MYC gene rearrangements are associated with a poor prognosis in diffuse large B-cell lymphoma patients treated with R-CHOP chemotherapy

Approximately 5% to 10% of diffuse large B-cell lymphomas (DLBCLs) harbor an MYC oncogene rearrangement (MYC+). The prognostic significance of MYC+ DLBCL was determined in an unselected population of patients with newly diagnosed DLBCL treated with rituximab in combination with cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy (R-CHOP). Using a Vysis break-apart fluorescence in situ hybridization probe, 12 of 135 (8.8%) cases of MYC+ DLBCL were identified that had no defining high-risk features. MYC+ DLBCL was associated with an inferior 5-year progression-free survival (66% vs 31%, P = .006) and overall survival (72% vs 33%, P = .016). Multivariate analysis confirmed the prognostic importance of MYC for both progression-free survival (hazard ratio = 3.28; 95% confidence interval, 1.49-7.21, P = .003) and overall survival (hazard ratio = 2.98; 95% confidence interval, 1.28-6.95, P = .011). Cases of MYC+ DLBCL also had a higher risk of central nervous system relapse (P = .023), independent of other risk factors. The diagnosis of MYC+ DLBCL is likely underappreciated; and given the lack of defining risk factors, fluorescence in situ hybridization for MYC rearrangements should be performed in all patients with DLBCL. In the R-CHOP treatment era, MYC+ DLBCLs have an inferior prognosis. Treatment regimens similar to those used in Burkitt lymphoma may be more appropriate in this patient population and need to be prospectively tested.

A pilot study of epratuzumab and rituximab in combination with cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy in patients with previously untreated, diffuse large B-cell lymphoma

BACKGROUND

In this pilot study, the authors assessed the feasibility of combination epratuzumab and rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (ER-CHOP) in patients with newly diagnosed diffuse large B-cell lymphoma (DLBCL).

METHODS

Patients received chemotherapy on the following schedule: epratuzumab 360 mg/m2, rituximab 375 mg/m2, and standard-dose CHOP every 3 weeks for 6 to 8 cycles. The primary endpoint was the incidence of grade 4 neutropenia and grade 3 or 4 antibody infusional toxicity. Secondary endpoints were the complete response (CR) rate, the overall response rate (ORR), and progression-free survival (PFS). Weekly blood counts were obtained to monitor hematologic toxicity. Fifteen patients were enrolled and treated. Baseline patient characteristics included a median age of 63 years (range, 42-78 years), 60% of patients had stage III or IV disease, 7 patients had a low-risk International Prognostic Index (IPI) score (0 or 1), 7 patients had an intermediate-risk IPI score (2 or 3), and 1 patient was high risk.

RESULTS

Grade 3 or 4 neutropenia was observed in 14 patients (93%) or in 28 of 92 treatment cycles (30%). Three patients developed grade > or =3 infection or fever. Eleven patients (73%) required dose reductions. No grade 3 antibody infusion-related toxicity was reported. Thirteen of 15 patients responded (ORR, 87%,), including 10 CRs (67%), 3 partial responses (20%), 1 patient with stable disease, and 1 patient with disease progression. At a median follow-up of 30 months, 13 of 15 patients remained alive. The 1-year PFS and OS rates were 93% and 100%, respectively; and the 2-year PFS and OS rates were 86% and 86%, respectively.

CONCLUSIONS

ER-CHOP every 21 days was feasible as treatment for newly diagnosed patients with DLBCL. A Phase II multicenter study is underway.

Rituximab for the treatment of diffuse large B-cell lymphomas

For more than 25 years, the combination of cyclophosphamide, doxorubicin, vincristine and prednisone (CHOP) was considered the gold standard for the treatment of aggressive lymphomas, 90% of which are diffuse, large B-cell lymphomas (DLBCLs). Attempts to improve results by more intensive chemotherapy regimens, including high-dose chemotherapy approaches necessitating stem-cell support, have not convincingly shown improved outcome of DLBCL. The chimeric monoclonal antibody rituximab, which binds to the CD20 antigen expressed on normal B cells and the malignant cells of more than 90% of DLBCLs, and mediates lysis of these cells by direct induction of apoptosis, activation of complement- and antibody-dependent cellular cytotoxicity in vitro, is an attractive candidate for the treatment of B-cell lymphomas. Initial studies in follicular lymphoma demonstrated its efficacy as a single agent or in combination with chemotherapy without adding relevant toxicity. After the demonstration of rituximab single-agent activity in DLBCL, a pivotal trial in elderly patients demonstrated that combining rituximab with eight applications of CHOP significantly improved complete remission, event-free and overall survival rates when compared with CHOP alone. These positive results have meanwhile been confirmed by two additional randomized trials in elderly patients and have been extended to young patients with good-prognosis DLBCL by a fourth trial. While not yet formally established in young, poor-prognosis patients, rituximab in combination with CHOP has become accepted worldwide as the new standard for the treatment of DLBCL. Questions remain concerning the optimal dosage and schedule of rituximab for DLBCL, as well as the optimal chemotherapy regimen partner for rituximab. Rituximab is the first monoclonal antibody to consistently improve survival rates of patients with a malignant disease. Its excellent efficacy in combination with cytotoxic chemotherapy, together with its favorable toxicity profile, establishes rituximab as an indispensable component of modern standard immunochemotherapy of DLBCL.

Novel treatment strategies for aggressive non-Hodgkin's lymphoma

The World Health Organization has included different types of lymphoma under the aggressive category. In the US, diffuse large B-cell lymphoma is the most common aggressive lymphoma and accounts for > 30% of the 55,000 new cases diagnosed annually. Recent advances in the knowledge of the molecular biology have provided an increased understanding of the heterogeneity of non-Hodgkin's lymphoma. New treatments, especially those with the use of monoclonal antibodies, are improving both the survival and the response rate.

American Society of Clinical Oncology 41st annual meeting

For many years the annual meeting of the American Society of Clinical Oncology (ASCO) has been the premier meeting in clinical oncology, and one that is closely scrutinised by Wall Street and international investors because of the economic significance of cancer therapies to the pharmaceutical and biotechnology industries. The area of biologicals and targeted therapies exploded in the late 1990s after the blockbuster results with the monoclonal antibody rituximab in the treatment of lymphoma. Although historically a somewhat conservative organisation that is still closely tied to classical cytotoxic chemotherapy, ASCO has been able to integrate various areas of biological therapy into its scope of clinical activity. Although ASCO still has 'American' in its title, it is really the 'International' Society of Clinical Oncology, as reflected by the attendance at this year's meeting by approximately 30,000, with approximately two-thirds attending from outside the US. There were 9708 abstracts published in conjunction with the meeting, 86 of which are referenced in this review. There were 10 papers chosen for plenary presentations and many other key papers were presented at other oral abstract sessions and poster discussion session that were organised by tumour type. In addition to key papers submitted by specific tumour type, for this year's meeting there were 103 abstracts published in the session entitled 'Developmental Therapeutics: Immunotherapy', and 218 in the session entitled Developmental Therapeutics: Molecular Targets', for a total of 321 biological therapy abstracts compared with only 125 abstracts for the session entitled 'Developmental Therapeutics: Cytotoxic Therapy'. This meeting review is organised by biotherapy modality rather than tumour type.