The role of interferon as maintenance therapy in malignant lymphoma

Interferon induced thrombotic microangiopathy (TMA): Analysis and concise review

Interferon (IFN) has been associated with development of thrombotic microangiopathy including thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS). We reviewed literature from the earliest reported association in 1993, to July 2016 and found 68 cases. Analysis of this data shows: (1) Mean age at diagnosis was 47 years (95% CI, 44-50). (2) Majority of cases were seen where IFN was used for the treatment of chronic myelogenous leukemia (CML), multiple sclerosis (MS), chronic hepatitis C virus infection (HCV) and one case each for hairy cell leukemia (HCL) and Sezary syndrome. (3) There were no cases reported for polycythemia vera (PV) or lymphoma. (4) Sex distribution was nearly equivalent with the exception in patients with multiple sclerosis where there was female predominance (12 of 16 with reported data). (5) For pooled analysis, the average duration of treatment with IFN before TMA was diagnosed was 40.4 months. (6) Comparative analysis showed that patients with MS required the highest cumulative dose exposure before developing TMA (MS 68.6 months, CML 35.5 months, HCV 30.4 months). (7) Cases of confirmed TTP (where A disintegrin and Metalloprotease with thrombospondin type 1 motif 13: ADAMTS 13 level was measured) showed presence of an inhibitor. (8) In all cases of confirmed TTP, moderate to severe thrombocytopenia was a striking clinical feature at presentation while this was not a consistent finding in all other cases of TMA. (9) Outcome analysis revealed complete remission in 27 (40%), persistent chronic kidney disease (CKD) in 28 (42%) and fatality in 12 patients (18%). (10) Treatment with corticosteroids, plasma exchange and rituximab resulted in durable responses.

Chemotherapy plus interferon-alpha2b versus chemotherapy in the treatment of follicular lymphoma

The best treatment of follicular lymphoma remains to be determined because the long natural history of follicular lymphoma requires mature data for accurate analysis. Although the goal of primary treatment remains durable remission, the sequential application of effective treatments may also result in a prolongation of median survival time. The use of interferon (IFN) with doxorubicin-based chemotherapy has demonstrated an increase of event-free survival but not in overall survival; however, its acute and late cardiac toxicity limits its use. For this reason, we began a controlled clinical trial to assess the efficacy and toxicity of chemotherapy: COPP (cyclophosphamide, vincristine, prednisone, and procarbazine) + IFN alternating every month for six cycles compared to six cycles of chemotherapy. In an intent-to treat analysis, 55 patients were enrolled (median age 61 years). Most cases (91%) with advanced disease were randomly assigned to chemotherapy + IFN (28 cases) or chemotherapy (27 cases). Complete remission was observed in 16 patients: 59% (95% CI, 53-70%) in the chemotherapy arm compared to 20 patients 71% (95% CI, 58-79%) in the chemotherapy + IFN arm; total responses were 74% and 86%, respectively. At a median follow-up of 60 months, event-free survival was 100% for patients treated with chemotherapy + IFN, which was statistically different from patients treated with chemotherapy 70%. At 7 years, median survival has not yet been reached; 72% of patients chemotherapy + IFN remain alive without disease (95% CI, 59-81%), which is not statistically different from 72% (95%CI, 50-73%) in the chemotherapy arm. Non-hematological toxicity was most frequent and severe in the chemotherapy arm; hematological toxicity was similar in both groups. Thus, it appears that chemotherapy + IFN, as described herein, improves event-free survival but the overall survival rates remain unchanged. The use of COPP appears to be better that anthracycline-based chemotherapy because it avoids the presence of acute and late cardiac toxicity.

Interferon alfa 2b as maintenance therapy in poor risk diffuse large B-cell lymphoma in complete remission after intensive CHOP-BLEO regimens

OBJECTIVES

We conducted a randomized clinical trial to evaluate the role of interferon alfa 2b (IFN) as maintenance therapy in patients with diffuse large B-cell lymphoma with high or high-intermediate clinical risk on complete remission (CR) after CHOP-BLEO regimens.

METHODS

Patients were initially treated with CHOP-BLEO regimens (which include increased doses of cyclophosphamide and epirubicine, instead of doxorubicin). If the patients achieved CR they were randomly assigned to receive either maintenance therapy with IFN 5.0 MU, three times at week by 1 yr, or no treatment (control group).

RESULTS

Two hundred and twenty-three patients were considered as candidates for the study. They were of high (80%) or high-intermediate (20%) clinical risk; additionaly most patients had poor prognostic factors such as high levels of beta 2 microglobulin, lactic dehydrogenase levels, bulky disease (defined as a tumor mass >10 cm) or multiple extranodal involvement. In an intent-to-treat analysis all patients were evaluable to efficacy and toxicity. Median follow-up was 45 months, the estimated 5-yr overall survival and event-free survival (EFS) for patients who received IFN were 71% (95% confidence interval (CI): 61-83%) and 57% (95% CI: 39-69%), respectively, values which were not statistically different from the control group: 69% (95% CI: 63-79%) and 54% (95% CI: 37-63%), respectively (p=0.2). Toxicity was mild.

CONCLUSIONS

These results suggest that IFN used as maintenance therapy at these doses and schedules is not useful in aggressive malignant lymphoma when more intensive chemotherapy has been employed during induction treatment. Nevertheless, follow-up is too short, and long-term follow-up would be necessary in order to draw definitive conclusions. Probably, an multicenter study is necessary to define the role of IFN as maintenance therapy in this patient setting.