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"Figitumumab, an investigational fully human monoclonal antibody, is a highly specific inhibitor of the insulin growth factor-1 receptor (IGF-1R) pathway. The IGF-1R pathway is thought to be one of the fundamental signaling pathways that leads to uncontrolled growth and survival of tumor cells, and may represent a resistance mechanism against EGFR inhibitors and other anti-cancer therapies."
The data at ASCO focused on which patients were most likely to respond to the agent:
"Over 60 percent response rate observed in 56 patients with squamous cell carcinoma NSCLC treated with chemotherapy plus figitumumab."
Sounds very promising, right?
Except since Monday this week, the trial appears to have been suddenly suspended.
Given that it is now 18 months since the study was entered onto the database, we can reasonably assume from that information that either the interim analysis showed a lack of efficacy or there were serious side effects associated with the treatment. IGF-1R is, after all, expressed ubiquitously in organs of the body including the heart, not just on cancer cells, as we pointed out in a previous blog post about IGF-1R.
Drug development is tough – Pfizer have had a bad roll this year with multiple phase III trials failing, including CRC and breast cancer for Sutent, after promising phase II results.
There aren't any press releases on the Pfizer website about this yet, but it's Friday afternoon and no doubt something will be forthcoming soon to explain the mystery.