Italian investigators say that two seriously ill patients taking Pfizer's experimental lung cancer drug crizotinib saw signs of a rare malignancy disappear, with no sign of a relapse over the following six months. The patients suffered from anaplastic large-cell lymphoma--which shares an ALK gene mutation which crizotinib targets--and had already failed multiple chemo treatments.
Reporting in the New England Journal of Medicine, doctors said both patients were given crizotinib after relapsing.
"After the initiation of crizotinib, Patient 1's fever disappeared within 48 hours; by day 7, all palpable adenopathy had resolved. PET and CT images and bone marrow aspiration performed at 28 days showed complete regression of previous lesions," they wrote in a letter. "Within 8 days after treatment with crizotinib, his constitutional symptoms subsided, and palpable adenopathy disappeared. On day 12, a PET scan showed complete regression of all lesions," they said of the second patient.
Pfizer, which has experienced a string of bitter setbacks in the clinic, has been steadily building a case for crizotinib. The pharma giant plans to file for an approval of the therapy later this year, and a string of analysts tracked by Bloomberg estimate annual sales at $755 million, making it a potentially important new product for Pfizer.
Non-small cell lung cancer is one of the toughest cancers to treat and often proves resistant to standard therapies. But developers have been zeroing in on new markers, drilling down into specific patient populations to find groups that will respond to more targeted therapies. And crizotinib is part of the new wave of NSCLC drugs in development, in this case targeting the ALK gene. In one of the most recent trials completed on the drug, 90 percent of 82 patients demonstrated shrinkage in their tumors. Only a relatively small population of NSCLC patients, however, are likely to benefit. And doctors will need a diagnostic test to identify the patients who qualify for the drug.