Conversion between sirolimus and everolimus in heart transplant recipients

BACKGROUND

Sirolimus and everolimus are mechanistic target of rapamycin inhibitors (mTORi) that may be included in immunosuppression regimens for orthotopic heart transplant (OHT) recipients. mTORi play a role in slowing progression of cardiac allograft vasculopathy; however, they have poor tolerability, sometimes necessitating a change between agents or therapies. The literature surrounding a conversion between mTORi are incongruent, thus this study was designed to assess the concentration/dose ratio for each medication around the time of conversion to provide guidance for a conversion strategy between mTORi.

METHODS

We conducted a retrospective study of adult OHT recipients who were maintained on both sirolimus- and everolimus-based immunosuppression regimens. The primary outcome was the concentration/dose (C/d) ratio of sirolimus to everolimus. Secondary outcomes included changes in hematologic and lipid labs and patient-reported intolerances.

RESULTS

The C/d ratio of sirolimus was 4.42, whereas the everolimus ratio was 2.23, resulting in a sirolimus: everolimus ratio of 1.98. Secondarily, after converting between mTORi, 93% of patients who reported intolerance(s) to one agent had a resolution of that intolerance. In our patient population, everolimus appeared better tolerated than sirolimus, with significantly more patients having no reported intolerances and significantly fewer patients experiencing edema. Other lab values were similar between patients receiving sirolimus and everolimus, except for an increased hemoglobin level in those receiving everolimus.

CONCLUSIONS

The conversion ratio of 1:2 observed in our population suggests OHT recipients may require an increased dose of EVL compared with SRL to maintain the same goal trough levels. A conversion between mTORi appeared to improve tolerability and did not lead to clinically significant worsening of any measured lab value.

mTORC1 Inhibitor Rapamycin Inhibits Growth of Cerebral Cavernous Malformation in Adult Mice

BACKGROUND

Cerebral cavernous malformations (CCMs) are vascular malformations that frequently cause stroke. CCMs arise due to loss of function in one of the genes that encode the CCM complex, a negative regulator of MEKK3-KLF2/4 signaling in vascular endothelial cells. Gain-of-function mutations in PIK3CA (encoding the enzymatic subunit of the PI3K (phosphoinositide 3-kinase) pathway associated with cell growth) synergize with CCM gene loss-of-function to generate rapidly growing lesions.

METHODS

We recently developed a model of CCM formation that closely reproduces key events in human CCM formation through inducible CCM loss-of-function and PIK3CA gain-of-function in mature mice. In the present study, we use this model to test the ability of rapamycin, a clinically approved inhibitor of the PI3K effector mTORC1, to treat rapidly growing CCMs.

RESULTS

We show that both intraperitoneal and oral administration of rapamycin arrests CCM growth, reduces perilesional iron deposition, and improves vascular perfusion within CCMs.

CONCLUSIONS

Our findings further establish this adult CCM model as a valuable preclinical model and support clinical testing of rapamycin to treat rapidly growing human CCMs.

Case Report and Literature Review: Bisphosphonate, Sirolimus, and Atenolol Treatment in a 4-Year-Old Child Diagnosed with Gorham-Stout Disease

We report a 4-year-old with Gorham-Stout disease (GSD) who was treated with a combination of bisphosphonate, sirolimus, and atenolol. A previously healthy 4-year-old girl presented with back pain after falling on her back 2 months prior. Thoracolumbar spine X-ray revealed diffuse compression spinal fractures in T9-L2. Magnetic resonance imaging (MRI) confirmed multiple compression fractures at T9-L5 and revealed a paraspinal mass along the T1-L1 level. Based on clinical, radiological, and histopathological findings, Gorham-Stout disease was diagnosed. Treatment with sirolimus (0.5 mg twice daily, 1.6 mg/m2) was initiated and intravenous bisphosphonate (pamidronate, 1 mg/kg for 3 days, total 3 mg/kg every 4 months) was added for back pain; she had immediate improvement in back pain. After 9 months with this treatment, she had a mild increase in paraspinal lymphangiomatosis and aggravation in T9-L5 compression fractures; atenolol was administered. The patient underwent 11 months of combination treatment with bisphosphonate, sirolimus, and atenolol, and MRI showed mild degree of reduction in the paraspinal lesions at L1-L5. The patient is currently in stable condition with no back pain or side effects. The triple combination treatment with bisphosphonate, sirolimus, and atenolol may be helpful in stabilizing the disease course of GSD.

Multi-Omic, Histopathologic, and Clinicopathologic Effects of Once-Weekly Oral Rapamycin in a Naturally Occurring Feline Model of Hypertrophic Cardiomyopathy: A Pilot Study

Hypertrophic cardiomyopathy (HCM) remains the single most common cardiomyopathy in cats, with a staggering prevalence as high as 15%. To date, little to no direct therapeutical intervention for HCM exists for veterinary patients. A previous study aimed to evaluate the effects of delayed-release (DR) rapamycin dosing in a client-owned population of subclinical, non-obstructive, HCM-affected cats and reported that the drug was well tolerated and resulted in beneficial LV remodeling. However, the precise effects of rapamycin in the hypertrophied myocardium remain unknown. Using a feline research colony with naturally occurring hereditary HCM (n = 9), we embarked on the first-ever pilot study to examine the tissue-, urine-, and plasma-level proteomic and tissue-level transcriptomic effects of an intermittent low dose (0.15 mg/kg) and high dose (0.30 mg/kg) of DR oral rapamycin once weekly. Rapamycin remained safe and well tolerated in cats receiving both doses for eight weeks. Following repeated weekly dosing, transcriptomic differences between the low- and high-dose groups support dose-responsive suppressive effects on myocardial hypertrophy and stimulatory effects on autophagy. Differences in the myocardial proteome between treated and control cats suggest potential anti-coagulant/-thrombotic, cellular remodeling, and metabolic effects of the drug. The results of this study closely recapitulate what is observed in the human literature, and the use of rapamycin in the clinical setting as the first therapeutic agent with disease-modifying effects on HCM remains promising. The results of this study establish the need for future validation efforts that investigate the fine-scale relationship between rapamycin treatment and the most compelling gene expression and protein abundance differences reported here.

Decrease in α-Globin and Increase in the Autophagy-Activating Kinase ULK1 mRNA in Erythroid Precursors from β-Thalassemia Patients Treated with Sirolimus

The β-thalassemias are hereditary monogenic diseases characterized by a low or absent production of adult hemoglobin and excess in the content of α-globin. This excess is cytotoxic for the erythroid cells and responsible for the β-thalassemia-associated ineffective erythropoiesis. Therefore, the decrease in excess α-globin is a relevant clinical effect for these patients and can be realized through the induction of fetal hemoglobin, autophagy, or both. The in vivo effects of sirolimus (rapamycin) and analogs on the induction of fetal hemoglobin (HbF) are of key importance for therapeutic protocols in a variety of hemoglobinopathies, including β-thalassemias. In this research communication, we report data showing that a decrease in autophagy-associated p62 protein, increased expression of ULK-1, and reduction in excess α-globin are occurring in erythroid precursors (ErPCs) stimulated in vitro with low dosages of sirolimus. In addition, increased ULK-1 mRNA content and a decrease in α-globin content were found in ErPCs isolated from β-thalassemia patients recruited for the NCT03877809 clinical trial and treated with 0.5-2 mg/day sirolimus. Our data support the concept that autophagy, ULK1 expression, and α-globin chain reduction should be considered important endpoints in sirolimus-based clinical trials for β-thalassemias.

In vitro assessment of the combined effect of letermovir and sirolimus on cytomegalovirus replication

OBJECTIVE

Letermovir (LMV) is used for prophylaxis of cytomegalovirus (CMV) reactivation and end-organ disease in adult CMV-seropositive allogeneic hematopoietic stem cell transplant recipients (allo-HSCT). In turn, sirolimus (SLM) which displays in vitro anti-CMV activity, is frequently employed for prophylaxis of Graft vs. Host disease in allo-HSCT. Here, we aimed at assessing whether LMV and SLM used in combination may act synergistically in vitro on inhibiting CMV replication.

METHODS

The antiviral activity of LMV and SLM alone or in combination was evaluated by a checkerboard assay, using ARPE-19 cells infected with CMV strain BADrUL131-Y. LMV and SLM were used at concentrations ranging from 24 nM to 0.38 nM and 16 nM to 0.06 nM, respectively.

RESULTS

The mean EC50 for LMV and SLM was 2.44 nM (95% CI, 1.66-3.60) and 1.40 nM (95% CI, 0.41-4.74), respective. LMV and SLM interaction yielded mainly additive effects over the range of concentrations tested.

CONCLUSIONS

The additive nature of the combination of LMV and SLM against CMV may have relevant clinical implications in management of CMV infection in allo-HSCT recipients undergoing prophylaxis with LMV.

Use of sirolimus as an adjuvant therapy for kidney transplant recipients with high-risk cutaneous squamous cell carcinomas: a prospective non-randomized controlled study

INTRODUCTION

Previous research demonstrated benefits of late conversion to mTOR inhibitors against cutaneous squamous cell carcinomas (cSCC) in kidney transplant recipients (KTR), despite of poor tolerability. This study investigated whether stepwise conversion to sirolimus monotherapy without an attack dose modified the course of disease with improved tolerability.

METHODS

This prospective exploratory study included non-sensitized KTR with more than 12-months post-transplant, on continuous use of calcineurin inhibitors (CNI)-based therapy, and with poor-prognosis cSCC lesions. Incidence densities of high-risk cSCC over 3-years after conversion to sirolimus-monotherapy were compared to a non-randomized group with high-risk cSCC but unsuitable/not willing for conversion.

RESULTS

Forty-four patients were included (83% male, mean age 60 ± 9.7years, 62% with skin type II, mean time after transplantation 9 ± 5.7years). There were 25 patients converted to SRL and 19 individuals kept on CNI. There was a tendency of decreasing density of incidence of all cSCC in the SRL group and increasing in the CNI group (1.49 to 1.00 lesions/patient-year and 1.74 to 2.08 lesions/patient-year, p = 0.141). The density incidence of moderately differentiated decreased significantly in the SRL group while increasing significantly in the CNI group (0.31 to 0.11 lesions/patient-year and 0.25 to 0.62 lesions/patient-year, p = 0.001). In the SRL group, there were no sirolimus discontinuations, no acute rejection episodes, and no de novo DSA formation. Renal function remained stable.

CONCLUSIONS

This study suggests that sirolimus monotherapy may be useful as adjuvant therapy of high-risk cSCC in kidney transplant recipients. The conversion strategy used was well tolerated and safe regarding key mid-term transplant outcomes.

Pharmacomicrobiomics of Classical Immunosuppressant Drugs: A Systematic Review

The clinical response to classical immunosuppressant drugs (cIMDs) is highly variable among individuals. We performed a systematic review of published evidence supporting the hypothesis that gut microorganisms may contribute to this variability by affecting cIMD pharmacokinetics, efficacy or tolerability. The evidence that these drugs affect the composition of intestinal microbiota was also reviewed. The PubMed and Scopus databases were searched using specific keywords without limits of species (human or animal) or time from publication. One thousand and fifty five published papers were retrieved in the initial database search. After screening, 50 papers were selected to be reviewed. Potential effects on cIMD pharmacokinetics, efficacy or tolerability were observed in 17/20 papers evaluating this issue, in particular with tacrolimus, cyclosporine, mycophenolic acid and corticosteroids, whereas evidence was missing for everolimus and sirolimus. Only one of the papers investigating the effect of cIMDs on the gut microbiota reported negative results while all the others showed significant changes in the relative abundance of specific intestinal bacteria. However, no unique pattern of microbiota modification was observed across the different studies. In conclusion, the available evidence supports the hypothesis that intestinal microbiota could contribute to the variability in the response to some cIMDs, whereas data are still missing for others.

Pre-clinical investigation of liquid sirolimus for local drug delivery

Introduction

Sirolimus is currently being explored as an alternative drug to paclitaxel for the treatment of peripheral artery disease (PAD). To date, sirolimus has only been used as drug coatings for stents and balloons and no studies have yet demonstrated the delivery of sirolimus in liquid form. The purpose of this pilot study was to investigate the feasibility of the delivery of liquid sirolimus into arterial segments in a benchtop peripheral artery bioreactor.

Methods

The feasibility to deliver liquid therapy was first tested on four drug delivery devices using a fluorescently tagged liquid drug and an ex vivo porcine artery benchtop model. The four devices included the Bullfrog micro-infusion device, ClearWay RX catheter, Occlusion perfusion catheter (OPC), and the targeted adjustable pharmaceutical administration system (TAPAS). Penetration of the fluorescently tagged drug was measured via microscopic imaging and quantification of the depth of drug penetration into all device-treated tissue. Based on the penetration outcome, we then selected a single device to deliver liquid sirolimus into the ex vivo porcine artery model undergoing physiological flow and pressure conditions. The liquid sirolimus-treated arteries were collected from the ex vivo bioreactor at 1- and 24-hour post-delivery and arterial drug retention analyzed by liquid chromatography-tandem mass spectrometry.

Results

Fluorescent microscopy demonstrated that drug delivery with the OPC had greater drug penetration into the medial wall as compared to other devices (OPC: 234 ± 161 µm; TAPAS: 127 ± 68 µm; ClearWay: 118 ± 77 µm; Bullfrog: 2.12 ± 3.78 µm; p = 0.098). The results of the ex vivo flow-circuit bench top model showed that the OPC device successfully delivered the liquid sirolimus at 1-hour (5.17 ± 4.48 ng/mg) and 24-hour (0.78 ± 0.55 ng/mg).

Conclusions

These results demonstrate for the first time the ability to deliver liquid sirolimus directly to the medial layer of an artery via a liquid delivery catheter.

Ultrathin bioresorbable polymer sirolimus-eluting stents in US patients undergoing coronary revascularization: 1-Year outcomes from the BIOFLOW VII trial

BACKGROUND

Ultrathin strut coronary drug-eluting stents (DES) have demonstrated improved safety and efficacy in large contemporary trials. The evaluation of an ultrathin strut DES in a post-market United States (US) patient population was undertaken.

OBJECTIVE

The purpose of this post-approval study is to confirm that the clinical performance of an ultrathin strut bioresorbable polymer sirolimus-eluting stent (BP SES) in clinical practice is similar to that observed with BP SES in the BIOFLOW V pivotal trial.

METHODS

BIOFLOW VII is a prospective, multicenter, single-arm US post-market approval study to confirm the clinical performance of BP SES in a real-world setting. The primary endpoint of 1-year target lesion failure (TLF) was compared with a performance goal of 6.9% based on an adapted BIOFLOW V trial BP SES TLF rate and TLF rates from other US market-released DES utilizing the Society for Cardiovascular Angiography and Interventions definition for peri-procedural myocardial infarction (MI). Subjects undergoing percutaneous coronary intervention with BP SES were consented within 24 h post-index procedure with planned follow-up through 5 years.

RESULTS

Among 556 enrolled patients, clinical demographics included: 34.7% female, 35.6% with diabetes mellitus, and 56.8% with acute coronary syndromes. The average stent length (mean ± standard deviation) was 20.2 ± 11.8 mm, and the mean number of stents per patient was 1.3 ± 0.6. Procedure success was 99.1% (551/556), and device success was 99.9% (689/690). Among 531 subjects included in the primary endpoint analysis, the 1-year rate of TLF rate was 1.7% (9/531), and the primary endpoint was met compared with the performance goal (p < 0.0001, 95% confidence interval: 0.69%, 3.43%). Rates of target vessel MI and clinically driven target lesion revascularization were 1.3% (7/531) and 0.9% (5/531), with no occurrence of cardiac death. Definite stent thrombosis was observed for two cases (0.4%; 2/556) with one acute (≤24 h) and one late (>30 days and ≤1 year) event.

CONCLUSION

In a post-approval study, 1-year clinical outcomes with BP SES were consistent with prior trials supporting the safety and effectiveness of ultrathin BP SES.

Comparative Safety and Efficacy of Immunosuppressive Regimens Post-kidney Transplant: A Systematic Review

Immunosuppressive agents are used post-organ transplant to prevent acute rejection and graft losses. Tacrolimus, the most widely used immunosuppressive agent for kidney transplant recipients, has unfavorable side effects such as new-onset diabetes after transplant, nephrotoxicity, and electrolyte imbalances. Other drug groups such as the mammalian target of rapamycin (mTOR) inhibitors, belatacept, and bleselumab have been used to either substitute calcineurin inhibitors or reduce their exposure. This systematic analysis reviews evidence from randomized controlled trials to compare the safety and efficacy of various immunosuppressive regimens for kidney transplant recipients. An in-depth methodical search was conducted across PubMed, Cochrane Library, and Mendeley. PRISMA 2020 guidelines were followed for this study. Randomized controlled trials comparing varying regimens were included in this study. While there was no difference in safety and efficacy between once-daily and twice-daily tacrolimus, mTOR inhibitors showed to be a viable option for a reduced tacrolimus exposure regimen. Calcineurin inhibitor avoidance and early steroid withdrawal regimens both showed increased rates of rejection. Based on these findings, a regimen containing once-daily tacrolimus and an mTOR inhibitor with or without corticosteroid is a viable immunosuppressive regimen post-kidney transplant. Further trials, especially ones with longer follow-up periods, are needed to explore these regimens' long-term safety and efficacy.

Unbiased evaluation of rapamycin's specificity as an mTOR inhibitor

Rapamycin is a macrolide antibiotic that functions as an immunosuppressive and anti-cancer agent, and displays robust anti-ageing effects in multiple organisms including humans. Importantly, rapamycin analogues (rapalogs) are of clinical importance against certain cancer types and neurodevelopmental diseases. Although rapamycin is widely perceived as an allosteric inhibitor of mTOR (mechanistic target of rapamycin), the master regulator of cellular and organismal physiology, its specificity has not been thoroughly evaluated so far. In fact, previous studies in cells and in mice hinted that rapamycin may be also acting independently from mTOR to influence various cellular processes. Here, we generated a gene-edited cell line that expresses a rapamycin-resistant mTOR mutant (mTORRR ) and assessed the effects of rapamycin treatment on the transcriptome and proteome of control or mTORRR -expressing cells. Our data reveal a striking specificity of rapamycin towards mTOR, demonstrated by virtually no changes in mRNA or protein levels in rapamycin-treated mTORRR cells, even following prolonged drug treatment. Overall, this study provides the first unbiased and conclusive assessment of rapamycin's specificity, with potential implications for ageing research and human therapeutics.

Impact of Sirolimus versus Mycophenolate Mofetil on Kidney Function after Calcineurin Inhibitor Dose Reduction in Liver Transplant Recipients

Impaired kidney function is associated with increased morbidity and mortality in patients undergoing liver transplantation. Although immunosuppressants are essential in these patients, they impair kidney function. This study aimed to compare adverse kidney outcomes between patients treated with a reduced dose of tacrolimus (calcineurin inhibitor) plus sirolimus or mycophenolate mofetil (MMF) in the liver transplant center at Kaohsiung Chang Gung Memorial Hospital between April 2011 and December 2017. Propensity score matching was used to identify 232 patients. The risk of adverse kidney outcomes was estimated using Cox proportional hazards regression, and changes in kidney function over time were analyzed using linear mixed modeling. Acute kidney disease risks in this study cohort were not significantly different for the two immunosuppressants (aHR 1.04; 95% CI: 0.70-1.55, p = 0.8328). However, sirolimus use was significantly associated with a higher risk of estimated glomerular filtration rate decline > 30% than MMF (aHR, 2.09; 95% CI: 1.33-3.28; p = 0.0014). Our results demonstrate that sirolimus use may have worsened long-term kidney outcomes compared to MMF. Close monitoring of kidney function, dose adjustment, and timely transition to MMF is necessary for LT patients receiving sirolimus.

The side effect profile of sirolimus and its relationship with some variables: A retrospective study of Iranian renal transplant patients

Background

Sirolimus is a potent immunosuppressive in renal transplantation. However, its use is limited by some reported side effects. The objective of this study was to determine the side effect profile of sirolimus in renal transplant patients.

Materials and Methods

In the present study, we retrospectively reviewed the medical records of 116 renal transplant patients treated with sirolimus alone or in combination with other immunosuppressive agents at private therapeutic centers in Isfahan, Iran, between March 2009 and February 2020. A checklist was used to collect data on demographic and clinical variables. Data were analyzed with independent samples t-test and Chi-squared test.

Results

Our findings indicated that the most prevalent sirolimus-related side effects were edema (42.3%), proteinuria (37.5%), cytopenia (26.9%), abnormal level of liver enzymes (11.7%), and pneumonitis (9.7%). Stratification of side effects by sirolimus dose (<2 mg and ≥2 mg) demonstrated their dose-independent occurrence (P > 0.05). Pneumonitis was the most frequent reason for sirolimus cessation (58.7%). No significant differences were observed between males and females regarding the frequency of reasons for sirolimus cessation (P > 0.05).

Conclusion

Edema, proteinuria, cytopenia, abnormal level of liver enzymes, and pneumonitis were the most prevalent sirolimus-related side effects in renal transplant patients. Further prospective cohort studies are warranted to detect underlying mechanisms and determinants of these side effects in renal transplant patients treated with sirolimus.

Effects of Sirolimus Treatment on Fetal Hemoglobin Production and Response to SARS-CoV-2 Vaccination: A Case Report Study

The β-thalassemias are a group of monogenic hereditary hematological disorders caused by deletions and/or mutations of the β-globin gene, leading to low or absent production of adult hemoglobin (HbA). For β-thalassemia, sirolimus has been under clinical consideration in two trials (NCT03877809 and NCT04247750). A reduced immune response to anti-SARS-CoV-2 vaccination has been reported in organ recipient patients treated with the immunosuppressant sirolimus. Therefore, there was some concern regarding the fact that monotherapy with sirolimus would reduce the antibody response after SARS-CoV-2 vaccination. In the representative clinical case reported in this study, sirolimus treatment induced the expected increase of fetal hemoglobin (HbF) but did not prevent the production of anti-SARS-CoV-2 IgG after vaccination with mRNA-1273 (Moderna). In our opinion, this case report should stimulate further studies on β-thalassemia patients under sirolimus monotherapy in order to confirm the safety (or even the positive effects) of sirolimus with respect to the humoral response to anti-SARS-CoV-2 vaccination. In addition, considering the extensive use of sirolimus for the treatment of other human pathologies (for instance, in organ transplantation, systemic lupus erythematosus, autoimmune cytopenia, and lymphangioleiomyomatosis), this case report study might be of general interest, as large numbers of patients are currently under sirolimus treatment.

Rapamycin and rapalogs for tuberous sclerosis complex

BACKGROUND

Potential benefits of rapamycin or rapalogs for treating people with tuberous sclerosis complex (TSC) have been shown. Currently everolimus (a rapalog) is only approved for TSC-associated renal angiomyolipoma and subependymal giant cell astrocytoma (SEGA), but not other manifestations of TSC. A systematic review needs to establish evidence for rapamycin or rapalogs for various manifestations in TSC. This is an updated review.

OBJECTIVES

To determine the effectiveness of rapamycin or rapalogs in people with TSC for decreasing tumour size and other manifestations and to assess the safety of rapamycin or rapalogs in relation to their adverse effects.

SEARCH METHODS

We identified relevant studies from the Cochrane-Central-Register-of-Controlled-Trials (CENTRAL), Ovid MEDLINE and ongoing trials registries with no language restrictions. We searched conference proceedings and abstract books of conferences. Date of the last searches: 15 July 2022.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-RCTs of rapamycin or rapalogs in people with TSC.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risk of bias of each study; a third review author verified the extracted data and risk of bias decisions. We assessed the certainty of the evidence using GRADE.

MAIN RESULTS

The current update added seven RCTs, bringing the total number to 10 RCTs (with 1008 participants aged 3 months to 65 years; 484 males). All TSC diagnoses were by consensus criteria as a minimum. In parallel studies, 645 participants received active interventions and 340 placebo. Evidence is low-to-high certainty and study quality is mixed; mostly a low risk of bias across domains, but one study had a high risk of performance bias (lack of blinding) and three studies had a high risk of attrition bias. Manufacturers of the investigational products supported eight studies. Systemic administration Six studies (703 participants) administered everolimus (rapalog) orally. More participants in the intervention arm reduced renal angiomyolipoma size by 50% (risk ratio (RR) 24.69, 95% confidence interval (CI) 3.51 to 173.41; P = 0.001; 2 studies, 162 participants, high-certainty evidence). In the intervention arm, more participants in the intervention arm reduced SEGA tumour size by 50% (RR 27.85, 95% CI 1.74 to 444.82; P = 0.02; 1 study; 117 participants; moderate-certainty evidence) ,and reported more skin responses (RR 5.78, 95% CI 2.30 to 14.52; P = 0.0002; 2 studies; 224 participants; high-certainty evidence). In one 18-week study (366 participants), the intervention led to 25% fewer seizures (RR 1.63, 95% CI 1.27 to 2.09; P = 0.0001) or 50% fewer seizures (RR 2.28, 95% CI 1.44 to 3.60; P = 0.0004); but there was no difference in numbers being seizure-free (RR 5.30, 95% CI 0.69 to 40.57; P = 0.11) (moderate-certainty evidence). One study (42 participants) showed no difference in neurocognitive, neuropsychiatry, behavioural, sensory and motor development (low-certainty evidence). Total adverse events (AEs) did not differ between groups (RR 1.09, 95% CI 0.97 to 1.22; P = 0.16; 5 studies; 680 participants; high-certainty evidence). However, the intervention group experienced more AEs resulting in withdrawal, interruption of treatment, or reduced dose (RR 2.61, 95% CI 1.58 to 4.33; P = 0.0002; 4 studies; 633 participants; high-certainty evidence and also reported more severe AEs (RR 2.35, 95% CI 0.99 to 5.58; P = 0.05; 2 studies; 413 participants; high-certainty evidence). Topical (skin) administration Four studies (305 participants) administered rapamycin topically. More participants in the intervention arm showed a response to skin lesions (RR 2.72, 95% CI 1.76 to 4.18; P < 0.00001; 2 studies; 187 participants; high-certainty evidence) and more participants in the placebo arm reported a deterioration of skin lesions (RR 0.27, 95% CI 0.15 to 0.49; 1 study; 164 participants; high-certainty evidence). More participants in the intervention arm responded to facial angiofibroma at one to three months (RR 28.74, 95% CI 1.78 to 463.19; P = 0.02) and three to six months (RR 39.39, 95% CI 2.48 to 626.00; P = 0.009; low-certainty evidence). Similar results were noted for cephalic plaques at one to three months (RR 10.93, 95% CI 0.64 to 186.08; P = 0.10) and three to six months (RR 7.38, 95% CI 1.01 to 53.83; P = 0.05; low-certainty evidence). More participants on placebo showed a deterioration of skin lesions (RR 0.27, 95% CI 0.15 to 0.49; P < 0.0001; 1 study; 164 participants; moderate-certainty evidence). The intervention arm reported a higher general improvement score (MD -1.01, 95% CI -1.68 to -0.34; P < 0.0001), but no difference specifically in the adult subgroup (MD -0.75, 95% CI -1.58 to 0.08; P = 0.08; 1 study; 36 participants; moderate-certainty evidence). Participants in the intervention arm reported higher satisfaction than with placebo (MD -0.92, 95% CI -1.79 to -0.05; P = 0.04; 1 study; 36 participants; low-certainty evidence), although again with no difference among adults (MD -0.25, 95% CI -1.52 to 1.02; P = 0.70; 1 study; 18 participants; low-certainty evidence). Groups did not differ in change in quality of life at six months (MD 0.30, 95% CI -1.01 to 1.61; P = 0.65; 1 study; 62 participants; low-certainty evidence). Treatment led to a higher risk of any AE compared to placebo (RR 1.72, 95% CI 1.10, 2.67; P = 0.02; 3 studies; 277 participants; moderate-certainty evidence); but no difference between groups in severe AEs (RR 0.78, 95% CI 0.19 to 3.15; P = 0.73; 1 study; 179 participants; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

Oral everolimus reduces the size of SEGA and renal angiomyolipoma by 50%, reduces seizure frequency by 25% and 50% and implements beneficial effects on skin lesions with no difference in the total number of AEs compared to placebo; however, more participants in the treatment group required a dose reduction, interruption or withdrawal and marginally more experienced serious AEs compared to placebo. Topical rapamycin increases the response to skin lesions and facial angiofibroma, an improvement score, satisfaction and the risk of any AE, but not severe adverse events. With caution regarding the risk of severe AEs, this review supports oral everolimus for renal angiomyolipoma, SEGA, seizure, and skin lesions, and topical rapamycin for facial angiofibroma.

Influence of genetic variants on the pharmacokinetics and pharmacodynamics of sirolimus: a systematic review

Sirolimus is an antiproliferative and immunosuppressive compound inhibiting the mTOR pathway, which is often activated in congenital low-flow vascular malformations. Studies have demonstrated the efficacy of sirolimus for this disease. Studies in kidney transplant patients suggest that genetic variants can influence these pharmacokinetic parameters. Therefore, a systematic literature search was performed to gain insight into pharmacogenetic studies with sirolimus. Most studies investigated CYP3A4 and CYP3A5, with inconsistent results. No pharmacogenetic studies focusing on sirolimus have been performed for low-flow vascular malformations. We analyzed two common variants of CYP3A4 and CYP3A5 (CYP3A4*22 and CYP3A5*3, respectively) in patients (n = 59) with congenital low-flow vascular malformations treated with sirolimus. No association with treatment outcome was identified in this small cohort of patients.

Effect of Immune-Modulatory Interventions on Asymptomatic Cytomegalovirus Shedding During Suppressive Antiretroviral Therapy

Long-term consequences of human immunodeficiency virus (HIV) are likely the result of persistent inflammation and immune dysfunction of which cytomegalovirus (CMV) is a known contributor. We leveraged 2 AIDS Clinical Trials Group clinical trials exploring the effects of immune modulators (ruxolitinib and sirolimus) on inflammation in people with HIV on antiretroviral therapy to determine whether these interventions affected CMV shedding at various mucosal sites. Analyzing 635 mucosal samples collected, we found no significant difference in CMV levels across study arms or time points. Men had more CMV shedding than women. We did confirm an association between higher CMV DNA and immune markers associated with HIV persistence and HIV-associated mortality rates.

A pilot study evaluating the use of sirolimus in children and young adults with desmoid-type fibromatosis

Deregulation of the mTOR pathway may play an important role in tumor biology when the APC/β-catenin pathway is disrupted in desmoid-type fibromatosis (DT). A pilot study was conducted to determine whether sirolimus can block the mTOR pathway (primary aim) as well as determine whether it can safely be given in the preoperative setting, decrease tumor size/recurrence, and decrease tumor-associated pain in children and young adults (secondary aims) with DT. Nine subjects ages 5-28 years were enrolled from 2014 to 2017 across four centers. Sirolimus was feasible and was associated with a nonstatistically significant decrease in pS706K activation.

Exploratory study of autophagy inducer sirolimus for childhood cerebral adrenoleukodystrophy

Objectives

X-linked adrenoleukodystrophy (ALD) is a peroxisomal disease caused by mutations in the ABCD1 gene. Childhood cerebral ALD (CCALD) is characterized by inflammatory demyelination, rapidly progressing, often fatal. Hematopoietic stem cell transplant only delays disease progression in patients with early-stage cerebral ALD. Based on emergency humanitarianism, this study aims to investigate the safety and efficacy of sirolimus in the treatment of patients with CCALD.

Methods

This was a prospective, single-center, one-arm clinical trial. We enrolled patients with CCALD, and all enrolled patients received sirolimus treatment for three months. Adverse events were monitored and recorded to evaluate the safety. The efficacy was evaluated using the neurologic function scale (NFS), Loes score, and white matter hyperintensities.

Results

A total of 12 patients were included and all presented with CCALD. Four patients dropped out and a total of eight patients in the advanced stage completed a 3-month follow-up. There were no serious adverse events, and the common adverse events were hypertonia and oral ulcers. After sirolimus treatment, three of the four patients with an initial NFS > 10 showed improvements in their clinical symptoms. Loes scores decreased by 0.5-1 point in two of eight patients and remained unchanged in one patient. Analysis of white matter hyperintensities revealed a significant decrease in signal intensity (n = 7, p = 0.0156).

Conclusions

Our study suggested that autophagy inducer sirolimus is safe for CCALD. Sirolimus did not improve clinical symptoms of patients with advanced CCALD significantly. Further study with larger sample size and longer follow-up is needed to confirm the drug efficacy.Clinical Trial registration: https://www.chictr.org.cn/historyversionpuben.aspx, identifier ChiCTR1900021288.

Intraorbital lymphatic-venous malformation in an adult patient: is sirolimus the key?

Intraorbital lymphatic-venous malformations are rare lesions that represent a therapeutic challenge given their location and high rate of recurrence, with only a few cases in adult patients having been published in the literature. We present the case of a 30-year-old male with a right intraorbital lymphatic-venous malformation treated with sirolimus at a dose of 4 mg/day with complete clinical and radiologic remission. Mild cold-like symptoms ensued during the first week of treatment and elevation of liver function enzymes and D-dimer occurred in the context of acute SARS-CoV-2 pneumonia. No major adverse effects were documented. After 18 months of treatment, the patient remains asymptomatic and ophthalmologic examinations including optical coherence tomography and visual field test are within normal values.

Sirolimus Induced Toxic Optic Neuropathy

Objective

To describe a case of optic neuropathy after prolonged sirolimus therapy in the setting of cardiac transplant.

Background

Sirolimus is an immunosuppressant that inhibits Mechanistic Target of Rapamycin (mTOR) and blocks T-cell activation and B-cell differentiation by preventing response to Interleukin-2 (IL-2). Tacrolimus is another immunosuppressive agent, one of the known but uncommon side effects of which is bilateral optic neuropathy years after taking the medication. To the best of our knowledge, this is the first report of sequential optic neuropathy after years of treatment with sirolimus.

Case Presentation

A 69-year-old male with a history of cardiac transplantation presented with progressive, sequential, and painless vision loss. Visual acuity was 20/150 OD and 20/80 OS, with impaired color vision in both eyes (Ishihara 0/10) and bilateral disc pallor and mild optic disc edema in the left eye. Visual field was constricted in both eyes. The patient was on prolonged sirolimus therapy for over 7 years. Orbital MRI revealed bilateral chiasmatic thickness and FLAIR hyperintensity, without optic nerve enhancement post gadolinium. After extensive work up, other etiologies such as infectious, inflammatory, and neoplastic lesions were ruled out. Subsequently, sirolimus was substituted with cyclosporin that led to gradual improvement of vision and visual fields bilaterally.

Conclusion

Optic neuropathy is a rare side effect of tacrolimus, which has been seen as sudden, painless, and bilateral vision loss in post-transplant patients. Other concurrent medications influencing the cytochrome P4503A enzyme complexes may alter the pharmacokinetics of tacrolimus and increase the likelihood of toxicity. Discontinuation of offending agent has been shown to improve visual defects. We presented a rare case of optic neuropathy in a patient on sirolimus, whose visual defects improved upon discontinuation of sirolimus and switching to cyclosporin.

Drug Coated Balloon in the Treatment of De Novo Coronary Artery Disease: A Narrative Review

Drug coated balloons (DCBs) are currently indicated in guidelines as a first choice option in the management of instant restenosis, whereas their use in de novo lesions is still debated. The concerns raised after the contrasting results of the initial trials with DCBs in de novo lesions have been more recently overcome by a larger amount of data confirming their safety and effectiveness as compared to drug-eluting stents (DES), with potentially greater benefits being achieved, especially in particular anatomical settings, as in very small or large vessels and bifurcations, but also in selected subsets of higher-risk patients, where a 'leave nothing behind' strategy could offer a reduction of the inflammatory stimulus and thrombotic risk. The present review aims at providing an overview of current available DCB devices and their indications of use based on the results of data achieved so far.

Case Report: Kaposiform hemangioendothelioma with PIK3CA mutation successfully treated with sirolimus

Kaposiform hemangioendothelioma (KHE) is an extremely rare, locally aggressive vascular neoplasm. The etiopathogenesis of KHE is still poorly understood. In the present study, we found a new mutation in KHE (c.685delA, p.Thr229fs). The KHE patient with the PIK3CA mutation showed complete regression after sirolimus treatment. We propose that the presence of the PIK3CA mutation in KHE may correlate with good response to sirolimus.

Subconjunctival Sirolimus-Loaded Liposomes for the Treatment of Moderate-to-Severe Dry Eye Disease

Purpose

To determine the effectiveness of subconjunctival application of a novel sirolimus liposomal formulation for the treatment of dry eye.

Methods

A randomized, triple-blind, Phase II clinical trial. Thirty-eight eyes of 19 patients were included. Nine patients (18 eyes) assigned to the sham group (Sham) and 10 patients (20 eyes) to sirolimus-loaded liposomes group (Sirolimus). The treatment group received three doses of subconjunctival liposome-encapsulated sirolimus and the sham group received three doses of liposomal suspension without sirolimus. Subjective (Ocular Surface Disease Index, OSDI) and measured (corrected distance visual acuity, conjunctival hyperemia, tear osmolarity, Schirmer's test, corneal/conjunctival staining and matrix metalloproteinase-9) variables were measured.

Results

Sirolimus-entrapped liposomes-treated group OSDI scores changed from 62.19 (± 6.07) to 37.8 (± 17.81) (p=0.0024), and conjunctival hyperemia from 2.0 (± 0.68) to 0.83 (± 0.61) (p<0.0001); Sham group with OSDI scores from 60.02 (± 14.2) to 36.02 (± 20.70) (p=0.01), and conjunctival hyperemia from 1.33 (± 0.68) to 0.94 (± 0.87) (p=0.048). All the other evaluated outcomes only showed significant differences in the sirolimus group: corneal/conjunctival staining score (p=0.0015), lipid layer interferometry (p=0.006), and inferior meibomian gland dropout (p=0.038). No local or systemic adverse effects regarding the medication itself were reported, and the administration route was well accepted.

Conclusion

Our findings suggest that sub-conjunctival sirolimus-loaded liposomes are effective in reducing both signs and symptoms of dry eye in patients with poorly controlled moderate-to-severe DED, while avoiding other topical administration adverse effects. Further investigation with a larger sample size is required to determine long-term effects.

Activated Carbon-Enriched Electrospun-Produced Scaffolds for Drug Delivery/Release in Biological Systems

To vectorize drug delivery from electrospun-produced scaffolds, we introduce a thin outer drug retention layer produced by electrospinning from activated carbon nanoparticles (ACNs)-enriched polycaprolacton (PCL) suspension. Homogeneous or coaxial fibers filled with ACNs were produced by electrospinning from different PCL-based suspensions. Stable ACN suspensions were selected by sorting through solvents, stabilizers and auxiliary components. The ACN-enriched scaffolds produced were characterized for fiber diameter, porosity, pore size and mechanical properties. The scaffold structure was analyzed by scanning electron microscopy and X-ray photoelectron spectroscopy. It was found that ACNs were mainly coated with a polymer layer for both homogeneous and coaxial fibers. Drug binding and release from the scaffolds were tested using tritium-labeled sirolimus. We showed that the kinetics of sirolimus binding/release by ACN-enriched scaffolds was determined by the fiber composition and differed from that obtained with a free ACN. ACN-enriched scaffolds with coaxial and homogeneous fibers had a biocompatibility close to scaffold-free AC, as was shown by the cultivation of human gingival fibroblasts and umbilical vein cells on scaffolds. The data obtained demonstrated that ACN-enriched scaffolds had good physico-chemical properties and biocompatibility and, thus, could be used as a retaining layer for vectored drug delivery.

Successful Prenatal Treatment of Cardiac Rhabdomyoma in a Fetus with Tuberous Sclerosis

Cardiac rhabdomyomas are a possible early manifestation of the Tuberous Sclerosis Complex (TSC). They often regress spontaneously but may grow and cause cardiac dysfunction, threatening the child's life. Treatment with rapalogs can stop the growth of these cardiac tumors and even make them shrink. Here, we present the case of a successful treatment of a cardiac rhabdomyoma in a fetus with TSC by administering sirolimus to the mother. The child's father carries a TSC2 mutation and the family already had a child with TSC. After we confirmed the TSC diagnosis and growth of the tumor with impending heart failure, we started treatment at 27 weeks of gestation. Subsequently, the rhabdomyoma shrank and the ventricular function improved. The mother tolerated the treatment very well. Delivery was induced at 39 weeks and 1 day of gestation and proceeded without complications. The length, weight, and head circumference of the newborn were normal for the gestational age. Rapalog treatment was continued with everolimus. Metoprolol and vigabatrin were added because of ventricular preexcitation and epileptic discharges in the EEG, respectively. We provide the follow-up data on the child's development in her first two years of life and discuss the efficacy and safety of this treatment.

Overnight use of oral appliance with sirolimus sustained-release varnish delivery system: a clinical note and an observational study

OBJECTIVE

Maintaining appropriate salivary levels of an active ingredient is challenging. Intraoral trays can be used to deliver medications for localized treatment. Based on previous successful daytime studies with a slow-release sirolimus varnish, the aim was to optimize intraoral appliances/trays for overnight use to deliver slow-release medications in a manner that maintains therapeutic salivary levels of the active ingredient to treat oral conditions.

METHOD AND MATERIALS

An acrylic tray appliance containing 0.5 mg of sirolimus in a sustained-release varnish was placed on six anterior teeth for 12 hours, in ten healthy volunteers. Whole unstimulated saliva was collected at 1, 2, 10, and 12 hours after application. Blood was collected at the time of recruitment to confirm eligibility, and 12 hours after device removal to measure sirolimus levels. Drug levels in the blood and saliva were analyzed. Slow- and fast-release formulations, varnish position (buccal, palatal, or lingual), and tray placement (mandibular or maxillary) were qualitatively compared. Participants evaluated the varnish and tray.

RESULTS

Moderate concentrations of sirolimus were detected in the saliva when the fast-release formulation was used. The highest levels were from the mandibular tray with lingual varnish application. Sialometry of all participants was within normal range, and the highest drug levels were detected when low flow was measured. No traces of the medication were found in the blood.

CONCLUSIONS

Salivary concentrations of medications applied to an intraoral appliance are affected by the placement in the maxilla or mandible, varnish formulation, location of varnish, and salivation rate. These results may help optimize medication release following application to various oral devices. (Quintessence Int 2023;54:242-249; doi: 10.3290/j.qi.b3604821).

Long-term outcomes of sirolimus treatment for kaposiform hemangioendothelioma: Continuing successes and ongoing challenges

Treatment with sirolimus, an inhibitor of the mammalian target of rapamycin pathway, has improved the prognosis of patients with kaposiform hemangioendothelioma (KHE). However, the efficacy, durability and tolerability of long-term sirolimus treatment in patients with KHE have not been well elucidated. We performed efficacy and safety assessments based on more than 4.5 years of follow-up in patients receiving sirolimus therapy for KHE. One hundred sixty-seven patients were analyzed, including 102 (61.1%) patients with the Kasabach-Merritt phenomenon (KMP). Follow-up was conducted after a median of 56.0 months. A total of 154 (92.2%) patients had a durable response to sirolimus treatment. No difference in durable response was found between patients without KMP and patients with KMP (95.4% vs 90.2%; difference, 5.2%; 95% confidence interval [CI], -4.0% to 13.1%). Rebound growth occurred in 17.3% of patients upon sirolimus discontinuation. Early treatment discontinuation (odds ratio [OR]: 3.103; 95% CI: 1.529-6.299; P = .002) and mixed lesion type (OR: 2.271; 95% CI: 0.901-5.727; P = .047) were associated with tumor rebound growth. No KHE-related deaths occurred in this cohort. At the last follow-up, approximately 17.4% of patients had active disease and/or changes in body structures to a variable extent. Serious adverse events occurred most commonly during the first year of sirolimus therapy. Follow-up of almost 4.5 years demonstrated that the efficacy of sirolimus persisted over time and that long-term treatment with sirolimus was not associated with unacceptable cumulative toxicities. However, nonresponse, tumor relapse and long-term sequelae remained challenges despite intensified and prolonged sirolimus therapy.

Assessment of the adverse effects of sirolimus versus everolimus in pediatric heart transplant recipients

BACKGROUND

Literature is limited comparing adverse effects (AEs) of the proliferation signal inhibitors (PSIs) sirolimus (SRL) and everolimus (EVL) in pediatric heart transplant (HTx) recipients.

METHODS

Single-center, observational cohort analysis assessing first use of SRL or EVL in pediatric HTx recipients <21 years of age with up to 2 years follow-up between 2009 and 2020.

RESULTS

Eighty-seven patients were included, with 52 (59.8%) receiving EVL and 35 (40.2%) receiving SRL. Tacrolimus with PSI was the most common regimen. Intergroup comparison revealed lower baseline estimated glomerular filtration rate (eGFR) and greater increase in eGFR from baseline to 6 months and latest follow-up in SRL cohort compared to EVL cohort. There was greater increase in HDL cholesterol in SRL cohort compared to EVL cohort. Intragroup analysis revealed eGFR and HDL cholesterol increased significantly within SRL cohort, triglycerides and glycosylated hemoglobin increased in EVL cohort, and LDL cholesterol and total cholesterol increased in both cohorts (all p < .05). There were no differences in hematological indices or rates of aphthous ulcers, effusions, or infections between cohorts. Incidence of proteinuria was not significantly different among those screened within cohorts. Of those included in our analysis, one patient in SRL cohort (2.9%) and two in EVL cohort (3.8%) had PSI withdrawn due to AE.

CONCLUSION

Low-dose PSIs in calcineurin inhibitor minimization regimens appear well-tolerated with low withdrawal rate secondary to AE in pediatric HTx recipients. While incidence of most AE was similar between PSI, our results suggest EVL may be associated with less favorable metabolic impact than SRL in this population.

The Ranger drug-coated balloon: advances in drug-coated technology for treatment of femoropopliteal segment arterial disease

Paclitaxel drug-coated balloons (DCBs) have been shown to improve patency and lower revascularization rates compared with plain old balloon angioplasty. DCBs continue to evolve by improving balloon-coating techniques that minimize the quantity of particles washed off into the bloodstream while maximizing drug retention and vascular-healing profile. Against this backdrop, it is clear that the future of antiproliferatives for the superficial femoral artery will focus on enhancements in device coating materials that will improve the efficiency of drug delivery. The Ranger DCB system recently gained US FDA approval for use. This review discusses the background of DCBs and how the Ranger DCB builds on these previous platforms based on experimental and clinical data.

Determinants of Progression and Mortality in Lymphangioleiomyomatosis

BACKGROUND

Lymphangioleiomyomatosis is a progressive diffuse cystic lung disease with approximately 85% survival at 10 years. The determinants of disease progression and mortality after the introduction of sirolimus therapy and vascular endothelial growth factor D (VEGF-D) as a biomarker have not been well defined.

RESEARCH QUESTION

Which factors, including VEGF-D and sirolimus therapy, influence disease progression and survival prognosis in patients with lymphangioleiomyomatosis?

STUDY DESIGN AND METHODS

The progression dataset and the survival dataset included 282 and 574 patients, respectively, from Peking Union Medical College Hospital, Beijing, China. A mixed-effects model was used to compute the rate of decline in FEV₁, and generalized linear models were used to identify variables affecting FEV₁ decline. A Cox proportional hazards model was used to explore the association between clinical variables and the outcomes of death or lung transplantation in patients with lymphangioleiomyomatosis.

RESULTS

VEGF-D levels and sirolimus treatment were associated with FEV₁ changes and survival prognosis. Compared with patients with VEGF-D of < 800 pg/mL at baseline, patients with VEGF-D of ≥ 800 pg/mL lost FEV₁ faster (SE, -38.86 mL/y; 95% CI, -73.90 to -3.82 mL/y; P = .031). The 8-year cumulative survival rates of patients with VEGF-D of ≥ 2,000 pg/mL and < 2,000 pg/mL were 82.9% and 95.1%, respectively (P = .014). The generalized linear regression model also demonstrated the benefit of delaying the decline of FEV₁ by 65.56 mL/y (95% CI, 29.06-102.06 mL/y) in patients treated with sirolimus compared with those without sirolimus (P < .001). The 8-year risk of death was reduced by 85.1% (hazard ratio, 0.149; 95% CI, 0.075-0.299) after sirolimus treatment. After inverse treatment probability weighting, the risks of death in the sirolimus group were reduced by 85.6%. CT scan results of grade III severity were associated with worse progression than results of grades I or II severity. Patients with baseline FEV₁ of 70% predicted or St. George's Respiratory Questionnaire Symptoms domain 50 or higher predicted a higher risk of worse survival.

INTERPRETATION

Serum VEGF-D levels, a biomarker of lymphangioleiomyomatosis, are associated with disease progression and survival. Sirolimus therapy is associated with slower disease progression and better survival in patients with lymphangioleiomyomatosis.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT03193892; URL: www.

CLINICALTRIALS

gov.

Combination Chemotherapy in Severe Pulmonary Vein Stenosis-A Case Series

Pulmonary vein stenosis results from a proliferative process that leads to the progressive obstruction of venous return to the left atrium. It is often resistant to catheterization and surgical based interventions and is frequently fatal when encountered in its severe form. Here, we describe three patients with severe, primary pulmonary vein stenosis that was progressing despite aggressive conventional management strategies. All three patients were initiated on combination chemotherapy with imatinib and sirolimus, drugs which have been previously shown to independently have potential benefit against PVS. Soon after the initiation of these therapies, all three patients experienced a stabilization of their disease process and clinical improvement. All three patients remain alive, with tolerable side effects from the medications. Although early in our experience and with only a small number of patients, combination chemotherapy with imatinib and sirolimus shows promise and merits further investigation as a therapeutic option for this aggressive disease.

[Rapid and simultaneous determination of two immunosuppressants in whole blood by high performance liquid chromatography]

Cyclosporine A and sirolimus are immunosuppressants that are widely used in many organ transplantation procedures. They exhibit some complementary mechanisms of action and interact synergistically when used together. However， they are critical-dose drugs and have a narrow therapeutic index. They provide the desired therapeutic effect with acceptable tolerability only within a specific range of blood concentrations. Therefore， the rapid and simultaneous detection of the concentrations of cyclosporine A and sirolimus in whole blood could provide valuable information on planning medicine administration after organ transplantations. In this study， firstly， the chromatographic behaviors of cyclosporine A and sirolimus on a biological liquid chromatography （BioLC） column and traditional liquid chromatography （TraLC） columns were investigated systematically under the same chromatographic conditions. The results suggested that the peak height and peak width of cyclosporine A and sirolimus on the BioLC column， ZORBAX 300SB C8 （250 mm×4.6 mm， 5.0 μm）， were the highest and narrowest， respectively. The number of theoretical plates of cyclosporine A and sirolimus on the ZORBAX 300SB C8 column increased significantly when the volume ratio of acetonitrile in the mobile phases was greater than 70%. Their retention time on the BioLC and TraLC columns was negligibly affected by the use of formic acid and trifluoroacetic acid as the mobile phases. In the range of the experimental column temperature， the number of theoretical plates of cyclosporine A and sirolimus on the ZORBAX 300SB C8 column was significantly higher than that on the two TraLC columns. Furthermore， the relationship between the retention factor and column temperature of cyclosporine A on the ZORBAX 300SB C8 column was different from that on the two TraLC columns. Subsequently， a high performance liquid chromatography method based on the ZORBAX 300SB C8 column was established for the rapid separation and determination of cyclosporin A and sirolimus in whole blood. A sample of whole blood with a volume of 50 μL was prepared by protein precipitation with 1 mol/L sodium hydroxide and then extracted into 500 μL of ether-methanol （95∶5， v/v）. After centrifugation at 14000 r/min for 10 min， the organic layer was removed and evaporated under a stream of nitrogen at 50 ℃. The residue was then reconstituted in 200 μL of methanol for use. Cyclosporin A and sirolimus were separated through isocratic elution on the ZORBAX 300SB C8 column. The column temperature was set at 60 ℃. The mobile phase was acetonitrile-water （70∶30， v/v） and the flow rate was 1.0 mL/min. The detection wavelengths were 205 nm for cyclosporine A and 278 nm for sirolimus. The injection volume was 20 μL. The external standard method was used to quantify cyclosporine A and sirolimus. Under the optimized conditions， cyclosporine A and sirolimus were well-separated within 6 min with a resolution of 3.7 at 205 nm. In addition， the endogenous substances in whole blood negligibly interfered in the detection of sirolimus， while two endogenous substances slightly affected the detection of cyclosporine A. Cyclosporine A and sirolimus both showed good linear relationships in their respective concentration （r>0.997）. The limits of detection （LODs） of cyclosporine A and sirolimus were respectively calculated to be 10 ng/mL and 1 ng/mL based on a signal-to-noise ratio of 3， and the limits of quantification （LOQs） were 30 ng/mL and 2 ng/mL based on a signal-to-noise ratio of 10. In the whole blood samples， the recoveries of cyclosporine A and sirolimus at three spiked levels were in the ranges of 83.5%-89.7% and 95.8%-97.8% with relative standard deviations （RSDs） of 3.2%-9.0% and 3.4%-6.7% （n=5）， respectively. The established method is simple in operation， can be performed with a simple mobile phase， has a short analysis time， and provides a wide linear range and high sensitivity； hence， it can be applied to the determination of cyclosporine A and sirolimus in whole blood.

The Effects of Sirolimus and Magnesium on Primary Human Coronary Endothelial Cells: An In Vitro Study

Drug eluting magnesium (Mg) bioresorbable scaffolds represent a novel paradigm in percutaneous coronary intervention because Mg-based alloys are biocompatible, have adequate mechanical properties and can be resorbed without adverse events. Importantly, Mg is fundamental in many biological processes, mitigates the inflammatory response and is beneficial for the endothelium. Sirolimus is widely used as an antiproliferative agent in drug eluting stents to inhibit the proliferation of smooth muscle cells, thus reducing the occurrence of stent restenosis. Little is known about the potential interplay between sirolimus and Mg in cultured human coronary artery endothelial cells (hCAEC). Therefore, the cells were treated with sirolimus in the presence of different concentrations of extracellular Mg. Cell viability, migration, barrier function, adhesivity and nitric oxide synthesis were assessed. Sirolimus impairs the viability of subconfluent, but not of confluent cells independently from the concentration of Mg in the culture medium. In confluent cells, sirolimus inhibits migration, while it cooperates with Mg in exerting an anti-inflammatory action that might have a role in preventing restenosis and thrombosis.

Development of UHPLC-MS/MS method for simultaneous determination of tacrolimus and sirolimus in human whole blood and comparisons with two immunoassays

Tacrolimus (TAC) and sirolimus (SIR) antirejection medications are widely used in organ transplantation. We aimed to develop an ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) assay for quantifying TAC and SIR simultaneously and evaluating agreement with chemiluminescence microparticle immunoassay (CMIA) and electrochemiluminescence immunoassay (ECLIA). Whole blood samples collected from 209 TAC and 208 SIR patients were assessed by UHPLC-MS/MS, CMIA and ECLIA. The agreement of the three techniques was assessed using the Bland-Altman plot. The UHPLC-MS/MS assay had a calibration range of 1-100 ng/ml for TAC and SIR. The accuracy and precision were -2.73-4.32% and <4.71% for TAC, respectively, and 0.07-4.84% and <6.5% for SIR, respectively. The three methods had good correlation. In comparison with UHPLC-MS/MS, two immunoassays showed a slight deviation in proportion. An UHPLC-MS/MS method for simultaneously detecting TAC and SIR in human whole blood was developed, validated and comparatively analyzed with CMIA and ECLIA. For determining TAC and SIR, immunoassays displayed acceptable analytical performances in terms of precision and correlation compared with UHPLC-MS/MS. However, further investigation is warranted to examine the novel method.

Effect of Sirolimus/Metformin Co-Treatment on Hyperglycemia and Cellular Respiration in BALB/c Mice

Sirolimus (SRL) is widely used as an immunosuppressant to prevent graft rejection, despite the risk of impairing glucose metabolism. Metformin (MET) can reduce the detrimental effects of SRL in many patients, including diabetes and renal transplant recipients. Limited in vivo studies have reported on SRL and MET therapy, particularly in relation to cellular bioenergetics, glucose metabolism, and insulin resistance. Herein, we investigated the efficacy of SRL and MET co-treatment in BALB/c mice over 4 weeks. Balb/c mice (4-6 weeks old) were divided into four groups and injected intraperitoneally (i.p.) with water (control, CTRL), MET (200 µg/g), SRL (5 µg/g), or MET (200 µg/g) +SRL (5 µg/g) over a period of one month. We evaluated the body weight, food consumption rate, random blood glucose (BG), insulin levels, serum biochemistry parameters (ALT, Albumin, BUN, Creatinine), and histomorphology in all groups using standardized techniques and assays. All drug-treated groups showed a statistically significant decrease in weight gain compared to the CTRL group, despite normal food intake. Treatment with SRL caused elevated BG and insulin levels, which were restored with SRL + MET combination. Serum biochemical parameters were within the normal range in all the studied groups. SRL+ MET co-treatment decreased liver cellular respiration and increased cellular ATP levels in the liver. In the pancreas, co-treatment resulted in increased cellular respiration and decreased cellular ATP levels. Liver and pancreatic histology were unchanged in all groups. This study showed that co-treatment of SRL with MET alleviates hyperglycemia induced by SRL without any deleterious effects. These results provide initial insights into the potential use of SRL + MET therapy in various settings.

Safety of Sirolimus in Patients with Tuberous Sclerosis Complex under Two Years of Age-A Bicenter Retrospective Study

BACKGROUND

mTOR inhibitors are a novel pharmacotherapy recommended for subependymal giant astrocytomas, refractory epilepsy, and the treatment of the other clinical manifestations of tuberous sclerosis complex (TSC). Clinical trials on everolimus proved it to be effective and safe in children. Despite its common use in clinical practice, the research on sirolimus is limited. This study is the first to determine and assess the severity of the adverse effects (AEs) of sirolimus administered to children with TSC under two years of age.

METHODS

We performed a bicenter retrospective data analysis of medical records of individuals with TSC who initiated therapy with sirolimus under the age of two.

RESULTS

Twenty-one patients were included in the study. At least one AE was reported in all participants. The most prevalent AEs were anemia, thrombocytosis, and hyperlipidemia. Infections and mouth ulcerations, often reported in the studies on older patients, were infrequent and of mild or moderate grade.

CONCLUSIONS

Adverse effects associated with sirolimus use in infants and young children with TSC are frequent yet not life- or health-threatening. Further multicenter prospective clinical trials should determine the long-term safety of sirolimus.

Case report: Blue rubber bleb nevus syndrome with Kasabach-Merritt phenomenon in a neonate

Blue rubber bleb nevus syndrome (BRBNS) is a rare disease characterized by multifocal venous malformations that can affect any organ or tissue. Kasabach-Merritt phenomenon (KMP) is a serious and extremely rare complication of BRBNS. This report describes a neonate with BRBNS with KMP who was successfully diagnosed and treated with low-dose sirolimus and glucocorticoids. A 13-day-old female infant was born with multiple tumors on her head, neck, shoulder, back, abdomen, limbs, perineum, etc. some of which were blue. Laboratory examinations showed thrombocytopenia, anemia and coagulopathy. BRBNS with KMP was diagnosed. Oral low-dose sirolimus combined with glucocorticoids was administered. After 6 months of regular follow-up, the lesions in the child were significantly decreased, and there were no signs of KMP recurrence. The presence of KMP should be considered in patients diagnosed with BRBNS who present with thrombocytopenia, anemia and coagulopathy. Sirolimus combined with glucocorticoid therapy can be administered to save the patient's life.

Identification of a Novel TSC2 c.170G>A Missense Variant: A Case Report and Elaboration on the Yield of Targeted Options against Tuberous Sclerosis Complex Manifestations

BACKGROUND

Tuberous sclerosis complex (TSC) is a rare genetic disease that affects multiple organs and affects the quality of life. Mutations in TSC1 and TSC2 genes are causing dysregulations in the mammalian target of the rapamycin (mTOR) pathway, inducing mostly benign but also malignant tumors, including renal cell carcinoma (RCC). The diagnosis of TSC, based on established clinical and genetic criteria, is essential for the optimal surveillance and management of patients.

CASE PRESENTATION

With the current report, we present the case of two sisters who were consequently diagnosed with early-stage chromophobe-like RCC, possibly familial given their young age. The younger sister also had a previous diagnosis of differentiated thyroid carcinoma, for which she had been treated properly. Genetic testing of both revealed the same heterozygous TSC2 variant that is currently regarded as a variant of unknown significance, while both patients did not fulfill the clinical criteria for the diagnosis of TSC. Owing to these data, we opted to manage and surveil both sisters as TSC patients, while we also considered the specific TSC2 variant to be pathogenic - but of low penetrance - based on clinical judgment and functional analyses. Furthermore, we discussed the implementation of mTOR inhibitors for the treatment of TSC complications.

CONCLUSION

As novel pathogenic variants of TSC genes are constantly being explored, the identification of TSC variants of unknown significance in combination with absent clinical diagnostic criteria cannot exclude a TSC diagnosis. We support the implementation of clinical judgment in assisting the diagnosis of TSC, as well as the enrollment of patients in clinical trials due to the rarity of the disease.

Sturge-Weber Syndrome: A Review of Pathophysiology, Genetics, Clinical Features, and Current Management Approache

Sturge-Weber syndrome (SWS) is a congenital, sporadic, and rare neurocutaneous disorder, characterized by the presence of a facial port-wine birthmark (PWB), glaucoma, and neurological manifestations including leptomeningeal angiomatosis and seizures. It is caused by a postzygotic, somatic, gain-of-function variant of the GNAQ gene, and more recently, the GNA11 gene in association with distinctive clinical features. Neuroimaging can help identify and stratify patients at risk for significant complications allowing closer follow-up; although no presymptomatic treatment has been demonstrated to be effective to date, these patients could benefit from early treatment and/or supportive interventions. Choroid plexus (CP) thickness measurements in brain magnetic resonance imaging (MRI) have a high sensitivity and specificity for early and incipient changes in SWS. In contrast, the absence of pathologic findings makes it possible to rule out associated neurological involvement and leads to periodical observation, with new imaging studies only in cases of new clinical signs/symptoms. Periodic ophthalmological examination is also recommended every 3 months during the first year and yearly afterwards to monitor for glaucoma and choroidal hemangiomas. Treatment for SWS depends on the extent and areas that are affected. These include laser surgery for PWB, anticonvulsants in the case of brain involvement, with either seizures or abnormal EEG, and medical treatment or surgery for glaucoma. Sirolimus has been used in a limited number of patients and appears to be a safe and potentially effective treatment for cutaneous and extra-cutaneous features, however controlled clinical studies have not been carried out. Better knowledge of GNAQ/GNA11 molecular pathways will help to develop future targeted treatments.

Case report: Neonatal autoimmune lymphoproliferative syndrome with a novel pathogenic homozygous FAS variant effectively treated with sirolimus

Background

Autoimmune lymphoproliferative syndrome (ALPS) is a rare disease characterized by defective FAS signaling, which results in chronic, nonmalignant lymphoproliferation and autoimmunity accompanied by increased numbers of "double-negative" T-cells (DNTs) (T-cell receptor αβ+ CD4-CD8-) and an increased risk of developing malignancies later in life.

Case presentation

We herein report a case of a newborn boy with a novel germline homozygous variant identified in the FAS gene, exon 9, c.775del, which was considered pathogenic. The consequence of this sequence change was the creation of a premature translational stop signal p.(lle259*), associated with a severe clinical phenotype of ALPS-FAS. The elder brother of the proband was also affected by ALPS and has been found to have the same FAS homozygous variant associated with a severe clinical phenotype of ALPS-FAS, whereas the unaffected parents are heterozygous carriers of this variant. This new variant has not previously been described in population databases (gnomAD and ExAC) or in patients with FAS-related conditions. Treatment with sirolimus effectively improved the patient clinical manifestations with obvious reduction in the percentage of DNTs.

Conclusion

We described a new ALPS-FAS clinical phenotype-associated germline FAS homozygous pathogenic variant, exon 9, c.775del, that produces a premature translational stop signal p.(lle259*). Sirolimus significantly reduced DNTs and substantially relieved the patient's clinical symptoms.

Sirolimus- and cyclosporine-loaded nanostructured lipid carriers: Development, characterization, and in vitro evaluation in T-cell profiles of patients with a history of recurrent pregnancy loss

Purpose

The authors developed nanostructured lipid carriers (NLCs) loaded with sirolimus (SRL) and cyclosporine (CsA) to improve their therapeutic efficacy in recurrent pregnancy loss (RPL) patients.

Methods

Mono-delivery and co-delivery of SRL and CsA by NLCs (S-NLCs, C-NLCs, and S-C-NLCs) were developed. The MTT assay was used to study the optimum dose of formulations. PCR, Western blotting, and ELISA were also conducted.

Results

Well-designed nanodrugs with a suitable size, zeta potential, desirable encapsulation efficiency drug loading, and cellular uptake confirmed optimum formulations. Based on cell viability, the amounts of SRL and CsA could be reduced greatly due to the co-delivery by NLCs. Following S-NLCs and C-NLCs interventions in T cells of patients with RPL and immune abnormality, a significant difference was observed in transcription factors and cytokine levels of Th1, Th17, and Tregs compared with healthy samples. Thus, a higher level of pro-inflammatory cytokines (IFN-γ, TNF-α, IL-17, and IL-21) and their regulators (T-bet and RORγt), as well as a lower level of an anti-inflammatory cytokine (IL-10) and its regulatory (Foxp3), were observed. However, no significant difference was found following the S-C-NLCs intervention.

Conclusions

S-C-NLCs effectively balance the immune responses in peripheral T cells in RPL patients to induce maternal immune tolerance.

Case report: COPA syndrome with interstitial lung disease, skin involvement, and neuromyelitis spectrum disorder

This report describes a case of a 22 months Chinese boy with COPA syndrome bearing the c.715G > C (p.A239P) genotype. In addition to interstitial lung diseae, he also suffered from recurrent chilblain-like rashes, which has not been previously reported, and neuromyelitis optica spectrum disorder (NMOSD), which is a very rare phenotype. Clinical manifestations expanded the phenotype of COPA syndrome. Notably, there is no definitive treatment for COPA syndrome. In this report, the patient has achieved short-term clinical improvement with sirolimus.

BioMatrix Versus Orsiro Stents for Coronary Artery Disease: A Multicenter, Randomized, Open-Label Study

BACKGROUND

Comparative studies of ultrathin-strut biodegradable polymer sirolimus-eluting stent (BP-SES) have reported promising results and validated its excellent outcomes in terms of safety and efficacy. However, there are limited studies comparing BP drug-eluting stents with struts of different thicknesses. We compared the long-term clinical outcomes of patients treated with an ultrathin-strut BP-SES or a thick-strut biodegradable polymer biolimus-eluting stent (BP-BES).

METHODS

The BIODEGRADE trial (Biomatrix and Orsiro Drug-Eluting Stents in Angiographic Result in Patients With Coronary Artery Disease) is a multicenter prospective randomized study comparing coronary revascularization in patients with ultrathin-strut BP-SES and thick-strut BP-BES with the primary end point of target lesion failure at 18 months posttreatment. We performed the prespecified analysis of 3-year clinical outcomes.

RESULTS

In total, 2341 patients were randomized to receive treatment with ultrathin-strut BP-SES (N=1175) or thick-strut BP-BES (N=1166). The 3-year incidence rate of target lesion failure was 3.2% for BP-SES and 5.1% for BP-BES (P=0.023). The difference was primarily due to differences in ischemia-driven target lesion revascularization (BP-SES, 1.5%; BP-BES, 2.8%; P=0.035) between groups. A landmark analysis of the late follow-up period showed significant differences in target lesion failure, with outcomes being better in BP-SES. Cardiac death and target lesion revascularization were significantly lower in the BP-SES group.

CONCLUSIONS

In a large, randomized trial, the long-term clinical outcome of target lesion failure at 3 years was significantly better among patients treated with the ultrathin-strut BP-SES. The results indicate the superiority of the ultrathin-strut BP-SES compared with the thick-strut BP-BES.

REGISTRATION

URL: https://clinicaltrials.gov; Unique identifier: NCT02299011.

Progressive kaposiform hemangioendothelioma and sirolimus-related severe thrombocytopenia

Kaposiform hemangioendothelioma is a locally invasive tumor and we were unable to find any previous reports of multifocal progression. Sirolimus, a mammalian target of rapamycin inhibitor, has been widely used to treat kaposiform hemangioendothelioma. Herein, we report a case of multifocal progressive kaposiform hemangioendothelioma, wherein sirolimus treatment caused severe thrombocytopenia. A 12-year-old East Asian girl presented with indurated dark-purple masses on her back. The patient had received three surgical interventions following the first appearance of the masses in 2012 and subsequent reappearances in 2014 and 2016. Kaposiform hemangioendothelioma was diagnosed based on radiological and pathological findings. Two more masses appeared in the following year. The patient was treated with oral sirolimus (2.5 mg/ m2/day) and developed grade 3 thrombocytopenia 8 days later. The patient was uneventfully relieved 5 days later after the withdrawal of sirolimus and the administration of appropriate medications. This rare case indicated that kaposiform hemangioendothelioma could be progressive with local metastatic characteristics in children. Besides, the severe sirolimus-induced complication highlights the importance of serum drug level monitoring during treatment. Physicians should be extremely cautious while treating kaposiform hemangioendothelioma patients with sirolimus.

Case report: Multiple brain intravascular papillary endothelial hyperplasia: incidence, diagnostic challenges, and management approach

Multiple hemorrhagic brain lesions are mainly diagnosed based on clinico-radiological features integrated with histological data. Intravascular papillary endothelial hyperplasia (IPEH), or Masson's tumor, is a very rare entity, particularly when localized in the brain. In this study, we describe a case of multiple recurrent brain IPEHs and provide details on the diagnostic phase, therapeutic approaches, and related challenges. A 55-year-old woman presented with a relapsing neurological deficit. Brain magnetic resonance imaging (MRI) revealed a hemorrhagic right frontal-parietal lesion. When new neurological symptoms occurred, subsequent MRI scans detected more bleeding cerebral lesions. She underwent a series of single hemorrhagic lesion debulking. For any samples that underwent histopathological examination, the first results were not informative; the second and the third results revealed hemangioendothelioma (HE); and the fourth results led to the IPEH diagnosis. Interferon alpha (IFN-α) and subsequently sirolimus were prescribed. Both were well tolerated. Clinical and radiological features remained stable 43 months after starting sirolimus therapy and 132 months after the first diagnosis. To date, 45 cases of intracranial IPEH have been reported, mostly as single lesions without parenchymal location. They are usually treated by surgery and sometimes by radiotherapy upon recurrence. Our case is notable for two main reasons: because of the consecutive recurrent multifocal exclusively cerebral lesions and the therapeutic approach we used. Based on multifocal brain recurrence and good performance, we propose pharmacological therapy, including IFN-α and sirolimus, to stabilize IPEH.

Reduced Prevalence of Dementia in Patients Prescribed Tacrolimus, Sirolimus, or Cyclosporine

BACKGROUND

Evidence suggests patients prescribed calcineurin inhibitors (CNIs) have a reduced prevalence of dementia, including Alzheimer's disease (AD); however, this result has never been replicated in a large cohort and the involved mechanism(s) and site of action (central versus periphery) remain unclear.

OBJECTIVE

We aim to determine if prescription of CNIs is associated with reduced prevalence of dementia, including AD, in a large, diverse patient population. Furthermore, we aim to gain insight into the mechanism(s) and site of action for CNIs to reduce dementia prevalence.

METHODS

Electronic health records (EHRs) from patients prescribed tacrolimus, cyclosporine, or sirolimus were analyzed to compare prevalence, odds, and hazard ratios related to dementia diagnoses among cohorts. EHRs from a random, heterogeneous population from the same network were obtained to generate a general population-like control.

RESULTS

All drugs examined reduced dementia prevalence compared to the general population-like control. There were no differences in dementia diagnoses upon comparing tacrolimus and sirolimus; however, patients prescribed tacrolimus had a reduced dementia prevalence relative to cyclosporine.

CONCLUSION

Converging mechanisms of action between tacrolimus and sirolimus likely explain the similar dementia prevalence between the cohorts. Calcineurin inhibition within the brain has a greater probability of reducing dementia relative to peripherally-restricted calcineurin inhibition. Overall, immunosuppressants provide a promising therapeutic avenue for dementia, with emphasis on the brain-penetrant CNI tacrolimus.