ORLANDO, Fla. — An investigational drug developed by Pfizer to selectively attack certain genetic features of non-small cell lung cancer cells was able to stop or shrink tumor growth in a majority of patients enrolled in an early study, according to an abstract presented at the American Society of Clinical Oncology's annual meeting here this weekend.
PF-02341066, a dual inhibitor of mesenchymal epithelial transition growth factor (c-met) and anaplastic lymphoma kinase translocation genes, caused tumor shrinkage in 10 out of 19 patients for between two and 23 weeks in the Phase I study. The drug also stopped tumor growth in five patients for between eight weeks and 40 weeks.
The drug "is the first agent in clinical development that selectively targets a unique genetic feature of cancer cells," Pfizer said in a statement released at ASCO, where the theme of the annual meeting was personalizing cancer care.
Specifically, PF-02341066 targets echinoderm microtubule-associated protein-like 4 (EML4)-ALK translocation, which is present in some NSCLC patients. It is unclear if Pfizer is planning to market the drug with a companion diagnostic that can gauge which lung cancer patients express EML4-ALK mutations.
"Treatment with PF-02341066 resulted in promising clinical activity against tumors carrying activating ALK gene rearrangements. Further study of PF in patients with ALK-dependent tumors is warranted," concluded researchers from Massachusetts General Hospital Cancer Center and other institutions.
The abstract for the study, by Kwak et al., is available here.
"We are encouraged by the high proportion of patients whose tumors shrank substantially or stopped growing," Mace Rothenberg, senior VP of clinical development and medical affairs for Pfizer's Oncology Business Unit, said in a statement. "These data support further study of PF-02341066 for the potential treatment of NSCLC and possibly other difficult-to-treat cancers."
This study was part of a dose-escalation trial of 35 patients with various tumors, including NSCLC, pancreatic, colorectal, sarcoma, and anaplastic large cell lymphoma. Patients in this study tolerated a maximum dose of 250 mg twice daily, and experienced common adverse events, such as nausea, emesis, diarrhea, and fatigue.
In the trial one patient experienced Grade 3 alanine aminotransferase with 20 mg/day and another patent experienced Grade 3 fatigue with 300 mg/twice daily. These dose limit toxicities, however, were reversible, the investigators said.