Recent developments in gene therapy research in India.

Inherited genetic disorders are progressive in nature and lead to organ dysfunction or death in severe cases. At present, there are no permanent treatment options for >95% of inherited disorders. Different modes of inheritance, type of gene(s) involved, and population-based variations add further complexity to finding suitable cures for approximately 400 million patients worldwide. Gene therapy is a very promising molecular technique for the treatment of rare genetic disorders. Gene therapy functions on the basis of restoration, replacement, inhibition, and, most recently, editing of gene(s) to rescue the disease phenotype. Recent reports show that increasing numbers of gene therapy clinical trials are using viral vectors (64.2%) when compared with non-viral vectors. Rapid development of efficient viral vector systems like the adeno-associated virus (AAV) and lentivirus has significantly contributed to this progress. Notably, AAV-mediated gene therapy has shown high potential for genetic disease treatment as evident from recent clinical trials for the eye (NCT00999609), blood (NCT00979238), and neuro-muscular systems (NCT02122952). Safety and efficacy are the two most critical features required for vector(s) to qualify for pre-clinical and clinical trial approval. The process of clinical-grade vector production, evaluation, and approvals for gene therapy products requires significant technological development, knowledge enhancement, and large financial investments. Additionally, trained manpower is required to meet the demands for constant technical innovation. These factors together contribute towards exorbitant prices for every dose of a gene therapy product and thus pose a challenge for the gene therapy field. The Indian subcontinent has traditionally lagged behind North America, Europe, Japan, and others in gene therapy clinical trials due to factors like inadequate industrial-scientific infrastructure, lack of accessible and organized patient databases, low financial investments, etc. However, over the last decade, increasing awareness of rare diseases, and international approvals of gene therapies such as Luxturna, Zolgensma, Hemgenix, etc., have spurred gene therapy development in India as well. In view of these advances, this article outlines gene therapy research, regulatory processes, and the launch of gene therapy clinical trials in India in the context of major developments worldwide. We briefly describe ongoing gene therapy research across Indian organizations and the nascent gene therapy product manufacturing. Further, we highlight the various initiatives from the medical and patient community to avail rehabilitation and gene therapy options. We briefly discuss the roles of regulatory agencies and guidelines for gene therapy clinical trials in India. We anticipate that this concise review will highlight the promise of gene therapy for the large population of rare disease patients in India.

Multicenter assessment and longitudinal study of the prevalence of antibodies and related adaptive immune responses to AAV in adult males with hemophilia.

Adeno-associated virus (AAV) based gene therapy has demonstrated effective disease control in hemophilia. However, pre-existing immunity from wild-type AAV exposure impacts gene therapy eligibility. The aim of this multicenter epidemiologic study was to determine the prevalence and persistence of preexisting immunity against AAV2, AAV5, and AAV8, in adult participants with hemophilia A or B. Blood samples were collected at baseline and annually for ≤3 years at trial sites in Austria, France, Germany, Italy, Spain, and the United States. At baseline, AAV8, AAV2, and AAV5 neutralizing antibodies (NAbs) were present in 46.9%, 53.1%, and 53.4% of participants, respectively; these values remained stable at Years 1 and 2. Co-prevalence of NAbs to at least two serotypes and all three serotypes was present at baseline for ~40% and 38.2% of participants, respectively. For each serotype, ~10% of participants who tested negative for NAbs at baseline were seropositive at Year 1. At baseline, 38.3% of participants had detectable cell mediated immunity by ELISpot, although no correlations were observed with the humoral response. In conclusion, participants with hemophilia may have significant preexisting immunity to AAV capsids. Insights from this study may assist in understanding capsid-based immunity trends in participants considering AAV vector-based gene therapy.

Toward low-cost gene therapy: mRNA-based therapeutics for treatment of inherited retinal diseases.

Inherited retinal diseases (IRDs) stem from genetic mutations that result in vision impairment. Gene therapy shows promising therapeutic potential, exemplified by the encouraging initial results with voretigene neparvovec. Nevertheless, the associated costs impede widespread access, particularly in low-to-middle income countries. The primary challenge remains: how can we make these therapies globally affordable? Leveraging advancements in mRNA therapies might offer a more economically viable alternative. Furthermore, transitioning to nonviral delivery systems could provide a dual benefit of reduced costs and increased scalability. Relevant stakeholders must collaboratively devise and implement a research agenda to realize the potential of mRNA strategies in equitable access to treatments to prevent vision loss.

Using Real-World Data to Inform Value-Based Contracts for Cell and Gene Therapies in Medicaid.

OBJECTIVE: High upfront costs and long-term benefit uncertainties of gene therapies challenge Medicaid budgets, making value-based contracts a potential solution. However, value-based contract design is hindered by cost-offset uncertainty. The aim of this study is to determine actual cost-offsets for valoctocogene roxaparvovec (hemophilia A) and etranacogene dezaparvovec (hemophilia B) from Colorado Medicaid's perspective, defining payback periods and its uncertainty from the perspective of Colorado Medicaid. METHODS: This cost analysis used 2018-2022 data from the Colorado Department of Health Care Policy & Financing to determine standard-of-care costs and employed cost simulation models to estimate the cost of Medicaid if patients switched to gene therapy versus if they did not. Data encompassed medical and pharmacy expenses of Colorado Medicaid enrollees. Identified cohorts were patients aged 18+ with ICD-10-CM codes D66 (hemophilia A) and D67 (hemophilia B). Severe hemophilia A required ≥ 6 claims per year for factor therapies or emicizumab, while moderate/severe hemophilia B necessitated ≥ 4 claims per year for factor therapies. Patients were included in the cohort in the year they first met the criteria and were subsequently retained in the cohort for the duration of the observation period. Standard-of-care included factor VIII replacement therapy/emicizumab for hemophilia A and factor IX replacement therapies for hemophilia B. Simulated patients received valoctocogene roxaparvovec or etranacogene dezaparvovec. Main measures were annual standard-of-care costs, cost offset, and breakeven time when using gene therapies. RESULTS: Colorado Medicaid's standard-of-care costs for hemophilia A and B were $426,000 [standard deviation (SD) $353,000] and $546,000 (SD $542,000) annually, respectively. Substituting standard-of-care with gene therapy for eligible patients yielded 8-year and 6-year average breakeven times, using real-world costs, compared with 5 years with published economic evaluation costs. Substantial variability in real-world standard-of-care costs resulted in a 48% and 59% probability of breakeven within 10 years for hemophilia A and B, respectively. Altering eligibility criteria significantly influenced breakeven time. CONCLUSIONS: Real-world data indicates substantial uncertainty and extended payback periods for gene therapy costs. Utilizing real-world data, Medicaid can negotiate value-based contracts to manage budget fluctuations, share risk with manufacturers, and enhance patient access to innovative treatments.

The estimated annual financial impact of gene therapy in the United States.

Gene therapy is a new class of medical treatment that alters part of a patient's genome through the replacement, deletion, or insertion of genetic material. While still in its infancy, gene therapy has demonstrated immense potential to treat and even cure previously intractable diseases. Nevertheless, existing gene therapy prices are high, raising concerns about its affordability for U.S. payers and its availability to patients. We assess the potential financial impact of novel gene therapies by developing and implementing an original simulation model which entails the following steps: identifying the 109 late-stage gene therapy clinical trials underway before January 2020, estimating the prevalence and incidence of their corresponding diseases, applying a model of the increase in quality-adjusted life years for each therapy, and simulating the launch prices and expected spending of all available gene therapies annually. The results of our simulation suggest that annual spending on gene therapies will be approximately $20.4 billion, under conservative assumptions. We decompose the estimated spending by treated age group as a proxy for insurance type, finding that approximately one-half of annual spending will on the use of gene therapies to treat non-Medicare-insured adults and children. We conduct multiple sensitivity analyses regarding our assumptions and model parameters. We conclude by considering the tradeoffs of different payment methods and policies that intend to ensure patient access to the expected benefits of gene therapy.

Interspecies Scaling of Transgene Products for Viral Vector Gene Therapies: Method Assessment Using Data from Eleven Viral Vectors.

The prediction of transgene product expression in human is important to guide first-in-human (FIH) dose selection for viral vector-based gene replacement therapies. Recently, allometric scaling from preclinical data and interspecies normalization of dose-response (D-R) relationship have been used to predict human transgene product expression of adeno-associated virus (AAV) vectors. In this study, we assessed two interspecies allometric scaling methods and two dose-response methods in predicting human transgene product expression of nine intravenously administered AAV vectors, one intramuscularly administered AAV vector, and one intravesical administered adenoviral vector. Among the four methods, normalized D-R method generated the highest prediction accuracy, with geometric mean fold error (GMFE) of 2.9 folds and 75% predictions within fivefold deviations of observed human transgene product levels. The vg/kg-based D-R method worked well for locally delivered vectors but substantially overpredicted human transgene product levels of some hemophilia A and B vectors. For both intravenously and locally administered vectors, the prediction accuracy of allometric scaling using body weight^-0.25 (AS by W^-0.25) was superior to allometric scaling using log(body weight) (AS by logW). This study successfully extended the use of allometric scaling and interspecies D-R normalization methods for human transgene product prediction from intravenous viral vectors to locally delivered viral vectors.

Gene therapies for sickle cell disease: Effectiveness and value.

DISCLOSURES: Drs. Nikitin, McKenna, Rind, Nhan, and Pearson report grants from Arnold Ventures, grants from Blue Cross Blue Shield of MA, grants from California Healthcare Foundation, grants from The Commonwealth Fund, grants from The Patrick and Catherine Weldon Donaghue Medical Research Foundation, during the conduct of the study; other from America's Health Insurance Plans, other from Anthem, other from AbbVie, other from Alnylam, other from AstraZeneca, other from Biogen, other from Blue Shield of CA, other from CVS, other from Editas, other from Express Scripts, other from Genentech/Roche, other from GlaxoSmithKline, other from Harvard Pilgrim, other from Health Care Service Corporation, other from Kaiser Permanente, other from LEO Pharma, other from Mallinckrodt, other from Merck, other from Novartis, other from National Pharmaceutical Council, other from Premera, other from Prime Therapeutics, other from Regeneron, other from Sanofi, other from United Healthcare, other from HealthFirst, other from Pfizer, other from Boehringer-Ingelheim, other from uniQure, other from Envolve Pharmacy Solutions, other from Humana, other from Sunlife, outside the submitted work.

The Regulation of Cell Therapy and Gene Therapy Products in Switzerland.

This chapter describes the regulation of cell and gene therapy products (CGTPs) in Switzerland and its legal basis. The Swiss Agency for Therapeutic Products, Swissmedic, is the lead Regulatory Authority and its ATMP Division is responsible for the regulation of these products at the level of clinical trials and marketing authorization. CGTPs are regulated similarly to medicinal products. The legal basis is set by the Therapeutic Product Act, the Transplantation Act, the Human Research Act, and associated ordinances. The ATMP Division is involved in processes such as scientific advice meetings, presubmission advice meetings, pharmacovigilance, market surveillance, import/export approvals, manufacturing license approval, and inspections. In Switzerland, guidance documents relevant for cell and gene therapy provided by PIC/S, OECD, ICH, Ph.Eur., EMA, or FDA are considered. In order to harmonize requirements for CGTPs, the ATMP Division is in constant exchange of information with foreign Regulatory Authorities and part of working groups of ICH, IPRP, and Ph.Eur. As CGTPs are biologically and technically complex, a risk-based approach is applied on a case-by-case basis for the evaluation of clinical trial and marketing applications. A substantial part of this chapter will provide requirements with respect to the manufacturing and quality, nonclinical and clinical evaluation of CGTPs. Furthermore, information will be provided regarding the use of real-world evidence in evaluation of clinical long-term efficacy and safety in case of rare diseases where the numbers of patients are too small for statistically meaningful analysis during clinical trials. Finally, the chapter will provide information on a health technology assessment (HTA) program that was launched in 2015 in Switzerland by the federal authorities.

Positron Emission Tomography Quantitative Assessment of Off-Target Whole-Body Biodistribution of I-124-Labeled Adeno-Associated Virus Capsids Administered to Cerebral Spinal Fluid.

Based on studies in experimental animals demonstrating that administration of adeno-associated virus (AAV) vectors to the cerebrospinal fluid (CSF) is an effective route to transfer genes to the nervous system, there are increasing number of clinical trials using the CSF route to treat nervous system disorders. With the knowledge that the CSF turns over four to five times daily, and evidence in experimental animals that at least some of CSF administered AAV vectors are distributed to systemic organs, we asked: with AAV administration to the CSF, what fraction of the total dose remains in the nervous system and what fraction goes off target and is delivered systemically? To quantify the biodistribution of AAV capsids immediately after administration, we covalently labeled AAV capsids with iodine 124 (I-124), a cyclotron generated positron emitter, enabling quantitative positron emission tomography scanning of capsid distribution for up to 96 h after AAV vector administration. We assessed the biodistribution to nonhuman primates of I-124-labeled capsids from different AAV clades, including 9 (clade F), rh.10 (E), PHP.eB (F), hu68 (F), and rh91(A). The analysis demonstrated that 60-90% of AAV vectors administered to the CSF through either the intracisternal or intrathecal (lumbar) routes distributed systemically to major organs. These observations have potentially significant clinical implications regarding accuracy of AAV vector dosing to the nervous system, evoking systemic immunity at levels similar to that with systemic administration, and potential toxicity of genes designed to treat nervous system disorders being expressed in non-nervous system organs. Based on these data, individuals in clinical trials using AAV vectors administered to the CSF should be monitored for systemic as well as nervous system adverse events and CNS dosing considerations should account for a significant AAV systemic distribution.

Implementation of a gene therapy education initiative by the ASGCT and Muhimbili University of Health and Allied Sciences.

There has been rapid growth in gene therapy development with an expanding list of approved clinical products. Several therapies are particularly relevant to patients in low- and middle-income countries. Moreover, investing in research and manufacturing presents an opportunity for economic development. To increase awareness of gene therapy, the American Society of Gene and Cell Therapy partnered with the Muhimbili University of Health and Allied Sciences, Tanzania, to create a certificate-bearing course. The goal was to provide faculty teaching in graduate and medical schools with the tools needed to add gene therapy to the university curriculum. The first virtual course was held in October of 2022, and 45 individuals from 9 countries in Africa completed the training. The content was new to approximately two-thirds of participants, with the remaining third indicating that the course increased their knowledge base. The program was well received and will be adapted for other under-resourced regions.

The Cost of Biotech Innovation: Exploring Research and Development Costs of Cell and Gene Therapies.

BACKGROUND: Clinical development paradigms for cell and gene therapies appear to be different to those of more conventional treatments: therefore, it is informative to explore this from the perspective of investments required to bring a new cell and/or gene therapy to the market. While there are a number of studies in the literature analyzing clinical-stage R&D costs for novel therapeutics, these are 'modality-agnostic' and thus do not elucidate costs specifically for the emerging class of cell and gene therapies. OBJECTIVES: The objective of this study was to understand the research and development (R&D) costs associated with the clinical development of new cell and gene therapy assets METHODS: As part of our analysis of clinical-stage R&D costs for cell and gene therapies, we focused our efforts on cell and gene therapy assets recently approved by the US Food and Drug Administration (FDA) or expected to receive FDA approval by the end of 2024. A total of 25 therapies were identified for the study, 11 of which had sufficient level of detail for our clinical-stage R&D costing study. We calculated the clinical-stage R&D costs to bring a new cell and/or gene therapy to the market following a three-step approach, starting with (1) calculation of the out-of-pocket investment reported in US SEC reports; (2) we adjusted these figures for the risk of failure by applying a clinical trial phase-dependent attrition risk rate; (3) we accounted for the cost of capital of 10.5%. RESULTS: After accounting for R&D attrition rate (i.e., costs of failed programs) and applying a cost of capital at 10.5%, we estimate that the clinical-stage R&D investment required to bring a new cell and/or gene therapy to market is US$1943 M (95% CI US$1395 M, US$2490 M). CONCLUSION: This knowledge can inform financial planning for biopharma companies looking to enter the space and inform policy makers within the context of the commercialization and pricing of such therapies.

Treatment to cure: Advancing AAV gene therapy manufacture.

Advanced therapy medicinal products are a reality. With the opportunity to treat patients at the genetic level, the pharmaceutical industry has extended the treatment paradigm to innovative and potentially curative approaches. Gene therapy modifies or manipulates the expression of a gene, through gene repair, replacement, or modification, to alter living cells for therapeutic use, requiring delivery mechanisms through viral vectors. Market analysis not only demonstrates that the gene therapy sector has strong growth potential, but also indicates infancy with the number of currently approved products. Within gene therapy, adeno-associated viruses (AAVs) have high prominence, allowing for the targeted delivery of a transgene for therapeutic effect. To be able to realise the full potential of AAV-based gene therapy, focus has shifted to the ability to manufacture and deliver high titre, high quality, and efficacious product. However, manufacturing is not simple, with multiple complex challenges ranging from starting material generation, ensuring cellular production of high titres of viral vectors, to purification, where not all AAV particles contain the intended genetic payload. As an industry, we must learn from established manufacturing processes, such as for monoclonal antibodies (mAbs), to deliver rapidly scalable, robust, and cost-effective platform solutions that can be truly multiproduct, while working hand-in-hand with regulatory agencies. Additionally future innovation remains important and there are several opportunities for disruptive and further advanced manufacturing approaches. With a true end in mind approach, can we turn the tide from treatment to cure?

Reversed Phase-Liquid Chromatography for Recombinant AAV Genome Integrity Assessment.

After decades of research, gene therapy products have reached market maturity in recent years. Recombinant adeno-associated viruses (rAAVs) are one of the most promising gene delivery vehicles and are currently under intense scientific investigation. These next-generation medicines remain very challenging when it comes to designing appropriate analytical techniques for quality control. One critical quality attribute is the integrity of ssDNA incorporated in these vectors. The genome is the active compound driving rAAV therapy and therefore requires proper assessment and quality control. Current techniques for rAAV genome characterization include next-generation sequencing, quantitative polymerase chain reaction, analytical ultracentrifugation (AUC), and capillary gel electrophoresis (CGE), yet each of them presents their limitations or lack of user-friendliness. In this work, we demonstrate for the first time the potential of ion pairing-reverse phase-liquid chromatography (IP-RP-LC) to characterize the integrity of rAAV genomes. The obtained results were supported by two orthogonal techniques, AUC and CGE. IP-RP-LC can be performed above DNA melting temperatures, avoiding the detection of secondary DNA isoforms, and does not require the use of dyes due to UV detection. We demonstrate that this technique is suitable for batch comparability, different rAAV serotypes (AAV2 and AAV8), internal vs external (inside vs outside the capsid) DNA analysis, and contaminated samples. Overall, it is exceptionally user-friendly, needs limited sample preparation, has high reproducibility, and permits fractionation for further peak characterization. All of these factors add significant value of IP-RP-LC to the analytical toolbox of rAAV genome assessment.

Recommendations for economic evaluations of cell and gene therapies: a systematic literature review with critical appraisal.

OBJECTIVE: No consensus exists on the ideal methodology to evaluate the economic impact and value of new, potentially curative gene therapies. We aimed to identify and describe published methodologic recommendations for the economic evaluation of gene therapies and assess whether these recommendations have been applied in published evaluations. METHODS: This study was conducted in three stages: a systematic literature review of methodologic recommendations for economic evaluation of gene therapies; an assessment of the appropriateness of recommendations; and a review to assess the degree to which the recommendations were applied in published evaluations. RESULTS: A total of 2,888 references were screened, 83 articles were reviewed to assess eligibility, and 20 papers were included. Fifty recommendations were identified, and 21 reached consensus thresholds. Most evaluations were based on naive treatment comparisons and did not apply consensus recommendations. Innovative payment mechanisms for gene therapies were rarely considered. The only widely applied recommendations related to modeling choices and methods. CONCLUSIONS: Methodological recommendations for economic evaluations of gene therapies are generally not being followed. Assessing the applicability and impact of the recommendations from this study may facilitate the implementation of consensus recommendations in future evaluations.