Defibrotide: a review of its use in severe hepatic veno-occlusive disease following haematopoietic stem cell transplantation

Role of Defibrotide in the Prevention of Murine Model Graft-versus-Host Disease after Allogeneic Hematopoietic Cell Transplantation

Graft-versus-host disease (GVHD) is a major complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Vascular endothelial cells are entirely exposed and damaged during the pathogenesis of acute GVHD (aGVHD). Defibrotide (DF) is a mixture of single-stranded oligonucleotides that has several pharmacologic effects that contribute to its endothelial protective properties. B10.BR mice were conditioned, followed by the infusion of donor C57BL/6J T cell-depleted bone marrow cells with or without splenocytes. The mice were either treated with DF or appropriate controls daily for the first week and then 3 times per week thereafter. Allogeneic DF-treated recipients demonstrated significantly better survival with reduced clinical GVHD. Significantly reduced organ pathology in the gut was associated with significantly decreased T cell infiltration in the ileum and colon on day +28. Serum cytokine analysis revealed significantly reduced levels of TNF and IL-6 at day +7 and of TNF at day +28 in allogeneic DF-treated recipients. Significantly reduced levels of ICAM-1 and angiopoietin-2 in serum and reduced VCAM-1 and HCAM levels in the ileum and colon of allogeneic DF-treated recipients were observed. Improved survival was seen in the graft-versus-leukemia (GVL) model (C3H.SW into C57BL/6J mice with C1498-luc). Through its anti-inflammatory and endothelial protective effects, DF treatment reduces the severity of aGVHD while not impairing GVL activity.

Defibrotide: Real World Management of Veno-Occlusive Disease/ Sinusoidal Obstructive Syndrome after Stem Cell Transplant

Hepatic veno-occlusive disease or sinusoidal obstructive syndrome (VOD/ SOS) is a life-threatening complication of hematopoietic stem cell transplantation (HSCT). Defibrotide is the only FDA-approved medication for the management of severe VOD/ SOS after HSCT. We report our center's experience with commercially available defibrotide as treatment for patients with VOD/SOS. We retrospectively identified 28 cases of VOD/ SOS, based on the European Society for Blood and Marrow Transplantation criteria, from March 2016 through June 2019. The median day of VOD/ SOS onset was 25 days (range, 8 to 69) and defibrotide was initiated on day of diagnosis in 71% of patients. Complete resolution of VOD/ SOS occurred in 75% of patients. Day +100 survival was 64% for all HSCT patients and 53% for those with very severe VOD/ SOS. Response rates and survival were similar in patients with VOD/SOS after myeloablative or reduced intensity chemotherapy HSCT. Therapy related adverse events were mild and included hematuria (43%), epistaxis (18%) and hypotension (11%). Severe hemorrhagic adverse events occurred in 2 patients (pulmonary and upper gastrointestinal hemorrhage; 7%) and both in the setting of progressive VOD/SOS. Early diagnosis, prompt initiation of defibrotide, and minimizing dosing interruptions may be key to successful treatment of VOD/ SOS.

Outcomes of combination treatment with MARS and TIPS for hepatic veno-occlusive disease: a report of 12 cases

BACKGROUND

In patients with acute liver injury caused by hepatic veno-occlusive disease (HVOD), molecular adsorbent recirculation system (MARS) may be used to improve liver function in conjunction with transjugular intrahepatic portosystemic shunt (TIPS) to reduce portal hypertension.

METHODS

Twelve patients were admitted to our hospital following treatment for HVOD for 10 to 21 days at other hospitals. All patients were treated with a combination of MARS and TIPS, and they were evaluated clinically including liver function tests.

RESULTS

After the initial treatment with MARS, liver function improved significantly in all patients. TIPS placement decreased the hepatic venous pressure gradient (HVPG) to 10.17 ± 2.26 mmHg from a pre-TIPS HVPG of 23.58 ± 9.43 mmHg. The outcomes of combination treatment with MARS and TIPS in 12 patients with HVOD were as follows: 1) improvement of various clinical and biological parameters leading to full recovery in 1 year in 6 patients; 2) full recovery following liver transplantation for acute liver failure in three patients; and 3) three patients died due to hepatic failure after TIPS placement.

CONCLUSION

The combination of MARS and TIPS creation is promising as a potential treatment for acute HVOD, and it showed an improvement in overall survival.

Independent risk factors and long-term outcomes for acute kidney injury in pediatric patients undergoing hematopoietic stem cell transplantation: a retrospective cohort study

BACKGROUND

Acute kidney injury (AKI) remains a frequent complication in children undergoing hematopoietic stem cell transplantation (HSCT) and an independent risk factor of the patient's survival and a prognostic factor of progression to chronic kidney disease (CKD). However, the causes of these complications are diverse, usually overlapping, and less well understood.

METHODS

This retrospective analysis was performed in 43 patients (28 boys, 15 girls; median age, 5.5 years) undergoing HSCT between April 2006 and March 2019. The main outcome was the development of AKI defined according to the Pediatric Risk, Injury, Failure, Loss, End-stage Renal Disease (pRIFLE) criteria as ≥ 25% decrease in estimated creatinine clearance. The secondary outcome was the development of CKD after a 2-year follow-up.

RESULTS

AKI developed in 21 patients (49%) within 100 days after HSCT. After adjusting for possible confounders, posttransplant AKI was associated with matched unrelated donor (MUD) (HR, 6.26; P = 0.042), but not total body irradiation (TBI). Of 37 patients who were able to follow-up for 2 years, 7 patients died, but none had reached CKD during the 2 years after transplantation.

CONCLUSIONS

Posttransplant AKI was strongly associated with HSCT from MUD. Although the incidence of AKI was high in our cohort, that of posttransplant CKD was lower than reported previously in adults. TBI dose reduced, GVHD minimized, and infection prevented are required to avoid late renal dysfunction after HSCT in children since their combinations may contribute to the occurrence of AKI.

Defibrotide enhances fibrinolysis in human endotoxemia - a randomized, double blind, crossover trial in healthy volunteers

Defibrotide is approved for the treatment of sinusoidal obstruction syndrome after allogeneic stem cell transplantation. The exact mode of action of defibrotide is unclear and human in vivo data are scarce. In this randomized, double blind, crossover trial we included 20 healthy volunteers. Four were randomized to receive placebo, while 16 received a 2 ng/kg bodyweight bolus of lipopolysaccharide (LPS). Infusion of 6.25 mg/kg defibrotide or placebo was started one hour before the injection of the LPS bolus. Plasma levels of prothrombin fragments F1 + 2, thrombin-antithrombin complexes, von Willebrand factor, E-selectin, tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1), plasmin-antiplasmin complexes (PAP), tumor necrosis factor-α, interleukin 6, and C-reactive protein were measured. Thromboelastometry was performed. Infusion of defibrotide did not reduce the LPS-induced activation of coagulation, the endothelium or the release of pro-inflammatory cytokines. However, defibrotide increased t-PA antigen levels by 31% (Quartiles: 2–49%, p = 0.026) and PAP concentrations by 13% (−4–41%, p = 0.039), while PAI-1 levels remained unaffected. Moreover, defibrotide reduced C-reactive protein levels by 13% (0–17%, p = 0.002). A transient increase in the clotting time in thromboelastometry and a decrease in F1 + 2 prothrombin fragments suggests modest anticoagulant properties. In conclusion, defibrotide infusion enhanced fibrinolysis and reduced C-reactive protein levels during experimental endotoxemia.

Gynura Rhizoma containing pyrrolizidine alkaloids induces the hepatic sinusoidal obstruction syndrome in mice via upregulating fibrosis-related factors

Recently, hepatic sinusoidal obstruction syndrome (HSOS) caused by herbal preparations containing pyrrolizidine alkaloids (PAs), such as Gynura Rhizoma (Tusanqi), has gained global attention. However, the lack of a reliable and reproducible animal model has greatly hampered mechanistic studies. Therefore, we aimed to establish a reproducible HSOS mouse model and investigate the hepatotoxic mechanism. The model was established by intragastrical administration of Gynura Rhizoma extract, i.e., 1.0 g extract/kg per day (equal to 16.7 g crude drug/kg per day based on extraction rate and 49.1 mg PA/kg per day based on the total PA content in the extract determined) for 40 successive days. Then, the mice were sacrificed, and their blood samples and livers were collected for analyses. Using hematoxylin-eosin (HE) and Masson staining, scanning electron microscopy imaging, clinical biomarkers, and other assays, we showed that the HSOS was successfully induced in our mouse model. Furthermore, we detected the key factors involved in liver fibrosis in the mice, revealing significantly increased hydroxyproline concentration; elevated expression of α-smooth muscle actin (α-SMA) and fibrosis-related genes such as Collagen-1, Collagen-3, Mmp2, Mmp13, Timp1, Timp3, and Activin, upregulated Smad3 phosphorylation, and increased serum TGF-β levels. Moreover, pro-inflammatory cytokines, including Tnf-α, Il-1β, and Il-6, were also increased in the model. All these results demonstrate the key roles of the TGF-β-Smad3 and inflammatory signaling pathways in this Gynura Rhizoma-induced HSOS mouse model, suggesting that blockade of fibrosis and/or inflammation should be an effective treatment for HSOS.

Identification and Management: Sinusoidal Obstruction Syndrome/Veno-Occlusive Disease Eelated to Hematopoietic Stem Cell Transplantation

BACKGROUND

Sinusoidal obstruction syndrome (SOS), also called hepatic veno-occlusive disease (VOD), is a potentially life-threatening complication of hematopoietic stem cell transplantation (HSCT) that affects about 1 in 7 patients undergoing this procedure. SOS/VOD is caused by the conditioning regimens administered prior to HSCT; in some cases, SOS/VOD results from chemotherapy alone. SOS/VOD usually develops within three weeks following HSCT; however, it can have later onset. 
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OBJECTIVES

Clearly understanding how SOS/VOD develops may support prompt detection and treatment when the condition arises.
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METHODS

Research on identification and management of SOS/VOD is summarized, and data from clinical trials are reviewed.
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FINDINGS

This article describes the syndrome, risk factors, signs and symptoms, and appropriate supportive care and treatment. The authors also offer some practical tips for detecting SOS/VOD and providing patient care, as well as the latest information on treating and preventing this condition.

Economic Burden of Veno-occlusive Disease in Patients With B-cell Acute Lymphoblastic Leukemia in the United States

PURPOSE

The goal of this study was to evaluate the incidence, inpatient mortality, and economic burden of hepatic veno-occlusive disease (VOD) in adults with B-cell acute lymphoblastic leukemia (ALL) in the United States.

METHODS

Using MarketScan Commercial Claims and Encounters Database and Medicare Supplemental and Coordination of Benefits Database, data for patients with B-cell ALL from April 1, 2009, to October 31, 2016, were extracted by using diagnosis codes. VOD was identified based on clinical criteria and expert opinions. Patients with VOD were followed up from diagnosis of VOD until the earliest occurrence of inpatient death, end of continuous enrollment, end of study period, or for a maximum of 100days. The incidence of VOD and VOD-associated inpatient mortality were calculated. VOD-related health care costs based on paid adjudicated claims were calculated.

FINDINGS

Of the 2571 adults with B-cell ALL, the overall incidence of VOD was low at 3.4% (88 of 2571). Of these patients with VOD, 52% (46 of 88) experienced multiorgan failure and were identified as having severe VOD. VOD was only identified in patients having undergone hematopoietic stem cell transplantation (5.4% [88 of 1624]). The inpatient mortality rate of those with any VOD over the 100-day postindex period was 26.1%, and the inpatient mortality was even higher for patients with severe VOD (37.0%). Total mean (SD) medical costs per patient during the 100 days' post-VOD diagnosis were $55,975 ($160,335); mean (SD) costs per patient were ∼4-fold higher for severe ($86,953 [$206,906]) versus nonsevere ($22,047 [$72,847]) VOD.

IMPLICATIONS

Clinical criteria were used to identify VOD events and thus VOD might be underdiagnosed. The mortality of VOD also might be underestimated because only inpatient deaths are captured in the data. The incidence and mortality of VOD could also be underestimated because we focused on adult patients who might receive reduced-intensity treatment. The economic burden of VOD may be underestimated because the Healthcare Common Procedure Coding System code specific for defibrotide was not available, and thus the cost for defibrotide might not be included. Finally, as the study population consisted of patients with commercial or Medicare supplemental insurance, results may not be generalizable to all patients with VOD in the United States. Although VOD occurred infrequently in adults with B-cell ALL, it was associated with high inpatient mortality and substantial costs. Patients with severe VOD were associated with highest mortality and highest costs. Given the clinical and economic burden associated with VOD, it is important that patients at high risk for VOD be identified and treated to minimize this risk.

The budget impact and cost-effectiveness of defibrotide for treatment of veno-occlusive disease with multi-organ dysfunction in patients post-hematopoietic stem cell transplant

BACKGROUND

A Phase-3 study of defibrotide compared with historical controls demonstrated a 23% improvement in 100-day survival post-hematopoietic stem cell transplantation (HSCT) among patients with veno-occlusive disease with multi-organ dysfunction (VOD with MOD).

AIM

To estimate the budget impact and cost-effectiveness of introducing defibrotide to a transplant center.

METHODS

The authors developed a budget impact model from the perspective of a bone-marrow transplant center. It was estimated that 2.3% of adults and 4.2% of children would develop VOD with MOD following HSCT based on a retrospective hospital database analysis and the effect that treating patients with defibrotide would have on costs for adult and pediatric centers was estimated. A cost-utility analysis (CUA) was also developed to capture the long-term cost-effectiveness of defibrotide. Projected life expectancies in the two groups were estimated based on trial data, transplant registry data, studies of long-term survival among HSCT patients, and US population life-tables.

RESULTS

There was an estimated 3% increase ($330,706) per year in total adult transplantation center costs associated with adopting defibrotide, and a <1% increase ($106,385) for pediatric transplant centers, assuming 100 transplants per year. In the CUA, the lifetime increase in cost per patient was $106,928, life expectancy increased by 3.74 years, and quality-adjusted life-years (QALYs) increased by 2.24. The incremental cost-effectiveness ratio (ICER) was $47,736 per QALY gained; 88% probability defibrotide was cost-effective at a $100,000/QALY threshold.

CONCLUSION

The budget impact of defibrotide for a transplant center is relatively modest compared to the overall cost of transplantation. Defibrotide provides an important survival advantage for VOD with MOD patients, and the life years gained lead to defibrotide being highly cost-effective.

Pharmacological Activity and Clinical Use of PDRN

PDRN is a proprietary and registered drug that possesses several activities: tissue repairing, anti-ischemic, and anti-inflammatory. These therapeutic properties suggest its use in regenerative medicine and in diabetic foot ulcers. PDRN holds a mixture of deoxyribonucleotides with molecular weights ranging between 50 and 1,500 KDa, it is derived from a controlled purification and sterilization process of Oncorhynchus mykiss (Salmon Trout) or Oncorhynchus keta (Chum Salmon) sperm DNA. The procedure guarantees the absence of active protein and peptides that may cause immune reactions. In vitro and in vivo experiments have suggested that PDRN most relevant mechanism of action is the engagement of adenosine A_2A receptors. Besides engaging the A_2A receptor, PDRN offers nucleosides and nucleotides for the so called “salvage pathway.” The binding to adenosine A_2A receptors is a unique property of PDRN and seems to be linked to DNA origin, molecular weight and manufacturing process. In this context, PDRN represents a new advancement in the pharmacotherapy. In fact adenosine and dipyridamole are non-selective activators of adenosine receptors and they may cause unwanted side effects; while regadenoson, the only other A_2A receptor agonist available, has been approved by the FDA as a pharmacological stress agent in myocardial perfusion imaging. Finally, defibrotide, another drug composed by a mixture of oligonucleotides, has different molecular weight, a DNA of different origin and does not share the same wound healing stimulating effects of PDRN. The present review analyses the more relevant experimental and clinical evidences carried out to characterize PDRN therapeutic effects.

Defibrotide in the treatment of hepatic veno-occlusive disease

Hepatic veno-occlusive disease (VOD), also known as sinusoidal obstruction syndrome (SOS), represents the most frequent complication in patients in early phase following hematopoietic stem-cell transplantation (HSCT). In its severe form, VOD/SOS can be associated with multiorgan failure and with a mortality rate >80% by day +100. Defibrotide (DF) (a mixture of 90% single-stranded phosphodiester oligonucleotides and 10% double-stranded phosphodiester oligonucleotides derived from controlled depolarization of porcine intestinal mucosal DNA) has been proposed for the treatment of SOS due to its ability to restore thrombo-fibrinolytic balance and protect endothelial cells. The present review highlights why the mechanisms of action of DF allow its successful use in the prevention and treatment of SOS following HSCT.

Chlorogenic acid suppresses monocrotaline-induced sinusoidal obstruction syndrome: The potential contribution of NFκB, Egr1, Nrf2, MAPKs and PI3K signals

Hepatic sinusoidal obstruction syndrome (SOS) is a highly lethal liver disease. This study aims to observe the protection and its engaged mechanism of chlorogenic acid (CGA) against monocrotaline (MCT)-induced SOS. Results of detecting liver ascites, measuring serum transaminases, liver histological evaluation and scanning electron microscope observation all demonstrated that CGA prevented MCT-induced SOS in rats. CGA reduced MCT-induced increased liver myeloperoxidase (MPO) activity, tumor necrosis factor (TNF)α and interleukin (IL)-1β mRNA expression, toll-like receptor (TLR)-2,3,6,9 expression, and nuclear factor κB (NFκB) transcriptional activation. CGA also decreased MCT-induced early growth response1 (Egr1) activation. CGA reduced MCT-induced elevated liver malondialdehyde (MDA) amount and enhanced nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2). CGA blocked MCT-induced PI3K and MAPKs activation. In conclusion, this study demonstrates the protection of CGA against MCT-induced SOS. Transcriptional factor NFκB, Egr1 and Nrf2-regulated inflammation, coagulation-fibrinolysis, and antioxidant, and PI3K and MAPKs all contribute to such protection.

Veno-occlusive disease nurse management: development of a dynamic monitoring tool by the GITMO nursing group

Veno-occlusive disease (VOD) is a complication arising from the toxicity of conditioning regimens that have a significant impact on the survival of patients who undergo stem cell transplantation. There are several known risk factors for developing VOD and their assessment before the start of conditioning regimens could improve the quality of care. Equally important are early identification of signs and symptoms ascribable to VOD, rapid diagnosis, and timely adjustment of support therapy and treatment. Nurses have a fundamental role at the stages of assessment and monitoring for signs and symptoms; therefore, they should have documented skills and training. The literature defines nurses’ areas of competence in managing VOD, but in the actual clinical practice, this is not so clear. Moreover, there is an intrinsic difficulty in managing VOD due to its rapid and often dramatic evolution, together with a lack of care tools to guide nurses. Through a complex evidence-based process, the Gruppo Italiano per il Trapianto di Midollo Osseo (GITMO), cellule staminali emopoietiche e terapia cellulare nursing board has developed an operational flowchart and a dynamic monitoring tool applicable to haematopoietic stem cell transplantation patients, whether they develop this complication or not.