ZURICH, Oct 20 (Reuters) - An experimental cancer drug that Novartis hopes will raise the profile of its oncology portfolio cut the risk of death or disease progression by more than a third in breast cancer patients with a hard-to-target gene mutation.
The Swiss drugmaker's BYL719, a so-called PI3K inhibitor also known as alpelisib, combined with hormone therapy fulvestrant boosted median progression-free survival (PFS) to 11 months, up from 5.7 months for patients who got only hormone therapy, the company said on Saturday.
BYL719 plus fulvestrant cut risk of death or progression in those patients by an estimated 35 percent, Novartis said.
Novartis said earlier this year that this study, called SOLAR-1, of hormone receptor positive, HER2- breast cancer with mutations of the PIK3CA gene showed that YL719 helped patients.
But this specific benefit data is being released on Saturday at the European Society for Medical Oncology's annual conference in Munich.
Even though PIK3CA mutations are the most common genetic change in hormone-receptor positive breast cancer, trials of agents seeking to put a brake on this pathway to tumour growth have largely disappointed including on safety issues.
Other drugmakers including Roche have seen similar investigational medicines stumble, making Novartis's progress here hopeful news, doctors involved in the trial said.
"The results of SOLAR-1 are the most encouraging observed to date from a trial evaluating a PI3K inhibitor" for patients with this kind of breast cancer, said Fabrice Andre, a professor at France's Institut Gustave Roussy.
"These data have the potential to allow physicians to address an unmet need in this patient population by using a biomarker-driven treatment to inform their sequencing decisions," Andre added.
Like other companies, Novartis is seeking to personalise treatment for cancer patients by using biomarkers like those showing PIK3CA gene mutations to help guide treatment.
This week, Novartis signed a deal to have Roche unit Foundation Medicine provide genomic profiling of patient samples taken from Novartis' clinical oncology trials. Other cancer drugmakers like Bristol-Myers Squibb and Merck also have Foundation deals.
Samit Hirawat, head of Novartis's cancer drug development, said in an interview the side-effects profile of alpelisib held up.
"We don't see as much diarrhea, we do not have CNS (central nervous system) side effects, we do not have the liver effects," he said.
Novartis plans to file with regulators for approval of the drug this year, Hirawat said, adding he also has strategies to broaden the indication, including tough-to-treat triple-negative breast cancer.
"PIK3CA mutations are present in many other tumour types," Hirawat said. "There is a larger programme we are putting into place." (Reporting by John Miller. Editing by Jane Merriman)