• to determine whether the combination of doxycycline with Avonex will reduce the mean number of new GD+ lesions
  

• to determine pre- and on-treatment relapse rate,proportion relapse free, %free of new MRI activity, and % experencing greater than 25% reduction in new MRI activity
  
• determine safety and tolerability of combination therapy with Avonex plus doxycycline
  
• determine pre- and on-treatment cytokine ELISA, MMP ELISA and bioassay
  

Inclusion Criteria:

• age 18-55
• RRMS
• Avonex therapy for 6 months prior continous
• annualized relapse rate >2 during Avonex therapy
• most recent relapse within 60 days of baseline
• entry EDSS 1.5-4.5
• one or more Gd+ MRI lesions on a baseline MRI
• no history of immune modulator or immunosuppressant therapy used in combination with Avonex (other then GSC administer for clinical relapses)
• not participating in any other study of ms therapeutics
• Serum neutralizing antibodies (NABs) titer to Avonex <20

Exclusion Criteria:

• Medical or Psychiatric conditions that will affect patients ability to provide informed consent
• inability to undergo MRI
• clinically serious medical conditions or significantly abnormal labs

• no use of these medications or procedures within six months prior to study:

  *monoclonal antibodies,total lymphoid radiation,systemic steroids,cytotoxic or immunosuppressive medications such as mitoxantrone or cyclophosphamide or any other investigational drugs

• Interferon neutralizing antibody titers >20
• no breast feeding or pregnant
• no patients with any systemic illness,psychiatric condition or other disorder that would concern safety of patient to complete procedures of protocol
• abnormal blood test
• clinically significant abnormality on CXR