ABSTRACT: Radioimmunoconjugates are radioisotope-bound monoclonal antibodies that target radiation specifically to sites of lymphoma involvement. Initial studies of (131)I-tositumomab in non-Hodgkin lymphoma (NHL) have suggested benefit in patients with relapsed or refractory indolent disease. However, the routine adoption of this agent is tempered by concerns about associated toxicities and unclear long-term benefit. Based on a comprehensive search for studies on (131)I-tositumomab use in lymphoma, this systematic review summarizes and evaluates the evidence on the benefits and risks of this novel therapy,the predictors for response and toxicity, and the role of dosimetry and imaging studies before treatment.We identified 18 trials investigating the use of (131)I-tositumomab for the treatment of adult patients with nhl. In trials of patients with relapsed or refractory indolent nhl, overall response rates ranged from 67% to 83%. In patients with follicular nhl refractory to the monoclonal antibody rituximab, response rates remained high (65%-72%). However, in rituximab-naïve patients with relapsed or refractory indolent or transformed nhl, improvements in time to progression or survival have not been clearly established. (131)I-Tositumomab is an active agent in relapsed and refractory non-Hodgkin lymphoma that should be considered in selected patients.
Project description:Radioimmunotherapy (RIT) is effective treatment for indolent non-Hodgkin lymphomas (NHLs), but response durations are usually limited, especially in aggressive NHL. We hypothesized that administration of bortezomib as a radiosensitizer with RIT would be tolerable and improve efficacy in NHL. This phase 1 dose-escalation study evaluated escalating doses of bortezomib combined with 131I-tositumomab in patients with relapsed/refractory NHL. Twenty-five patients were treated. Treatment was well tolerated, with primarily hematologic toxicity. The maximum tolerated dose (MTD) was determined to be 0.9 mg/m2 bortezomib, in combination with a standard dose of 75 cGy 131I-tositumomab. Sixteen patients responded (64%), including 44% complete responses (CRs), with 82% CR in patients with follicular lymphoma (FL). At a median follow-up of 7 months, median progression-free survival was 7 months, and seven of 11 patients with FL remained in remission at a median of 22 months. In conclusion, bortezomib can be safely administered in combination with 131I-tositumomab with promising response rates.
Project description:Although initial rituximab-containing chemotherapies achieve high response rates, indolent B-cell non-Hodgkin lymphoma (B-NHL), such as follicular lymphoma (FL), is still incurable. Therefore, new effective agents with novel mechanisms are anticipated. In this multicentre phase II study, patients with relapsed/refractory indolent B-NHL and mantle cell lymphoma (MCL) received vorinostat 200 mg twice daily for 14 consecutive days in a 21-d cycle until disease progression or unacceptable toxicity occurred. The primary endpoint was overall response rate (ORR) in FL patients and safety and tolerability in all patients. Secondary endpoints included progression-free survival (PFS). Fifty-six eligible patients were enrolled; 50 patients (39 with FL, seven with other B-NHL, and four with MCL) were evaluable for ORR, and 40 patients had received rituximab-containing prior chemotherapeutic regimens. For the 39 patients with FL, the ORR was 49% [95% confidence interval (CI): 32·4, 65·2] and the median PFS was 20 months (95% CI: 11·2, 29·7). Major toxicities were manageable grade 3/4 thrombocytopenia and neutropenia. Vorinostat offers sustained antitumour activity in patients with relapsed or refractory FL with an acceptable safety profile. Further investigation of vorinostat for clinical efficacy is warranted.
Project description:Myeloablative therapy and autologous stem cell transplantation (ASCT) are underutilized in older patients with B cell non-Hodgkin (B-NHL) lymphoma. We hypothesized that myeloablative doses of (131)I-tositumomab could be augmented by concurrent fludarabine, based on preclinical data indicating synergy. Patients were ? 60 years of age and had high-risk, relapsed, or refractory B-NHL. Therapeutic infusions of (131)I-tositumomab were derived from individualized organ-specific absorbed dose estimates delivering ? 27 Gy to critical organs. Fludarabine was initiated 72 hours later followed by ASCT to define the maximally tolerated dose. Thirty-six patients with a median age of 65 years (range, 60 to 76), 2 (range, 1 to 9) prior regimens, and 33% with chemoresistant disease were treated on this trial. Dose-limiting organs included lung (30), kidney (4), and liver (2) with a median administered (131)I activity of 471 mCi (range, 260 to 1620). Fludarabine was safely escalated to 30 mg/m(2) × 7 days. Engraftment was prompt, there were no early treatment-related deaths, and 2 patients had ? grade 4 nonhematologic toxicities. The estimated 3-year overall survival, progression-free survival, and nonrelapse mortality were 54%, 53%, and 7%, respectively (median follow up of 3.9 years). Fludarabine up to 210 mg/m(2) can be safely delivered with myeloablative (131)I-tositumomab and ASCT in older adults with B-NHL.
Project description:CD37 is cell surface tetraspanin present on normal and malignant B cells. Otlertuzumab (TRU-016) is a novel humanized anti-CD37 protein therapeutic that triggers direct caspase independent apoptosis of malignant B cells and induces antibody-dependent cell-mediated cytotoxicity. This study evaluated the safety, pharmacokinetics, and efficacy of otlertuzumab administered in combination with rituximab and bendamustine to patients with relapsed, indolent B-cell non-Hodgkin Lymphoma (NHL).Patients with relapsed or refractory NHL received otlertuzumab (10 or 20 mg/kg) intravenously (IV) on days 1 and 15, bendamustine (90 mg/m(2)) on days 1 and 2, and rituximab (375 mg/m(2)) on day 1 for up to six 28 day cycles. Responses were determined using standard criteria.Twelve patients were treated with 6 patients at each dose level; median age was 57 years (range, 51-79), and median number of prior regimens was 3 (range, 1-4). All patients had relapsed after prior rituximab including 7 refractory to their most recent previous treatment. In the 10 and 20 mg/kg dose cohorts, the mean half-life was 8 and 10 days following the first dose, and 12 or 14 days following 12 doses of otlertuzumab, respectively. Overall response rate was 83% (10/12) with 4 CRs (32%). The most frequent adverse events were neutropenia, nausea, fatigue, leukopenia, and insomnia; most were grade 1 or 2.Otlertuzumab in combination with rituximab and bendamustine was well tolerated and induced responses in the majority of patients with relapsed indolent B-NHL. NCI Clinical Trials Network registration: NCT01317901.
Project description:As a result of the anti-tumour activity observed in vitro and in vivo with combined anti-CD20 and anti-CD74 antibodies, we initiated a phase I/II trial of veltuzumab and milatuzumab in patients with relapsed or refractory B-cell non-Hodgkin lymphoma (NHL). Patients received an induction of veltuzumab 200 mg/m(2) weekly combined with escalating doses of milatuzumab at 8, 16 and 20 mg/kg weekly for 4 weeks. Patients without disease progression could receive an extended induction with treatment on weeks 12, 20, 28 and 36. A total of 35 patients enrolled on the study. Median age was 63 years, median number of prior therapies was 3, and 63% of patients were rituximab refractory. No dose-limiting toxicities were observed in the phase I study. Related grade 3-4 toxicities included lymphopenia, leucopenia, neutropenia, anaemia, infusion reactions, hyperglycaemia, fatigue and atrial tachycardia. Median weeks of therapy was 12 and 29% of patients completed all 36 weeks of therapy. The overall response rate was 24%, median duration of response was 12 months, and responses were observed at all dose levels and in 50% of patients refractory to rituximab. Combination therapy with veltuzumab and milatuzumab demonstrated activity in a population of heavily pre-treated patients with relapsed or refractory indolent NHL.
Project description:Outcomes for patients with non-Hodgkin's lymphoma (NHL) that proves refractory to treatment remain poor. Treatment of such patients is individualized and can include enrolment in a clinical trial of novel agents or use of one of a wide array of drug regimens. Initial treatment with anthracyclines such as doxorubicin limits options at later stages of treatment because of anthracycline-related cumulative cardiotoxicity. The aza-anthracenedione pixantrone was developed to reduce the likelihood of cardiotoxicity without compromising efficacy and is currently conditionally approved for use as monotherapy in patients with multiply-relapsed or refractory aggressive B cell NHL. The use of pixantrone in combination therapy, often to replace doxorubicin or mitoxantrone, has or is currently being investigated in numerous studies in patients with aggressive or indolent NHL and is the focus of this review. These include the R-CPOP regimen (rituximab, cyclophosphamide, pixantrone, vincristine, prednisone) for aggressive NHL in the first-line setting, including a study in elderly patients with limited cardiac function, and for patients with relapsed NHL with prior anthracycline exposure; the PSHAP regimen (pixantrone, cytarabine, prednisone, cisplatin), also in the latter setting; the PREBen/PEBen regimen (pixantrone, bendamustine and etoposide with or without rituximab) as salvage therapy; and pixantrone in combination with fludarabine, dexamethasone, and rituximab (FPD-R) for relapsed indolent NHL.
Project description:PRO131921 is a third-generation, humanized anti-CD20 monoclonal antibody with increased antibody-dependent cytotoxicity and complement-dependent cytotoxicity compared to rituximab. In this phase I study, PRO131921 was administered as a single agent to patients with CD20+, relapsed or refractory, indolent non-Hodgkin lymphoma (NHL) who had been treated with a prior rituximab-containing regimen. The primary aim of this study was safety and tolerability of PRO131921. The secondary aim of the study, and focus of this report, was to determine the pharmacokinetics (PK) profile of PRO131921 and establish a correlation between drug exposure and clinical efficacy. Patients were treated with PRO131921 by intravenous infusion weekly for 4 weeks and the dose was escalated based on safety in a 3+3 design. Twenty-four patients were treated with PRO131921 at doses from 25mg/m(2) to 800 mg/m(2). Analysis of PK data demonstrated a correlation between higher normalized drug exposure (normalized AUC) and tumor shrinkage (p = .0035). Also, normalized AUC levels were higher among responders and subjects displaying tumor shrinkage versus subjects progressing or showing no regression (p = 0.030). In conclusion, PRO131921 demonstrated clinical activity in rituximab-relapsed and refractory indolent NHL patients. The observation that higher normalized AUC may be associated with improved clinical responses has potential implications in future trials of monoclonal antibody-based therapies, and emphasizes the importance of early PK studies to optimize antibody efficacy.
Project description:For patients with advanced indolent non-Hodgkin's lymphoma (NHL) or elderly patients with mantle cell lymphoma (MCL), the recently reported results of the German StiL NHL-1 2003 and the international BRIGHT phase III trials showed that, as first-line treatment, the combination of bendamustine and rituximab is at least as effective as rituximab/cyclophosphamide/doxorubicin/vincristine/prednisone or rituximab/cyclophosphamide/vincristine/prednisone, possibly with a better therapeutic index. Bendamustine is therefore increasingly used in clinical practice. Because bendamustine has been used for many years in Germany and in Switzerland, our institutions have had extensive experience with bendamustine, both as a single agent and in combination with rituximab. In this comprehensive review, we summarize the most important clinical data from phase II/III trials with bendamustine in patients with indolent NHL and MCL, both in the relapsed/refractory setting and in the first-line setting. In addition, this review provides practical advice on how to optimally manage bendamustine therapy in patients with NHL.
Project description:Lenalidomide, an immunomodulatory drug that the US Food and Drug Administration (FDA) approved for the treatment of multiple myeloma, 5q- myelodysplasia and mantle-cell lymphoma (MCL), has encouraging efficacy in other B-cell malignancies. Its unique mechanism of action is in part due to altering the tumor microenvironment and potentiating the activity of T and natural-killer (NK) cells. Impressive clinical activity and excellent tolerability allows broad applicability. Lenalidomide has been used in a wide range of B-cell malignancies for years, but in 2013, the FDA marked its approval as a single agent only in relapsed/refractory mantle-cell lymphoma. Perhaps most impressive is the efficacy of lenalidomide when combined with monoclonal antibodies. Impressive efficacy and toxicity profiles with the combination of lenalidomide and rituximab in B-cell lymphomas in both the upfront and relapsed/refractory setting may allow a shift in our current treatment paradigm in both indolent and aggressive non-Hodgkin lymphoma (NHL). This review will summarize the current data in the relapsed/refractory and front-line setting of NHL with single-agent lenalidomide as well as its use in combination with other agents.
Project description:Rituximab therapy is associated with a long in vivo persistence, yet little is known about the effect of circulating rituximab on B-cell non-Hodgkin lymphoma (B-NHL) targeting by the other available anti-CD20 monoclonal antibodies (MoAbs) (131)iodine-tositumomab and (90)yttrium-ibritumomab tiuxetan. Therefore we assessed the impact of preexisting rituximab on the binding and efficacy of second anti-CD20 MoAbs to B-NHL and determined whether targeting an alternative lymphoma-associated antigen, CD45, could circumvent this effect. We demonstrated that rituximab concentrations as low as 5 microg/mL nearly completely blocked the binding of a second anti-CD20 MoAbs (P < .001), but had no impact on CD45 targeting (P = .89). Serum from patients with distant exposures to rituximab also blocked binding of anti-CD20 MoAbs to patient-derived rituximab-naive B-NHL at concentrations at low as 7 microg/mL, but did not affect CD45 ligation. A mouse xenograft model (Granta, FL-18, Ramos cell lines) showed that rituximab pretreatment significantly reduced B-NHL targeting and tumor control by CD20-directed radioimmunotherapy (RIT), but had no impact on targeting CD45. These findings suggest that circulating rituximab impairs the clinical efficacy of CD20-directed RIT, imply that novel anti-CD20 MoAbs could also face this same limitation, and indicate that CD45 may represent an alternative target for RIT in B-NHL.