Also, clinical trials have become more decentralised, i.e. the investigational medical product was shipped directly to the trial participant. 46% of respondents are planning or implementing such decentralised trials, 44% are considering new vendors, and 36% are considering new geographies for trial locations. However, this move is facing challenges such as patient monitoring and engagement, ensuring data reliability, quality, and data collection.

Most people are not aware how many participants and sites are involved in a clinical trial. Apart from the researchers and clinical doctors overseeing the trial and the patients, it’s caregivers and nurses, postgraduate researchers, postdocs, data scientists and people involved in funding and paperwork. Particular problems have been caused by the stress put on hospitals by the admission of so many critically ill patients and the necessity to avoid an infection of trial participants (or vice versa, as well as the staff at the trial sites).

Decentralising clinical trials

Regulators have been quick to react by changing their guidance so that physical distancing has been possible without compromising the safety of patients in testing and treatment. As an example, if possible, trial participants were provided with the test medication for a longer period of time, or the drug was distributed to their homes by a distributor so that they don’t need to visit the trial site – something that is called decentralisation of trials.

Decentralised trials, however, create problems in terms of compliance, medical control and data assessment. Solutions such as telemedicine have been known for a long time, but have not yet been implemented in clinical trials due to administrative and bureaucratic hurdles, cost and reimbursement.

Nevertheless, at least U.S. regulators have accepted patient evaluation and data sampling via remote solutions, either via email, phone calls or videoconferences or by tele-medical monitoring. The same approach has been applied to many COVID-related trials. Even completely decentralised trials have been conducted – from recruiting via social media to medication distribution to data collection. However, researchers have warned that several of these clinical trials lack control groups, have poorly defined endpoints, lack generalisability to those of a lower socioeconomic status or were designed too early in the pathophysiological course of the disease to result in substantive recommendations.

Creating a roadmap for the future of clinical research

The developments described above raise a lot of questions:

• Are design and data of trials conducted during the pandemic solid?
• Can self-reported outcome be equalled to an independent assessment by a specialist?
• Do online recruiting and telemedical assessment increase or decrease patient heterogeneity?
• What impact do concomitant COVID infections and stress caused by social distancing have on side effects and outcome?
• Can telemedicine be implemented in the clinical trial routine in the post-pandemic era to save costs?
• What else can be copied for the future?

At the same time, it is clear to researchers in academia as well as in industry that the way clinical trials are conducted is outdated in many aspects and overly burdened by red tape. Conducting trials can and should be improved and modernised to benefit patients, clinicians, and researchers. Therefore, the pandemic may act as a catalyst for positive changes in terms of recruitment, monitoring and innovation to create a more efficient, integrated research platform for the future.

To discuss your project, contact:

info@evotec.com

In January 2020, the US FDA finalised its 2017 draft regulatory guidance for industry on in vitro DDI studies by publishing the In Vitro Drug Interactions Studies – Cytochrome P450 Enzyme- and Transporter-Mediated Drug Interactions Guidance for Industry. This document outlines how experimental in vitro studies should be carried out and provides instruction on how results should be used to determine potential clinical DDI risk.

Functionally, very little has changed between the draft guidance of 2017 and this final version, mainly consisting of clarifications with very few additional requirements. In this blog, we take a closer look at the small differences there are and explain how they impact on data interpretation for in vitro regulatory DDI studies.

In covering the differences from the draft version of the guidance, we will explore metabolism-mediated drug interactions including CYP inhibition, CYP induction and substrate identification (reaction phenotyping) studies, and then discuss transporter inhibition and transporter substrate studies.

Metabolism Mediated Drug Interactions

Initially, the guidance now promotes the investigation of in vitro metabolic studies before conducting first-in-human studies to better inform the necessity and design of clinical PK studies. Further clarifications are focussed on CYP inhibition, induction and enzyme substrate identification.

CYP Inhibition: One of the changes in terms of metabolism mediated drug interactions relates to CYP inhibition where the FDA has indicated that IC₅₀/2 can be used as an estimate of K_i for reversible inhibitors if the probe substrate concentration used is at the K_m for the CYP enzyme. This suggests that assessing Ki may no longer be necessary under these conditions – saving both time and cost in DDI assessment. Of further note is that the K_i and K_I have been corrected to K_i,u and K_I,u to highlight the fact that the unbound values should be used in the calculations.

CYP Induction: The assay design remains the same but the FDA has provided more detail on the data interpretation for CYP induction studies, in particular, for the fold change method. For example, CYP induction is presumed if a concentration-dependent increase in CYP mRNA is observed which is ≥ 2-fold the vehicle control at the expected hepatic concentrations of the drug. The guidance proposes 30-fold of mean unbound maximal steady state plasma concentration at the therapeutic dose as an estimation of the expected hepatic drug concentration. It also recommends, that even if the induction is less than 2-fold, induction potential cannot be ruled out if the increase in CYP mRNA is greater than 20% of the positive control. The alternative methods for calculating CYP induction risk (basic kinetic R3 model and correlation methods) have remained similar to the previous draft guidance.

Enzyme Substrate Identification: In terms of substrate studies, very little has changed, the guidance has extended the panel of possible non-CYP enzymes to consider if CYPs are not found to contribute towards metabolism. These additional enzymes include aldehyde oxidases (AO), carboxylesterases (CES) and sulfotransferases (SULTs) in addition to other non-CYP Phase I and Phase II enzymes.

Transporter Mediated Drug Interactions

Transporter Inhibition: The main change to highlight relates to the basic static equation cut-off for the MATE transporters which has now increased to 0.1 and falls in line with the existing cut-off for the other renal transporters (OATs and OCT2). This amended cut-off is more relaxed than the previous guidance and will reduce the likelihood of investigational drugs being flagged as potential in vivo MATE inhibitors. Another welcome change is the removal of the suggested 30 min pre-incubation time for the duration of the inhibitor pre-incubation step for OATP transporters. This omission recognises research performed by Cyprotex demonstrating that a shorter inhibitor pre incubation time of 15 min is adequate for assessing correct OATP inhibition as no statistically significant difference in IC₅₀ existed following a 15 min or 30 min inhibitor pre-incubation step. Finally, one notable addition to the P-gp and BCRP inhibition guidance is the specific consideration of investigational drugs administered through the parenteral route or of systemically circulating metabolites acting as inhibitors. In these circumstances, a different basic static equation is used to determine DDI risk, namely I₁/IC₅₀ (or K_i) ≥ 0.1, where I₁ is the total C_max of the inhibitor drug or metabolite.

Transporter Substrate Identification: Last but not least, both assay design and data interpretation remain relatively unchanged from the draft guidance for transporter substrate studies.

In summary, the majority of the amendments to the draft 2017 guidance focus on the data analysis stage rather than assay design stage. The main changes affect transporter inhibition studies where new cut-offs have been specified for the MATE transporters. One unexpected amendment relates to the use of IC₅₀/2 as an estimate of K_i for reversible CYP inhibitors, potentially reducing the reliance on K_i studies.

With over 20 years’ experience conducting DDI studies, Cyprotex have a team of experts who can guide you through the process and assist in the planning, execution and interpretation of these regulatory studies. Our popular ADME and DDI guides have also been updated to reflect the 2020 guidance and help you further understand why, when, and how to perform these studies.

Contact enquiries@cyprotex.com to discuss your DDI study

updated ADME and DDI guides

Date:12-18th March 2021

Location: Virtual

Attending:

Cyprotex (booth 1941): Ralf Geiben Lynn, Christopher Strock, Paul Walker, Stephanie Ryder, Julie Eakins, Felix von Haniel, David Cerny, Jack Shepherd

Evotec (booth 2040): Marco Pergher, Dario Salerno, Maria Pilla, Michela Pecoraro, David Straight, Josh Gillum, Claire White 

Learn more about our research at SOT

Given the arrival of SARS-CoV-2 vaccines, why do we still need therapeutics?

After more than a year into the COVID-19 pandemic, vaccines against the new coronavirus are all over the news. However, there is still a long way to go until people have been vaccinated worldwide, and as yet it is not clear how long the protection will last and whether the different vaccines will protect against re-infection and/or infection against mutated viruses.

Therefore, it is clear that even in 2021 and beyond millions of people will get infected by the virus and many thousands will become critically ill and require medical treatment.

Strategies for making SARS-CoV-2 therapeutics broadly available

Similar to vaccines, biopharmaceutical companies all over the world are trying to develop medications to combat Sars-CoV-2 infections: some are trying to repurpose existing drugs, others are developing small molecules or biologicals such as antibodies against a variety of targets – viral as well as cellular.

Evotec is also participating in this worldwide effort – but with a twist. The goal is to develop a monoclonal antibody that is not only effective, but can also be produced at low cost so that it is ideally suited to be administered even in the world’s poorest countries. And if all goes well, Evotec will also provide small, efficient manufacturing sites that can be operated all over the world.

Already in April last year, Evotec´s U.S. subsidiary Just - Evotec Biologics, Inc. entered into a partnership with Ology Bioservices, Inc. to evaluate and characterize antibodies against SARS-CoV-2. A few months later, in July, Just – Evotec Biologics was awarded up to $ 18.2 m by the U.S. Department of Defense for the development and manufacturing of monoclonal antibodies that might be able to prevent or treat COVID-19. And in September last year, the Bill & Melinda Gates Foundation joined in by granting another $1.9 million to develop and manufacture monoclonal antibodies at lowest possible cost of goods for the prevention of severe COVID-19 in vulnerable populations in low- and middle-income countries.

The concept of decentralised, affordable drug manufacturing

Just – acquired by Evotec in 2019 – was founded in 2015 in Seattle by former Amgen employees with the goal to make the entire manufacturing process of biotherapeutic drugs more efficient and affordable – not only by lowering development costs, but also by establishing smaller, more efficient manufacturing sites. The initial therapeutic focus was on anti-infectives, as infections constitute the biggest problems in poor countries that often don’t have enough money to purchase lifesaving drugs or to support their manufacturing, so lowering the costs of developing and producing anti-infectives are of great importance.

To accomplish this goal, Just is using artificial intelligence and an entirely data-driven drug discovery and development process. Its J.DESIGN technology platform integrates the discovery and optimization of drug candidates, process and product development, and manufacturing with the goal of providing a product that can be manufactured at low cost of goods. Using large, diverse data libraries and machine learning, the platform from the outset screens and designs biologics that can be developed and manufactured under the most favourable development conditions.

The know-how of the company comprises cell line development, upstream bioreactor design (fed-batch or continuous), and the development of downstream purification, analytical methods, final drug product, formulation, and long-term storage.

Just – Evotec Biologics also has developed a small, flexible, low-cost facility solution to biotherapeutics manufacturing called J.POD. This facility can be installed easily wherever production is needed.

As infectious diseases are on the rise across the globe and SARS-CoV-2 will unlikely be the last pandemic affecting the human population, the approach developed by Just - Evotec Biologics will become even more important in the future.

Interested in learning more?

Just- Evotec Biologics´ technologies and services are being offered to clients and partners interested in the fast and cost-effective development of biologics.

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The current Sars-CoV-2 pandemic has shown what a powerful threat pathogens can be to human civilisation. However, not only viruses threaten the human population. Every year, at least 700,000 people worldwide die of drug-resistant diseases, including 230,000 people who die from multidrug-resistant tuberculosis. An increasing number of diseases, including respiratory tract infections, sexually transmitted infections and urinary tract infections, has become untreatable, while lifesaving medical procedures are becoming much riskier. Last year, the U.S. CDC listed 18 antibiotic-resistant bacteria and fungi that are a threat to humans. Novel anti-infectives are urgently required to address this unmet medical need.

Evotec is dedicated to the fight against resistant pathogens and the development of novel anti-infectives. In 2018, the Company acquired Sanofi´s infectious disease unit and thereby laid the foundation for accelerating an comprehensive R&D portfolio to combat infectious diseases. Moreover, the Company entered into a five-year partnership with the Bill & Melinda Gates Foundation in June 2019 to discover new treatment regimens that better address tuberculosis (“TB”), a severe global health burden and one of the leading lethal infectious diseases worldwide. Also in 2019, Evotec and Lygature announced their cooperation in a new initiative for the development of novel antibacterial agents against Gram-negative bacteria called “GNA NOW”.

In August 2020, Evotec entered into a new partnership with Resolute Therapeutics to combat infectious diseases and antimicrobial resistance. 

Evotec has established a leading-edge platform enabling the discovery and development of new therapies and therapeutic approaches to treat and prevent serious and life-threatening infections. The Company´s anti-infectives platform includes

• EvostrAIn™ – An extensive range of geographically diverse human pathogenic bacteria and fungi including isolates that are susceptible and resistant to current antimicrobial drugs.
• In vitro and in vivo microbiology encompassing Gram positive and Gram negative pathogens (including anaerobes) in a wide range of animal models with a broad range of endpoints.
• Translational in vitro and in vivo PK/PD and mathematical modelling with emphasis on in vitro Hollow Fibre Systems to mimic defined drug exposure profiles.
• In vitro and in vivo virology, focusing on respiratory viruses such as RSV, HRV, influenza virus and human coronavirus (enabling COVID-19 work).
• In vitro and in vivo mycology: human pathogens including Candida spp. Aspergillus spp. and parasitology

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