Voxelotor 500mg tablets

This systematic review aims to summarise the clinical outcomes of l-glutamine, crizanlizumab, and voxelotor in the treatment of sickle cell disease (SCD) based on clinical trials and real-world data and to identify any gaps in the observations. The review identified 97 studies reporting data until 31 May 2024. A pivotal phase III study of l-glutamine showed that patients treated with l-glutamine had a 25 % reduction in pain crises and 33 % fewer hospital days compared to placebo. l-glutamine was generally well tolerated with minimal side effects. Real-world studies of l-glutamine emphasize patient adherence and obstacles to medication accessibility and approval as key concerns. In the SUSTAIN study, a 5-mg/kg dose of crizanlizumab reduced the occurrence of vaso-occlusive crises (VOCs) and hospitalizations by 45 % and 41 %, respectively. Real-world studies of crizanlizumab showed a reduction in complicated VOC events. The high discontinuation rate and results of the STAND trial led to a significant decrease in the use of crizanlizumab. The HOPE trial demonstrated a 51 % improvement in hemoglobin response and a reduction in hemolytic markers in patients treated with voxelotor. While some real-world studies have reported a decrease in VOCs and hospitalizations, the results are inconsistent and not conclusive. Further studies are needed to assess the impact of these novel therapies on end-organ-specific complications of SCD.

Abstract licence: CC BY-NC-ND

Sickle cell disease (SCD) is characterized by chronic hemolytic anemia and intermittent vasoocclusive crises. To date, 4 disease-modifying drugs have been approved for the treatment of SCD: hydroxyurea (an S-phase inhibitor), L-glutamine (an amino acid), crizanlizumab (a P-selectin inhibitor), and voxelotor (a hemoglobin S polymerization inhibitor). Preclinical studies suggested that voxelotor effectively treats SCD and sickle cell anemia (SCA). In a phase III trial, voxelotor-treated patients showed significantly elevated hemoglobin levels (>1 g/dL from baseline) compared to placebo-treated patients. The group that received voxelotor also showed a greater decrease in hemolytic markers but a comparable incidence of side effects. Six ongoing clinical trials also sought to ascertain the effectiveness and safety of high-dose voxelotor when administered to children younger than 12 years. Studies assessing their long-term efficacy and safety are needed to fully understand the role of voxelotor in treating SCD/SCA. In this review, we discuss the mechanisms, trials to date, and future treatment directions of voxelotor.

Abstract licence: CC BY-NC

The results of Voxelotor treatment in Sickle Cell Disease, as assessed through clinical outcomes, demonstrated its efficacy in reducing hemolysis and improving hemoglobin levels. This effect can be attributed to Voxelotor's inhibition of HbS polymerization, thereby restoring the deformability and compliance of sickle RBCs. Our mathematical model provided mechanistic insights into how altered rheological properties of sickle RBCs impact their flow dynamics in microcirculation. Specifically, we observed that Voxelotor-induced improvements in RBC deformability and compliance lead to enhanced plasma film height in capillaries, promoting smoother blood flow and reducing the risk of vaso-occlusive events. We established a direct relationship between the molecular mechanism of Voxelotor action and its clinical outcomes. The mathematical model served as a bridge, elucidating how Voxelotor-induced changes in sickle RBC mechanics translate to improved microcirculatory flow and reduced vaso-occlusion. This holistic understanding not only validates the therapeutic efficacy of Voxelotor but also underscores the importance of considering biomechanical factors in evaluating treatment outcomes in SCD. Furthermore, this study highlighted the relevance of microfluidics based diagnostic tools in assessing the efficacy of Voxelotor treatment. By leveraging insights from our mathematical model, microfluidics devices can be designed to mimic physiological conditions and effectively evaluate the deformability of sickle RBCs before and after treatment. This integrated approach not only facilitates the development of personalized therapeutic interventions but also accelerates the translation of novel treatments, such as Voxelotor, from preclinical studies to clinical practice for the management of Sickle Cell Disease. Int. J. Appl. Sci. Biotechnol. Vol 12(1): 46-53.

Abstract licence: CC BY-NC

Abstract Sickle cell anemia disease has been a great challenge to the world in the present situation. It occurs only due to the polymerization of sickle hemoglobin (HbS) having Pro–Val–Glu typed mutation, while the polymerization does not occur in normal hemoglobin (HbA) having Pro–Glu–Glu peptides. It is also well confirmed that the oxygenated HbS (OHbS) does not participate in the polymerization, while the deoxygenated HbS (dHbS) does, which causes the shape of red blood cells sickled. After polymerization, the blood has a low oxygen affinity. Keeping this fact into consideration, only those drugs are being synthesized that stabilize the OHbS structure so that the polymerization of HbS can be stopped. The literature data showed no systematic description of the changes occurring during the OHbS conversion to dHbS before polymerization. Hence, an innovative reasonable study between HbA and HbS, when they convert into their deoxygenated forms, was done computationally. In this evaluation, physiochemical parameters in HbA/HbS before and after deoxygenation were studied and compared deeply. The computationally collected data was used to understand the abnormal behaviour of dHbS arising due to the replacement of Glu6 with Val6. Consequently, during the presented computational study, the changes occurring in HbS were found opposite/abnormal as compared to HbA after the deoxygenation of both. The mechanism of Voxelotor (GBT-440) action to stop the HbS polymerization was also explained with the help of computationally collected data. Besides, a comparative study between GBT-440 and another suggested drug was also done to know their antisickling strength. Additionally, the effect of pH, CO, CO 2 , and 2,3-diphosphoglycerate (2,3-DPG) on HbS structure was also studied computationally.

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ABSTRACT: Crizanlizumab and voxelotor were several of the first drugs to receive the US Food and Drug Administration (FDA) approval for sickle cell disease (SCD) since the approval of hydroxyurea in 1998. Although initially exciting, additional data regarding efficacy and safety have since emerged for both drugs, first with the removal of crizanlizumab from the European market in August 2023. This was followed by Pfizer's abrupt decision in September 2024 to pull voxelotor from global markets owing to higher mortality in those on the drug vs placebo. These drugs highlight the importance and limitations of the FDA's accelerated approval process. In addition, the impact of these events, without transparent messaging, potentially threatened the fragile trust that providers have more recently been able to build with the SCD population regarding the medical system and research. Although there is a need for new therapies in SCD, we must prioritize both safety and efficacy and maintain trust in this population.

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ABSTRACT: Voxelotor is an inhibitor of sickle hemoglobin polymerization that is used to treat sickle cell disease. Although voxelotor has been shown to improve anemia, the clinical benefit on the brain remains to be determined. This study quantified the cerebral hemodynamic effects of voxelotor in children with sickle cell anemia (SCA) using noninvasive diffuse optical spectroscopies. Specifically, frequency-domain near-infrared spectroscopy combined with diffuse correlation spectroscopy were used to noninvasively assess regional oxygen extraction fraction (OEF), cerebral blood volume, and an index of cerebral blood flow (CBFi). Estimates of CBFi were first validated against arterial spin-labeled magnetic resonance imaging (ASL-MRI) in 8 children with SCA aged 8 to 18 years. CBFi was significantly positively correlated with ASL-MRI-measured blood flow (R2 = 0.651; P = .015). Next, a single-center, open-label pilot study was completed in 8 children with SCA aged 4 to 17 years on voxelotor, monitored before treatment initiation and at 4, 8, and 12 weeks (NCT05018728). By 4 weeks, both OEF and CBFi significantly decreased, and these decreases persisted to 12 weeks (both P < .05). Decreases in CBFi were significantly correlated with increases in blood hemoglobin (Hb) concentration (P = .025), whereas the correlation between decreases in OEF and increases in Hb trended toward significance (P = .12). Given that previous work has shown that oxygen extraction and blood flow are elevated in pediatric SCA compared with controls, these results suggest that voxelotor may reduce cerebral hemodynamic impairments. This trial was registered at www.ClinicalTrials.gov as #NCT05018728.

Abstract licence: CC BY-NC-ND