Inclusion Criteria:

• Males and females 18 years of age or older.
• Subjects must have started Tarceva® therapy within three (3) days of trial enrollment.
• Patients must have signed informed consent prior to registration on study.
• Currently receiving erlotinib therapy at 150 mg per day for locally advanced or metastatic NSCLC.
• Patients - both males and females - with reproductive potential (ie, menopausal for less than 1 year and not surgically sterilized) must utilize barrier methods in combination with spermicidal agents for contraception when engaging in sexual intercourse. Women of childbearing potential must provide a negative pregnancy test (serum or urine) within 14 days prior to registration.

Exclusion Criteria:

• Allergy to tetracyclines.
• Use of concurrent agents for papulopustular rash.
• Currently receiving anticancer agents other than erlotinib.
• Inability to interrupt other antibiotic therapy.
• Current use of topical steroids
• Current use of systemic immunosuppressants (e.g., methotrexate, cyclosporine, azathioprine, mycophenolate mofetil)
• Photosensitivity or lupus erythematosus.
• Active gastroesophageal reflux disease.
• Women who have a positive pregnancy test or are lactating by history.
• ECOG performance status ≤3.
• Self report of current smoking or history of smoking within 60 days of screening, or positive urine cotinine test.

• Current use of agents that are known to be strong inducers or inhibitors of CYTP3A4:

  • inhibitors: atazanavir, clarithromycin, indinavir, itraconazole, ketoconazole, nefazodone, nelfi navir, ritonavir, saquinavir, telithromycin, troleandomycin (TAO), voriconazole, grapefruit or grapefruit juice
  • inducers: rifampicin, rifabutin, rifapentine, phenytoin, carbamazepine, phenobarbital, and St. John's Wort

• Impaired hepatic function (≤ 30 days before randomization):

  • Alkaline phosphatase > 3x ULN
  • Aspartate aminotransferase (AST) > x ULN
  • Alanine aminotransferase (ALT) > 3 x ULN
  • Total Bilirubin > 1.5 x ULN