Jorge Romaguera

Targeting BTK with Ibrutinib in Relapsed or Refractory Mantle-Cell Lymphoma

BACKGROUND Brutons tyrosine kinase (BTK) is a mediator of the B-cell-receptor signaling pathway implicated in the pathogenesis of B-cell cancers. In a phase 1 study, ibrutinib, a BTK inhibitor, showed antitumor activity in several types of non-Hodgkins lymphoma, including mantle-cell lymphoma. METHODS In this phase 2 study, we investigated oral ibrutinib, at a daily dose of 560 mg, in 111 patients with relapsed or refractory mantle-cell lymphoma. Patients were enrolled into two groups: those who had previously received at least 2 cycles of bortezomib therapy and those who had received less than 2 complete cycles of bortezomib or had received no prior bortezomib therapy. The primary end point was the overall response rate. Secondary end points were duration of response, progression-free survival, overall survival, and safety. RESULTS The median age was 68 years, and 86% of patients had intermediate-risk or high-risk mantle-cell lymphoma according to clinical prognostic factors. Patients had received a median of three prior therapies. The most common treatment-related adverse events were mild or moderate diarrhea, fatigue, and nausea. Grade 3 or higher hematologic events were infrequent and included neutropenia (in 16% of patients), thrombocytopenia (in 11%), and anemia (in 10%). A response rate of 68% (75 patients) was observed, with a complete response rate of 21% and a partial response rate of 47%; prior treatment with bortezomib had no effect on the response rate. With an estimated median follow-up of 15.3 months, the estimated median response duration was 17.5 months (95% confidence interval [CI], 15.8 to not reached), the estimated median progression-free survival was 13.9 months (95% CI, 7.0 to not reached), and the median overall survival was not reached. The estimated rate of overall survival was 58% at 18 months. CONCLUSIONS Ibrutinib shows durable single-agent efficacy in relapsed or refractory mantle-cell lymphoma. (Funded by Pharmacyclics and others; ClinicalTrials.gov number, NCT01236391.)

Phase III Study to Evaluate Temsirolimus Compared With Investigator's Choice Therapy for the Treatment of Relapsed or Refractory Mantle Cell Lymphoma

PURPOSE Temsirolimus, a specific inhibitor of the mammalian target of rapamycin kinase, has shown clinical activity in mantle cell lymphoma (MCL). We evaluated two dose regimens of temsirolimus in comparison with investigators choice single-agent therapy in relapsed or refractory disease. PATIENTS AND METHODS In this multicenter, open-label, phase III study, 162 patients with relapsed or refractory MCL were randomly assigned (1:1:1) to receive one of two temsirolimus regimens: 175 mg weekly for 3 weeks followed by either 75 mg (175/75-mg) or 25 mg (175/25-mg) weekly, or investigators choice therapy from prospectively approved options. The primary end point was progression-free survival (PFS) by independent assessment. RESULTS Median PFS was 4.8, 3.4, and 1.9 months for the temsirolimus 175/75-mg, 175/25-mg, and investigators choice groups, respectively. Patients treated with temsirolimus 175/75-mg had significantly longer PFS than those treated with investigators choice therapy (P = .0009; hazard ratio = 0.44); those treated with temsirolimus 175/25-mg showed a trend toward longer PFS (P = .0618; hazard ratio = 0.65). Objective response rate was significantly higher in the 175/75-mg group (22%) compared with the investigators choice group (2%; P = .0019). Median overall survival for the temsirolimus 175/75-mg group and the investigators choice group was 12.8 months and 9.7 months, respectively (P = .3519). The most frequent grade 3 or 4 adverse events in the temsirolimus groups were thrombocytopenia, anemia, neutropenia, and asthenia. CONCLUSION Temsirolimus 175 mg weekly for 3 weeks followed by 75 mg weekly significantly improved PFS and objective response rate compared with investigators choice therapy in patients with relapsed or refractory MCL.

Phase II Study of Proteasome Inhibitor Bortezomib in Relapsed or Refractory B-Cell Non-Hodgkin's Lymphoma

PURPOSE Evaluate efficacy and toxicity of bortezomib in patients with relapsed or refractory B-cell non-Hodgkins lymphoma. PATIENTS AND METHODS Patients were stratified, based on preclinical data, into arm A (mantle-cell lymphoma) or arm B (other B-cell lymphomas) without limitation in number of prior therapies. Bortezomib was administered as an intravenous push (1.5 mg/m2) on days 1, 4, 8, and 11 every 21 days for a maximum of six cycles. RESULTS Sixty patients with a median number of prior therapies of 3.5 (range, one to 12 therapies) were enrolled; 33 patients were in arm A and 27 were in arm B, including 12 diffuse large B-cell lymphomas, five follicular lymphomas (FL), three transformed FLs, four small lymphocytic lymphomas (SLL), two Waldenstroms macroglobulinemias (WM), and one marginal zone lymphoma. In arm A, 12 of 29 assessable patients responded (six complete responses [CR] and six partial responses [PR]) for an overall response rate (ORR) of 41% (95% CI, 24% to 61%), and a median time to progression not reached yet, with a median follow-up of 9.3 months (range, 1.7 to 24 months). In arm B, four of 21 assessable patients responded (one SLL patient had a CR, one FL patient had a CR unconfirmed, one diffuse large B-cell lymphoma patient had a PR, and one WM patient had a PR) for an ORR of 19% (95% CI, 5% to 42%). Grade 3 toxicity included thrombocytopenia (47%), gastrointestinal (20%), fatigue (13%), neutropenia (10%), and peripheral neuropathy (5%). Grade 4 toxicity occurred in nine patients (15%), and three deaths from progression of disease occurred within 30 days of withdrawal from study. CONCLUSION Bortezomib showed promising activity in relapsed mantle-cell lymphoma and encouraging results in other B-cell lymphomas. Future studies will explore bortezomib in combination with other cytotoxic or biologic agents.

High Rate of Durable Remissions After Treatment of Newly Diagnosed Aggressive Mantle-Cell Lymphoma With Rituximab Plus Hyper-CVAD Alternating With Rituximab Plus High-Dose Methotrexate and Cytarabine

PURPOSE To determine the response, failure-free survival (FFS), and overall survival rates and toxicity of rituximab plus an intense chemotherapy regimen in patients with previously untreated aggressive mantle-cell lymphoma (MCL). PATIENTS AND METHODS This was a prospective phase II trial of rituximab plus fractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone (hyper-CVAD; considered one cycle) alternating every 21 days with rituximab plus high-dose methotrexate-cytarabine (considered one cycle) for a total of six to eight cycles. RESULTS Of 97 assessable patients, 97% responded, and 87% achieved a complete response (CR) or unconfirmed CR. With a median follow-up time of 40 months, the 3-year FFS and overall survival rates were 64% and 82%, respectively, without a plateau in the curves. For the subgroup of patients < or = 65 years of age, the 3-year FFS rate was 73%. The principal toxicity was hematologic. Five patients died from acute toxicity. Four patients developed treatment-related myelodysplasia/acute myelogenous leukemia, and three patients died while in remission from MCL. A total of eight treatment-related deaths (8%) occurred. CONCLUSION Rituximab plus hyper-CVAD alternating with rituximab plus high-dose methotrexate and cytarabine is effective in untreated aggressive MCL. Toxicity is significant but expected. Because of the shorter FFS concurrent with significant toxicity in patients more than 65 years of age, this regimen is not recommended as standard therapy for this age subgroup. Larger prospective randomized studies are needed to define the role of this regimen in the treatment of MCL patients compared with existing and new treatment modalities.

ESHAP--an effective chemotherapy regimen in refractory and relapsing lymphoma: a 4-year follow-up study.

PURPOSE This study attempted to determine the efficacy of the combination of etoposide (VP-16), methyl-prednisolone, and cytarabine (Ara-C) with or without cisplatin in relapsing and refractory adult lymphoma patients. PATIENTS AND METHODS The first 63 patients were randomized to receive VP-16 40 mg/m2/d for 4 days, methylprednisolone 500 mg intravenously daily for 5 days, and Ara-C 2 g/m2 intravenously over 2 to 3 hours on day 5 with or without cisplatin 25 mg/m2 IV administered by 24-hour infusion for 4 days (ESHA +/- P). Markedly different responses between ESHA (33%) and ESHAP (75%) led to deletion of the ESHA arm. A total of 122 patients on the ESHAP regimen were studied. RESULTS Forty-five patients (37%) attained a complete remission (CR) and 33 (27%) attained a partial remission (PR), for a total response rate of 64%. The median duration of CR was 20 months, with 28% of remitters still in CR at 3 years. The overall median survival duration was 14 months; the survival rate at 3 years was 31%. Overall time to treatment failure (TTF) showed 10% of all patients to be alive and disease-free at 40 months. Response and survival rates were similar in patients with low-grade (n = 34), intermediate-grade (n = 67), transformed (n = 18), and high-grade (n = 3) lymphoma. The most significant factors for response and survival by multivariate analysis were the serum lactic dehydrogenase (LDH) level, tumor burden, and age (when analyzed as a continuous variable), while prior CR was highly significant by univariate analysis. A significant difference in survival was noted for patients with normal LDH levels and low- or intermediate-tumor burden or patients with low tumor burden and elevated LDH levels (55% 3-year survival rate) versus patients with elevated LDH levels and intermediate or high tumor burden (< 20%). Major toxicities included myelosuppression, with a median granulocyte count of 500/microL and platelet count of 70,000/microL. CONCLUSION ESHAP was found to be an active, tolerable chemotherapy regimen for relapsing and refractory lymphoma. Applying a prognostic model based on tumor burden and serum LDH level shows significant differences in survival in this patient population.

Hyper-CVAD and high-dose methotrexate/cytarabine followed by stem-cell transplantation: an active regimen for aggressive mantle-cell lymphoma.

PURPOSE Diffuse and nodular forms of mantle-cell lymphoma (MCL) are consistently associated with poor prognosis. In an effort to improve the outcome, we adopted a treatment plan that consisted of four courses of fractionated cyclophosphamide (CY) 1,800 mg/m2 administered with doxorubicin (DOX), vincristine (VCR), and dexamethasone (Hyper-CVAD) that alternated with high-dose methotrexate (MTX) and cytarabine (Ara-C). After four courses, patients were consolidated with high-dose CY, total-body irradiation, and autologous or allogeneic blood or marrow stem-cell transplantation. PATIENTS AND METHODS Forty-five patients were enrolled; 25 patients were previously untreated, 43 patients had Ann Arbor stage IV disease, and 42 patients had marrow involvement. Forty-one patients had diffuse histology, two patients had nodular, and two patients had blastic variants. RESULTS Hyper-CVAD/MTX-Ara-C induced a response rate of 93.5% (complete response [CR], 38%; partial response [PR], 55.5%) after four cycles of pretransplantation induction chemotherapy. All patients who went on to undergo transplantation achieved CRs. For the 25 previously untreated patients, the overall survival (OS) and event-free survival (EFS) rates at 3 years were 92% (95% confidence interval [CI], 80 to 100) and 72% (95% CI, 45 to 98) compared with 25% (95% CI, 12 to 62; P = .005) and 17% (95% CI, 10 to 43; P = .007), respectively, for the previously treated patients. When compared with a historic control group who received a CY, DOX, VCR, and prednisone (CHOP)-like regimen, untreated patients in the study had a 3-year EFS rate of 72% versus 28% (P = .0001) and a better OS rate (92% v 56%; P = .05). Treatment-related death occurred in five patients: all were previously treated and two received allogeneic transplants. CONCLUSION The Hyper-CVAD/MTX-Ara-C program followed by stem-cell transplantation is a promising new therapy for previously untreated patients with MCL.

Safety and Activity of PD1 Blockade by Pidilizumab in Combination with Rituximab in Patients with Relapsed Follicular Lymphoma: a Single Group, Open-label, Phase 2 Trial

BACKGROUND Endogenous or iatrogenic antitumour immune responses can improve the course of follicular lymphoma, but might be diminished by immune checkpoints in the tumour microenvironment. These checkpoints might include effects of programmed cell death 1 (PD1), a co-inhibitory receptor that impairs T-cell function and is highly expressed on intratumoral T cells. We did this phase 2 trial to investigate the activity of pidilizumab, a humanised anti-PD1 monoclonal antibody, with rituximab in patients with relapsed follicular lymphoma. METHODS We did this open-label, non-randomised trial at the University of Texas MD Anderson Cancer Center (Houston, TX, USA). Adult (≥18 years) patients with rituximab-sensitive follicular lymphoma relapsing after one to four previous therapies were eligible. Pidilizumab was administered at 3 mg/kg intravenously every 4 weeks for four infusions, plus eight optional infusions every 4 weeks for patients with stable disease or better. Starting 17 days after the first infusion of pidilizumab, rituximab was given at 375 mg/m(2) intravenously weekly for 4 weeks. The primary endpoint was the proportion of patients who achieved an objective response (complete response plus partial response according to Revised Response Criteria for Malignant Lymphoma). Analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00904722. FINDINGS We enrolled 32 patients between Jan 13, 2010, and Jan 20, 2012. Median follow-up was 15.4 months (IQR 10.1-21.0). The combination of pidilizumab and rituximab was well tolerated, with no autoimmune or treatment-related adverse events of grade 3 or 4. The most common adverse events of grade 1 were anaemia (14 patients) and fatigue (13 patients), and the most common adverse event of grade 2 was respiratory infection (five patients). Of the 29 patients evaluable for activity, 19 (66%) achieved an objective response: complete responses were noted in 15 (52%) patients and partial responses in four (14%). INTERPRETATION The combination of pidilizumab plus rituximab is well tolerated and active in patients with relapsed follicular lymphoma. Our results suggest that immune checkpoint blockade is worthy of further study in follicular lymphoma. FUNDING National Institutes of Health, Leukemia and Lymphoma Society, Cure Tech, and University of Texas MD Anderson Cancer Center.

Fludarabine, mitoxantrone, and dexamethasone: an effective new regimen for indolent lymphoma.

PURPOSE Although most patients with indolent lymphomas respond to initial therapy, virtually all experience relapse. Secondary therapy is often beneficial, but responses are rarely, if ever, durable. We conducted this phase II trail to evaluate the therapeutic efficacy and toxicity of fludarabine, mitoxantrone, and dexamethasone (FND) in patients with relapsed indolent lymphoma. PATIENTS AND METHODS Fifty-one patients with recurrent or refractory indolent lymphoma were treated with a regimen of fludarabine 25 mg/m2/d intravenously (IV) on days 1 to 3, mitoxantrone 10 mg/m2 IV on day 1, and dexamethasone 20 mg/d IV or orally on days 1 to 5. Treatment was repeated at 4-week intervals for a maximum of eight courses. Late in the course of this trial, trimethoprim-sulfamethoxazole (TMP-SMX) was incorporated for Pneumocystis carinii (PCP) prophylaxis. RESULTS Responses were complete (CR) in 24 patients (47%) and partial (PR) in 24 (47%). The median failure-free survival time was 21 months for CR patients and 9 months for PR patients. Notable activity of FND was seen even in the elderly, in those with high serum lactate dehydrogenase (LDH) or beta2-microglobulin levels, and in those with multiple prior treatment regimens. The predominant toxic effects were myelosuppression and infections; other toxic effects were modest. Infections occurred in 12% of courses. Almost half of the infections were proven or suspected opportunistic infections, including six cases of dermatomal herpes zoster and two cases of proven PCP pneumonia. CONCLUSION The FND combination is highly active in patients with recurrent or relapsed indolent lymphoma and results in a high percentage of CRs. Because of the risk of opportunistic infections, we currently recommend prophylaxis with TMP-SMX and advise deletion of corticosteroids for patients who develop opportunistic infections.

Antibiotic Treatment of Gastric Lymphoma of Mucosa-Associated Lymphoid Tissue: An Uncontrolled Trial

Gastric low-grade B-cell lymphoma is related to Helicobacter pylori infection according to histopathologic, epidemiologic, and clinical characteristics. Although normal gastric mucosa does not contain organized lymphoid tissue, lymphoid follicles develop with H. pylori infection (1) and with autoimmune diseases, such as the Sjgren syndrome (2). Low-grade B-cell lymphoma has been postulated to arise within this mucosa-associated lymphoid tissue (MALT) and is often called low-grade MALT lymphoma (3, 4). The incidence of gastric low- and high-grade MALT lymphoma is increased in populations with a high prevalence of H. pylori infection, and H. pylori infection has been reported in up to 90% of patients with low-grade MALT lymphoma (4-6). In addition, investigators have shown that growth of this tumor may depend on antigenic stimulation by H. pylori: They demonstrated that the proliferation of lymphoma B cells in cell culture can be stimulated by H. pylori-specific T cells and related cytokines in the presence of H. pylori (7). On the basis of these findings, trials of antibiotic treatment of gastric low-grade MALT lymphoma have been initiated, and the regression of lymphoma after cure of H. pylori infection has been reported in a high proportion of patients with low tumor burden (8-13). Data on patients with significant tumor infiltration are still forthcoming (13, 14). Because MALT lymphoma has only recently been approached as a distinct clinicopathologic entity (15, 16), its natural history and clinical course are not fully defined. Current data suggest that it is often an indolent tumor with long periods of mild activity and confinement to the stomach. Patients often present with nonspecific upper intestinal discomfort, ulcer-associated symptoms, or gastric bleeding. The endoscopic appearance may suggest benign gastritis, and extensive biopsies may be required for diagnosis. Progression to significant tumor mass, dissemination, or transformation to high-grade, aggressive lymphoma occur in an undefined subset of patients, who may present with early satiety or weight loss. Spontaneous remissions are rare (17-20). Because low-grade MALT lymphoma is an uncommon, often indolent form of cancer with few clinical findings and because the risk for progression to high-grade MALT lymphoma is still unknown (15, 16), definitive data on cure require long-term follow-up of large cohorts from standardized clinical trials. This report presents an interim analysis of an ongoing trial designed to determine the long-term response of low-grade gastric MALT lymphoma to antibiotic treatment and to define criteria for treatment and follow-up. Methods Patients Patients with gastric MALT lymphoma restricted to the stomach and perigastric lymph nodes (modified Ann Arbor stage I and II N1) were eligible for the study. The University of Texas, M.D. Anderson Cancer Center (MDACC), Internal Review Board approved the study, and all patients provided written informed consent. The National Cancer Institute and the institutional review boards of participating institutions approved the multi-institutional protocol. To enable a follow-up period of at least 18 months, only patients treated before May 1997 were included in this analysis. Study Design and Treatment The interim data are derived from an ongoing, prospective, uncontrolled treatment trial with third-party patient registry. Patients were studied at four participating centers. Pathologic diagnosis and resolution of MALT lymphoma were confirmed at MDACC, and all but one patient were examined endoscopically at MDACC. Study design included 1) tumor staging with bilateral bone marrow biopsies and aspirates and computed tomography of the abdomen and pelvis done at baseline and yearly; 2) endoscopy at baseline, at weeks 6 to 8, at 3- to 4-month intervals thereafter until resolution of MALT lymphoma was seen on two consecutive endoscopies, at 6-month intervals thereafter for 2 years, and then yearly thereafter; and 3) endoscopic ultrasonography at baseline and at each endoscopy until resolution of masses or infiltration of the muscularis propria, if present (defined as thickness>2 mm or obliteration of wall architecture), and then at 6- to 12-month intervals. The treatment protocol consisted of two of the following three oral antibiotic regimens1] amoxicillin, 750 mg three times daily, and clarithromycin, 500 mg three times daily; 2) tetracycline, 500 mg four times daily, and clarithromycin, 500 mg three times daily; or 3) tetracycline, 500 mg four times daily, and metronidazole, 500 mg three times dailyadministered sequentially for 21 days at baseline and at 8 weeks along with a proton-pump inhibitor (lansoprazole, 30 mg twice daily [n=29], or omeprazole, 20 mg twice daily [n=5]), and bismuth subsalicylate, two tablets four times daily. Patients who were allergic to penicillin received the tetracycline-based regimens. Tumor Staging Tumors were staged endoscopically to separate superficial gastritis from significant ulcers and infiltration and from mass lesions. A modified Ann Arbor staging system that incorporated changes proposed by Blackledge, Musshoff, and Rohatiner and their coworkers was used initially (21-23). The TNM (tumor, node, metastasis) classification of the American Joint Committee on Cancer and Union Internationale Contre le Cancer (24, 25), which corresponds to the modified Ann Arbor staging, was subsequently adapted and applied (Table 1). The extent of tumor (T) infiltration through the stomach wall and to adjacent organs corresponds to T staging of gastric cancer. Modified Ann Arbor stage I corresponds to stage I T1-4 N0 M0. Modified Ann Arbor stage II1 (22) (involvement of perigastric lymph nodes) corresponds to stage II T1-4 N1 M0. Modified Ann Arbor stage II2 (22) (involvement of distant lymph nodes caudal to the diaphragm, including para-aortic and retroperitoneal lymph nodes) corresponds to stage II T1-4 N2 M0. Ann Arbor stage III (lymph node involvement on both sides of the diaphragm) is designated by stage III T1-4 N3 M0. Ann Arbor stage IV (organ metastasis or involvement of a second extranodal site) is designated by stage IV T1-4 N0-3 M1. Table 1. Staging of Gastric Lymphoma of Mucosa-Associated Lymphoid Tissue Criteria for Response Response to treatment was evaluated at 3- to 4-month intervals beginning with the fifth month after treatment. Treatment was considered to have failed if patients did not meet criteria for improvement; these patients were removed from the study. In stage I T2, I T3, and II N1 tumors, improvement was defined as regression to a lower stage, 30% reduction in abnormal wall thickness, or 30% reduction in the size of the tumor mass (product of the greatest diameters). These patients remained in the study if sequential improvement was evident at each 3-month interval. Patients with persistent mucosal disease (stage I T1) documented by histopathology were formally reviewed at 12-month intervals; a consensus on withdrawal from or continuation in the study was based on clinical considerations, current knowledge, and patient preference. Initially, patients with persistent stage I T1 disease were withdrawn from the study at 12 months (n=2). Subsequently, patients with persistent stage I T1 disease were observed for more than 36 months if improvement was documented at 12-month intervals. Criteria for improvement in stage I T1 disease included reduction in the number of affected gastric sites or affected biopsy specimens or improved histologic score (8), endoscopic appearance of progressive atrophy and scarring, or resolution of abnormal wall thickness on endoscopic ultrasonography. Complete remission was defined as the absence of histopathologic evidence of lymphoma and an endoscopic appearance of gastritis or better. Partial remission was defined as a reduction in endoscopic stage in stage I T2 disease or at least 50% reduction in the size of the mass lesions in stage I T3 or II T3 N1 disease. In stage I T1 disease, partial remission was defined as at least 75% reduction in the number of gastric sites or biopsy specimens showing lymphoma. Treatment was considered to have failed in patients who met criteria for failure or who were withdrawn from the study before complete remission occurred. Endoscopy and Biopsies The gastric mapping protocol included 2 or more maximum-capacity biopsies from each of 7 to 12 areas of the gastric map (26) and at least 6 biopsies from 2 or more of the most abnormal areas. The more extensive mapping was done at baseline and at clinically relevant time points. Studies, done at defined intervals, included routine histopathology, H. pylori testing by Genta stain, rapid urease test (CLO-test, Delta West, Bentley, Australia) or serology, Southern blot or polymerase chain reaction (PCR) for immunoglobulin gene rearrangement analysis, and immunoglobulin light-chain immunocytochemistry. Diagnostic Criteria Low-grade B-cell MALT lymphoma was diagnosed by established histologic criteria [15, 27], including 1) a dense diffuse infiltrate of marginal-zone centrocyte-like B cells with round to slightly irregular nuclear contours, often with abundant pale cytoplasm; 2) presence of lymphoepithelial lesions, characterized by infiltration and disruption of gastric glands or crypts by groups of neoplastic lymphoid cells; and 3) absence of any areas where large cells predominate. Minor criteria supporting but not essential for diagnosis included presence of immunoglobulin light-chain restriction; presence of residual secondary follicle centers with or without intact mantles; and presence of follicular colonization, defined as replacement of follicle centers by neoplastic lymphoid cells. Immunophenotypic expression of pan-B-cell antigens, such as CD20, and lack of expression of CD5 or CD10 supported the diagnosis. Patients with foci of large-cell transformation were excluded from the study. Southern Blot and Polymerase Chain Reaction High-molec

Improvement of Overall and Failure-Free Survival in Stage IV Follicular Lymphoma: 25 Years of Treatment Experience at The University of Texas M.D. Anderson Cancer Center

PURPOSE Advanced-stage follicular lymphoma is considered incurable. The pace of improvements in treatment has been slow. This article analyzes five sequential cohorts of patients with stage IV follicular lymphoma treated between 1972 and 2002. METHODS Five consecutive studies (two were randomized trials) involving 580 patients were analyzed for overall survival (OS), failure-free survival (FFS), and survival after first relapse. A proportional hazards analysis, and subset analyses using the follicular lymphoma international prognostic index (FLIPI) score were performed. Treatment regimens included: cyclophosphamide, doxorubicin, vincristine, prednisone, bleomycin (CHOP-Bleo); CHOP-Bleo followed by interferon alfa (IFN-alpha); a rotation of three regimens (alternating triple therapy), followed by IFN-alpha; fludarabine, mitoxantrone, dexamethasone (FND) followed by IFN-alpha; and FND plus delayed versus concurrent rituximab followed by IFN-alpha. RESULTS Improvements in 5-year OS (from 64% to 95%) and FFS (from 29% to 60%) indicate steady progress, perhaps partly due to more effective salvage therapies, but the FFS data also indicate improved front-line therapies; these observations held true after controlling for differences in prognostic factors among the cohorts. The FLIPI model adds rigor to and facilitates comparisons among the different cohorts. An unexpected finding in this study was a trend toward an apparent FFS plateau. CONCLUSION Evolving therapy, including the incorporation of biologic agents, has led to stepwise significant outcome improvements for patients with advanced-stage follicular lymphoma. The apparent plateau in the FFS curve, starting approximately 8 to 10 years from the beginning of treatment, raises the issue of the potential curability of these patients.