Pediatric Cancer Drug Development: Leveraging Insights in Cancer Biology and the Evolving Regulatory Landscape to Address Challenges and Guide Further Progress.

The discovery and development of anticancer drugs for pediatric patients have historically languished when compared to both past and recent activity in drug development for adult patients, notably the dramatic spike of targeted and immune-oncology therapies. The reasons for this difference are multifactorial. Recent changes in the regulatory landscape surrounding pediatric cancer drug development and the understanding that some pediatric cancers are driven by genetic perturbations that also drive disparate adult cancers afford new opportunities. The unique cancer-initiating events and dependencies of many pediatric cancers, however, require additional pediatric-specific strategies. Research efforts to unravel the underlying biology of pediatric cancers, innovative clinical trial designs, model-informed drug development, extrapolation from adult data, addressing the unique considerations in pediatric patients, and use of pediatric appropriate formulations, should all be considered for efficient development and dosage optimization of anticancer drugs for pediatric patients.

FDA Approval Summary: Dabrafenib in Combination with Trametinib for BRAFV600E Mutation-Positive Low-Grade Glioma.

On March 16, 2023, the FDA approved dabrafenib in combination with trametinib (Tafinlar, Mekinist; Novartis Pharmaceuticals Corporation) for the treatment of pediatric patients with low-grade glioma (LGG) with a BRAFV600E mutation who require systemic therapy. FDA also approved oral formulations of both drugs suitable for patients who cannot swallow pills. This approval was based on the LGG cohort from study CDRB436G2201 (NCT02684058), a multicenter, open-label trial in which pediatric patients with LGG with a BRAFV600E mutation were randomly assigned 2:1 to dabrafenib plus trametinib (D+T) or carboplatin plus vincristine (C+V). The overall response rate (ORR) by independent review based on Response Assessment in Neuro-oncology LGG (2017) criteria was assessed in 110 patients randomly assigned to D+T (n = 73) or C+V (n = 37). ORR was 47% [95% confidence interval (CI), 35-59] in the D+T arm and 11% (95% CI, 3.0-25) in the C+V arm. Duration of response (DOR) was 23.7 months (95% CI, 14.5-NE) in the D+T arm and not estimable (95% CI, 6.6- NE) in the C+V arm. Progression-free survival (PFS) was 20.1 months (95% CI: 12.8, NE) and 7.4 months (95% CI, 3.6- 11.8) [HR, 0.31 (95% CI, 0.17-0.55); P < 0.001] in the D+T and C+V arms, respectively. The most common (>20%) adverse reactions were pyrexia, rash, headache, vomiting, musculoskeletal pain, fatigue, diarrhea, dry skin, nausea, hemorrhage, abdominal pain, and dermatitis acneiform. This represents the first FDA approval of a systemic therapy for the first-line treatment of pediatric patients with LGG with a BRAFV600E mutation.

FDA Approval Summary: Selumetinib for Plexiform Neurofibroma.

On April 10, 2020, the FDA approved selumetinib (KOSELUGO, AstraZeneca) for the treatment of pediatric patients 2 years of age and older with neurofibromatosis type 1 who have symptomatic, inoperable plexiform neurofibromas. Approval was based on demonstration of a durable overall response rate per Response Evaluation in Neurofibromatosis and Schwannomatosis criteria and supported by observed clinical improvements in plexiform neurofibroma-related symptoms and functional impairments in 50 pediatric patients with inoperable plexiform neurofibromas in a single-arm, multicenter trial. The overall reponse rate per NCI investigator assessment was 66% (95% confidence interval, 51-79) with at least 12 months of follow-up. The median duration of response was not reached, and 82% of responding patients experienced duration of response ≥12 months. Clinical outcome assessment endpoints provided supportive efficacy data. Risks of selumetinib are consistent with MAPK (MEK) inhibitor class effects, including ocular, cardiac, musculoskeletal, gastrointestinal, and dermatologic toxicities. Safety was assessed across a pooled database of 74 pediatric patients with plexiform neurofibromas and supported by adult and pediatric selumetinib clinical trial data in cancer indications. The benefit-risk assessment for selumetinib in patients with inoperable plexiform neurofibromas was considered favorable.

FDA Oncology Center of Excellence Project Renewal: Engaging the Oncology Community to Update Product Labeling for Older Oncology Drugs.

The FDA conducts independent reviews of scientific data obtained with investigational drug products to ensure that they are safe and effective. As a result of this process, FDA-approved product labeling is generated that is considered one of the most trusted sources of information for use of an approved drug. But FDA approval is only the beginning of the life cycle of a new drug; the first oncology drugs now have more than 7 decades of clinical experience in the postmarketing setting. Due, in part, to lack of incentives, some companies may not seek inclusion of new data, other than new safety information, in FDA-approved product labeling. Ensuring that product labeling provides adequate directions for use is important for all drugs, including older therapies that may form the backbone of many standard combination regimens for pediatric and adult cancers. Project Renewal is an FDA Oncology Center of Excellence pilot program that leverages expertise from the clinical and scientific oncology communities to review published literature and generate a drug-specific product report summarizing data that may support updates to FDA-approved product labeling. This article provides a broad overview of Project Renewal's collaborative pilot process for identifying and assessing literature supporting potential labeling updates, while engaging the oncology community to increase awareness of FDA's evidentiary standards and deliberative processes used when considering the addition of new indications and dosing regimens to product labeling.

FDA Approval Summary: (Daunorubicin and Cytarabine) Liposome for Injection for the Treatment of Adults with High-Risk Acute Myeloid Leukemia.

On August 3, 2017, the FDA granted regular approval to Vyxeos (also known as CPX-351; Jazz Pharmaceuticals), a liposomal formulation of daunorubicin and cytarabine in a fixed combination, for the treatment of adults with newly diagnosed therapy-related acute myeloid leukemia (t-AML) or acute myeloid leukemia (AML) with myelodysplasia-related changes (AML-MRC). Approval was based on data from Study CLTR0310-301, a randomized, multicenter, open-label, active-controlled trial comparing Vyxeos with a standard combination of daunorubicin and cytarabine ("7+3") in 309 patients 60-75 years of age with newly diagnosed t-AML or AML-MRC. Because of elemental copper concerns with the Vyxeos formulation, patients with Wilson disease were excluded from the study. Vyxeos demonstrated an improvement in overall survival (HR 0.69; 95% confidence interval, 0.52-0.90; P = 0.005) with an estimated median overall survival of 9.6 months compared with 5.9 months for the "7+3" control arm. The toxicity profile of Vyxeos was similar to that seen with standard "7+3" with the exception of more prolonged neutropenia and thrombocytopenia on the Vyxeos arm. Because the pharmacology of Vyxeos differs from that of other formulations of daunorubicin and cytarabine, labeling includes a warning against interchanging formulations during treatment. This is the first FDA-approved treatment specifically for patients with t-AML or AML-MRC.

FDA Approval Summary: Tocilizumab for Treatment of Chimeric Antigen Receptor T Cell-Induced Severe or Life-Threatening Cytokine Release Syndrome.

On August 30, 2017, the U.S. Food and Drug Administration approved Actemra (tocilizumab, Genentech, Inc., South San Francisco, CA) for the treatment of severe or life-threatening chimeric antigen receptor (CAR) T cell-induced cytokine release syndrome (CRS) in adults and in pediatric patients 2 years of age and older. The approval was based on a retrospective analysis of data for patients who developed CRS after treatment with CTL019 and KTE-C19 on prospective clinical trials. Evaluable patients had been treated with intravenous tocilizumab 8 mg/kg (12 mg/kg for patients <30 kg) for severe or life-threatening CRS; only the first episode of CRS was included in the analysis. The efficacy population for the CTL019 cohort included 24 male and 21 female patients (total 45 patients) of median age 12 years. The median time from the start of CRS to the first dose of tocilizumab was 4 days (range, 0-18 days). Patients were considered responders if CRS resolved within 14 days of the first dose of tocilizumab, if no more than 2 doses of tocilizumab were needed, and if no drugs other than tocilizumab and corticosteroids were used for treatment. Thirty-one patients (69%; 95% confidence interval, 53%-82%) achieved a response as defined. In an independent cohort of 15 patients with KTE-C19-induced CRS, 53% responded. Further study is needed to determine the optimal dose of tocilizumab and to confirm the safety of its use for treatment of patients with CAR T cell-induced CRS. IMPLICATIONS FOR PRACTICE: Severe or life-threatening chimeric antigen receptor (CAR) T cell-induced cytokine release syndrome (CRS) requires urgent treatment to prevent fatal outcomes. In two independent cohorts, the majority of patients with severe or life-threatening CAR T cell-induced CRS responded to treatment with one or two doses of tocilizumab in addition to advanced supportive care. More research is needed to determine the optimal dose and schedule of tocilizumab for treatment of CAR T cell-induced CRS.

Epigenetics and oncology.

Epigenetic modifications play a critical role in the development of pediatric and adult cancers, contributing to the cumulative changes observed as normal cells undergo malignant transformation. These modifications have been studied to develop epigenome-targeted therapies and new diagnostic tools. The U.S. Food and Drug Administration has approved four epigenome-targeted anticancer drugs. Two are drugs that inhibit DNA methyltransferases: azacitidine and decitabine, and two are drugs that inhibit histone deacetylases: vorinostat and romidepsin. These initial successes demonstrate the potential effectiveness of epigenome-targeted therapies as monotherapy in hematologic malignancies, but newer studies are focused on combination therapy in many cancers. Epigenetic modifications have also been used to evaluate potential biomarkers to diagnose patients with cancer, identify patient populations likely to respond to specific anticancer therapies, and select reasonable dosages for investigational anticancer drugs, as observed with other newer targeted anticancer drugs. Although much has been learned about the relationship between the epigenome and cancer, many questions remain unanswered at this time. The next step is to continue to translate emerging epigenetic knowledge into anticancer drug development. In this review, we discuss the role of epigenetic modifications in the development of cancer and anticancer drug resistance, and we describe the progress and challenges associated with developing epigenome-targeted anticancer drugs and diagnostic tools that identify epigenetic modifications.

Desired professional development pathways for clinical pharmacists.

The 2012 American College of Clinical Pharmacy (ACCP) Certification Affairs Committee was charged with developing guidelines for the desired professional development pathways for clinical pharmacists. This document summarizes recommendations for postgraduate education and training for graduates of U.S. schools and colleges of pharmacy and describes the preferred pathways for achieving, demonstrating, and maintaining competence as clinical pharmacists. After initial licensure within the state or jurisdiction in which the pharmacist intends to practice, completion of an accredited PGY1 pharmacy residency is recommended to further develop the knowledge and skills needed to optimize medication therapy outcomes. An accredited PGY2 pharmacy residency should be completed if a pharmacist wishes to seek employment in a specific therapeutic area or practice setting, if such a residency exists. Clinical pharmacists intending to conduct advanced research that is competitive for federal funding are encouraged to complete a fellowship or graduate education. Initial certification by the Board of Pharmacy Specialties (BPS) or other appropriate sponsoring organizations should be completed in the desired primary therapeutic area or practice setting within 2 years after accepting a position within the desired specific therapeutic area or practice setting. Clinical pharmacists subsequently will need to meet the requirements to maintain pharmacist licensure and board certification. Traineeships, practice-based activities, and certificate programs can be used to obtain additional knowledge and skills that support professional growth. Pharmacists are strongly encouraged to adopt a lifelong, systematic process for professional development and work with ACCP and other professional organizations to facilitate the development and implementation of innovative strategies to assess core practice competencies.

Transfusions increase with nationally driven reimbursement changes of erythropoiesis stimulating agents for chemotherapy-induced anemia.

BACKGROUND: The Centers for Medicare and Medicaid Services (CMS) issued a national coverage determination (NCD) in July 2007, which imposed restrictions on the reimbursement of ESAs for Medicare and Medicaid beneficiaries. Since a majority of our patients are Medicare or Medicaid beneficiaries, we changed our clinical practice regarding the use of erythropoiesis stimulating agents (ESAs) to coincide with the NCD's reimbursement restriction. OBJECTIVE: To evaluate the number of transfusions in patients diagnosed with chemotherapy-induced anemia (CIA) receiving ESAs before and after the clinical practice was changed at the University of Illinois Medical Center (UIMC). METHODS: The medical records of all adult patients diagnosed with a nonmyeloid malignancy and CIA who received an ESA between July 2006 and June 2008 at the UIMC were evaluated. The patients were divided into two groups: patients in receipt of ESAs BEFORE (group 1) and AFTER (group 2). The number of transfusions, the response rates to chemotherapy and ESAs therapy, and overall survival were compared. RESULTS: Medical records for 110 patients were reviewed. More transfusions were given to patients AFTER we implemented the change in clinical practice (BEFORE 18 transfusions vs. AFTER 52 transfusions, p = 0.004). More patients responded to ESA therapy AFTER we implemented the change (67% vs. 83%, p = NS). The treatment response to chemotherapy and overall survival were similar between the two groups. CONCLUSION: The primary goal of reducing the number of transfusions in patients with CIA by administering ESAs cannot be met when clinical practice coincides with the NCD.

Effects of oral clotrimazole troches on the pharmacokinetics of oral and intravenous midazolam.

AIMS: The aim of the study was to determine the effects of oral clotrimazole troches on the pharmacokinetics of oral and intravenous midazolam in the plasma. METHODS: We conducted a randomized, open-label, four-way crossover study in 10 healthy volunteers. Each volunteer received oral midazolam 2 mg or intravenous midazolam 0.025 mg kg(-1) with and without oral clotrimazole troches 10 mg taken three times daily for 5 days. Each study period was separated by 14 days. Serial blood samples were collected up to 24 h after oral midazolam and 6 h after intravenous midazolam. Plasma concentrations for midazolam and its metabolite 1-hydroxymidazolam were measured and fitted to a noncompartmental model to estimate the pharmacokinetic parameters. RESULTS: Ten healthy volunteers aged 21-26 years provided written informed consent and were enrolled into the study. Clotrimazole decreased the apparent oral clearance of midazolam from 57 +/- 13 l h(-1)[95% confidence interval 48, 66] to 36 +/- 9.8 l h(-1) (95% confidence interval 29, 43) (P= 0.003). These changes were accompanied by a decrease in the area under the concentration-time curve (mean difference 22 microg h(-1) l(-1), P= 0.001) and bioavailability (mean difference 0.21, P= NS). There were no significant differences in the systemic clearance of midazolam with or without clotrimazole troches. CONCLUSIONS: Oral clotrimazole troches decreased the apparent oral clearance of midazolam; no significant differences in the systemic clearance of midazolam were found.

The interactions of anti-cancer drugs approved in the last decade in the United States with membrane transporters.

Membrane transporters play a role in determining the absorption, distribution, metabolism and excretion of small molecule anticancer drugs and mediating chemosensitivity and resistance of tumor cells to these drugs. Our understanding of the influence of these transporters on the pharmacokinetics, clinical effectiveness and tolerability has considerably increased in the last decade. Therefore, determining the interaction of membrane transporters with small molecule anticancer drugs can facilitate the development of effective and safe treatments. We reviewed the interaction of the small molecule anticancer drugs approved in the last decade with the more common membranes transporters, such as ABCB1, ABCG2, and OATP. The drugs were divided into three categories: targeted therapies, cytotoxic agents and hormonal therapies. The literature appears to focus on the interaction of the targeted therapies compared to the remaining two categories. Furthermore, most data stemmed from nonclinical studies with only a few clinical examples where transporters corresponded with systemic exposure or clinical effectiveness or tolerability. More nonclinical and clinical studies are needed to improve the ability to use the findings from these nonclinical studies to predict clinical outcomes, but the literature appears to be rapidly expanding as our understanding of these transporters groups. Therefore, determining the interaction of membrane transporters with small molecule anticancer drugs can be facilitate the development of effective and safe treatment.

Drug-botanical interactions: a review of the laboratory, animal, and human data for 8 common botanicals.

Many Americans use complementary and alternative medicine (CAM) to prevent or alleviate common illnesses, and these medicines are commonly used by individuals with cancer.These medicines or botanicals share the same metabolic and transport proteins, including cytochrome P450 enzymes (CYP), glucuronosyltransferases (UGTs), and P-glycoprotein (Pgp), with over-the-counter and prescription medicines increasing the likelihood of drug-botanical interactions.This review provides a brief description of the different proteins, such as CYPs, UGTs, and Pgp.The potential effects of drug-botanical interactions on the pharmacokinetics and pharmacodynamics of the drug or botanical and a summary of the more common models used to study drug metabolism are described.The remaining portion of this review summarizes the data extracted from several laboratory, animal, and clinical studies that describe the metabolism, transport, and potential interactions of 8 selected botanicals. The 8 botanicals include black cohosh, Echinacea, garlic, Gingko biloba, green tea, kava, milk thistle, and St John's wort; these botanicals are among some of the more common botanicals taken by individuals with cancer.These examples are included to demonstrate how to interpret the different studies and how to use these data to predict the likelihood of a clinically significant drug-botanical interaction.

Paclitaxel alters the expression and specific activity of deoxycytidine kinase and cytidine deaminase in non-small cell lung cancer cell lines.

BACKGROUND: We observed that paclitaxel altered the pharmacokinetic properties of gemcitabine in patients with non-small cell lung cancer (NSCLC) and limited the accumulation of gemcitabine and its metabolites in various primary and immortalized human cells. Therefore, we classified the drug-drug interaction and the effects of paclitaxel on deoxycytidine kinase (dCK) and cytidine deaminase (CDA) in three NSCLC cell lines. These enzymes are responsible for the metabolism of gemcitabine to its deaminated metabolite dFdU (80% of the parent drug) and the phosphorylated metabolites dFdCMP, dFdCDP and dFdCTP. These metabolites appear to relate to sensitivity and tolerability of gemcitabine based on previous animal and laboratory studies. METHODS: Three immortalized human cells representative of the most common histological subtypes identified in patients with advanced NSCLC were exposed to the individual drugs or combinations to complete a multiple drug effect analysis. These same cell lines were exposed to vehicle-control or paclitaxel and the mRNA levels, protein expression and specific activity of dCK and CDA were compared. Comparisons were made using a two-tailed paired t-test or analysis of variance with a P value of < 0.05 considered significant. RESULTS: The multiple drug effect analysis indicated synergy for H460, H520 and H838 cells independent of sequence. As anticipated, paclitaxel-gemcitabine increased the number of G2/M cells, whereas gemcitabine-paclitaxel increased the number of G0/G1 or S cells. Paclitaxel significantly decreased dCK and CDA mRNA levels in H460 and H520 cells (40% to 60%, P < 0.05) and lowered dCK protein (24% to 56%, P < 0.05) without affecting CDA protein. However, paclitaxel increased both dCK (10% to 50%) and CDA (75% to 153%) activity (P < 0.05). Paclitaxel caused substantial declines in the accumulation of the deaminated and phosphorylated metabolites in H520 cells (P < 0.05); the metabolites were not measurable in the remaining two cell lines. The ratio of dCK to CDA mRNA levels corresponded to the combination index (CI) estimated for sequential paclitaxel-gemcitabine. CONCLUSION: In summary, paclitaxel altered the mRNA levels and specific activity of dCK and CDA and these effects could be dependent on histological subtype. More cell and animal studies are needed to further characterize the relationship between mRNA levels and the overall drug-drug interaction and the potential to use histological subtype as a predictive factor in the selection of an appropriate anticancer drug regimen.

Understanding and managing the possible adverse effects associated with bevacizumab.

PURPOSE: The adverse events associated with bevacizumab therapy are characterized, and the underlying pathophysiology, risk factors, frequency, and management of these events are described. SUMMARY: The adverse events associated with bevacizumab include hypertension, proteinuria, thromboembolism, impaired wound healing, bleeding, perforation, reversible leukoencephalopathy syndrome, skin rash, and infusion-related hypersensitivity reactions. Patients should be monitored for these events throughout the course of bevacizumab therapy. Hypertension is by far the most common adverse event associated with bevacizumab. Blood pressure should be routinely monitored, and hypertension should be medically managed with antihypertensive drugs as deemed appropriate during bevacizumab therapy. Patients should be monitored for proteinuria every three to four weeks, and bevacizumab should be discontinued with persistent proteinuria of >2+. Thromboembolic events, impaired wound healing, bowel and nasal septum perforation, and bleeding share similar pathophysiology. Thromboembolic events should be managed in accordance with guidelines established by the American College of Chest Physicians, and bevacizumab should be discontinued for new life-threatening venous or arterial thromboembolism. To minimize the risk of bleeding or impaired wound healing, bevacizumab should be started at least four weeks after surgery or discontinued for at least six to eight weeks before elective surgery. The management of other adverse events is more anecdotal, with relatively few reports of their occurrence with bevacizumab. CONCLUSION: Many of the potential serious complications of bevacizumab can be averted by close monitoring of patient-specific variables, which should be measured at baseline and then at predetermined intervals throughout the course of therapy to maximize patient safety.

The pharmacokinetics of codeine and its metabolites in Blacks with sickle cell disease.

PURPOSE: We conducted a prospective, open-label study in 54 adult subjects with sickle cell disease to determine the relationship between morphine concentrations, cytochrome P450 (CYP) 2D6 genotype, and clinical outcomes. METHODS: A blood sample was obtained for genotyping and serial blood samples were drawn to measure codeine and its metabolites in the plasma before and after oral codeine sulfate 30 mg. Codeine and its metabolites were measured by liquid chromatography-tandem mass spectrometry (LC-MS). CYP2D6 genetic testing included four single nucleotide polymorphisms (SNP) indicative of three variant alleles: *17 (1023T); *29 (1659A, 3183A); and *41 (2988A) alleles. RESULTS: Thirty subjects (group I) had a mean (standard deviation) maximal morphine concentration of 2.0 (1.0) ng/ml. Morphine was not measurable in the remaining 24 subjects (group II). Nine (30%) subjects in group I and 11 (46%) subjects in group II carried a variant *17, *29, or *41 allele (p = 0.23); one (3%) subject in group I and 5 (21%) subjects in group II were homozygous for *17 or *29 allele (p = 0.07). Emergency room visits (group I 1.5 +/- 1.8 vs. group II 2.1 +/- 4.3, p = NS) did not differ based on metabolic status, but more hospital admissions (0.9 +/- 1.4 vs. 2.2 +/- 4.1, p = 0.05) were documented in patients with no measurable morphine concentrations. CONCLUSIONS: We conclude that Blacks with sickle cell disease without measurable plasma morphine levels after a single dose of codeine were not more likely to be a carrier of a single variant allele commonly associated with reduced CYP2D6 metabolic capacity; however, homozygosity for a variant CYP2D6 allele may result in reduced metabolic capacity. Furthermore, it appears that subjects without measurable morphine concentrations were more likely to be admitted to the hospital for an acute pain crisis.

Influence of cyclooxygenase-1 genotype on ex vivo aspirin response in patients at risk for stroke.

BACKGROUND: We sought to determine whether cyclooxygenase-1 (PTGS1) genotype is associated with the ability of aspirin to inhibit platelet aggregation in patients at risk for stroke. METHODS: Blood and urine samples were collected from 60 subjects, including 28 African Americans, who were taking aspirin for primary or secondary stroke prevention. Samples were analyzed for the PTGS1 A-707G, PTGS1 P17L, and glycoprotein IIIa (ITGB3)P1(A1/A2) genotypes, ex-vivo platelet aggregation, serum cholesterol, plasma salicylate levels, and urinary 11-dehydrothromboxane B(2) (11-dhTxB(2)) concentrations. The association between PTGS1 A-707G and P17L genotypes and aspirin response, as assessed by ex vivo studies and 11-dhTxB(2) concentrations, was evaluated by statistical testing and nonlinear mapping. RESULTS: Salicylate concentrations, ITGB3 genotype distribution and 11-dhTxB(2) concentrations were similar among PTGS1 genotype groups. More subjects with the PTGS1 17PP versus PL genotype had incomplete ex-vivo inhibition of platelet aggregation by aspirin (57 vs. 20%; p = 0.04). Fifty-nine percent of subjects homozygous for both the PTGS -707A and 17P alleles, but none with both the PTGS1 -707G and 17L alleles had incomplete inhibition with aspirin; p = 0.04. Similarly, nonlinear mapping showed a direct relationship between the PTGS1 17P allele and decreased aspirin response. When analyzed separately by ethnicity, the association with the P17L genotype and aspirin response persisted in African Americans, but not Caucasians. CONCLUSIONS: Our data suggest that the PTGS1 P17L genotype contributes to response to aspirin as assessed by ex-vivo platelet aggregation. Our data further suggest that the association between PTGS1 genotype and aspirin response might vary by ethnicity.