A Phase II Trial Investigating Primary Immunochemotherapy for Malignant Pleural Mesothelioma and the Feasibility of Adjuvant Immunochemotherapy After Maximal Cytoreduction

Background: The treatment of malignant pleural mesothelioma (MPM) continues to be inadequate with the use of standard techniques, including surgery, radiotherapy and chemotherapy. We initiated a phase II trial of immunochemotherapy with cisplatinum (25 mg/m2 four times weekly), interferon-alpha (5 mU/m2 s.c. three times weekly, and tamoxifen (20 mg orally twice a day for 35 days) (CIT) based on in vitro and in vivo data suggesting interrelating efficacy of this combination.

Methods: Since July 1991, 36 patients have been evaluable for response after receiving one to five cycles of CIT. Ten additional patients had debulking surgery followed by two cycles of postoperative adjuvant CIT commencing a mean of 6 weeks after surgery.

Results: Toxicity was acceptable (4% grade III/IV). One treatment-related death (2%) occurred, from myocardial infarction. A 19% partial response rate, objectively quantified using three-dimensional computerized tomographic (CT) measurement of solid disease volume, was recorded. The median survival for the seven responders was 14.7 months, whereas that of the nonresponders was 8 months (p2 = 0.2). Median survival for the entire group was 8.7 months. Preoperative size, platelet count > 360,000/ml, and nonepithelial histology were associated with shortened survival.

Conclusions: The CIT regimen has some activity in MPM and can be delivered after debulking resection. In good-risk patients, as defined by favorable prognostic factors, a randomized trial using this combination may be warranted.