Intravesical cidofovir to treat BK virus-associated hemorrhagic cystitis in children after hematopoietic stem cell transplantation

Cidofovir for Viral Infections in Immunocompromised Children: Guidance on Dosing, Safety, Efficacy, and a Review of the Literature

OBJECTIVE

To describe the use of cidofovir (CDV) for viral infections in immunocompromised children (IC) and provide guidance on dosing and supportive care.

DATA SOURCES

A PubMed search was conducted for literature published between 1997 and January 2022 using the following terms: cidofovir, plus children or pediatrics.

STUDY SELECTION AND DATA EXTRACTION

Limits were set to include human subjects less than 24 years of age receiving intravenous (IV) or intrabladder CDV for treatment of infections due to adenovirus, polyomavirus-BK (BKV), herpesviruses, or cytomegalovirus.

DATA SYNTHESIS

Data were heterogeneous, with largely uncontrolled studies. Conventional dosing (CDV 5 mg/kg/dose weekly) was commonly used in 60% (31/52) of studies and modified dosing (CDV 1 mg/kg/dose 3 times/week) was used in 17% (9/52) of studies, despite being off-label. Nephrotoxicity reported across studies totaled 16% (65/403 patients), which was higher for conventional dosing 29 of 196 patients (15%) than modified dosing 1 of 27 patients (4%). Saline hyperhydration and concomitant probenecid remain the cornerstones of supportive care, while some regimens omitting probenecid are emerging to target BKV.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

To our knowledge, this is the first comprehensive review of CDV use (indications, dosing, supportive care, response, and nephrotoxicity) in pediatric IC.

CONCLUSIONS

Effective utilization of CDV in IC remains challenging. Further prospective studies are needed to determine the optimal CDV dosing; however, less aggressive dosing regimens such as modified thrice weekly dosing or low dosing once weekly omitting probenecid to enhance urinary penetration may be reasonable alternatives to conventional dosing in some IC.

Clinical study of late-onset hemorrhagic cystitis after allo-HSCT without in vitro T-cell depletion

This study is to investigate the hemorrhagic cystitis (HC) after allogeneic hematopoietic stem cell transplantation (allo-HSCT) without in vitro T-cell depletion. Patients receiving allo-HSCT in 2019 were enrolled. The occurrence and clinical characteristics of HC after HLA-identical HSCT and haploidentical HSCT were retrospectively analyzed. BK, JC, cytomegalovirus, and other viruses were monitored when HC occurred. Conventional HC treatment was performed. Additionally, 5 cases of severe refractory HC were treated with adipose-derived mesenchymal stem cell (ADSC) besides conventional HC treatment. Totally, 54 patients with allo-HSCT were enrolled, including 12 cases with HLA-identical HSCT and 42 cases with haploidentical HSCT. Among them, 17 developed late-onset HC (LOHC). There was no early-onset HC. The median onset time was 33.5 (9-189) days, with a median duration of 19 (5-143) days. There were 8 cases of grade III HC and 2 cases of grade IV HC. The cumulative incidence of LOHC in 54 patients was 29.6%, and the cumulative incidence of LOHC in 42 patients with haploidentical HSCT was 40.5%. The 1-year expected progression-free survival (PFS) of 26 patients without HC was 86.6%, and the 1-year expected PFS of 16 HC patients was 74.5%. However, there was no statistically significant difference (P = .326). The urine BK virus of 14 patients was positive, with the lowest of 1.98 × 105 copies/mL, and the highest of 8.96 × 105 copies/mL. For the 5 patients with severe refractory HC, the lowest infusion dose of ADSC was 0.9 × 106/kg and the highest was 1.4 × 106/kg. All 5 patients were cured. The incidence of LOHC is higher after haploidentical HSCT. LOHC is positively correlated with urine BK virus. LOHC has no obvious effect on the overall PFS of patients. ADSC infusion has a good therapeutic effect on severe and prolonged LOHC.

Effect of late-onset hemorrhagic cystitis on PFS after haplo-PBSCT

Introduction

This study is to investigate the effect of late-onset hemorrhagic cystitis (LOHC) on progression-free survival (PFS) of patients after haploidentical peripheral blood hematopoietic stem cell transplantation (haplo-PBSCT).

Methods

This retrospective study enrolled 74 patients with hematological malignancies treated with a myeloablative conditioning regimen and haplo-PBSCT. The effect of LOHC on PFS was studied in terms of HC occurrence, grade, disease type, duration, onset time, gender, and age.

Results

There were 28 patients with LOHC, and no case was with early-onset HC. The cumulative incidence of LOHC was 37.8% (95% CI: 26.9–48.7%). The 2-year expected PFS of 74 patients and 34 AML patients was not significantly different between LOHC patients and patients without HC (P > 0.05). Among 27 ALL patients, the 2-year expected PFS of LOHC patients was 75%, significantly higher than patients without HC (54.2%) (P < 0.05). The 2-year expected PFSs of patients with mild LOHC and severe LOHC were 69.8 and 77.8%, respectively (P > 0.05). Similarly, the onset time, duration, age, and gender of LOHC patients did not show significant effects on PFS (P > 0.05).

Conclusions

After haplo-PBSCT, LOHC has a significant effect on the PFS of ALL patients. The HC grade, duration, onset time, gender, and age have no significant effect on PFS.

BK virus infection in allogeneic hematopoietic cell transplantation: An update on pathogenesis, immune responses, diagnosis and treatments

In hematopoietic cell transplantation (HCT) patients, BK polyomavirus (BKPyV) infection results in significant morbidity mainly due to hemorrhagic cystitis (HC). Despite increased knowledge acquired over recent decades, no treatment has shown effectiveness in the management of organ damage in HCT allografts. This review summarizes the current knowledge on BKPyV, from the virus constitution to the pathophysiology and immune-related mechanisms. We next focus on BKPyV-induced HC in HCT to discuss the benefit of monitoring BKPyV viruria and viremia in the management of patients. At last, we review currently used therapeutics, along with future promising therapies to propose clinical and practical guidelines and further interesting research areas.

BK Virus Associated Haemorrhagic Cystitis. A systematic review of current prevention and treatment strategies

BACKGROUND

BK virus is a major cause of late onset haemorrhagic cystitis in patients undergoing Haematopoietic Cell Transplantation (HCT). The evidence for the management of BK Virus Associated Haemorrhagic Cystitis (BKV-HC) is limited. Much of the published data consists of non-randomised case series and case reports. To our knowledge this is the first systematic review for the management of BKV-HC in both paediatric and adult populations. Our primary outcome was to examine the evidence for strategies of 1) prevention and 2) cessation of haematuria associated with BKV. Secondary outcomes were to assess the toxicity of treatment strategies and devise management recommendations for clinicians.

MATERIALS AND METHODS

We performed a systematic review of the PubMed and Central databases to evaluate the current evidence. A search protocol was prepared and registered with the PROSPERO database (CRD42017082442). The review was conducted in accordance to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) statement and AMSTAR (Assessing the methodological quality of systematic reviews) guidelines. Results were classified by treatment type. Qualitative analysis of included articles was performed, and grades of recommendations were devised for each treatment.

RESULTS

Of 896 titles screened, 44 articles were included for qualitative analysis. The overall quality of evidence was low. There is insufficient evidence to recommend prophylactic quinolones. 40 studies evaluated treatments for established BKV-HC. There are no high-quality comparative studies. Cidofovir is the most studied treatment but quality of evidence is low, and grade of recommendation is weak. Hyperbaric oxygen therapy, Fibrin glue, Leflunomide, Sodium Pentosan Polysulfate, Intravesical Alum and Radiological embolisation have all been described but the effectiveness of these treatments is unclear.

CONCLUSION

There remains no clear specific treatment for BKV-HC. An effective multi-disciplinary approach leading to early recognition and initiation of treatment is encouraged. The development of novel therapies followed by well-designed clinical studies are urgently needed.

Hemorrhagic cystitis after hematopoietic stem cell transplantation: A challenge for the pediatric urologist

OBJECTIVE

Hemorrhagic cystitis (HC) is a serious event that can occur after hematopoietic stem cell transplantation (HSCT). Treatment goals are primarily to preserve life, and then the functionality of the bladder. There is no standard therapeutic approach for HC. Described treatment options provide low success rates and are related to potential life-threatening side effects. The aim of this study was to describe our experience in treatment of HC following HSCT.

PATIENTS AND METHODS

This was a retrospective study of patients with HC treated at our institution between January 2010 and October 2016. We analyzed demographics, underlying diagnosis, and treatment modalities.

RESULTS

We treated 39 patients with HC. Mean age was 9.4 years (SD 4.20) and 64% were males. Acute leukemia was the most common underlying diagnosis in 27 (69%). Mean time from HSCT to HC onset was 55.46 days (SD 112.35). HC grades were: I (3), II (21), III (8), and IV (7). BK-viuria was present in 34 patients (87.2%). Non-invasive treatment was performed in 28 patients (71.8%). The remaining 11 (28.2%) required urological intervention (all high-grade), consisting of bladder irrigation in all of these. Additional treatments consisted of: intravesical cidofovir (4), intravesical sodium hyaluronate (5), cystoscopy and clot evacuation (4), selective angioembolization (2), percutaneous nephrostomy (1), and open extraction of bladder clots and cutaneous cystotomy (1). Overall, eight patients (20.5%) died as a result of the malignancy (3 in the urological intervention group), and of these four had active HC at death. Mean follow-up was 36.2 months (SD 24.9).

CONCLUSION

HC is associated with high morbidity and mortality. Treatment should be individualized and designed to prioritize survival. However, bladder function should be preserved for the future.

ECIL guidelines for the prevention, diagnosis and treatment of BK polyomavirus-associated haemorrhagic cystitis in haematopoietic stem cell transplant recipients

Objectives

To define guidelines for BK polyomavirus (BKPyV)-associated haemorrhagic cystitis (BKPyV-HC) after paediatric and adult HSCT.

Methods

Review of English literature and evidence-based recommendations by expert consensus.

Results

BKPyV-HC occurs in 8%-25% of paediatric and 7%-54% of adult recipients undergoing allogeneic HSCT. Diagnosis requires the triad of cystitis, macro-haematuria and high urine BKPyV loads >7 log10 copies/mL, and exclusion of other relevant aetiologies. BKPyV viraemia is frequent and may serve as a more specific semiquantitative follow-up marker. No randomized controlled trials are available to inform antiviral prophylaxis or treatment. However, hyper-hydration and/or bladder irrigation showed limited prophylactic value. Fluoroquinolones are not effective for prophylaxis or treatment, but rather increase antibiotic resistance. Hyperbaric oxygen or fibrin glue is marginally effective based on small case series from correspondingly equipped centres. Although cidofovir has been reported to improve and/or reduce BKPyV viraemia or viruria, the current data do not support its regular use.

Conclusions

BKPyV-HC remains a disabling unmet clinical need in HSCT that requires novel approaches supported by proper clinical trials.

High incidence of BK virus-associated hemorrhagic cystitis in children after second or third allogeneic hematopoietic stem cell transplantation

BKV-HC is a serious complication of allogeneic HSCT. To characterize the incidence, risk factors, and clinical outcomes of post-HSCT BKV-HC, we retrospectively analyzed 112 patients who underwent one or more allogeneic HSCTs at our hospital between 2001 and 2017. Twenty underwent second or third HSCT thereafter. Ten patients developed BKV-HC at a median of 30 days after HSCT. The 100-day cumulative incidences of grade 0-4 and grade 2-4 BKV-HC were 7.8% and 6.2%, respectively. HSCTs performed in 2011-2017 associated with significantly higher 100-day cumulative incidence of grade 2-4 BKV-HC (14.0%) than HSCTs performed in 2001-2010 (1.3%, P = 0.004). On multivariate analysis, second or third HSCT was the only independent significant risk factor for development of grade 2-4 BKV-HC (P = 0.015). Serial PCR monitoring of urine and blood BKV load did not predict BKV-HC. The recent increase in the incidence of BKV-HC may reflect recent innovations in transplant technologies that facilitate second or third HSCT, which are known to cause prolonged immune deficiency. If safe and effective treatment or prophylaxis becomes available, it could be used to target the high-risk patients for BKV-HC.

Intravesicular cidofovir for BK hemorrhagic cystitis in pediatric patients after hematopoietic stem cell transplant

BK virus hemorrhagic cystitis is a complication of HCST. Response to IV cidofovir is unpredictable, and treatment carries risk of toxicity. We report the largest series of pediatric patients with BKHC after HSCT successfully treated with intravesicular cidofovir. There was no significant decrease in urine or plasma BK PCR. There was significant decrease in pain score on days 3 and 7, with associated decrease in morphine use. No patients experienced toxicities associated with IV cidofovir. Intravesicular cidofovir appears to be safe and effective for symptomatic treatment of BKHC in pediatric patients after HSCT.

Efficacy of Cidofovir in Treatment of BK Virus-Induced Hemorrhagic Cystitis in Allogeneic Hematopoietic Cell Transplant Recipients

BK virus-associated hemorrhagic cystitis (BK-HC) is a common complication after allogeneic hematopoietic stem cell transplantation (allo-HCT), with incidences up to 70%. Cidofovir is an antiviral agent with growing evidence as a therapeutic intervention. To assess the safety profile and efficacy of intravenous and intravesical cidofovir in allo-HCT patients with BK-HC, a retrospective study was undertaken of the allo-HCT cohort who received cidofovir for symptomatic BK-HC (hematuria with BK viruria or viremia) from January 2010 until March 2017 in a single transplant center in Ontario, Canada. The primary outcome measure was a reduction in BK-HC severity (graded from 1 to 4); secondary outcomes included overall survival, BK virus titers, and the onset of acute kidney injury. Twelve allo-HCT patients received cidofovir for BK-HC, with pretreatment clinical severity of 3 (50%) or 4 (50%). Cidofovir was administered via intravenous (33%), intravesical (58%), or both modalities (8%). After a median cumulative dose of 10 mg/kg (range, 1 to 37), mean BK-HC grade decreased significantly by 1.8 (3.5 precidofovir, 1.7 postcidofovir, P < .01). Sixty-six percent of patients had at least partial response to cidofovir, with similar response rates between intravenous (66%) and intravesical (62%) administration. Sixty-seven percent of patients died, and 33% of patients experienced renal toxicity, including 2 patients receiving intravesical therapy. In this retrospective series, there was a significant reduction in BK-HC severity after cidofovir administration; most patients achieved at least partial response after cidofovir administration. Even with intravesical instillation, acute kidney injury remains a potential complication of cidofovir. Although cidofovir may be an efficacious therapy for BK-HC, albeit with potential demonstrated toxicities, further prospective trials are needed.

Epstein-Barr virus-associated leukemic lymphoma after allogeneic stem cell transplantation

Leukemic Epstein-Barr virus (EBV)-associated post-transplant lymphoproliferative diseases (PTLD) following allogeneic hematopoietic stem cell transplantation are extremely rare. We can successfully treat an EBV-associated leukemic lymphoma patient with rituximab, cidofovir, and donor lymphocyte infusion (DLI). In the present case, EBV-specific T cells that were present in the peripheral blood before rituximab administration treatment rapidly increased after DLI in association with a decrease in the EBV-DNA load.

Treatment of CMV infection after allogeneic hematopoietic stem cell transplantation

Despite a remarkable reduction in the past decades, cytomegalovirus (CMV) disease in allogeneic hematopoietic stem cell transplant (HSCT) recipients remains a feared complication, still associated with significant morbidity and mortality. Today, first line treatment of CMV infection/reactivation is still based on dated antiviral compounds Ganciclovir (GCV), Foscarnet (FOS) and Cidofovir (CDF) with their burdensome weight of side effects. Maribavir (MBV), Letermovir (LMV) and Brincidofovir (BDF) are three new promising anti-CMV drugs without myelosuppressive properties or renal toxic effects that are under investigation in randomized phase II and III trials. Adoptive T-cell therapy (ATCT) in CMV infection possesses a strong rationale, demonstrated by several proof of concept studies; its feasibility is currently under investigation by clinical trials. ATCT from third-party and naïve donors could meet the needs of HSCT recipients of seronegative donors and cord blood grafts. In selected patients such as recipients of T-cell depleted grafts, ATCT, based on CMV-specific host T-cells reconstitution kinetics, would be of value in the prophylactic and/or preemptive CMV treatment. Vaccine-immunotherapy has the difficult task to reduce the incidence of CMV reactivation/infection in highly immunocompromised HSCT patients. Newer notions on CMV biology may represent the base to flush out the Troll of transplantation.

Successful treatment with intravesical cidofovir for virus-associated hemorrhagic cystitis after allogeneic hematopoietic stem cell transplantation: A case report and a review of the literature

Virus-associated hemorrhagic cystitis (VAHC) is a formidable complication after allogeneic hematopoietic stem cell transplantation (allo-HSCT). The standard management of severe VAHC after allo-HSCT has not been established. Intravenous administration of cidofovir (CDV), an acyclic nucleoside analogue with broad-spectrum activity against DNA viruses, has been reported to be effective for VAHC, but it can cause severe renal toxicity. Here we report four cases who achieved clinical responses with intravesical instillation of CDV for severe VAHC after allo-HSCT. Median age was 57 years (40-63), and all were male. The underlying diseases were hematological malignancies. Three had received bone marrow transplantation, and one received cord blood transplantation twice. Conditioning regimen was myeloablative for one, and reduced-intensity for three. The viral types were BK virus and/or adenovirus. Two patients had received CDV intravenously prior to the intravesical therapy. A dose of intravesical CDV was 2-5 mg/kg. In all cases, symptoms of cystitis improved dramatically within a few days without showing any systemic adverse effects. The virological response was observed in two cases. This local therapy was effective even in the cases refractory to the intravenous CDV and a case with severe renal failure. Along with the review of literature, we propose that the intravesical instillation of CDV can be a therapeutic option for severe VAHC after allo-HSCT.

Pharmacokinetics and safety of intravesicular cidofovir in allogeneic HSCT recipients

OBJECTIVES

The objective of this study was to evaluate the pharmacokinetics and safety of cidofovir administered via the intravesicular route to patients with haemorrhagic cystitis following allogeneic HSCT (allo-HSCT).

METHODS

Patients with gross haematuria and confirmed BK or adenovirus viruria following allo-HSCT were prospectively enrolled in an open-label pharmacokinetic study (ClinicalTrials.gov registration: NCT01816646). Three hours after an oral probenecid dose (2 g), cidofovir (2.5-5 mg/kg in 50-100 mL of normal saline) was given via a transurethral catheter for up to 2 h of dwell time. Serial plasma samples were obtained over 24 h and assayed for cidofovir concentrations using LC-MS/MS. A custom pharmacokinetic model with a time-limited absorption compartment was fitted to the concentration-time profile of each patient. Systemic drug exposure was expressed as AUC0-24, by integrating the best-fit profile with respect to time.

RESULTS

Six subjects (mean ± SD age = 38 ± 21 years) with baseline serum creatinine <1.4 mg/dL were enrolled. Mean values for volume of distribution, clearance and elimination half-life were 19.5 L, 5.6 L/h and 2.8 h, respectively. Compared with the reported AUC0-24 for an equivalent intravenous dose, intravesicular instillation of cidofovir resulted in 1%-74% of the corresponding systemic exposure. Owing to primarily lower abdominal pain, only two patients were able to tolerate a 2 h dwell time. One patient developed a >50% increase in serum creatinine within 7 days of administration.

CONCLUSIONS

Intravesicular administration of cidofovir resulted in highly variable systemic exposures. The safety and efficacy of intravesicular cidofovir should be further evaluated before routine use.