When used in combination with another breast cancer drug, Tykerb (lapatinib) appeared to reduce the size of brain tumours in women whose breast cancer had spread to the brain.

This was the main result of an extended arm of a phase 2 clinical trial, said the drug company GlaxoSmithKline Plc to the 30th Annual San Antonio Breast Cancer Symposium in San Antonio, Texas, on Sunday 16th December. The symposium was sponsored by GlaxoSmithKline and the study was listed as abstract 60761 in the symposium.

The study, which included 49 patients with breast cancer that had spread to other parts of the body (metastatic breast cancer), including the brain, showed that 20 per cent of the ones on Tykerb and Xeloda (capecitabine, another cancer drug) experienced a 50 per cent reduction in measurable volume of brain tumours due to metastasis.

Also, 37 per cent of the patients had a brain tumour volume reduction of at least 20 per cent.

These results are important because nearly one third of women with HER2-positive advanced breast cancer are likely to experience the cancer spreading to the brain and central nervous system.

Dr Nancy U. Lin, lead study investigator and Instructor in Medicine, Dana-Farber Cancer Institute, in Boston, Massachusetts said:

“As women live longer with advanced breast cancer, some are developing brain metastases that are getting worse despite standard treatments, such as radiation.”

“Very few medications have shown activity in the treatment of brain metastases, in particular HER2-positive metastatic breast cancer patients and therefore, these data are quite encouraging,” she added.

Tykerb is a small molecule HER2 (ErbB2) kinase inhibitor taken in tablet form, once a day. It was approved by the US Food and Drug Administration in March this year. It is used with Xeloda to treat patients with advanced or metastatic breast cancer whose tumours over express HER2 and who have already been treated with other drugs such as anthracycline, a taxane and trastuzumab (Herceptin).

The drug manufacturer said other studies were under way to discover the full potential of Tykerb for preventing and treating brain metastases.

Founder and president of the HER2 Support Group, Christine Druther, said:

“I know first hand that HER2-positive breast cancer can have unique, difficult-to-treat complications. Brain metastases can be particularly devastating for patients, as they may cause blurred vision, speech impairments and can limit patients’ ability to engage in even simple day-to-day activities.”

“We look forward to the results of any and all research in the treatment of HER2-positive breast cancer and its complications,” she added.

The study reported the most common grade 1 and 2 adverse events to be hand-foot syndrome (37 per cent), diarrhea (34 per cent), nausea (22 per cent), vomiting (12 per cent), anorexia (12 per cent), and nail disorder (12 per cent).

The most common grade 3 events were: hand-foot syndrome (8 per cent), nausea (8 per cent), vomiting (6 per cent), diarrhea (4 per cent) and fatigue (2 per cent).

Senior Vice President of the Oncology Medicine Development Center at GlaxoSmithKline (GSK), Dr Paolo Paoletti, said:

“This trial and the ongoing clinical development program for Tykerb represent GSK Oncology’s commitment to developing treatments that help improve the lives of cancer patients.”

“We plan to further study the effects of Tykerb in HER2-positive patients with brain metastases,” he added.

About 10 per cent of breast cancer patients newly diagnosed with the disease have locally advanced or metastatic forms, and between 20 and 85 per cent (depending on stage at diagnosis, tumour type, and treatment) of early breast cancers turn into recurrent or metastatic forms.

Metastatic breast cancer is the second most common cancer that spreads to the brain.

Click here for San Antonio Breast Cancer Symposium.

Written by: Catharine Paddock