Valoctocogene roxaparvovec gene therapy provides durable haemostatic control for up to 7 years for haemophilia A.

INTRODUCTION: Valoctocogene roxaparvovec is an adeno-associated virus vector serotype 5 (AAV5)-mediated gene therapy approved for severe haemophilia A (HA). AIM: To report the safety and efficacy of valoctocogene roxaparvovec 7 years after dosing in a phase 1/2 clinical study (NCT02576795). METHODS: Males ≥18 years with severe HA (factor VIII [FVIII] ≤1 international unit [IU]/dL) who were previously receiving exogenous FVIII and had no history of FVIII inhibitors or anti-AAV5 antibodies received valoctocogene roxaparvovec treatment and were followed for 7 (6 × 1013 vg/kg; n = 7) and 6 (4 × 1013 vg/kg; n = 6) years. RESULTS: In the last year, one participant in each cohort reported treatment-related adverse events (AEs): grade 1 (G1) hepatomegaly (6 × 1013), and G1 splenomegaly and G1 hepatic steatosis (4 × 1013). During all follow-up, mean annualized treated bleeds and exogenous FVIII infusion rates were ≥88% lower than baseline values. At years 7 and 6, mean (median) FVIII activity (chromogenic assay) was 16.2 (10.3) and 6.7 (7.2) IU/dL in the 6 × 1013 (n = 5) and 4 × 1013 (n = 4) cohorts, respectively, corresponding to mild haemophilia. Regression analyses of the last year estimated rate of change in FVIII activity was -0.001 and -0.07 IU/dL/week for the 6 × 1013 and 4 × 1013 cohorts, respectively. Two participants (6 × 1013) resumed prophylaxis in year 7: one after a non-treatment-related G4 serious AE of spontaneous internal carotid artery bleed, and the other to manage bleeds and FVIII activity. CONCLUSIONS: The safety and efficacy of valoctocogene roxaparvovec remain generally consistent with previous reports, with good haemostatic control for most participants. Two participants returned to prophylaxis.

The translational gap for gene therapies in low- and middle-income countries.

Gene therapies are designed to address the root cause of disease. As scientific understanding of disease prevention, diagnosis, and treatment improves in tandem with technological innovation, gene therapies have the potential to become safe and effective treatment options for a wide range of genetic and nongenetic diseases. However, as the medical scope of gene therapies expands, consideration must be given to those who will benefit and what proactive steps must be taken to widen development and access potential, particularly in regions carrying a high disease burden.

Long-term safety and efficacy outcomes of valoctocogene roxaparvovec gene transfer up to 6 years post-treatment.

INTRODUCTION: Valoctocogene roxaparvovec uses an adeno-associated virus serotype 5 (AAV5) vector to transfer a factor VIII (FVIII) coding sequence to individuals with severe haemophilia A, providing bleeding protection. AIM: To assess safety and efficacy of valoctocogene roxaparvovec 5-6 years post-treatment. METHODS: In a phase 1/2 trial, adult male participants with severe haemophilia A (FVIII ≤1 IU/dL) without FVIII inhibitors or anti-AAV5 antibodies received valoctocogene roxaparvovec and were followed for 6 (6 × 1013 vg/kg; n = 7) and 5 (4 × 1013 vg/kg; n = 6) years. Safety, including investigation of potential associations between a malignancy and gene therapy, and efficacy are reported. RESULTS: No new treatment-related safety signals emerged. During year 6, a participant in the 6 × 1013  vg/kg cohort was diagnosed with grade 2 parotid gland acinar cell carcinoma; definitive treatment was uncomplicated parotidectomy with lymph node dissection. Target enrichment sequencing of tumour and adjacent healthy tissue revealed low vector integration (8.25 × 10-5 per diploid cell). Integrations were not elevated in tumour samples, no insertions appeared to drive tumorigenesis, and no clonal expansion of integration-containing cells occurred. During all follow-ups, >90% decreases from baseline in annualised treated bleeds and FVIII infusion rates were maintained. At the end of years 6 and 5, mean FVIII activity (chromogenic assay) was 9.8 IU/dL (median, 5.6 IU/dL) and 7.6 IU/dL (median, 7.1 IU/dL) for the 6 × 1013 and 4 × 1013 vg/kg cohorts, respectively, representing proportionally smaller year-over-year declines than earlier timepoints. CONCLUSIONS: Valoctocogene roxaparvovec safety and efficacy profiles remain largely unchanged; genomic investigations showed no association with a parotid tumour.

Nonacog Alfa for Prophylaxis and Treatment of Bleeding Episodes in Previously Treated Patients with Moderately Severe or Severe Hemophilia B in India.

Purpose: Hemophilia B is an X-linked congenital bleeding disorder caused by a deficiency of coagulation factor IX (FIX) clotting activity. This study evaluated safety and efficacy of nonacog alfa, a recombinant human blood coagulation FIX replacement product, in males aged 12-65 years with hemophilia B (FIX activity ≤ 2%) with or without inhibitors in India. Methods: In this multicenter, open-label, post-approval phase 4 study, participants were treated for up to 8 weeks, with up to a 4-week screening period and a subsequent post-treatment 28-day safety observation period. Intravenous nonacog alfa 40 IU/kg (range 13-78 IU/kg) was administered at intervals of 3-4 days, in accordance with the approved local product document. Results: A total of 25 participants were enrolled and completed the study. No participants developed FIX inhibitors during the study, experienced treatment-related adverse events (AEs) or serious AEs, or developed a thrombotic event and/or hypersensitivity reaction. No participants experienced bleeding events requiring on-demand treatment with nonacog alfa. Seventeen bleeding episodes (16 spontaneous and 1 traumatic) were reported in 10 participants; all occurred post treatment, with the exception of a minor gum-bleeding event, and were managed without treatment. The mean (SD) annualized total factor consumption (TFC) per patient was 224,582 (75,527) IU; the mean (SD) annualized TFC by weight per patient was 3639 (573) IU/kg. Conclusion: Nonacog alfa was safe and effective for the prevention of hemorrhagic episodes in Indian males with congenital, severe hemophilia B. No participants developed FIX inhibitors, and no new safety signals were reported.

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.

RNAi for the Treatment of People with Hemophilia: Current Evidence and Patient Selection.

Severe hemophilia is associated with spontaneous, prolonged and recurrent bleeding. Inadequate prevention and treatment of bleeding can lead to serious morbidity and mortality. Due to the limitations of intravenous clotting factor replacement, including the risk of inhibitory antibodies, innovative novel therapies have been developed that have dramatically changed the landscape of hemophilia therapy. Ribonucleic acid interference (RNAi) has brought the opportunity for multiple strategies to manipulate the hemostatic system and ameliorate the bleeding phenotype in severe bleeding disorders. Fitusiran is a RNAi therapeutic that inhibits the expression of the natural anticoagulant serpin antithrombin. Reduction in antithrombin is known to cause thrombosis if coagulation parameters are otherwise normal and can rebalance hemostasis in severe hemophilia. Reports from late stage clinical trials of fitusiran in hemophilia A and B participants, with and without inhibitory antibodies to exogenous clotting factor, have demonstrated efficacy in preventing bleeding events showing promise for a future "universal" prophylactic treatment of individuals with moderate-severe hemophilia.

Fitusiran prophylaxis in people with severe haemophilia A or haemophilia B without inhibitors (ATLAS-A/B): a multicentre, open-label, randomised, phase 3 trial.

BACKGROUND: Fitusiran, a subcutaneous investigational siRNA therapeutic, targets antithrombin with the goal of rebalancing haemostasis in people with haemophilia A or haemophilia B, regardless of inhibitor status. We aimed to evaluate the efficacy and safety of fitusiran prophylaxis in people with severe haemophilia without inhibitors. METHODS: This multicentre, open-label, randomised phase 3 study was conducted at 45 sites in 17 countries. Male participants aged at least 12 years with severe haemophilia A or B without inhibitors, who had previously been treated on-demand with clotting factor concentrates, were randomly assigned in a 2:1 ratio to receive 80 mg subcutaneous fitusiran prophylaxis once per month or to continue on-demand clotting factor concentrates for a total of 9 months. Randomisation was stratified by the number of bleeding events in the 6 months before screening (≤10 bleeds and >10 bleeds) and by haemophilia type (haemophilia A or B). The primary endpoint was annualised bleeding rate, analysed in the intention-to-treat analysis set. Safety and tolerability were assessed in the safety analysis set. This trial is registered with ClinicalTrials.gov, NCT03417245, and is complete. FINDINGS: Between March 1, 2018, and July 14, 2021, 177 male participants were screened for eligibility and 120 were randomly assigned to receive fitusiran prophylaxis (n=80) or on-demand clotting factor concentrates (n=40). Median follow-up was 7·8 months (IQR 7·8-7·8) in the fitusiran group and 7·8 months (7·8-7·8) in the on-demand clotting factor concentrates group. The median annualised bleeding rate was 0·0 (0·0-3·4) in the fitusiran group and 21·8 (8·4-41·0) in the on-demand clotting factor concentrates group. The estimated mean annualised bleeding rate was significantly lower in the fitusiran prophylaxis group (3·1 [95% CI 2·3-4·3]) than in the on-demand clotting factor concentrates group (31·0 [21·1-45·5]; rate ratio 0·101 [95% CI 0·064-0·159]; p<0·0001). In the fitusiran group, 40 (51%) of 79 treated participants had no treated bleeds compared with two (5%) of 40 participants in the on-demand clotting factor concentrates group. Increased alanine aminotransferase concentration (18 [23%] of 79 participants in the safety analysis set) was the most common treatment-emergent adverse event in the fitusiran group and hypertension (four (10%) of 40 participants) was the most common in the on-demand clotting factor concentrates group. Treatment-emergent serious adverse events were reported in five (6%) participants in the fitusiran group (cholelithiasis [n=2, 3%], cholecystitis [n=1, 1%], lower respiratory tract infection [n=1, 1%], and asthma [n=1, 1%]) and five (13%) participants in the on-demand clotting factor concentrates group (gastroenteritis, pneumonia, suicidal ideation, diplopia, osteoarthritis, epidural haemorrhage, humerus fracture, subdural haemorrhage, and tibia fracture [all n=1, 3%]). No treatment-related thrombosis or deaths were reported. INTERPRETATION: In participants with haemophilia A or B without inhibitors, fitusiran prophylaxis resulted in significant reductions in annualised bleeding rate compared with on-demand clotting factor concentrates and no bleeding events in approximately half of participants. Fitusiran prophylaxis shows haemostatic efficacy in both haemophilia A and haemophilia B, and therefore has the potential to be transformative in the management of all people with haemophilia. FUNDING: Sanofi.

Efficacy and safety of fitusiran prophylaxis in people with haemophilia A or haemophilia B with inhibitors (ATLAS-INH): a multicentre, open-label, randomised phase 3 trial.

BACKGROUND: Fitusiran, a subcutaneous investigational small interfering RNA therapeutic, targets antithrombin to rebalance haemostasis in people with haemophilia A or haemophilia B, irrespective of inhibitor status. We evaluated the efficacy and safety of fitusiran prophylaxis in people with haemophilia A or haemophilia B with inhibitors. METHODS: This multicentre, randomised, open-label phase 3 study was done at 26 sites (primarily secondary or tertiary centres) in 12 countries. Men, boys, and young adults aged 12 years or older with severe haemophilia A or haemophilia B with inhibitors previously treated with on-demand bypassing agents were randomly assigned (2:1) to receive once-a-month 80 mg subcutaneous fitusiran prophylaxis (fitusiran prophylaxis group) or to continue with bypassing agents on-demand (bypassing agents on-demand group) for 9 months. The primary endpoint was mean annualised bleeding rate during the efficacy period in the intention-to-treat population estimated by negative binomial model. Safety was assessed as a secondary endpoint in the safety population. This trial is complete and is registered with ClinicalTrials.gov, NCT03417102. FINDINGS: Between Feb 14, 2018, and June 23, 2021, 85 participants were screened for inclusion, of whom 57 (67%; 57 [100%] men; median age 27·0 years [IQR 19·5-33·5]) were randomly assigned: 19 (33%) participants to the bypassing agent on-demand group and 38 (67%) participants to the fitusiran prophylaxis. Negative binomial model-based mean annualised bleeding rate was significantly lower in the fitusiran prophylaxis group (1·7 [95% CI 1·0-2·7]) than in the bypassing agents on-demand group (18·1 [10·6-30·8]), corresponding to a 90·8% (95% CI 80·8-95·6) reduction in annualised bleeding rate in favour of fitusiran prophylaxis (p<0·0001). 25 (66%) participants had zero treated bleeds in the fitusiran prophylaxis group versus one (5%) in the bypassing agents on-demand group. The most frequent treatment-emergent adverse event in the fitusiran prophylaxis group was increased alanine aminotransferase in 13 (32%) of 41 participants in the safety population; there were no increased alanine aminotransferase treatment-emergent adverse events in the bypassing agents on-demand group. Suspected or confirmed thromboembolic events were reported in two (5%) participants in the fitusiran prophylaxis group. No deaths were reported. INTERPRETATION: Subcutaneous fitusiran prophylaxis resulted in statistically significant reductions in annualised bleeding rate in participants with haemophilia A or haemophilia B with inhibitors, with two-thirds of participants having zero bleeds. Fitusiran prophylaxis might show haemostatic efficacy in participants with haemophilia A or haemophilia B with inhibitors; therefore, the therapeutic might have the potential to improve the management of people with haemophilia. FUNDING: Sanofi.

COVID-19 and preeclampsia: The unique and the mutually nonexclusive clinical manifestations.

Preeclampsia (PE) is a serious, unpredictable hypertensive disorder of pregnancy present in around 8-10% of all pregnancies resulting in high rate of maternal and fetal morbidity and mortality. With the pathophysiology partially known, delivery is the only cure for PE. The disease sets due to multiple pathologic processes involving endothelial cell activation, inflammation, multiorgan damage and syncytiotrophoblast stress.  Though the primary target organ is lungs in COVID-19, other systemic manifestations which include endothelial dysfunction, dysregulated angiogenesis, thrombosis, liver injury, thrombocytopenia, hypertension and kidney damage overlap with PE. COVID-19 patients show a higher incidence of PE as compared to their noninfected counterparts and vice versa. Similar pathophysiology and clinical features make differential diagnosis challenging. For effective and specific management, it is important to differentiate actual PE from COVID-19 with PE like features. There are contradictory reports about the accuracy of diagnostic tools in distinguishing PE from severe COVID-19 with PE like features. With the available data, it can only be stated that PE is a common adverse pregnancy event, which may be exacerbated by, or may exacerbate, COVID-19. Future research should focus on cohesive understanding of the pathophysiology of the clinical manifestations, and preventive strategies during pregnancy.

Moroctocog Alfa (AF-CC) for Prophylaxis and Treatment of Bleeding Episodes in Previously Treated Patients with Hemophilia A in India.

Purpose: Hemophilia A is an X-linked congenital disorder, characterized by factor VIII (FVIII) deficiency. Globally, India has the highest population of patients with hemophilia, and there is a clear unmet need for appropriate and effective treatment for this patient population. This multicenter, open-label, post-approval study evaluated the safety and efficacy of moroctocog alfa in patients with moderate or severe congenital hemophilia A in India. Methods: Intravenous moroctocog alfa was administered 30 ± 5 IU/kg 3 times weekly for bleeding prophylaxis, according to the local product document. Participants were treated for up to 8 weeks, with an up to 4-week screening period and a subsequent post-treatment, 28-day safety observation period. Patients continued in the study until at least 24 exposure days or a period of up to 8 weeks on moroctocog alfa. Results: A total of 50 participants were enrolled, and 48 (85.7%) completed the study. No participants developed FVIII inhibitors during the study. The mean (SD) annualized bleeding rate during moroctocog alfa prophylaxis was 0.79 (2.0) with a median (range) of 0.00 (0.0, 6.8). The mean (SD) annualized total factor consumption (TFC) per participant was 287,432 (93,866) IU; the mean (SD) annualized TFC by weight per participant was 4176 (858) IU/kg. Moroctocog alfa was well tolerated with no reported treatment-emergent adverse event-related dose reductions, discontinuations, or serious adverse events. Conclusion: Moroctocog alfa was safe, effective, and well tolerated in Indian participants with congenital moderate to severe hemophilia A. No participant developed FVIII inhibitors during the study.

Safety and efficacy of long-term emicizumab prophylaxis in hemophilia A with factor VIII inhibitors: A phase 3b, multicenter, single-arm study (STASEY).

Background: The bispecific monoclonal antibody emicizumab bridges activated factor IX and factor X, mimicking the cofactor function of activated factor VIII (FVIII), restoring hemostasis. Objectives: The Phase 3b STASEY study was designed to assess the safety of emicizumab prophylaxis in people with hemophilia A (HA) with FVIII inhibitors. Methods: People with HA received 3 mg/kg emicizumab once weekly (QW) for 4 weeks followed by 1.5 mg/kg QW for 2 years. The primary objective was the safety of emicizumab prophylaxis, including incidence and severity of adverse events (AEs) and AEs of special interest (thrombotic events [TEs] and thrombotic microangiopathies). Secondary objectives included efficacy (annualized bleed rates [ABRs]). Results: Overall, 195 participants were enrolled; 193 received emicizumab. The median (range) duration of exposure was 103.1 (1.1-108.3) weeks. Seven (3.6%) participants discontinued emicizumab. The most common AEs were arthralgia (n = 33, 17.1%) and nasopharyngitis (n = 30, 15.5%). The most common treatment-related AE was injection-site reaction (n = 19, 9.8%). Two fatalities were reported (polytrauma with fatal head injuries and abdominal compartment syndrome); both were deemed unrelated to emicizumab by study investigators. Two TEs occurred (myocardial infarction and localized clot following tooth extraction), also deemed unrelated to emicizumab. The negative binomial regression model-based ABR (95% confidence interval) for treated bleeds was 0.5 (0.27-0.89). Overall, 161 participants (82.6%) had zero treated bleeds. Conclusions: The safety profile of emicizumab prophylaxis was confirmed in a large population of people with HA with FVIII inhibitors and no new safety signals occurred. The majority of participants had zero treated bleeds.

Management of haemophilia A with inhibitors: A regional cross-talk.

INTRODUCTION: The development of inhibitors with factor VIII (FVIII) replacement therapy is one of the most common and challenging complications of haemophilia A (HA) treatment, jeopardising treatment efficacy and predisposing patients to high risks of morbidity and mortality. The management of patients with inhibitors is particularly challenging in countries where resources are limited. AIM: To provide a comprehensive summary of the management of HA with inhibitors while focusing on differences in practice between Western and non-Western countries and how resource scarcity can impact HA management, leading to suboptimal outcomes in patients with inhibitors. METHODS: Summary of key evidence and regional expert opinion. RESULTS: We address, particularly, the diagnosis of and testing for inhibitors, as well as the epidemiology of inhibitors, including incidence, prevalence and disease burden. Secondly, we provide an overview of the current treatment landscape in HA with inhibitors regarding the eradication of inhibitors with immune tolerance induction and the treatment and prevention of bleeding with bypassing agents, non-factor replacement agents and other experimental therapies. This is complemented with insights from the authors around the applicability of, and challenges associated with, such therapies in their settings of practice. CONCLUSIONS: We conclude by proposing some key steps towards bridging the gaps in the management of HA with inhibitors in resource-limited countries, including: (1) the collection of quality data that can inform healthcare reforms and policies; (2) improving disease knowledge among healthcare practitioners and patients with the aim of standardising disease management across centres and (3) working towards promoting equal access to HA care and therapies for everyone.

A prospective, multicenter, clinical Study to evaluate the Safety, Pharmacokinetics, and Efficacy of Bleed Outcomes, with HemoRel-A® in severe Hemophilia A Patients.

PURPOSE: To evaluate efficacy for an on-demand treatment of acute bleeding events, pharmacokinetics, safety, and tolerability of HemoRel-A® in severe hemophilia A. METHODS: A total of 44 male subjects with severe hemophilia A with an annualized bleed rate of 12 while on-demand treatment with factor VIII (FVIII) were enrolled in the study and received HemoRel-A® for bleed treatment. The efficacy of HemoRel-A® was evaluated based on a four-point scale (excellent, good, moderate, or none). Six-point pharmacokinetic (PK) assessment was performed following a single dose of 50 IU/kg in 12 subjects after a 7-day wash-out period. Safety evaluations were performed at each visit and inhibitor testing was performed in all patients at screening and end of study. RESULTS: Forty-four male subjects received at least a single dose of the study medication and were included in the intent-to-treat (ITT) analysis and safety outcome. In 23 (7.52%) out of the 306 bleeding events, HemoRel-A® efficacy was rated as excellent, in 272 (88.89 %) bleeds it was rated as good, and in 11 (3.68%) bleeding events it was rated as moderate. No failure of efficacy was noted in any of the bleeding events. Thus overall out of 306 bleeding events, 295 (96.41%) showed excellent or good efficacy. Pharmacokinetic assessment based on plasma FVIII activity measured by the chromogenic assay in 12 patients showed comparative results similar to FVIII preparations. A total of 12 adverse events (AEs) were reported in this study. There was no inhibitor development in this previously treated patients (PTP) cohort. CONCLUSION: HemoRel-A® was established to be efficacious and safe in the treatment of acute bleeding events in subjects with severe hemophilia A. TRIAL REGISTRATION NUMBER: CTRI/2018/05/013790. Registration date: 9th May 2018.

Seroprevalence to adeno-associated virus type 6 in people with hemophilia B from a UK adult cohort.

Background: Gene therapy shows promise as a potential "cure" for hemophilia A and B. Adeno-associated virus (AAV) vectors are the leading platform to deliver modified genetic code of factor VIII or IX to the liver effecting endogenous production. Patient exposure to wild-type AAV leads to the formation of neutralizing factors, which can prevent successful transduction. It is thus important to establish the seroprevalence of the AAV serotypes in people with hemophilia to aid prediction of successful gene transfer. The seroprevalence of AAV6 in UK people with hemophilia B is not yet reported. Objectives: We studied the prevalence of anti-AAV6 neutralizing factors in UK people with hemophilia B (n = 49). We collected data on people's hepatitis C exposure and treatment with plasma-derived factor IX (FIX) to identify if there was correlation with AAV6 exposure. Methods: Serum samples and patient data were collected from 49 people with hemophilia B registered at UK hemophilia comprehensive care centers. The samples were tested for neutralizing factors to AAV6 using a cell-based transduction inhibition assay. Results: Thirty-one percent of patients had serum neutralization against AAV6. There was no correlation between AAV6 seropositivity and previous treatment with plasma-derived FIX products or hepatitis C exposure. Conclusion: Based on limited data, there is no evidence of association between the presence of AAV6 neutralizing factors in people with hemophilia B and exposure to contaminated plasma derivatives. The frequency of AAV6 neutralizing factors in our hemophilia B cohort is similar to UK people with hemophilia A and non-hemophilia populations.

Low-dose prophylaxis and its impact on the health of haemophilia patients.

BACKGROUND AND OBJECTIVES: There is convincing evidence to show that low-dose prophylaxis (LDP) results in reduction in annualized bleeding rate (ABR) and better health-related quality of life (HRQoL) compared with on-demand or episodic treatment (ET) in haemophilia patients. The aim is to review various LDP protocols practised for the treatment of haemophilia, specifically in resource-limited countries. METHODS: A literature survey was made of articles published in English language in PubMed and EMBASE without any time limit using keywords 'low dose', 'prophylaxis' and 'haemophilia' in different combinations. RESULTS: A total of 19 reports involving LDP in patients with haemophilia were included in this review. Almost all studies reported reduction in ABR, improvement in joint function, pain and HRQoL compared with ET, but this did not fully translate into significant improvement in structural arthropathy already caused by earlier bleeds, suggesting that LDP may be less or ineffective in either stopping or reversing the damage. Individualized dose escalation protocols based on pharmacokinetic (PK) or clinical parameters were found to be superior to fixed LDP protocols and cost-effective compared with standard dose protocols. CONCLUSION: The developing countries can initiate LDP as the first step of prophylaxis, but certainly this should not be the final goal of the health care system in any country. Due to the complex pathophysiological mechanisms underlying haemophilic arthropathy, long-term data on LDP in haemophilia patients are warranted.

Interindividual variability in transgene mRNA and protein production following adeno-associated virus gene therapy for hemophilia A.

Factor VIII gene transfer with a single intravenous infusion of valoctocogene roxaparvovec (AAV5-hFVIII-SQ) has demonstrated clinical benefits lasting 5 years to date in people with severe hemophilia A. Molecular mechanisms underlying sustained AAV5-hFVIII-SQ-derived FVIII expression have not been studied in humans. In a substudy of the phase 1/2 clinical trial ( NCT02576795 ), liver biopsy samples were collected 2.6-4.1 years after gene transfer from five participants. Primary objectives were to examine effects on liver histopathology, determine the transduction pattern and percentage of hepatocytes transduced with AAV5-hFVIII-SQ genomes, characterize and quantify episomal forms of vector DNA and quantify transgene expression (hFVIII-SQ RNA and hFVIII-SQ protein). Histopathology revealed no dysplasia, architectural distortion, fibrosis or chronic inflammation, and no endoplasmic reticulum stress was detected in hepatocytes expressing hFVIII-SQ protein. Hepatocytes stained positive for vector genomes, showing a trend for more cells transduced with higher doses. Molecular analysis demonstrated the presence of full-length, inverted terminal repeat-fused, circular episomal genomes, which are associated with long-term expression. Interindividual differences in transgene expression were noted despite similar successful transduction, possibly influenced by host-mediated post-transduction mechanisms of vector transcription, hFVIII-SQ protein translation and secretion. Overall, these results demonstrate persistent episomal vector structures following AAV5-hFVIII-SQ administration and begin to elucidate potential mechanisms mediating interindividual variability.

Gene therapy access: Global challenges, opportunities, and views from Brazil, South Africa, and India.

Gene and cell therapies for a variety of life-limiting illnesses are under investigation, and a small number of commercial products have successfully obtained regulatory approval. The cost of treatment is high, and clinical studies evaluating safety and efficacy are performed predominately in high-income countries. We reviewed the current status of gene and cell therapies in low- and middle-income countries and highlighted the need and current barriers to access. The state of product development in Brazil, South Africa, and India is discussed, including lessons learned from American Society of Gene and Cell Therapy (ASGCT)-sponsored virtual symposia in each of these countries.

Predictive Role of Haematological Determinants on Outcomes of Critically Ill COVID-19 Patients Admitted to Intensive Care Unit.

BACKGROUND:  The mortality of patients admitted to the intensive care unit (ICU) with COVID-19 remains significantly high. Severe COVID-19 pneumonia is characterised by refractory hypoxemia with significant shunting due to a combination of alveolar damage, vascular vasoconstriction, and occlusion due to microthrombi. Similar pathological features are seen in extra-pulmonary organs. However, the influence of thrombotic markers on the risk of mechanical ventilation (MV) and the development of acute kidney injury (AKI) is not fully defined. METHODS:  This was a cross-sectional evaluation of haemostatic and thrombotic markers of COVID-19 patients admitted to the ICU to determine their predictability for the development of thromboembolism and the need for non-invasive or invasive MV, development of AKI, and mortality. RESULTS:  An extended coagulation profile was obtained in 71 SARS-CoV-2 positive patients admitted to the ICU. All patients had acute severe hypoxic respiratory failure and required non-invasive or invasive MV. There were increases in peak D-dimer (3.0 mg/L), factor VIII levels (255 IU/dL) vWF antigen (471 IU/dL) with low ADAMTS13 activity (54.7 IU/dL) compared to the reference ranges. Peak D-dimer was consistently raised in patients who developed AKI and required invasive MV. ADAMTS13/vWF/platelet axis was associated with disease severity, multi-organ dysfunction, and mortality. CONCLUSIONS:  Haematological abnormalities are a common feature of severe COVID-19 pneumonia. We found peak D-dimer and vWF-ADAMTS13-platelet axis are associated with increased ICU severity and outcome in severe COVID-19 patients admitted to ICU. Larger studies are needed to evaluate this more comprehensively.