A Study of Metronidazole Cream in the Prevention and Treatment of Tarceva (Erlotinib)-Associated Rash

This study will evaluate the efficacy and safety of metronidazole actavis 1 percent (%) topical cream in the prevention and treatment of rash associated with Tarceva treatment, in participants with non-small cell lung cancer. The first cohort of participants enrolled in the study will be treated twice daily with metronidazole cream on the right side of the face and upper thorax, the same day as they start treatment with Tarceva (150 mg orally daily). The corresponding body parts on the left side will be treated according to local standard procedures (ie, with non-active moisturizing cream). The second cohort of Tarceva-treated participants will only receive twice daily treatment with metronidazole cream if and when they develop rash. In both cohorts, efficacy will be evaluated at Week 2 and Week 4. The anticipated time on metronidazole treatment is less than (\<) 3 months, and the target sample size is \<100 individuals.