(ChemotherapyAdvisor) – First-line targeted therapy with doxycycline can eradicate Chlamydophila psittaci (Cp) in patients with stage I Cp-positive ocular adnexal marginal zone lymphoma (OAMZL), leading to disease regression, a study reported in the Journal of Clinical Oncology online July 16.
Such regression “can easily be monitored on conjunctival and blood samples,” noted Andre´s J.M. Ferreri, MD, of the San Raffaele Scientific Institute, Milan, Italy, on behalf of the International Extranodal Lymphoma Study Group. “To our knowledge, this is the first international phase II trial aimed at clarifying Cp prevalence and activity of first-line doxycycline in a homogeneous series of consecutive patients with newly diagnosed stage I OAMZL.”
Tumor tissue, conjunctival swabs, and peripheral blood from 44 of 47 patients registered for the trial were assessed for 7 Chlamydiaceae infections by 3 PCR protocols. The 34 patients with measurable or parametrable disease were treated with doxycycline; the primary end point was chlamydial eradication and lymphoma response.
“Cp DNA was detected in biopsies of 39 patients (89%); no other Chlamydiaceae were detected,” they found. “Twenty-nine patients had Cp DNA in baseline swabs and/or blood samples and were evaluable for chlamydial eradication, which was achieved in 14 patients (48%). Lymphoma regression was complete in 6 patients and partial in 16 (overall response rate, 65%; 95% CI, 49%–81%); 11 had stable disease, and one had progressive disease.”
At a median follow-up of 37 months (range, 15 to 62 months), 20 patients remained relapse free; 5-year progression-free survival (PFS) was 55%. Eradication of Cp was associated with both an improved response rate, 86% vs 47% (P=0.02) as well as improved 5-year PFS (68% v 47%; P=0.11).
“The definition of mechanisms of resistance to doxycycline and the design of more effective administration schedules are warranted to further improve Cp eradication and OAMZL regression rates,” they concluded.
Link to abstract: