An experimental drug has shown promise in treating malignant brain tumors in children, a small study unveiled at the annual American Society of Clinical Oncology conference showed Sunday.
The early stage trial tested the effects of GDC-0449 on drug-resistant medulloblastomas, the most common form of brain tumor found in children.
Developed by US biotech firms Curis and Genentec, the latter owned by Swiss pharmaceutical group Roche since 2009, the drug works by blocking the so-called "Hedgehog" pathway.
The pathway is key to regulating cell growth and is implicated in around 20 percent of medulloblastomas, as well as other cancers.
The trial involved just 13 children, 12 of whom tolerated the drug without any significant side effects. One of the children in the trial went a year on the drug without any tumor progression.
In a previous case, a young adult with medulloblastoma experienced a similarly positive result, according to Amar Gajjar, director of the Neuro-Oncology Division at St. Jude's Children's Research Hospital in Tennessee and lead investigator in the research.
"Some patients have remained on this trial for extended periods of time, and our early results are positive and encouraging," he said at a press conference during the annual meeting of cancer researchers.
"The trend in treating children with these cancers is toward targeted therapies like this one, which block key signaling pathways and disable the cancer's ability to function or reproduce," he added.
Another study presented Sunday showed new ways to slow the return of certain types of ovarian cancer in women who have undergone chemotherapy.
The research analyzed the effect of giving a drug called Avastin to women suffering from advanced epithelial ovarian cancer, primary peritoneal cancer or fallopian tube cancer.
The drug, known generically as bevacizumab, works by blocking the development of blood vessels that can promote tumor growth.
"This is the first time a Phase III trial has demonstrated that an anti-angiogenic agent improved progression-free survival in women with this very hard-to-treat-disease," said Robert Burger of the Fox Chase Cancer Center in Philadelphia, who led the research.
"Based on the results of this... trial, bevacizumab is an acceptable initial treatment option for patients with advanced ovarian, primary peritoneal and fallopian tube cancers," said Burger.
Avastin is sold by US firm Genetech, part of Swiss pharmaceutical group Roche and has already been authorized by the US Food and Drug Administration for use in treating cancers including colon, breast, kidney, brain and lung.
Previous small-scale clinical studies involving Avastin had shown the drug's potential for ovarian cancer patients, but this trial involved an international pool of 1,873 women with newly-diagnosed advanced stage ovarian, primary peritoneal or fallopian tube cancer.
The women had all undergone surgery to remove as much of the tumor as possible, and were assigned to one of three groups.
The first received standard chemotherapy supplemented with a placebo and then received a placebo for follow-up medicine; the second received chemotherapy plus Avastin and a placebo follow-up drug; the third received chemotherapy plus Avastin and also took Avastin to follow-up.
Those in the final group had a median recurrence-free survival rate of 14.1 months, compared with the 10.3 month rate among those who received chemotherapy alone -- a statistically significant difference.
The difference between the third group and those who only took Avastin during chemotherapy was judged statistically insignificant.
Ovarian cancer affects some 230,000 women each year, killing around 140,000. It is the eighth most deadly cancer among women.