Working memory and school readiness in preschool children with sickle cell disease compared to demographically matched controls.

Children diagnosed with sickle cell disease (SCD) are at risk of the development of neurobehavioural problems early in life. Specific impairments in executive function skills, including working memory, have been documented in school-aged children with SCD. These executive skills are known to strongly contribute to early academic skills and preparedness for entering kindergarten. This study examined working memory and school readiness in preschool children with SCD compared to a healthy control group matched for race, sex and parent education. A total of 84 patients diagnosed with SCD (61.9% haemoglobin [Hb]SS/HbSß0 -thalassaemia) and 168 controls completed testing. The mean (SD) ages of patients and controls at testing were 4.53 (0.38) and 4.44 (0.65) years respectively. The SCD group performed worse than controls on measures of executive function, working memory and school readiness (p < 0.01; Cohen's D range: 0.32-0.39). Measures of working memory were associated with school readiness after accounting for early adaptive development. Multiple linear regression models among patients diagnosed with SCD revealed that college education of the primary caregiver was positively associated with school readiness (p < 0.001) after controlling for sex, genotype, age and early adaptive development. These results highlight the need to implement school readiness interventions in young children diagnosed with SCD emphasising executive function skills.

Examining the influence of pain and fatigue on neurocognitive functioning in adolescents and young adults with sickle cell disease.

Pain and fatigue are among the most common and impactful complications of sickle cell disease (SCD). Individuals with SCD are also more likely to have neurocognitive deficits. Previous studies have suggested that pain and fatigue might influence neurocognitive functioning in patients with SCD. However, these studies are limited by small sample sizes and inadequate measurement of cognitive performance. The present study aimed to investigate the relationship between pain and fatigue with neurocognitive functioning using performance-based measures of neurocognition. Pain and fatigue were not associated with neurocognitive performance. Implications and directions for future research are discussed.

Recent Use of Pediatric Extrapolation in Pediatric Drug Development in US.

The regulatory standards of the United States Food and Drug Administration (FDA) require substantial evidence of effectiveness from adequate and well-controlled trials, for drugs developed in both adults and children. However, when scientifically justified, relying on extrapolation may be acceptable. Historically, the FDA's extrapolation approach was based on draft guidance published in 2014, which introduced the categories of full, partial, and no extrapolation. The European Medicines Agency (EMA) took a different view on pediatric extrapolation. To better understand the use of extrapolation to support pediatric drug development and approval, we reviewed the pediatric labeling changes published by the FDA, focusing on the labeling updates between 1/1/2015 and 7/31/2021, the period where the extrapolation approach is in transition to harmonize with the EMA. Within this time window, among the 265 drugs and biological products with pediatric labeling changes, 169 (63.8%) were identified where extrapolation was used. This includes 64 (24.2%) labeling changes, where full extrapolation was used, and 105 (39.6%) labeling changes, where partial extrapolation was used. The major disease areas that extrapolation was used include neuroscience (40/53, 75.5%) and infectious disease (20/28, 71.4%). The extrapolation approach was identified in terms of source population beyond the use of adult as well as extrapolation from clinical trials conducted in the same drug class. The use of extrapolation increased the rates of new and expanded pediatric indication in the period. This review gives the most recent landscape of pediatric labeling changes using extrapolation. With the released ICH (International Council for Harmonization) E11A guidance in April 2022, the paper also provides insights for future pediatric drug development programs.

A novel isoform of hydroxyacyl-CoA dehydrogenase inhibits cell proliferation.

Hydroxyacyl-CoA dehydrogenase (HADH) catalyzes the third reaction of mitochondrial ß-oxidation cascade, while the regulation of its expression and function remains to be elucidated. Using the quantitative translation initiation sequencing (QTI-seq), we have identified that murine Hadh mRNA has two alternative translation start codons. We demonstrated that translation from upstream start codon encodes the mitochondrial isoform of HADH, while translation from downstream start codon produces a short isoform (HADH-S) with predominant nuclear localization. Moreover, overexpression of HADH-S inhibits the proliferation of mouse embryonic fibroblasts. Overall, our results identify a novel isoform of HADH participating in cell proliferation.

Radiotherapy alone for pediatric patients with craniopharyngioma.

PURPOSE: Radiotherapy alone, without tumor-directed surgery, may be appropriate for selected patients with craniopharyngioma reducing the risks associated with neurosurgery. Understanding outcomes for patients with craniopharyngioma treated with radiotherapy alone will further refine patient selection and treatment options. METHODS: Since 2002, 13 children, adolescents and young adults, with craniopharyngioma were treated with radiotherapy alone and followed for disease control and functional outcomes at a single institution. The median age at treatment was 13 years (range, 3-21 years). All patients received 54 Gy/54 Gy(RBE) in 30 fractions. Five patients were treated with intensity-modulated photon therapy, four with passively scattered proton therapy, and four with intensity-modulated proton therapy. RESULTS: With a median follow-up of 5 years (range 3 months-14 years), all patients were alive. One experienced tumor progression 8.5 years after treatment. No significant changes in vision, hearing or neurologic function attributed to radiotherapy. Hormone deficiencies and body mass index were within the expected range at baseline and 5 years after treatment. There was no evidence of cognitive decline based on assessment of IQ, memory and attention. Unexpected complications included single cases of out-of-field malignancy, white matter changes, large vessel narrowing, and pontine capillary telangiectasia. Six patients had sphenoid bone abnormalities on follow-up imaging attributed to radiotherapy. CONCLUSION: Radiotherapy alone is an important treatment option to consider when radical resection is contraindicated, or surgical intervention is not required to alleviate symptoms. Disease control and functional outcomes are excellent after radiation therapy alone in appropriately selected patients.

Light Therapy for QoL/Depression in AYA With Cancer: A Randomized Trial.

OBJECTIVE: Secondary outcomes from a published feasibility and acceptability trial were examined to explore the effect of bright white light (BWL) on quality of life (QoL) and depressive symptoms compared to dim red light (DRL) control in adolescents and young adults (AYAs) receiving cancer-directed therapy. METHODS: Fifty-one AYAs (12-22 years, 51% male) newly diagnosed with cancer were randomized to receive 8 weeks of BWL (n = 26) or DRL (n = 25). The CDI-2 (total score, negative mood/physical symptoms, interpersonal problems, ineffectiveness, and negative self-esteem) and parent- and self-report PedsQL (total score and subscales of physical, emotional, social, and school QoL) were completed at multiple timepoints. RESULTS: BWL produced improvements in self-reported total depression (d = -.64; 95% confidence interval [CI] = -1.26, -0.01), negative self-esteem (d = -.80; 95% CI = -1.43, -.14), negative mood/physical symptoms (d = -.73; 95% CI = -1.36, -0.08), ineffectiveness (d = -.43; 95% CI = -1.04, .19), total self-reported QoL (d = .41; 95% CI = -.16, .96), emotional (d = .78; 95% CI = .19, 1.37), school functioning (d = .48; 95% CI = -.09, 1.04), and parent-reported school functioning (d = .66; 95% CI = 0.02, 1.33). BWL reported a greater rate of improvement than DRL for total depression (ß = .49, p < .05) and self-esteem (ß = .44, p < .05), and parent-reported school functioning (ß = -1.68, p < .05). CONCLUSIONS: BWL improved QoL and depressive symptoms for AYAs with cancer. These findings will inform larger randomized controlled trials.

Profiling of exosomal microRNAs expression in umbilical cord blood from normal and preeclampsia patients.

BACKGROUND: Epidemiological and experimental studies suggest that preeclampsia has a negative impact on maternity and offspring health. Previous studies report that dysregulation in utero-environment increases risk for elderly disease such as cardiovascular disease. However, the underlying mechanisms remain elusive. Specific microRNAs (miRNAs) are packaged in exosomes may regulate microvascular dysfunction in offspring of mothers with preeclampsia. The present study aimed to identify the differential expression profiles of microRNAs in the serum exosomes between patients with preeclampsia and normal pregnancies. METHODS: A comprehensive miRNA sequence-based approach was performed to compare exosomes carry miRNAs (Exo-miRNAs) expression levels in umbilical serum between normal and preeclampsia patients. Exosomes were isolated using the ExoQuick precipitation kit. Serum exosomes were then viewed under electron microscopy, and their characteristics determined by western blotting and nanoparticle-tracking analysis. Illumina platform was used to perform sequencing. Bioinformatics analysis was used to explore differentially expressed Exo-miRNAs in umbilical serum. RESULTS: Based on sequence similarity, 1733 known miRNAs were retrieved. Furthermore, 157 mature miRNAs in serum exosomes were significantly differential expressed between PE and those control groups (P<0.05, log2|FC| > 1). Out, of the 157 miRNAs, 96 were upregulated miRNAs whereas 61 miRNAs were downregulated. The 157 differentially expressed miRNAs targeted 51,424 differentially expressed genes. Functional analysis through KEGG pathway and Gene Ontology results uncovered that target genes of miRNAs with differential expression were significantly linked to several pathways and biological processes. CONCLUSION: The findings of this study showed differential expression of umbilical serum Exo-miRNAs in normal compared with PE patients, implying that these Exo-miRNAs may associate with microvascular dysfunction in offspring of mothers with preeclampsia.

A semi-mechanistic dose-finding design in oncology using pharmacokinetic/pharmacodynamic modeling.

While a number of phase I dose-finding designs in oncology exist, the commonly used ones are either algorithmic or empirical model-based. We propose a new framework for modeling the dose-response relationship, by systematically incorporating the pharmacokinetic (PK) data collected in the trial and the hypothesized mechanisms of the drug effects, via dynamic PK/PD modeling, as well as modeling of the relationship between a latent cumulative pharmacologic effect and a binary toxicity outcome. This modeling framework naturally incorporates the information on the impact of dose, schedule and method of administration (e.g., drug formulation and route of administration) on toxicity. The resulting design is an extension of existing designs that make use of pre-specified summary PK information (such as the area under the concentration-time curve [AUC] or maximum serum concentration [Cmax ]). Our simulation studies show, with moderate departure from the hypothesized mechanisms of the drug action, that the performance of the proposed design on average improves upon those of the common designs, including the continual reassessment method (CRM), Bayesian optimal interval (BOIN) design, modified toxicity probability interval (mTPI) method, and a design called PKLOGIT that models the effect of the AUC on toxicity. In case of considerable departure from the underlying drug effect mechanism, the performance of the design is shown to be comparable with that of the other designs. We illustrate the proposed design by applying it to the setting of a phase I trial of a γ-secretase inhibitor in metastatic or locally advanced solid tumors. We also provide R code to implement the proposed design.

Two-stage screened selection designs for randomized phase II trials with time-to-event endpoints.

Phase II exploratory multiarm studies that randomize among new treatments are found to be broadly useful and appear to be of value both scientifically and logistically, especially in the areas of unmet needs, for example, pediatric cancer. This multiarm design also has a faster recruitment rate because it provides patients with more treatment choices than traditional two-arm randomized controlled trials do. In contrast to direct formal comparisons in multiarm multistage designs, for example, umbrella or platform designs, the screened selection design (SSD) recommends using a promising treatment arm by ranking according to the effect size, which often needs lesser sample sizes than the former. In this paper, the usefulness of the phase II SSD design is exemplified by three real trials. However, the existing SSD methods can only deal with binary endpoints. Motivated by the real trials in the authors' respective institutions, we propose using the two-stage SSD and its variant for randomized phase II trials with the time-to-event endpoint. The proposed methods not only provide a high probability of selecting a superior treatment arm but also control the type I error rate for testing the efficacy of each treatment arm versus a common external control. Sample size calculations have been derived and simulation studies demonstrate desirable operating characteristics. The proposed design has been used for designing three real trials. An R package frequentistSSD has been developed and is freely accessible for practitioners.

A prospective, comprehensive registry that integrates the molecular analysis of pediatric and adolescent melanocytic lesions.

BACKGROUND: Childhood melanocytic tumors represent a diagnostic and therapeutic challenge, and additional research is needed to better define the natural history of these tumors. METHODS: The authors developed a comprehensive, prospective registry called Molecular Analysis of Childhood Melanocytic Tumors for children and adolescents with an atypical Spitz tumor/Spitz melanoma (AST/SM), conventional or adult-type melanoma (CM), melanoma arising in a giant congenital nevus (MCM), or atypical melanocytic proliferation of other types (OT) to better define the clinical behavior of these lesions by incorporating an integrated clinicopathologic and molecular analysis using centralized pathology review and various platforms, including fluorescence in situ hybridization; array comparative genomic hybridization; and whole genome, exome, and capture targeted panels. RESULTS: From May 2016 to November 2019, 70 children were enrolled with a median age at diagnosis of 9.1 years. Thirty-seven had AST/SM, 17 had CM, 4 had MCM, and 12 had OT. Patients with AST/SM were younger (median age, 7 years), and their tumor most commonly arose in the extremities and trunk. The most common gene rearrangements included MAP3K8 and ALK. None of the 33 patients who underwent a TERT promoter mutation analysis had a mutation, and all patients were alive. Among the CM patients, the median age was 13 years; 11 had a BRAFV600E mutation, and 7 had a TERT promoter mutation. Three patients died of their disease. All 4 patients with MCM harbored an NRASQ61 mutation and died of their disease. The OT group was heterogenous, and all patients survived. CONCLUSIONS: The incorporation of an integrated clinicopathologic and genomic analysis identifies distinct subgroups of pediatric melanocytic lesions that have different clinical behaviors. The integration of this combined diagnostic modality can help to individualize diagnoses and treatments for these patients.

Proteomic and functional analysis of proteins related to embryonic development of decidua in patients with recurrent pregnancy loss†.

Recurrent pregnancy loss (RPL) is defined as the loss of two or more consecutive pregnancies before the 20 weeks of gestation. RPL affects about 1-2% of couples trying to conceive; however, the mechanisms leading to this complication are largely unknown. Our previous studies using comparative proteomics identified 314 differentially expressed proteins (DEPs) in the placental villous. In this study, we identified 5479 proteins from a total of 34 157 peptides in decidua of patients with early RPL (data are available via ProteomeXchange with identifier PXD023849). Further analysis identified 311 DEPs in the decidua tissue; and 159 proteins were highly expressed, whereas 152 proteins were lowly expressed. These 311 proteins were further analyzed by using Ingenuity Pathway Analysis. The results suggested that 50 DEPs played important roles in the embryonic development. Upstream analysis of these DEPs revealed that angiotensinogen was the most important upstream regulator. Furthermore, protein-protein interaction analysis of the embryonic development DEPs from the placental villous and decidua was performed in the STRING database. This study identified several proteins specifically associated with embryonic development in decidua of patients with early RPL. Therefore, these results provide new insights into potential biological mechanisms, which may ultimately inform RPL.

iTRAQ-based quantitative proteomic analysis of thoracic aortas from adult rats born to preeclamptic dams.

BACKGROUND: Preeclampsia and gestational hypertension can cause vascular function impairment in offspring. In our previous work, we described the protein expression profiles of umbilical artery tissues from patients with preeclampsia. METHODS: To gain insights into the mechanisms of vascular dysfunction in adult rats born to preeclamptic dams, we analyzed thoracic aorta tissues by using iTRAQ isobaric tags and 2D nano LC-MS/MS. RESULTS: By using the iTRAQ method, we analyzed 1825 proteins, of which 106 showed significantly different expression in the thoracic aortic. Ingenuity pathway analysis (IPA) showed that the majority of differentially expressed proteins (DEPs) were associated with cardiovascular function. Further analysis indicated that glucose-6-phosphate dehydrogenase (G6PD), which is inhibited by miR-423-5p and activated by TP53, had the strongest effect on cardiovascular function. The expression of G6PD was upregulated in thoracic aorta tissues, as confirmed by Western blotting. The expression of two other vascular function-related proteins, cysteine- and glycine-rich protein 2 (CSRP2) and tubulin alpha-4 A (TUBA4A), was upregulated, as demonstrated by mass spectrometry (MS). CONCLUSIONS: Although the results require further functional validation, these data provide novel findings related to vascular function impairment in the adult offspring of preeclamptic mothers.

A Bayesian adaptive phase I/II platform trial design for pediatric immunotherapy trials.

Immunotherapy is the most promising new cancer treatment for various pediatric tumors and has resulted in an unprecedented surge in the number of novel immunotherapeutic treatments that need to be evaluated in clinical trials. Most phase I/II trial designs have been developed for evaluating only one candidate treatment at a time, and are thus not optimal for this task. To address these issues, we propose a Bayesian phase I/II platform trial design, which accounts for the unique features of immunotherapy, thereby allowing investigators to continuously screen a large number of immunotherapeutic treatments in an efficient and seamless manner. The elicited numerical utility is adopted to account for the risk-benefit trade-off and to quantify the desirability of the dose. During the trial, inefficacious or overly toxic treatments are adaptively dropped from the trial and the promising treatments are graduated from the trial to the next stage of development. Once an experimental treatment is dropped or graduated, the next available new treatment can be immediately added and tested. Extensive simulation studies have demonstrated the desirable operating characteristics of the proposed design.

An adaptive gBOIN design with shrinkage boundaries for phase I dose-finding trials.

BACKGROUND: With the emergence of molecularly targeted agents and immunotherapies, the landscape of phase I trials in oncology has been changed. Though these new therapeutic agents are very likely induce multiple low- or moderate-grade toxicities instead of DLT, most of the existing phase I trial designs account for the binary toxicity outcomes. Motivated by a pediatric phase I trial of solid tumor with a continuous outcome, we propose an adaptive generalized Bayesian optimal interval design with shrinkage boundaries, gBOINS, which can account for continuous, toxicity grades endpoints and regard the conventional binary endpoint as a special case. RESULT: The proposed gBOINS design enjoys convergence properties, e.g., the induced interval shrinks to the toxicity target and the recommended dose converges to the true maximum tolerated dose with increased sample size. CONCLUSION: The proposed gBOINS design is transparent and simple to implement. We show that the gBOINS design has the desirable finite property of coherence and large-sample property of consistency. Numerical studies show that the proposed gBOINS design yields good performance and is comparable with or superior to the competing design.

Feasibility and Acceptability of Light Therapy to Reduce Fatigue in Adolescents and Young Adults Receiving Cancer-Directed Therapy.

OBJECTIVE/BACKGROUND: Fatigue is one of the most consistent and distressing symptoms reported by adolescent/young adult (AYA) oncology patients. Bright white light (BWL) is used to treat fatigue in adult oncology but has not been explored in AYA oncology patients. The purpose of the current study was to determine the feasibility and acceptability of BWL for AYA who were receiving cancer-directed therapy. PARTICIPANTS: 51 AYA patients with newly diagnosed solid tumors, including lymphoma. METHODS: Participants were randomized to dim red light (DRL, n = 25) or BWL (n = 26) from devices retrofitted with adherence monitors for 30 minutes upon awakening daily for 8 weeks. Side effects were assessed via modified Systematic Assessment for Treatment-Emergent Effects (SAFTEE). Participants completed the PedsQL Multidimensional Fatigue Scale. RESULTS: Of patients approached, 73% consented and participated. Mean adherence was 57% of days on study with 30.68 average daily minutes of usage. BWL did not cause more extreme treatment-emergent effects over DRL. Patients in the BWL group demonstrated significant improvement on all fatigue outcomes by both self-report and parent proxy report, which was not observed in the DRL group. CONCLUSIONS: This is the first study to evaluate the feasibility and acceptability of light therapy to reduce fatigue in AYA patients receiving cancer-directed therapy. These findings demonstrate the feasibility and acceptability of the intervention and provide preliminary evidence of the potential benefits of BWL, which warrants further study in a confirmatory efficacy trial.ClinicalTrials.gov Identifier Number: NCT02429063.

Bayesian single-arm phase II trial designs with time-to-event endpoints.

For the cancer clinical trials with immunotherapy and molecularly targeted therapy, time-to-event endpoint is often a desired endpoint. In this paper, we present an event-driven approach for Bayesian one-stage and two-stage single-arm phase II trial designs. Two versions of Bayesian one-stage designs were proposed with executable algorithms and meanwhile, we also develop theoretical relationships between the frequentist and Bayesian designs. These findings help investigators who want to design a trial using Bayesian approach have an explicit understanding of how the frequentist properties can be achieved. Moreover, the proposed Bayesian designs using the exact posterior distributions accommodate the single-arm phase II trials with small sample sizes. We also proposed an optimal two-stage approach, which can be regarded as an extension of Simon's two-stage design with the time-to-event endpoint. Comprehensive simulations were conducted to explore the frequentist properties of the proposed Bayesian designs and an R package BayesDesign can be assessed via R CRAN for convenient use of the proposed methods.

Spinal changes after craniospinal irradiation in pediatric patients.

BACKGROUND: To evaluate long-term degenerative changes in bone and soft tissue after craniospinal irradiation (CSI). PROCEDURE: An analysis was performed for 892 vertebral bodies in 220 pediatric patients treated with CSI. To analyze vertebral growth, vertebral body height was calculated. Signal changes for vertebral bodies on MRI, scoliosis and kyphosis, degenerative changes of vertebral bones and discs, and wedging or vertebral height loss were analyzed on images, and factors that influenced these changes were investigated. RESULTS: Vertebral growth was significantly correlated with radiation dose and growth hormone (GH) deficiency. Growth rate was significantly worse at a dose >39 Gy. Fatty marrow change was found in 83% of patients, 31% had disc degenerative changes, 13% had degenerative changes of spinal bones, 17% had wedging or spinal height loss, and 27% had scoliosis. CONCLUSIONS: Vertebral bone growth was significantly reduced when high doses were administered, and adequate GH replacement was important for bone growth. Even with symmetrical irradiation, the risk of scoliosis is high after CSI. There was also frequent progression of spinal demineralization and degenerative changes after CSI. Therefore, careful attention should be paid to spinal symptoms as pediatric patients grow into adulthood.

Height after photon craniospinal irradiation in pediatric patients treated for central nervous system embryonal tumors.

BACKGROUND: We modeled height after craniospinal irradiation (CSI) in pediatric patients with central nervous system (CNS) embryonal tumors to identify factors that impair stature. PROCEDURE: During 1996-2012, 212 pediatric patients (131 male) with CNS embryonal tumors received postoperative CSI: 23.4 Gy (n = 147) or ≥36 Gy (n = 65), similar postirradiation chemotherapy, and were followed for at least 5 years without tumor progression or other event. The group was further characterized by age at CSI and hormone-replacement therapy received. Models were developed to identify factors associated with growth impairment and estimate final height. RESULTS: With median follow up of 10.2 years (range 5.0-20.4 years), the mean final height z-scores at 18 years of age, compared to United States standards, were -1.3 for female and -1.5 for male survivors. Younger age at the time of CSI, higher CSI dose, and female sex were associated with height impairment. Factors associated with higher growth rates before 15 years of age were older age at CSI, male sex, CSI dose < 36 Gy, replacement therapy for growth hormone (GH) and central adrenal insufficiency, and white race. Growth after age 15 in male survivors was associated with treatment of gonadotropin deficiency. Linear mixed-effects models were developed using clinical factors to estimate final height, demonstrate the unique growth curve of this cohort, and interactions between clinical variable and radiation dose. CONCLUSIONS: CSI significantly impaired height at current doses used to treat standard- or high-risk CNS embryonal tumors. Measures to reduce the impact of CSI on height should be sought, with our models serving as benchmarks.

Treatment-related calvarial lesions in pediatric brain tumor survivors.

BACKGROUND: Despite improved survival, many pediatric brain tumor survivors receiving radiation therapy (RT) experience late effects. PROCEDURE: To study calvarial lesions in this population, we retrospectively reviewed records of patients undergoing neurosurgical evaluation for calvarial bone lesions detected in posttreatment follow-up imaging at St. Jude Children's Research Hospital. Primary tumor diagnosis, treatment, imaging, surgical intervention, and histopathology from patients with radiographic evidence of lesions followed for ≥2 years post-RT were studied. RESULTS: For 17 patients with 18 index lesions, median time to lesion manifestation was 2.34 years. Medulloblastoma patients developed lesions at a shorter interval from RT than ependymoma patients (P = .05). Twelve of 14 lesions requiring surgery were benign fibro-osseous or sclerotic. Two malignant lesions distinct from the primary tumor had genetic predisposition to malignancy. CONCLUSION: Most calvarial lesions arising post-RT are benign and fibro-osseous. Serial imaging is recommended, and high index of suspicion for malignant lesions is warranted for patients genetically predisposed to cancer.

Bayesian adaptive linearization method for phase I drug combination trials with dimension reduction.

Many phase I drug combination designs have been proposed to find the maximum tolerated combination (MTC). Due to the two-dimension nature of drug combination trials, these designs typically require complicated statistical modeling and estimation, which limit their use in practice. In this article, we propose an easy-to-implement Bayesian phase I combination design, called Bayesian adaptive linearization method (BALM), to simplify the dose finding for drug combination trials. BALM takes the dimension reduction approach. It selects a subset of combinations, through a procedure called linearization, to convert the two-dimensional dose matrix into a string of combinations that are fully ordered in toxicity. As a result, existing single-agent dose-finding methods can be directly used to find the MTC. In case that the selected linear path does not contain the MTC, a dose-insertion procedure is performed to add new doses whose expected toxicity rate is equal to the target toxicity rate. Our simulation studies show that the proposed BALM design performs better than competing, more complicated combination designs.