The early and rapid response to daratumumab in children with chronic refractory immune thrombocytopenia from a referral single centre of China.

Chronic refractory primary immune thrombocytopenia (CRITP) is currently defined as refractory to multiple therapeutic of second-line agents with or without splenectomy, faced with the threat of severe bleeding and challenging to obtain effective treatment. Although stable and effective drug therapy is needed, it is tough to find one. Daratumumab (Dara), an anti-CD38 monoclonal antibody presented the target cloned plasma cells in multiple myeloma, has also been reported to be effective in refractory autoimmune cytopenia in some case or series reports and ongoing clinical trials for adult patients with CRITP. Here, we report the early and durable response of Dara combination with avatrombopag in three CRITP patients (2 male and 1 female aged 12, 5 and 7 years, respectively) in our centre, with a follow-up period of more than 25 weeks. Before Dara, the duration of immune thrombocytopenia was 9, 1.4 and 4 years, respectively, a baseline platelet count of 4, 6, 9 × 109/L, the bleeding score was all above level 2 and the number of previous drugs was >3. The time to response (R: Plt ≥30 × 109/L with at least a twofold increase in the baseline count) of Dara was on Day 45, 6 and 4 and achieved complete response (CR: Plt ≥100 × 109/L) on Day 51, 6 and 8, the sustained response (SR: Plt >30 × 109/L following Dara at ≥75% of the platelet count assessment at follow-up end-point since the patient achieved response) was 48, 175 and 204 days with the follow-up time of 39.1, 25.9 and 29.7 weeks. The bleeding score decreased from grade 3 to grade 0 during follow-up. No significant treatment-related adverse events were found during follow-up. Dara combination with avatrombopag may be a safe and efficacious therapy for children with CRITP, but it needs to be further explored.

Long-term eltrombopag in children with chronic immune thrombocytopenia: A single-centre extended real-life observational study in China.

We have previously confirmed the efficacy and safety of eltrombopag (ELT) in children with chronic immune thrombocytopenia (cITP). However, data on both long-term exposure and early use of TPO-RAs are lacking, so further 'field-practice' evidence on treatment is required. Here, we report the long-term follow-up results (between September 2018 and June 2023) of our previous study. The main objective of this study was to retrospectively review our large institutional experience with ITP patients previously enrolled in our paediatric cITP study. We had more than 3 years of follow-up by June 2023 for treatment patterns and outcomes. A total of 65 patients (28 males) were enrolled, with a median age at ELT initiation of 6.34 (range 1.65, 14.13) years and a follow-up of 47.07 (36.00, 57.00) months, with 40.36 (10.53, 56.83) months of ELT therapy at the time of analysis. In total, 29.23% (19/65) of patients discontinued ELT due to stable response, and 18.46% (12/65) of patients switched to other ITP therapies due to loss of response (LOR) after 19.13 (14.53, 26.37) months. Of the 19 patients who discontinued ELT due to a stable response, 24.62% (16/65) achieved a 12 m sustained response off-treatment (SRoT); the last recorded platelet count ranged from 56 to 166 × 109 /L (median 107 × 109/L); and 4.62% (3/65) patients relapsed at 5, 6 and 9 months after discontinuation. Of the 12 patients who LOR to ELT after 19.13 (14.53, 26.37) months of therapy, four switched to avatrombopag, three switched to hetrombopag, two switched to traditional Chinese medicine (TCM), one underwent splenectomy and two received additional prednisolone under ELT treatment. Thirty-four patients who tapered and maintained a durable response. The patients with LOR and the patients with tapering were compared; the platelet count at the start of ELT is lower, and the time to response is longer in the patients with LOR. The platelet count at the start of ELT and the time to response may be the predictive factors for LOR during ELT treatment. We report more than 3 years of long-term clinical data on children with cITP using ELT. These data do not raise any new safety concerns regarding the long-term use of ELT in children with cITP.

Efficacy and safety of avatrombopag in Chinese children with persistent and chronic primary immune thrombocytopenia: A multicentre observational retrospective study in China.

Avatrombopag (AVA) is a novel thrombopoietin receptor agonist (TPO-RA) that has been recently approved as a second-line therapy for immune thrombocytopenia (ITP) in adults; however, its safety and efficacy data in children are lacking. Here, we demonstrated the efficacy and safety of AVA as second-line therapy in children with ITP. A multicentre, retrospective, observational study was conducted in children with persistent or chronic ITP who did not respond to or relapsed from previous treatment and were treated with AVA for at least 12 weeks between August 2020 and December 2022. The outcomes were the responses (defined as achieving a platelet count ≥30 × 109/L, twofold increase in platelet count from baseline and absence of bleeding), including rapid response within 4 weeks, sustained response at weeks 12 and 24, bleeding control and adverse events (AEs). Thirty-four (18 males) patients with a mean age of 6.3 (range: 1.9-15.3) years were enrolled. The median number of previous treatment types was four (range: 1-6), and 41.2% patients switched from other TPO-RAs. Within 4 weeks, overall response (OR) was achieved in 79.4% patients and complete response (CR, defined as a platelet count ≥100 × 109/L and the absence of bleeding) in 67.7% patients with a median response time of 7 (range: 1-27) days. At 12 weeks, OR was achieved in 88.2%, CR in 76.5% and sustained response in 44% of patients. At 24 weeks, 22/34 (64.7%) patients who achieved a response and were followed up for 24 weeks were evaluated; 12/22 (54.55%) achieved a sustained response. During AVA therapy, median platelet counts increased by week 1 and were maintained throughout the treatment period. The proportion of patients with grade 1-3 bleeding decreased from 52.95% at baseline to 2.94% at 12 weeks, while concomitant ITP medications decreased from 36.47% at baseline to 8.82% at 12 weeks, with only 9 (26.47%) patients receiving rescue therapy 23 times within 12 weeks. There were 61.8% patients with 59 AEs: 29.8% with Common Terminology Criteria for Adverse Events grade 1 and the rest with grade 2. These findings show that AVA could achieve a rapid and sustained response in children with persistent or chronic ITP as a second-line treatment, with good clinical bleeding control and reduction of concomitant ITP therapy, without significant AEs.

Transient increase in platelet counts associated with COVID-19 infection during TPO-RA as the second-line treatment in children with ITP.

The thrombopoietin receptor agonists (TPO-RA) were recommended for primary immune thrombocytopenia (ITP) during the pandemic of COVID-19. However, the incidence of thrombocytosis and thrombosis was sporadically reported in the chronic immune thrombocytopenia (CITP) patients receiving TPO-RA during the COVID-19 infection. With the local prevalence of COVID-19 in December 2022 in the Beijing area, we got more powerful evidence about the change in platelet (Plt) counts associated with COVID-19 infection. A single-centre observational cohort study was performed from the beginning of December 2022 to the end of February 2023 to enrol CITP children treated with TPO-RA alone as the second-line treatment and suffering from the COVID-19 infection in December 2022. The Plt counts before, during and after COVID-19 infection were collected. In total, 67 (34 males and 33 females) patients with 8.10 (2.15, 15.70) years of age were enrolled. Sixty-three patients who had responded to the TPO-RA showed a transient increase in Plt counts after the infection of COVID-19. The time of starting to increase was on Day 3 (2, 7), and to the peak level on Day 14 (7, 19) of infection with the peak Plt count was 289 (88, 1974) × 109 /L. With at least 2 months observation period from COVID-19 infection, the Plt counts of 100% (63/63) patients declined to the baseline on Day 25 (14, 41). The phenomenon of transient increase in Plt counts has been shown in the CITP children who responded to TPO-RA when suffering from COVID-19 infection.

Outcomes of switching to avatrombopag following treatment failure with eltrombopag in paediatric immune thrombocytopenia: A real-world study in China.

Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder characterized by isolated thrombocytopenia and a haemorrhagic risk. Thrombopoietin receptor agonists (TPO-RAs) are highly effective for ITP and are widely used to treat patients with steroid treatment failure or dependency. However, although treatment response to TPO-RAs may differ according to the type, the potential impact of switching from eltrombopag (ELT) to avatrombopag (AVA) with respect to efficacy or tolerance in children remains unknown. This study aimed to evaluate the outcomes of switching from ELT to AVA in paediatric patients with ITP. We retrospectively evaluated children with chronic immune thrombocytopenia (cITP) switched from ELT to AVA owing to treatment failure at the Hematology-Oncology Center of Beijing Children's Hospital between July 2021 and May 2022. Overall, 11 children (seven and four boys and girls respectively) with a median age of 8.3 (range: 3.8-15.3) years were included. The overall response and complete response (platelet [PLT] count ≥100 × 109 /L) rates during AVA treatment were 81.8% (9/11) and 54.6% (6/11) respectively. The median PLT count was significantly increased from ELT to AVA (7 [range: 2-33] × 109 /L vs. 74 [15-387] × 109 /L; p = 0.007). The median time to PLT count ≥30 × 109 /L was 18 (range: 3-120) days. Overall, 7/11 patients (63.6%) used concomitant medications, and concomitant medication use was gradually discontinued within 3-6 months after AVA initiation. In conclusion, AVA after ELT is effective in the heavily pretreated paediatric cITP population, with high response rates even in those with an inadequate response to a prior TPO-RA.

Sustained response off treatment in eltrombopag for children with persistent/chronic primary immune thrombocytopenia: A multicentre observational retrospective study in China.

Eltrombopag (ELT) is effective and safe in adult persistent/chronic immune thrombocytopenia (p/cITP); a proportion could achieve a sustained response off treatment (SRoT); however, data on children are lacking. We attempted to analyse SRoT of ELT in children with p/cITP in this study. A multicentre retrospective observational study was performed in November 2022 for children with p/cITP who used ELT alone for >2 months between January 2017 and November 2021. Clinical data of pre-, during and post-ELT were collected. SRoT was defined as maintaining a platelet count of ≥30 × 109 /L without rescue therapy for at least 6 months off ELT. There were 143 patients enrolled; 69.2% (99/143) achieved an overall response of 43.3% and 25.9% achieved complete response (CR) and response (R). Among the 35 patients analysed from whom ELT was withdrawn, 71.4% (25/35) showed SRoT after discontinuing ELT without additional ITP therapy, with a median follow-up of 0.94 (range, 0.53-3.8) years, equal to 17.5% (25/143) in all patients treated with ELT. Compared with the patients with relapse (n = 10), the SRoT patients (n = 25) had a higher rate of CR (80% [20/25] vs. 40% [4/10]), shorter interval time from initiation to taper (6.4 months vs. 9.4 months), longer time from taper to withdrawal (1.1 years vs. 0.3 years) and a longer duration of ELT treatment (1.6 years vs. 0.5 years) with p < 0.05. Patients who achieved CR could attain SRoT more easily (p = 0.02). ELT had a response in 69.2% of children with p/cITP and 17.5% of them attained SRoT with good tolerance. The patients who achieved CR and began ELT treatment as early as possible, with a longer treatment duration and slower tapering, had a higher probability of SRoT.

Spotlight on eltrombopag concentration in pediatric immune thrombocytopenia: A single-center observational study in China.

Importance: Eltrombopag has been recommended for pediatric immune thrombocytopenia (ITP). Response and adverse drug reactions (ADRs) varied widely between individuals, even at the same dose of eltrombopag. The appropriate eltrombopag concentration in ITP has not been reported. Objective: This study aims to explore the appropriate eltrombopag concentration in pediatric ITP. Methods: This was a single-center, prospective cohort study. Children diagnosed with refractory persistent/chronic ITP and platelet count < 30×109/L were treated with eltrombopag and followed up for at least 2 months. Concentration was detected by high-performance liquid chromatography-mass spectrometry at least 2 weeks after eltrombopag. The clinical characteristics-concentration, concentration-response, and concentration-ADRs were analyzed. Results: A total of 30 patients were enrolled, comprising 13 males and 17 females, with a median age of 72 (45‒94) months. The median dose and concentration were 1.39 (1.09‒1.56) mg/kg and 2.70 (2.25‒4.13) mg/L, respectively. Of the enrolled patients, 14 responded to treatment, whereas 16 did not. Additionally, five experienced adverse drug reactions. No linear correlation was observed between eltrombopag concentration and clinical characteristics. The concentration was lower in the response group than in the nonresponse group, but there was no significant difference (t = 0.755, P = 0.457). Patients who experienced ADRs had a higher concentration than those without ADRs (t = 2.538, P = 0.017). The area under the receiver operating characteristic curve of ADRs was 0.78 (95% confidence interval: 0.56‒1.00). Youden's index identified the cutoff point as 4.33 mg/L, with a sensitivity of 88% and a specificity of 60%. Logistic regression analysis demonstrated that a higher platelet count before eltrombopag predicted a favorable response. Interpretation: Eltrombopag proves efficacious and well-tolerated for treating pediatric ITP. However, prolonged and high-dose administration may increase the likelihood of ADRs. Thus, examining the appropriate eltrombopag concentration assists in directing individualized management of pediatric ITP.

Machine learning models developed and internally validated for predicting chronicity in pediatric immune thrombocytopenia.

BACKGROUND: Primary immune thrombocytopenia (ITP) in children is typically self-limiting; however, 20% to 30% of patients may experience prolonged thrombocytopenia lasting over a year. The challenge is predicting chronicity to ensure personalized treatment approaches. OBJECTIVES: To address this issue, we developed and internally validated 4 machine learning (ML) models using demographic and immunologic characteristics to predict the likelihood of chronicity. METHODS: The present study was conducted at Beijing Children's Hospital from June 2018 to December 2021, aiming to develop predictive models for determining the chronicity of pediatric ITP. Four ML models, based on a logistic regression classifier, random forest classifier, eXtreme Gradient Boosting (XGBoost), and support vector machine, were employed. These models used a set of 16 variables, including 14 immunologic and 2 demographic predictors. The performance evaluation criteria included prediction accuracy, precision, recall, F1 score, and area under the receiver operating characteristic curve (AUROC). RESULTS: Data were collected from 662 patients who were randomly assigned to either a training dataset or a testing dataset using a random number generator. Among them, 26.5% had chronic disease. All models performed well, with AUROC values ranging from 0.81 to 0.84, and XGBoost was selected for its highest AUROC score and interpretability in constructing the predictive model. Age, T helper 17, T helper 17-to-regulatory T cell ratio, T helper 1, and double-negative T cells were identified as significant predictors by the XGBoost algorithm. CONCLUSION: We developed a precise predictive model for chronicity in pediatric ITP using ML during the initial phase. The XGBoost model achieved high predictive accuracy by using individual patient clinical parameters and demonstrated commendable interpretability.

Outcome Prediction of Spontaneous Supratentorial Intracerebral Hemorrhage after Surgical Treatment Based on Non-Contrast Computed Tomography: A Multicenter Study.

This study aims to explore the value of a machine learning (ML) model based on radiomics features and clinical features in predicting the outcome of spontaneous supratentorial intracerebral hemorrhage (sICH) 90 days after surgery. A total of 348 patients with sICH underwent craniotomy evacuation of hematoma from three medical centers. One hundred and eight radiomics features were extracted from sICH lesions on baseline CT. Radiomics features were screened using 12 feature selection algorithms. Clinical features included age, gender, admission Glasgow Coma Scale (GCS), intraventricular hemorrhage (IVH), midline shift (MLS), and deep ICH. Nine ML models were constructed based on clinical feature, and clinical features + radiomics features, respectively. Grid search was performed on different combinations of feature selection and ML model for parameter tuning. The averaged receiver operating characteristics (ROC) area under curve (AUC) was calculated and the model with the largest AUC was selected. It was then tested using multicenter data. The combination of lasso regression feature selection and logistic regression model based on clinical features + radiomics features had the best performance (AUC: 0.87). The best model predicted an AUC of 0.85 (95%CI, 0.75-0.94) on the internal test set and 0.81 (95%CI, 0.64-0.99) and 0.83 (95%CI, 0.68-0.97) on the two external test sets, respectively. Twenty-two radiomics features were selected by lasso regression. The second-order feature gray level non-uniformity normalized was the most important radiomics feature. Age is the feature with the greatest contribution to prediction. The combination of clinical features and radiomics features using logistic regression models can improve the outcome prediction of patients with sICH 90 days after surgery.

Risk factors for poor outcomes of spontaneous supratentorial cerebral hemorrhage after surgery.

OBJECTIVE: This study aimed to explore the factors affecting the outcomes of spontaneous supratentorial cerebral hemorrhage 90 days after surgery. METHODS: A total of 256 patients with spontaneous supratentorial intracerebral hemorrhage underwent craniotomy evacuation of hematoma. The control group included 120 patients who received conservative treatment. The patients were divided into two subgroups based on a bifurcation of the modified Rankin Scale (mRS) 90 days after clinical therapeutics: good outcome (mRS score 0-3) and poor outcome (mRS score 4-6). The differences in clinical and imaging data between the two subgroups were analyzed. Based on difference analysis results, a binary logistic regression model was constructed to analyze the influencing factors related to poor outcomes. RESULTS: The difference analysis results in the surgery group showed statistically significant differences in age, sex, Glasgow Coma Score (GCS) on admission, coronary atherosclerosis, smoking, stroke history, blood glucose, D-dimer, hematoma size, deep cerebral hemorrhage, midline shift, hematoma burst into the ventricle, vortex sign, island sign, and black hole sign. Binary logistic regression analysis showed that deep cerebral hemorrhage, midline shift, and age > 58 years independently correlated with the poor outcomes of patients after surgery. The binary logistic regression results of the control group showed that age > 58 years and GCS ≤ 8 independently correlated with the poor outcomes of patients. CONCLUSIONS: Deep cerebral hemorrhage, midline shift, and age > 58 years significantly increased the risk of adverse prognosis in patients after surgery. The findings might help select the clinical treatment plan and evaluate the postoperative prognosis of patients.

Prediction of Progression to Severe Stroke in Initially Diagnosed Anterior Circulation Ischemic Cerebral Infarction.

Purpose: Accurate prediction of the progression to severe stroke in initially diagnosed nonsevere patients with acute-subacute anterior circulation nonlacuna ischemic infarction (ASACNLII) is important in making clinical decision. This study aimed to apply a machine learning method to predict if the initially diagnosed nonsevere patients with ASACNLII would progress to severe stroke by using diffusion-weighted images and clinical information on admission. Methods: This retrospective study enrolled 344 patients with ASACNLII from June 2017 to August 2020 on admission, and 108 cases progressed to severe stroke during hospitalization within 3-21 days. The entire data were randomized into a training set (n = 271) and an independent test set (n = 73). A U-Net neural network was employed for automatic segmentation and volume measurement of the ischemic lesions. Predictive models were developed and used for evaluating the progression to severe stroke using different feature sets (the volume data, the clinical data, and the combination) and machine learning methods (random forest, support vector machine, and logistic regression). Results: The U-Net showed high correlation with manual segmentation in terms of Dice coefficient of 0.806 and R 2 value of the volume measurements of 0.960 in the test set. The random forest classifier of the volume + clinical combination achieved the best area under the receiver operating characteristic curve of 0.8358 (95% CI 0.7321-0.9269), and the accuracy, sensitivity, and specificity were 0.7780 (0.7397-0.7945), 0.7695 (0.6102-0.9074), and 0.8686 (0.6923-1.0), respectively. The Shapley additive explanation diagram showed the volume variable as the most important predictor. Conclusion: The U-Net was fully automatic and showed a high correlation with manual segmentation. An integrated approach combining clinical variables and stroke lesion volumes that were derived from the advanced machine learning algorithms had high accuracy in predicting the progression to severe stroke in ASACNLII patients.