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.