Topotecan-filgrastim combination is an effective regimen for mobilizing peripheral blood stem cells

Economic evaluation of pediatric cancer treatment: a systematic literature review

OBJECTIVE

Although there is a growing national focus on health care cost containment and accountability in resource utilization, childhood cancer therapy costs continue to increase without proportionate survival improvements. Economic evaluations (EEs) such as cost and/or cost effectiveness analysis may identify areas to improve resource efficiency. This review aims to identify and characterize the EE studies performed in this field.

METHODS

We performed a structured literature search of the Medline, PubMed, and the National Health Service EE databases from 2000 to 2011. Concepts for the search included "cost analyses," "child," and "cancer." Studies were limited to original research, comparison of 2 or more treatments using monetary units, English language, and originating from economically developed countries. Identified studies were assessed by the Drummond checklist and characterized by the therapy studied, data sources, and research perspectives.

RESULTS

Forty studies met inclusion criteria. Eleven studied chemotherapy, surgery, or radiation. Twenty-nine studied supportive measures such as growth factor support or treatment of infection. The median Drummond score was 6 of 10 (range, 2-9). Only 15 (36%) included treatment outcomes when comparing costs. Methodological limitations were common.

CONCLUSIONS

A wide variety of topics and methodological limitations made comparisons between studies difficult. Strategies for increasing the generalizability of future EE studies are presented. Substantial opportunity exists for EE research in childhood cancer.

Successful mobilization, harvest and transplant of peripheral blood stem cells using AMD3100 and G-CSF following high dose craniospinal irradiation for medulloblastoma in a young child

Contemporary protocols for the treatment of malignant brain tumors such as medulloblastoma (MB) in children, often involve craniospinal irradiation (CSI) at diagnosis followed by serial courses of high dose chemotherapy and autologous hematopoietic stem cell support. Patients often require several pheresis procedures in order to collect sufficient stem cells for this type of treatment, particularly if they have already had CSI. We describe the successful mobilization, collection and subsequent transplant of a 7-year-old female with medulloblastoma after recent CSI using granulocyte colony stimulating factor (G-CSF) and the CXCR4 antagonist AMD3100 after a failed previous mobilization attempt using G-CSF alone.

Results of a phase II upfront window of pharmacokinetically guided topotecan in high-risk medulloblastoma and supratentorial primitive neuroectodermal tumor

PURPOSE

To assess the antitumor efficacy of pharmacokinetically guided topotecan dosing in previously untreated patients with medulloblastoma and supratentorial primitive neuroectodermal tumors, and to evaluate plasma and CSF disposition of topotecan in these patients.

PATIENTS AND METHODS

After maximal surgical resection, 44 children with previously untreated high-risk medulloblastoma were enrolled, of which 36 were assessable for response. The topotecan window consisted of two cycles, administered initially as a 30-minute infusion daily for 5 days, lasting 6 weeks. Pharmacokinetic studies were conducted on day 1 to attain a topotecan lactone area under the plasma concentration-time curve (AUC) of 120 to 160 ng/mL.h. After 10 patients were enrolled, the infusion was modified to 4 hours, with dosage individualization.

RESULTS

Of 36 assessable patients, four patients (11.1%) had a complete response and six (16.6%) showed a partial response, and disease was stable in 17 patients (47.2%). Toxicity was mostly hematologic, with only one patient experiencing treatment delay. The target plasma AUC was achieved in 24 of 32 studies (75%) in the 30-minute infusion group, and in 58 of 93 studies (62%) in the 4-hour infusion group. The desired CSF topotecan exposure was achieved in seven of eight pharmacokinetic studies when the topotecan plasma AUC was within target range.

CONCLUSION

Topotecan is an effective agent against pediatric medulloblastoma in patients who have received no therapy other than surgery. Pharmacokinetically guided dosing achieved the target plasma AUC in the majority of patients. This drug warrants testing as part of standard postradiation chemotherapeutic regimens. Furthermore, these results emphasize the importance of translational research in drug development, which in this case identified an effective drug.

Topoisomerase I interactive agents

Increased insight into the mechanism of interaction of topoisomerase I interactive agents will maximize the therapeutic index and enhance the development of additional agents. Preclinical studies designed to elucidate mechanisms by which the topoisomerase I interactive agents induce cell death will be essential. The role of ABC transporters in resistance to topoisomerase I interactive agents has been recently appreciated and future studies should be directed at circumventing this resistance. The results of preclinical studies must be translated into the design of clinical trials so that these agents can be used rationally. In this regard results of preclinical studies have clearly pointed to the enhanced antitumor activity from protracted dosing of topoisomerase I interactive agents and results of clinical trials are now supporting these preclinical findings. Finally, investigators are trying to understand better the mechanism(s) of the dose-limiting toxicities observed with the currently available topoisomerase I interactive agents in an effort to enable the optimal dosing of these agents. Even though the first priority must be to determine the therapeutic potential of the currently available agents, it is reassuring to know that other topoisomerase I interactive agents are currently under development.

Primitive neuroectodermal tumors/medulloblastoma

The therapy for medulloblastoma/primitive neuroectodermal tumors of the central nervous system is surgery, followed by combination chemo-radiotherapy. The radiation field is the entire craniospinal axis, which is only avoided when treating infants. The treatment is, therefore, lengthy and toxic. Less aggressive therapy is given to patients who clinically appear to have less evidence of disease. Intensive basic research has begun to identify genetic factors of the disease, but these remain far from clinical application.