Effective low dose sirolimus regimen for kaposiform hemangioendothelioma with Kasabach-Merrit Phenomenon in young infants

Sirolimus combined with glucocorticoids in the treatment of Kasabach-Merritt phenomenon in a neonate: A case report

RATIONALE

Kaposiform hemangioendothelioma is an aggressive vascular tumor that is often associated with life-threatening coagulopathies and Kasabach-Merritt phenomenon. Pathologic biopsies can provide a good basis for diagnosis and treatment. Therapy with srolimus combined with glucocorticoids may offer patients a favorable prognosis.

PATIENT CONCERNS

A large purplish-red mass on the knee of a child with extremely progressive thrombocytopenia and refractory coagulation abnormalities. Conventional doses of glucocorticoids alone failed to improve coagulation abnormalities and the child developed large cutaneous petechiae and scalp hematomas.

DIAGNOSIS

Kaposiform hemangioendothelioma combined with Kasabach-Merritt phenomenon.

INTERVENTIONS

The patient received prednisolone 2.0 mg/kg*d for 4 days. Blood products were transfused to ensure vital signs and to complete the pathologic biopsy. Sirolimus combined with prednisolone was given after clarifying the diagnosis of Kaposiform hemangioendothelioma.

OUTCOMES

The tumor basically disappeared on examination and the ultrasound showed a subcutaneous hyperechoic mass with normal blood flow.

LESSONS

Sirolimus combined with glucocorticoids is effective in controlling Kasabach-Merritt phenomenon and pathologic biopsy is important for definitive diagnosis.

Sirolimus monotherapy for Kasabach-Merritt phenomenon in a neonate; Case report

INTRODUCTION AND IMPORTANCE

The Kasabach-Merritt Phenomenon (KMP), characterized by thrombocytopenia and consumptive coagulopathy due to endothelial cell growth in the infantile vascular tumor kaposiform hemangioendothelioma, presents a therapeutic challenge. This case highlights the novel use of sirolimus in a neonate, an approach less explored in this age group.

CASE PRESENTATION

A female neonate presented with a right anterior chest mass, progressing to respiratory distress and congestive heart failure. Diagnosed with KMP, she exhibited low platelet count and coagulation abnormalities. Treatment with sirolimus (0.06 mg/day) led to mass reduction, improved bleeding, and a stable tumor after 12 months, without side effects. This case contrasts with existing literature advocating for combination therapy or higher sirolimus concentrations for effective treatment. Yet, our patient achieved favorable outcomes with low-dose monotherapy, suggesting a potentially safer approach in neonates with immature hepatic and renal metabolism.

CLINICAL DISCUSSION

This case demonstrates the efficacy of low-dose sirolimus monotherapy in treating KMP in a neonate, challenging current preferences for combination therapies or higher doses. It emphasizes the need for further research into age-specific treatment protocols in KMP, considering the unique metabolic profiles of neonates and infants.

CONCLUSION

Sirolimus has demonstrated potential in treating KMP in pediatric patients. While initial results are promising, determining optimal dosages and trough concentrations, especially in neonates and infants, remains essential.

Cost and effectiveness comparison of sirolimus versus standard treatment in Kasabach-Merritt phenomenon: a real-world evidence study in Thailand

The conventional treatment of Kasabach-Merritt Phenomenon (KMP) consists of corticosteroids with vincristine/vinblastine or others. The aim of the study is to compare the first-year direct costs and effectiveness between sirolimus and conventional treatment. A retrospective case-control study of KMP patients was conducted at a mean age of 9 months (1 day to 12 years) between 2000 and 2022 from four tertiary centers in Thailand. The direct costs, hematologic and clinical complete response (HCR, CCR), hospitalization, length of stay, and complications were compared. Of 29 patients, 13 underwent sirolimus (four upfront and nine were refractory to the conventional). The first-year total cost had no statistically significant difference between sirolimus VS conventional treatment (8,852.63 VS 9,083.56 USD: p value: 0.94). The therapeutics achievement was the same in both HCR (244.75 VS 168.94 days; p value: 0.60) and CCR (419.77 VS 399.87 days; p value: 0.90). The subgroup analysis of the first-line sirolimus (n = 4) compared with the conventional (n = 25) showed a more reduced total cost (4,907.84 VS 9,664.05 USD; p value: 0.26) rendered net total cost of -4,756.21 USD per patient (cost saving). A more significant contrast of therapeutic achievement by reduction of both HCR (11.67 VS 224.20 days; p value: 0.36) and CCR (38.50 VS 470.88 days; p value: 0.04) was shown. The sirolimus had no difference in hospitalization, length of stay, and complications. Even though, it was unable to identify significant differences in cost-effectiveness. Sirolimus is suitable for all patients who have diagnosis of KMP either for rescue therapy or first-line treatment.

Sirolimus for vascular anomalies in the first year of life: a systematic review

Evidence on effectiveness and safety of sirolimus in congenital vascular anomalies in infancy is lacking. We aim to systematically review the efficacy and safety of sirolimus in treating congenital VA in infancy. We searched for and included all studies evaluating sirolimus for VA in the first year of life. The primary outcome was effectiveness. The secondary outcome was safety. We included 84 case series and reports (172 participants). Sirolimus decreased the size of the VA in >50% of participants, most of whom had minor transient side effects, and 27% had no adverse effects at all. When categorized by age (<1 month, 1-5 months and 6-12 months), the effectiveness was similar in all age groups. Available evidence suggests that sirolimus is effective and well tolerated. The effectiveness of sirolimus should be evaluated in a well-designed randomized controlled or observational studies.

Rapid response with good toleration of sirolimus for life-threatening neonatal lymphatic malformations

Introduction

Lymphatic malformations (LMs) are rare vascular anomalies predominantly affecting infants, which can be debilitating or life-threatening when complicated with intralesional bleeding or infection. Effective and safe management strategies are essential in such cases.

Case presentation

We report a case series involving four Chinese neonates with life-threatening LMs, initially treated with oral sirolimus. All patients achieved rapid relief and sustained remission, using a lower sirolimus dosage than previously recommended. Furthermore, adverse events were rarely recorded during follow-up.

Conclusion

Sirolimus can be considered a promising choice for neonates with intricate and life-threatening LMs. Initiation with a reduced sirolimus dose is advisable.

Kaposiform hemangioendothelioma complicated by Kasabach-Merritt phenomenon in an infant girl

Key Clinical Message

We report a successful treatment course of an infant with mediastinal Kaposiform hemangioendothelioma. As the current complex of diseases is rare and calls for highly specialized treatment, large prospective studies are lacking. This case provides an example of balanced treatment complicated by Kasabach-Merritt phenomenon, life-threatening infections, and pericardial effusion.

Abstract

Kaposiform hemangioendothelioma (KHE) and tufted angioma are vascular benign tumors that can be associated with the rare condition Kasabach-Merritt Phenomenon (KMP). KMP is characterized by consumption coagulopathy with severe thrombocytopenia, hypofibrinogenemia, and elevated D-dimer. We here report successful treatment of a female infant with a mediastinal KHE where treatment was complicated by KMP, life-threatening infections, and pericardial effusion. Due to the absence of randomized clinical trials, there is currently no standardized treatment protocol available for KHE. In our case, the infant was treated successfully with prednisolone, vincristine, and sirolimus.

Current concepts of vascular anomalies

Vascular anomalies encompass a variety of malformations and tumors that can result in severe morbidity and mortality in both adults and children. Advances have been made in the classification and diagnosis of these anomalies, with the International Society for the Study of Vascular Anomalies establishing a widely recognized classification system. In recent years, notable progress has been made in genetic testing and imaging techniques, enhancing our ability to diagnose these conditions. The increasing sophistication of genetic testing has facilitated the identification of specific genetic mutations that help treatment decisions. Furthermore, imaging techniques such as magnetic resonance imaging and computed tomography have greatly improved our capacity to visualize and detect vascular abnormalities, enabling more accurate diagnoses. When considering reconstructive surgery for facial vascular anomalies, it is important to consider both functional and cosmetic results of the procedure. Therefore, a comprehensive multidisciplinary approach involving specialists from dermatology, radiology, and genetics is often required to ensure effective management of these conditions. Overall, the treatment approach for facial vascular anomalies depends on the type, size, location, and severity of the anomaly. A thorough evaluation by a team of specialists can determine the most appropriate and effective treatment plan.

Oral antibiotic prophylaxis for infection in patients with vascular anomalies receiving sirolimus treatment: a multicenter retrospective study

OBJECTIVES

Patients with vascular anomalies (VAs) who receive oral sirolimus may be at high risk of infectious complications. Antibiotic prophylaxis with trimethoprim-sulfamethoxazole (TMP-SMZ) has been advocated. However, there have been few evidence-based analyses on this topic. This study assessed the effect of prophylactic TMP-SMZ on the incidence of infections in VA patients receiving sirolimus monotherapy.

METHODS

A retrospective, multicenter chart review was performed on all VA patients receiving sirolimus treatment from August, 2013 to January, 2021.

RESULTS

Before January 2017, 112 patients were treated with sirolimus without antibiotic prophylaxis. In the subsequent period, 195 patients were treated with TMP-SMZ for at least 12 months during sirolimus therapy. The percentage of patients with at least one serious infection during the initial 12 months of sirolimus treatment did not differ between the groups (difference, 1.1%; 95% CI - 7.0-8.0%). We observed no difference in the incidence of individual infection or total adverse events between the groups. The rate of sirolimus discontinuation due to adverse events did not differ significantly between groups.

CONCLUSIONS

We demonstrated that prophylactic TMP-SMZ does not decrease the incidence of infection or improve tolerance in VA patients receiving sirolimus monotherapy.

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.

Monitoring of sirolimus in the whole blood samples from pediatric patients with lymphatic anomalies

In recent years, off-label use of sirolimus (SIR) has been gaining attention in the clinical practice. However, since it is critical to achieve and maintain therapeutic blood levels of SIR during treatment, the regular monitoring of this drug in individual patients must be implemented, especially in off-label indications of this drug. In this article, a fast, simple, and reliable analytical method for determining SIR levels in whole blood samples is proposed. Sample preparation based on dispersive liquid-liquid microextraction (DLLME) followed by liquid chromatography-mass spectrometry (LC-MS/MS) was fully optimized toward the analysis of SIR and proposed as a fast, simple, and reliable analytical method for determining the pharmacokinetic profile of SIR in whole-blood samples. In addition, the practical applicability of the proposed DLLME-LC-MS/MS method was evaluated by analyzing the pharmacokinetic profile of SIR in whole blood samples obtained from two pediatric patients suffering from lymphatic anomalies, receiving this drug as off-label clinical indication. The proposed methodology can be successfully applied in routine clinical practice for the fast and precise assessment of SIR levels in biological samples, thus allowing SIR dosages to be adjusted in real time during pharmacotherapy. Moreover, the measured SIR levels in the patients indicate the need for monitoring between doses to ensure the optimal pharmacotherapy of patients.

Retroperitoneal kaposiform hemangioendothelioma with kasabach-merritt phenomenon in children: A case report and review of the literature

Objective

To investigate the clinical features, diagnosis and treatment methods and prognosis of retroperitoneal Kaposiform hemangioendothelioma (R-KHE) in children.

Methods

The clinical data of an infant with R-KHE was retrospectively analyzed. Literature on R-KHE in pediatrics were retrieved in databases including Wanfang, CNKI and PubMed as of April 2022.

Results

A 1 month and 6 days female infant with R-KHE was reported. After the diagnosis was confirmed by biopsy and pathological examination, the patient was treated by interventional embolization, and a combined therapy with glucocorticoid, vincristine, sirolimus and propranolol. The patient has been followed up for 1 year and 2 months, and is still alive with tumor. Through literature search, a total of 15 children, together with the case in our report, were included. The main manifestations were diversity among those patients. 14 cases have combined Kasabach-Merritt phenomenon (KMP). 6 cases accepted surgery plus drug therapy. 4 cases accepted only surgery, and 4 cases only accepted drug therapy. While drug therapy plus radiotherapy were employed to 1 case. Improvement was observed in 11 cases, with significantly reduced tumor and survival with tumor. Tumor disappeared completely in 2 cases. While 2 cases suffered death.

Conclusion

R-KHE has diverse clinical presentations and non-specificity in symptoms and imaging examinations, and most cases accompanied with KMP. Methods for R-KHE treatment include surgical resection, interventional embolization and drug therapy. Close attention needs to be paid to the adverse reactions of the drug during the course of treatment.