Geftinib could be suitable as a monotherapy in patients with advanced non-small cell lung cancer (NSCLC) wherein both platinum based and docetaxel chemotherapy failed, according to Dr T Raja, consultant oncologist, Apollo Cancer Hospital, Chennai.
In human NSCLC cell lines and xenografts, geftinib dose dependently inhibited cellular proliferation and tumour growth and potentiated the cytotoxic effects of chemotherapy and/or radiation, he pointed out while delivering a lecture organized by Natco Pharma on the 'Role of geftinib in the treatment of lung cancer' at Hyderabad, last week.
Geftinib is an orally active selective inhibitor of epidermal growth factor receptor tyrosine kinase, an enzyme that regulates intra-cellular signaling pathways implicated in the proliferation and survival of cancer cells.
Geftinib works by blocking one of the signaling pathways that is believed to be important for cancer cells to grow and develop into a tumour. This signaling pathway involves a chemical, the epidermal growth factor (EFG), which binds to a receptor on the surface of cells called the epidermal growth factor receptor (EGFR). The EGFR activates an enzyme, tyrosine kinase (TK), sending signals inside the cell, which ultimately instruct the cell to grow and divide.
In many common tumours, there is an excessive TK activation by EGFR. Geftinib blocks the activation of the TK enzyme, which effectively switches off the growth signal within the cell.
As there is an over-activation of TK in cancer cells, therapy that blocks this enzyme is specifically targeted at cancer cells, sparing the normal, healthy cells of the body. This means that it has less severe side effects than traditional cytotoxic drugs used to treat cancer, which are unable to distinguish between cancer and normal cells and therefore can lead to a range of side effects.
Geftinib has improved disease related symptoms in patients with NSCLC persisting after chemotherapy. It had a meaningful anti-tumour activity. It also provides a valuable addition to the treatment options as monotherapy in patients with advanced NSCLC after failure of both platinum based and docetaxel chemotherapy, Dr Raja added.
But, cases of interstitial lung disease (ILD) have been observed in patients receiving geftinib at an overall incidence of about one per cent. Patients with concurrent idiopathic pulmonary fibrosis whose condition worsens while receiving geftinib have been observed to have an increased mortality compared to those without concurrent idiopathic pulmonary fibrosis.