Survival differences after docetaxel, erlotinib are EGFR dependent

By Sarah Pritchard, medwireNews Reporter

Results from the DELTA trial indicate no significant differences in progression-free (PF) or overall survival (OS) after treatment with docetaxel versus erlotinib in non-small-cell lung cancer (NSCLC) patients unselected for their epidermal growth factor receptor (EGFR) mutation status.

By contrast, in the subgroup of patients whose tumours were positive for EGFR mutations, PFS and OS were nonsignificantly longer in the erlotinib than the docetaxel group, whereas in those with wild-type tumours, docetaxel was significantly superior to erlotinib in terms of PFS, observe the researchers in the Journal of Clinical Oncology.

Tomoya Kawaguchi (National Hospital Organization Kinki-Chuo Chest Medical Center, Osaka, Japan) and colleagues investigated the efficacy and tolerability of the EGFR tyrosine kinase inhibitor erlotinib versus docetaxel using Docetaxel and Erlotinib Lung Cancer Trial (DELTA) data. The study randomly assigned 301 NSCLC patients, who had all undergone one or two previous chemotherapy regimens, to receive erlotinib 150 mg per day (n=150) or docetaxel 60 mg/m² every 3 weeks (n=151).

After a median follow-up of 8.9 months, median PFS was nonsignificantly longer in the docetaxel than the erlotinib group, at 3.2 versus 2.0 months. Conversely, median OS duration was nonsignificantly longer for those who received erlotinib versus docetaxel, at 14.8 versus 12.2 months.

In patients whose tumours underwent polymerase chain reaction analysis (n=255), 199 had wild-type EGFR disease, while 55 had active mutations. In the latter group, median PFS and OS were longer for those who received erlotinib than docetaxel, at 9.3 versus 7.0 months and “not reached” versus 27.8 months, respectively; however, these were nonsignificant differences, note Kawaguchi et al. PFS was significantly longer among docetaxel-treated patients with wild-type tumours compared with their erlotinib-treated counterparts, at 2.9 versus 1.3 months.

The team used the Common Terminology Criteria for Adverse Events to evaluate safety outcomes, and observed that erlotinib was most commonly associated with rash (92.7% of patients) while docetaxel was linked more frequently to fatigue (71.3%), nausea (50.0%) and haematological toxicities. Furthermore, significantly more docetaxel than erlotinib patients experienced Grade 3 or 4 leukopaenia, neutropaenia and febrile neutropaenia.

The researchers warn that their failure to detect a difference in PFS in the unselected patient population could be a result of a small sample size, and that caution should be used when comparing their results with other studies of PFS in this population.

Nevertheless, they conclude: “Given the active drugs available for poststudy chemotherapy that might confer prolonged survival after progression, PFS can be a clinically relevant end point, and further research and discussion are required.”

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