Excellent Immune Recovery Following the Intensive Chemotherapy CODOX-M/IVAC, An Effective Therapy for HIV-Associated Burkitt’s Lymphoma (BL)

Background and aim: The outcome of patients with HIV-associated Burkitt’s lymphoma (HIV-BL) treated with infusional regimens remains poor, even in the highly active anti-retroviral (HAART) era. In contrast, promising results have been published in HIV-BL with the same intensive chemotherapies used in the non-HIV population. However, scarce data on immunological recovery following these regimens are available. The objective of this multicentre study was to analyse the outcome of patients with HIVBL treated with the intensive chemotherapy regimen CODOX-M/IVAC and HAART, with a particular emphasis on the analysis of immunological recovery after treatment.

Patients and methods: 29 patients (22 male; median age: 38) from 3 UK centres consecutively treated with CODOX-M/IVAC from 2003 to 2008 were included in the study. CODOX-M/IVAC consisted of 2 alternating cycles of CODOX-M (cyclophosphamide 800mg/sqm day 1 and 200mg/sqm days 2–5, doxorubicin 40mg/sqm day 1, vincristine 1.5mg/sqm days 1 and 8, methotrexate 3g/sqm day 10) and IVAC (etoposide 60mg/sqm days 1–5, ifosfamide 1g/sqm days 1–5, cytarabine 1g/sqm bd days 1 and 2) for patients with high-risk disease and 3 cycles of CODOX-M for patients with low-risk disease. High-risk disease was defined by the presence of at least 2 of the following: stage III–IV, ECOG≥2, extranodal sites≥2 or high serum LDH. All patients received concomitant treatment with HAART (NRTI + NNRTI: 21; NRTI + PI: 8) and prophylactic antimicrobials as well as intrathecal prophylaxis and G-CSF as per protocol. Four patients received rituximab in combination with the chemotherapy. Lymphocyte subsets and plasma HIV-1 viral load (VL) were measured during chemotherapy and at 3-month intervals during follow-up.

Results: HIV was diagnosed concomitantly with BL in 12 patients. The median CD4 count at BL diagnosis was 167/mm³ (range: 4–848), with CD4>200/mm³ in 41% of patients and VL being undetectable in 5 (18%) patients. Eight (28%) of the patients previously known to have HIV infection were on HAART before the diagnosis of BL. The majority of the patients (72%) had high-risk disease. Twenty patients (69%) were diagnosed in advanced stage (III–IV), with bone marrow (BM) involvement in 6 (21%) and central nervous system (CNS) infiltration in 5 (17%). The International Prognostic Index (IPI) was high (3–5) in 14 (48%) patients. Grade 3–4 non haematological toxicity was as follows: infection, 66% of the cycles; mucositis, 12%; and diarrhoea, 13%. Nine patients died during treatment, due to disease progression in 3 cases, toxicity in 5 (3 infections, 2 GI bleeding) and 1 patient died with a CNS lesion that was not biopsed. Response at the end of treatment amongst 23 assessable patients was as follows: complete response (CR)/CR uncertain (CRu): 16 patients (69%); partial response (PR): 4 (17%); progression: 3 patients (13%). After a median follow-up of 17 months (range: 9–67), 17 of 20 responding patients remain alive without disease progression, whilst 2 patients (1 CR, 1 PR) relapsed at 2 and 1 months after finishing treatment and died. One HAART non-compliant patient died in CR of HIV-related causes. Three patients in PR at the end of treatment survive without evidence of disease progression at 28, 37 and 51 months. Overall survival (OS) and disease-free survival (DFS) at 3 years were 49% and 70% respectively. Blood samples for immune recovery analyses were available for the majority of the patients during follow-up (81% 6 months after finishing chemotherapy, 86% at 12 and 24 months). VL was undetectable in 85% and CD4>200/mm³ in 53% of assessable patients 6 months after completing chemotherapy.

Conclusions: This retrospective analysis demonstrates that the intensive regimen CODOX-M/IVAC is feasible and effective in HIV positive patients on HAART with BL. Immunological recovery after treatment, not previously reported after such intensive chemotherapy, is excellent. Whether concomitant treatment with rituximab will improve outcome warrants further study.