A subset of lung cancer patients seem to live longer and experience delays in disease progression when a new drug that targets a cancer-associated molecule called MET is added to treatment with Erlotinib ( Tarceva ).

The study included 128 patients with advanced non-small cell lung cancer who were randomly assigned to treatment with either Erlotinib plus placebo, or Erlotinib plus MetMAb, a monoclonal antibody that binds specifically to the MET receptor on cancer cells.

MET is an important switch in cancer cells. When turned on, it influences the growth of these cells. Importantly, MET activation has also been implicated in the resistance of lung cancers to EGFR inhibitors such as Erlotinib. MetMAb helps target this switch and turn it off.

The researchers found that among the 51% of patients whose tumors expressed MET, those who received MetMAb plus Erlotinib had better overall survival and longer progression-free survival than those who received Erlotinib plus placebo.

In this subset of Met+ patients, adding MetMAb to Erlotinib nearly halved the risk of disease progression or death during the study compared to those treated with Erlotinib plus placebo.

Conversely, patients whose tumors did not express the MET protein appeared to do worse when treated with the MetMAb / Erlotinib combination. The reasons for this finding are unclear. It is possible that MetMAb may interfere with Erlotinib's activity in these patients, but further study would be necessary to better understand this potential negative association.

Source: ESMO Meeting, 2010


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