Targeting developmental pathways in children with cancer: what price success?

Pursuing Precision: Receptor Tyrosine Kinase Inhibitors for Treatment of Pediatric Solid Tumors

Receptor tyrosine kinases are critical for the growth and proliferation of many different cancers and therefore represent a potential vulnerability that can be therapeutically exploited with small molecule inhibitors. Over forty small molecule inhibitors are currently approved for the treatment of adult solid tumors. Their use has been more limited in pediatric solid tumors, although an increasing number of single-agent and combination studies are now being performed. These agents have been quite successful in certain clinical contexts, such as the treatment of pediatric tumors driven by kinase fusions or activating mutations. By contrast, only modest activity has been observed when inhibitors are used as single agents for solid tumors that do not have genetically defined alterations in the target genes. The absence of predictive biomarkers has limited the wider applicability of these drugs and much work remains to define the appropriate patient population and clinical situation in which receptor tyrosine kinase inhibitors are most beneficial. In this manuscript, we discuss these issues by highlighting past trials and identifying future strategies that may help add precision to the use of these agents for pediatric extracranial solid tumors.

Cutaneous reactions to pediatric cancer treatment part II: Targeted therapy

Cancer remains a leading cause of morbidity and mortality among children. Targeted therapies may improve survivorship; however, unique side-effect profiles have also emerged with these novel therapies. Changes in hair, skin, and nails-termed dermatologic adverse events (AEs)-are among the most common sequelae and may result in interruption or discontinuation of therapy. Though dermatologic AEs have been detailed in adults, these findings are not well described in the pediatric population. We reviewed the literature to characterize dermatologic AEs to anticancer targeted therapies available as of July 2020 and summarized the spectrum of clinical findings as well as treatment recommendations for children. Dermatologic AEs are among the most common AEs reported in pediatric patients receiving targeted therapy, but morphologic and histologic descriptions are often lacking in current publications. Pediatric dermatologists are uniquely poised to recognize specific morphology of dermatologic AEs and make recommendations for prevention and treatment that may improve quality of life and enable ongoing cancer therapy.

Perioperative Cardiothoracic and Vascular Risk in Childhood Cancer and its Survivors

CHILDREN with cancer and survivors of childhood cancer have an increased risk of cardiovascular disease, and this risk in the perioperative period must be understood. During diagnosis and treatment of pediatric cancer, multiple acute cardiovascular morbidities are possible, including anterior mediastinal mass, tamponade, hypertension, cardiomyopathy,and heart failure. Childhood cancer survivors reaching late childhood and adulthood experience substantially increased rates of cardiomyopathy, heart failure, valvular disease, pericardiac disease, ischemia, and arrhythmias. Despite considerable advances in the understanding and therapeutic options of pediatric malignancies, cardiac disease remains the most common treatment-related, noncancer cause of death in childhood cancer survivors. Increasingly, molecularly targeted agents, including small molecule inhibitors, are being incorporated into pediatric oncology. The acute and chronic risks associated with these newer therapeutic options in children are not yet well-described, which poses challenges for clinicians caring for these patients. In the present review, the unique risks factors, prevention strategies, and treatment of cardiovascular toxicities of the child with cancer and the childhood cancer survivor are examined, with an emphasis on the perioperative period.

Development of a Novel Series of Anticancer and Antidiabetic: Spirothiazolidines Analogs

4-(4-Aminophenyl)-1-thia-4-azaspiro[4.5]decan-3-one 1 was prepared and allowed to react with nitrogen nucleophiles to give the corresponding hydrazones 2–4. Further, compound 1 underwent diazotization and afforded the parallel hydrazono derivative 5; moreover, compound 1 refluxed with active methylene derivatives yielded the corresponding aminospirothiazolo pyridine–carbonitrile derivative 6 and spirothiazolopyridinone–carbonitrile derivative 7. Condensation of spirothiazolidine 1 with 4-chlorobenzaldehyde gave the corresponding spiro arylidiene derivative 8, which was utilized as a component of Micheal addition to react with excess of nitrogen nucleophiles to yield novel ring frameworks 4-(3′-(4-chlorophenyl)–spiro [cyclohexane-1,5′-pyrazolo[3,4-d]thiazol]-6′(1′H)-yl)aniline (9) and 4-(3′-(4-chlorophenyl)-6′H- spiro[cyclohexane-1,5′-thiazolo[5,4-d]isoxazol]-6′-yl)aniline (10). Finally, when spirothiazolo pyridinone–carbonitrile derivative 7 sodium salt generated in situ was reacted with different alkyl halides, it produced the corresponding N-derivatives 12–16. Three compounds, 6, 14, and 16, showed high significantly anticancer activities compared with Doxorubicin® (positive control) against human breast carcinoma (MCF-7) and human liver carcinoma (HepG-2) cell lines. On the other hand, compounds 6 and 9 showed higher therapeutic indices for both of alpha-amylase inhibitor and alpha-glucosidase inhibitor than the other tested compounds compared with the antidiabetic Acarbose (positive control).

Dasatinib in Pediatric Patients With Chronic Myeloid Leukemia in Chronic Phase: Results From a Phase II Trial

Purpose Safe, effective treatments are needed for pediatric patients with chronic myeloid leukemia in chronic phase (CML-CP). Dasatinib is approved for treatment of adults and children with CML-CP. A phase I study determined suitable dosing for children with Philadelphia chromosome-positive (Ph+) leukemias. Methods CA180-226/NCT00777036 is a phase II, open-label, nonrandomized prospective trial of patients < 18 years of age receiving dasatinib. There are three cohorts: (1) imatinib-resistant/intolerant CML-CP, (2) imatinib-resistant/intolerant CML in accelerated/blast phase or Ph+ acute lymphoblastic leukemia (n = 17), and (3) newly diagnosed CML-CP treated with tablets or powder for oral suspension. Major cytogenetic response > 30% for imatinib-resistant/intolerant patients and complete cytogenetic response (CCyR) > 55% for newly diagnosed patients were of clinical interest. Results Of 113 patients with CML-CP, 14 (48%) who were imatinib-resistant/intolerant and 61 (73%) who were newly diagnosed remained on treatment at time of analysis. Major cytogenetic response > 30% was reached by 3 months in the imatinib-resistant/intolerant group and CCyR > 55% was reached by 6 months in the newly diagnosed CML-CP group. CCyR and major molecular response by 12 months, respectively, were 76% and 41% in the imatinib-resistant/intolerant group and 92% and 52% in newly diagnosed CML-CP group. Progression-free survival by 48 months was 78% and 93% in the imatinib-resistant/intolerant and newly diagnosed CML-CP groups, respectively. No dasatinib-related pleural or pericardial effusion, pulmonary edema, or pulmonary arterial hypertension were reported. Bone growth and development events were reported in 4% of patients. Conclusion In the largest prospective trial to date in children with CML-CP, we demonstrate that dasatinib is a safe, effective treatment of pediatric CML-CP. Target responses to first- or second-line dasatinib were met early, and deep molecular responses were observed. Safety of dasatinib in pediatric patients was similar to that observed in adults; however, no cases of pleural or pericardial effusion or pulmonary arterial hypertension were reported.

Cell death-based treatment of childhood cancer

Any therapy that aims at eradicating a cancerous growth will have at its core a cell death-inducing component. Here we argue that paediatric oncology presents with its unique set of considerations and problems, which—while taking the lead from oncological research experiences obtained from the adult population—need to be clinically evaluated independently. This is particularly true when considering long-term side effects. Precision medicine offers a promising new approach in therapy, but given as a monotherapy and in a limited combination, as found in an apoptosis inducer/sensitiser combination, it will most likely lead to mutation escape of the target cell population and the emergence of resistance. However, using the increasing amount of the molecular data as the basis for a complex combination therapy combining several key components such as cell death-inducing agents, kinase inhibitors and BH3 mimetics, holds great promise.

Cryopreservation of Ovarian Tissue: Opportunities Beyond Fertility Preservation and a Positive View Into the Future

In current years, ovarian tissue cryopreservation (OTC) and transplantation is gaining ground as a successful method of preserving fertility in young women with primarily cancer diseases, hereby giving them a chance of becoming biological mothers later on. However, OTC preserves more than just the reproductive potential; it restores the ovarian endocrine function and thus the entire female reproductive cycle with natural levels of essential hormones. In a female population with an increased prevalence in the loss of ovarian function due to induced primary ovarian insufficiency (POI) and aging, there is now, a need to develop new treatments and provide new opportunities to utilize the enormous surplus of follicles that most females are born with and overcome major health issues associated with the lack of ovarian hormones. Cell/tissue-based hormone replacement therapy (cHRT) by the use of stored ovarian tissue could be one such option comprising both induction of puberty in prepubertal POI girls, treatment of POI and premature menopause, and as primary prevention at the onset of menopause. In the current review, we explore known and entirely new applications for the potential utilization of OTC including cHRT, social freezing, culture of immature oocytes, and a modern ovarian resection for women with polycystic ovaries, and discuss the indications hereof.

Modernizing Clinical Trial Eligibility: Recommendations of the American Society of Clinical Oncology-Friends of Cancer Research Minimum Age Working Group

Purpose Children have historically been excluded from first-in-human studies of promising new cancer drugs and later phase adult clinical trials. Delays in evaluation may result in off-label use without dosing information as the only access to new drugs. A multistakeholder workshop was convened in May 2016 by ASCO and Friends of Cancer Research to identify opportunities for when it would be scientifically appropriate to expand trial eligibility to include children younger than age 18 years in first-in-human and other adult cancer clinical trials. Methods This group convened experts from academia, government, and industry to review barriers to enrolling children and adolescents in oncology clinical trials. We evaluated the historical context, published literature, regulatory considerations, and myriad risks and benefits associated with lowering the age of enrollment on oncology clinical trials. Results We conclude that many of the historical concerns about including children early in oncology clinical trials do not apply in the current scientific and clinical environment of pediatric oncology and drug development; we provide specific recommendations for how the inclusion of children in early-phase investigational cancer drug trials might be accomplished. Automatic inclusion of pediatric patients is appropriate in early-phase trials that assess dose, safety, and pharmacokinetics in a variety of tumor types and later phase trials that assess efficacy in a specific disease that spans adult and pediatric populations. Conclusion Including children in appropriately designed adult clinical oncology trials is feasible and can be done in a way that enhances their access to these agents without compromising safety or development strategies.

A comparison of safety and efficacy of cytotoxic versus molecularly targeted drugs in pediatric phase I solid tumor oncology trials

BACKGROUND

Prior reviews of phase I pediatric oncology trials involving primarily cytotoxic agents have reported objective response rates (ORRs) and toxic death rates of 7.9-9.6% and 0.5%, respectively. These data may not reflect safety and efficacy in phase I trials of molecularly targeted (targeted) drugs.

METHODS

A systematic review of pediatric phase I solid tumor trials published in 1990-2013 was performed. The published reports were evaluated for patient characteristics, toxicity information, and response numbers.

RESULTS

A total of 143 phase I pediatric clinical trials enrolling 3,896 children involving 53 targeted and 48 cytotoxic drugs were identified. A meta-analysis demonstrated that the ORR is 2.1-fold higher with cytotoxic drugs (0.066 vs. 0.031 per subject; P = 0.007). By contrast, the pooled estimate of the stable disease rate (SDR) is similar for cytotoxic and targeted drugs (0.2 vs. 0.23 per subject; P = 0.27).  The pooled estimate of the dose-limiting toxicity rate is 1.8-fold larger with cytotoxic drugs (0.24 vs. 0.13 per subject; P = 0.0003). The hematologic grade 3-4 (G3/4) toxicity rate is 3.6-fold larger with cytotoxic drugs (0.43 vs. 0.12 per treatment course; P = 0.0001); however, the nonhematologic G3/4 toxicities and toxic deaths occur at similar rates for cytotoxic and targeted drugs.

CONCLUSIONS

In phase I pediatric solid tumor trials, ORRs were significantly higher for cytotoxic versus targeted agents. SDRs were similar in targeted and cytotoxic drug trials. Patients treated with cytotoxic agents were more likely to experience hematologic G3/4 toxicities than those patients receiving targeted drugs.

Improvements in Clinical Trials Information Will Improve the Reproductive Health and Fertility of Cancer Patients

There are a number of barriers that result in cancer patients not being referred for oncofertility care, which include knowledge about reproductive risks of antineoplastic agents. Without this information, clinicians do not always make recommendations for oncofertility care. The objective of this study was to describe the level of reproductive information and recommendations that clinicians have available in clinical trial protocols regarding oncofertility management and follow-up, and the information that patients may receive in clinical trials patient information sheets or consent forms. A literature review of the 71 antineoplastic drugs included in the 68 clinical trial protocols showed that 68% of the antineoplastic drugs had gonadotoxic animal data, 32% had gonadotoxic human data, 83% had teratogenic animal data, and 32% had teratogenic human data. When the clinical trial protocols were reviewed, only 22% of the protocols reported the teratogenic risks and 32% of the protocols reported the gonadotoxic risk. Only 56% of phase 3 protocols had gonadotoxic information and 13% of phase 3 protocols had teratogenic information. Nine percent of the protocols provided fertility preservation recommendations and 4% provided reproductive information in the follow-up and survivorship period. Twenty-six percent had a section in the clinical trials protocol, which identified oncofertility information easily. When gonadotoxic and teratogenic effects of treatment were known, they were not consistently included in the clinical trial protocols and the lack of data for new drugs was not reported. Very few protocols gave recommendations for oncofertility management and follow-up following the completion of cancer treatment. The research team proposes a number of recommendations that should be required for clinicians and pharmaceutical companies developing new trials.

Bioactivities of ethanol extract from the Antarctic freshwater microalga, Chloromonas sp. Int J Med Sci 2017;14. [PMID: 28638272 PMCID: PMC5479125 DOI: 10.7150/ijms.18702]

Cancer is the principal cause of human death and occurs through highly complex processes that involve the multiple coordinated mechanisms of tumorigenesis. A number of studies have indicated that the microalgae extracts showed anticancer activity in a variety of human cancer cells and can provide a new insight in the development of novel anti-cancer therapy. Here, in order to investigate molecular mechanisms of anticancer activity in the Antarctic freshwater microalga, Chloromonas sp., we prepared ethanol extract of Chloromonas sp. (ETCH) and performed several in vitro assays using human normal keratinocyte (HaCaT) and different types of cancer cells including cervical, melanoma, and breast cancer cells (HeLa, A375 and Hs578T, respectively). We revealed that ETCH had the antioxidant capacity, and caused significant cell growth inhibition and apoptosis of cancer cells in a dose-dependent manner, whereas it showed no anti-proliferation to normal cells. In addition, ETCH had a significant inhibitory effect on cell invasion without the cytotoxic effect. Furthermore, ETCH-induced apoptosis was mediated by increase in pro-apoptotic proteins including cleaved caspase-3 and p53, and by decrease in anti-apoptotic protein, Bcl-2 in ETCH-treated cancer cells. Taken together, this work firstly explored the antioxidant and anticancer activities of an Antarctic freshwater microalga, and ETCH could be a potential therapeutic candidate in the treatment of human cancer.

Restoring Ovarian Endocrine Function with Encapsulated Ovarian Allograft in Immune Competent Mice

Premature ovarian insufficiency (POI) is a major complication of cytotoxic treatments due to extreme ovarian sensitivity to chemotherapy and radiation. In pediatric cancer patients modern therapy has improved the long-term survival to over 80% in the United States. However, these cancer survivors face long-term health problems related to treatment toxicity. In female cancer survivors POI leads to sterility, along with the consequences of estrogen deficiency such as premature osteopenia, muscle wasting, accelerated cardiovascular diseases and a vast array of other health and developmental problems. These long-lasting effects are particularly significant for young girls reaching puberty. As such, restoring ovarian endocrine function is paramount in this population. In the present study, we evaluated the feasibility of restoring ovarian endocrine function in ovariectomized mice by transplanting syngeneic and allogeneic ovarian tissue encapsulated in alginate capsules or TheraCyte^®. Histological analysis of the implants retrieved after 7 and 30 days' post implantation showed follicular development up to the secondary and antral stages in both syngeneic and allogeneic implants. Implantation of syngeneic and allogeneic ovarian grafts encapsulated in TheraCyte devices restored ovarian endocrine function, which was confirmed by decreased serum FSH levels from 60 to 70 ng/mL in ovariectomized mice to 30-40 ng/mL 30 days after implantation. Absence of allo-MHC-specific IgG and IgM antibodies in the sera of implanted mice with allogeneic ovarian tissue encapsulated in TheraCyte indicate that the implants did not evoke an allo-immune response, while the allogeneic controls were rejected 21 days after implantation. Our results show that TheraCyte effectively isolates the graft from immune recognition but also supports follicular growth.

NKG2D ligand expression in pediatric brain tumors

Adult brain tumors establish an immunosuppressive tumor microenvironment as a modality of immune escape, with several immunotherapies designed to overcome this barrier. However, the relationship between tumor cells and immune cells in pediatric brain tumor patients is not as well-defined. In this study, we sought to determine whether the model of immune escape observed in adult brain tumors is reflected in patients with pediatric brain tumors by evaluating NKG2D ligand expression on tissue microarrays created from patients with a variety of childhood brain tumor diagnoses, and infiltration of Natural Killer and myeloid cells. We noted a disparity between mRNA and protein expression for the 8 known NKG2D ligands. Surprisingly, high-grade gliomas did not have increased NKG2D ligand expression compared to normal adjacent brain tissue, nor did they have significant myeloid or NK cell infiltration. These data suggest that pediatric brain tumors have reduced NK cell-mediated immune surveillance, and a less immunosuppressive tumor microenvironment as compared to their adult counterparts. These data indicate that therapies aimed to improve NK cell trafficking and functions in pediatric brain tumors may have a greater impact on anti-tumor immune responses and patient survival, with fewer obstacles to overcome.

HOX genes: potential candidates for the progression of laryngeal squamous cell carcinoma

Laryngeal squamous cell carcinoma (LSCC) is a very aggressive cancer, considered to be a subtype of the head and neck squamous cell carcinoma (HNSCC). Despite significant advances in the understanding and treatment of cancer, prognosis of patients with LSCC has not improved recently. In the present study, we sought to understand better the genetic mechanisms underlying LSCC development. Thirty-two tumor samples were collected from patients undergoing surgical resection of LSCC. The samples were submitted to whole-genome cDNA microarray analysis aiming to identify genetic targets in LSCC. We also employed bioinformatic approaches to expand our findings using the TCGA database and further performed functional assays, using human HNSCC cell lines, to evaluate viability, cell proliferation, and cell migration after silencing of selected genes. Eight members of the homeobox gene family (HOX) were identified to be overexpressed in LSCC samples when compared to normal larynx tissue. Quantitative RT-PCR analysis validated the overexpression of HOX gene family members in LSCC. Receiver operating characteristic (ROC) statistical method curve showed that the expression level of seven members of HOX gene family can distinguish tumor from nontumor tissue. Correlation analysis of clinical and gene expression data revealed that HOXC8 and HOXD11 genes were associated with the differentiation degree of tumors and regional lymph node metastases, respectively. Additionally, siRNA assays confirmed that HOXC8, HOXD10, and HOXD11 genes might be critical for cell colony proliferation and cell migration. According to our findings, several members of the HOX genes were overexpressed in LSCC samples and seem to be required in biological processes involved in tumor development. This suggests that HOX genes might play a critical role in the physiopathology of LSCC tumors.

Targeting childhood, adolescent and young adult non-Hodgkin lymphoma: therapeutic horizons

Non-Hodgkin lymphoma (NHL) is the third most common malignancy in children, adolescents and young adults (CAYA). NHL is a diverse set of diseases that arise at key regulatory checkpoints during B or T cell development in the bone marrow, germinal centre or thymus. While advances in the use of conventional cytotoxic agents have led to dramatic improvements in survival, these cures are associated with significant acute and long-term toxicities. Moreover, the prognosis for CAYA patients with relapsed or refractory NHL remains dismal, with the vast majority dying of their disease. Thanks to a large number of candidate-based biological studies, together with large-scale sequencing efforts, there has been an explosion of knowledge regarding the molecular pathophysiology of B- and T-NHL. This has ushered development of a flurry of novel therapeutic approaches that may simultaneously provide new hope for relapsed patients and an opportunity to reduce the therapeutic burden in newly diagnosed CAYA. Here we review a selection of the most promising new therapeutic approaches to these diseases. While the vast majority of these agents are untested in children, on-going work from many cooperative groups will soon explore their use in paediatric disease, in hope of further improving outcomes while maximizing quality of life.

Dermatologic adverse events in pediatric patients receiving targeted anticancer therapies: a pooled analysis

BACKGROUND

The dermatologic adverse events (AEs) of various molecularly targeted therapies are well-described in adult cancer patients. Little has been reported on the incidence and clinical presentation of such AEs in pediatric patients with cancer. To address this gap, we analyzed the dermatologic AEs reported across clinical trials of targeted anticancer therapies in pediatric patients.

PROCEDURES

We conducted an electronic literature search (PubMed, American Society of Clinical Oncology annual meetings' abstracts, ClinicalTrials.gov, NCI's Pediatric Oncology Branch webpage) to identify clinical trials involving targeted anticancer therapies that reported dermatologic AEs in their safety data. Studies were limited to the pediatric population, monotherapy trials (oncology), and English language publications.

RESULTS

Pooled data from 19 clinical studies investigating 11 targeted anticancer agents (alemtuzumab, rituximab, imatinib, dasatinib, erlotinib, vandetanib, sorafenib, cabozantinib, pazopanib, everolimus, and temsirolimus) were analyzed. The most frequently encountered dermatologic AEs were rash (127/660; 19%), xerosis (18/100; 18%), mucositis (68/402; 17%), and pruritus (12/169; 7%). Other AEs included pigmentary abnormalities of the skin/hair (13%), hair disorders (trichomegaly, hypertrichosis, alopecia, and madarosis; 14%), urticaria (7%), palmoplantar erythrodysesthesia (7%), erythema, acne, purpura, skin fissures, other 'unknown skin changes', exanthem, infection, flushing, telangiectasia, and photosensitivity.

CONCLUSION

This study describes the dermatologic manifestations of targeted anticancer therapy-related AEs in the pediatric population. Since these AEs are often associated with significant morbidity, it is imperative that pediatric oncologists be familiar with their recognition and management, to avoid unnecessary dose modifications and/or termination, and to prevent impairments in patients' quality of life.

Proof-of-concept rare cancers in drug development: the case for rhabdomyosarcoma

Rare diseases typically affect fewer than 200,000 patients annually, yet because thousands of rare diseases exist, the cumulative impact is millions of patients worldwide. Every form of childhood cancer qualifies as a rare disease-including the childhood muscle cancer, rhabdomyosarcoma (RMS). The next few years promise to be an exceptionally good era of opportunity for public-private collaboration for rare and childhood cancers. Not only do certain governmental regulation advantages exist, but these advantages are being made permanent with special incentives for pediatric orphan drug-product development. Coupled with a growing understanding of sarcoma tumor biology, synergy with pharmaceutical muscle disease drug-development programs, and emerging publically available preclinical and clinical tools, the outlook for academic-community-industry partnerships in RMS drug development looks promising.