Paediatric formulations of artemisinin combination therapies (ACTs) have recently been developed for the treatment of children with falciparum malaria. Compared with conventional tablet formulations, the new non-tablet preparations have shown equivalent efficacy, safety, and tolerability in individual trials. We aimed to investigate whether objective evidence supports the development and use of paediatric ACTs. A systematic review identified seven studies involving 2515 children that were eligible for meta-analysis. Similar efficacy and safety were seen in pooled analyses of paediatric and conventional formulations. 23 (2·0%) of 1154 patients in the paediatric formulation groups and 19 (1·7%) of 1137 in the tablet formulation groups were not cured (RR 1·27, 95% CI 0·66—2·44). Despite similar overall tolerability, the tolerability of drug administration was improved for paediatric formulations as shown by significantly fewer patients with drug-induced vomiting (93 of 1018 and 114 of 837 patients; risk ratio [RR] 0·78, 95% CI 0·61—0·99), and drug-related gastrointestinal disorders (8 of 545 and 15 of 358 patients; RR 0·36, 95% CI 0·15—0·85). These data provide, for the first time, evidence for improved management of children by use of paediatric formulations, and support the further development and use of paediatric ACTs.

A few years ago, this same group of investigators showed that NSCLCs being held in check by Tarceva can switch on an alternate growth circuit if they have too many copies of a gene called MET. Such tumors are considered Tarceva- and Iressa-resistant.

In the new paper, investigators led by Pasi Jänne, MD, PhD, of Dana-Farber, and Jeffrey Engelman, MD, PhD, of MGH, found that some patients with EGFR-mutant lung cancers harbor a small number of tumor cells with an overabundance, or "amplification," of MET even before treatment with a tyrosine kinase inhibitor, and that those few cells are enough to spark drug resistance.

One of the triggers for resistance, the researchers found, is HGF, a ligand or "hook" that activates the MET protein.

When activated, HGF works through two entirely different channels to produce drug resistance, the authors report. First, it can generate cell-growth signals through a protein called GAB1. Second, it expands the number of MET-amplified cancer cells, ensuring they will become the dominant type in the lung tumors.

"Not only can HGF spur cell growth on its own, it can speed up the process by which MET-amplified cells emerge and take over the composition of the tumor," says Jänne, who was co-senior author of the paper with Engelman.

In about 20 percent of NSCLC patients who are resistant to Tarceva the mechanism is amplification of MET, and in another 20 percent it may involve HGF.

The findings suggest that patients whose NSCLC tumors harbor even a few MET-amplified cells prior to treatment would benefit from drugs that specifically target those cells, in combination with a tyrosine kinase inhibitor. Jänne notes that such drugs are already being studied in clinical trials.

"Our findings provide a strong rationale for combination treatment strategies as initial therapies for some patients," Jänne remarks. "This is especially the case in patients with evidence of pre-existing MET amplifications."

Engelman adds, "A thorough analysis of a patient's cancer prior to treatment can establish how it would ultimately develop resistance to therapy, allowing us to tailor treatment with greater precision to prevent resistance.

"For example, cancers found to harbor a small population of cells with pre-existing MET amplification will likely benefit from adding MET inhibitors to initial treatment. Those without such cells may not benefit, and these patients can avoid the added toxicity of MET inhibitors and instead focus on other strategies to prevent their cancers from becoming resistant."

Engelman is an assistant professor of medicine and Jänne an associate professor of medicine at Harvard Medical School.

The study was supported by grants from the National Institutes of Health, American Association for Cancer Research, the V Foundation, American Cancer Society, Hazel and Samuel Bellin Research Fund, and the Ellison Foundation.

The study's co-lead authors were Alexa Turke of MGH, and Kreshnik Zejnullahu, of Dana-Farber. Co-authors include Yi-Long Wu, of Guangdong General Hospital, Guangzhou, China; Youngchul Song, Dora Dias-Santagata, PhD, Eugene Lifshits, Lecia Sequist, MD, MPH, Sara Akhavanfard, MD, Beow Yeap, and A. John Iafrate, MD, PhD, of MGH; Luca Toschi, MD, Andrew Rogers, and Marzia Capelletti of Dana-Farber; Tony Mok, MD, of the Chinese University of Hong Kong; Neal Lindeman, MD, Carly Murphy, Yun Xiao, and Charles Lee, PhD, of Brigham and Women's Hospital; and James Christensen, of Pfizer Global Research and Development, La Jolla, Calif.

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