Women with an aggressive subtype of metastatic breast cancer appear to live an average of almost five months longer when treated with Iniparib plus chemotherapy, compared to chemotherapy alone.
A randomized Phase-II trial included 123 patients with metastatic triple-negative breast cancer ( mTNBC ).

Triple-negative tumors are clinically negative for expression of estrogen receptors, progesterone receptors or HER2. When metastatic, these tumors are associated with poor prognosis and short survival rates.

Women in the trial had mTNBC and had received up to 2 prior regimens for metastatic disease. They were randomly assigned to receive either Gemcitabine, Carboplatin chemotherapy, or chemotherapy plus Iniparib.

Iniparib is an investigational anti-tumor agent with PARP inhibitory activity. Inhibition of PARP1, a key DNA repair enzyme, may prevent cancer cells from repairing their DNA, therefore, enhancing the effectiveness of DNA-damaging chemotherapy.

The treatment regimen significantly improved overall survival from 7.7 months with chemotherapy alone to 12.3 months with Iniparib and chemotherapy, an improvement of almost 5 months.
That magnitude of the survival advantage is unusual in breast cancer and in metastatic tumors in general.

More than half of women ( 55.7 percent ) in the Iniparib arm experienced clinical benefit, defined as complete or partial response or stable disease for at least 6 months compared with 33.9 percent of patients in the chemotherapy-alone arm.

There was little or no increase in adverse events between the two groups.

Questions that remain to be answered include whether the chemotherapy treatment tested in this trial is the best partner for Iniparib. Pre-clinical data suggest that other agents such as Cisplatin, Cyclophospamide and anthracyclines might be very good chemotherapy drugs to be combined with Iniparib.

Source: ESMO Meeting, 2010

XagenaMedicine2010


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