A Phase II Study of ACZONE™ (Dapsone) Gel, 5% As a Treatment For Tarceva® (Erlotinib)Related Rash

Inclusion Criteria: To be eligible for the study, subjects must fulfill all of the following criteria: 1. Be male or female ≥18 years of age (inclusive). 2. Have been prescribed Tarceva as a single agent to treat locally advanced or metastatic NSCLC, after failing at least 1 prior chemotherapy regimen. 3. Present with acute signs and symptoms of rash on the face that meet the following criteria: 1. Are suspected to be related to Tarceva, 2. Include at least 3 inflammatory lesions, and 3. Are less than CTCAE Grade 3 in severity. 4. Have an Eastern Co-operative Oncology Group (ECOG) performance status ≤2 and a life expectancy of at least 4 months. 5. Sign an approved informed consent form for the study. 6. Be willing to comply with the protocol. Exclusion Criteria: Subjects meeting any of the following criteria will be excluded from the study: 1. A skin examination reveals the presence of another skin disease and/or condition (excessive facial hair, excessive scarring, sunburn, or other disfigurement) located on the face that, in the study physician's opinion, would confound the evaluation of the rash. 2. A diagnosis of G6PD deficiency, defined as having a G6PD value below the lower limit of normal. 3. A diagnosis of anemia, defined as hemoglobin \<9.5 g/dL. 4. Undergoing any current therapy for NSCLC other than Tarceva. 5. Prior treatment with Iressa, Erbitux, or any experimental HER1/EGFR inhibitor. 6. Treatment with topical antibiotics, topical steroids, and other topical treatments on the face within 14 days of Day 0 (start of ACZONE/placebo study treatment). 7. Treatment with any systemic antibiotics within 7 days of Day 0 (start of ACZONE/placebo study treatment). 8. Treatment with any systemic medication or therapy known to affect anti-inflammatory responses within 30 days prior to Day 0 (start of ACZONE/placebo study treatment). These medications include, but are not limited to, oral corticosteroids, cyclosporine, and methotrexate. Short-term treatment with non-steroidal anti-inflammatory drugs (NSAIDs) before the study for non-rash related conditions is acceptable, provided that exposure is limited to ≤7 days per course. Chronic low-dose aspirin use is also acceptable. 9. Active participation in an experimental therapy study or received experimental therapy within 30 days of Day 0 (start of ACZONE/placebo study treatment). 10. A history of hypersensitivity to dapsone, sulfamethoxazole, trimethoprim, parabens, or any component of ACZONE. 11. A poor medical risk because of other systemic diseases or active uncontrolled infections. 12. Women who: are lactating; have a positive pregnancy test at Day 0, or; if sexually active and menstruating, are not practicing an adequate method of birth control. Acceptable methods of birth control include intrauterine device (IUD); oral, dermal ("patch"), implanted or injected contraceptives; tubal ligation or hysterectomy (medical documentation required); and/or barrier methods with spermicide. A surgically sterile partner is not considered an adequate method of birth control.