Real-world data from yttrium-90 ibritumomab tiuxetan treatment of relapsed or refractory indolent B-cell non-Hodgkin's lymphoma: J3Zi Study

Yttrium-90 ibritumomab tiuxetan (90YIT) is a radioimmunotherapy agent in which the radioisotope yttrium-90 is bound to ibritumomab via tiuxetan as a chelating agent, and is used for relapsed or refractory low-grade B-cell non-Hodgkin's lymphoma (rr-B-NHL). We conducted a joint study to evaluate the clinical outcome of 90YIT. The J3Zi study is composed of data from patients receiving 90YIT for rr-B-NHL from the top three institutions with 10 years of 90YIT treatment experience from October 2008 to May 2018 in Japan. The efficacy, prognostic factors and safety of 90YIT were retrospectively evaluated. Data from 316 patients were analyzed; the mean age was 64.6 years and the median number of prior treatments was 2. The median PFS was 3.0 years, the final OS rate was over 60%, and the median OS was not reached during the study period. Significant factors influencing PFS were sIL-2R ≤ 500 (U/mL) and no disease progression within 24 months of first treatment. Significant factors influencing OS were number of prior treatments ≤ 2 and sIL-2R ≤ 500 (U/mL). The PFS and OS rates were found to be significantly higher in the late half era (2013 to 2018) than in the early half era (2008 to 2013) during the study period. Prognosis following 90YIT treatment was improved in the late half era compared to the early half era. As treatment using 90YIT increased, administration of 90YIT shifted to the earlier treatment line. This may have contributed to the improvement of prognosis found in the late era. (UMIN000037105).

Radioimmunotherapy in Oncology: Overview of the Last Decade Clinical Trials

Simple Summary

Monoclonal antibody-bearing radionuclides have been under clinical investigation over the last two decades for their use in theranostic (diagnostic and therapeutic) applications in cancer. However, despite the numerous trials that have been conducted, only two radioimmunotherapies (RIT) have been approved by the FDA for the targeted therapy of hematologic tumors expressing CD20 antigens. Moreover, RIT applications for solid cancers faced major issues—such as radiotoxicity due to low antibodies penetrance requiring substantial curative dose—where new discoveries concerning antibody engineering or radionuclides are trying to overcome. Here, we performed an overview of the last 11-year clinical trials involving RIT for solid and non-solid cancers conducted either with full antibodies or antibody fragments. We discussed the low-to-moderate efficiency of RIT compared to conventional therapies and described the last advances in clinic for antibodies carriers (F(ab′)₂, Fab′, ScFv). Finally, we discussed about the complexity of RIT as a therapy and depicted both the issues and the prospects of such a strategy.

Abstract

The specific irradiation of tumors with selective radiolabeled antibodies constitutes an attractive therapeutic approach. Consequent preclinical research has been conducted by both biologists to identify pertinent targets and to select corresponding antibodies (mAb) and by radiochemists to radiolabel mAbs. These numerous preclinical investigations have ascertained the therapeutic interest of radioimmunotherapy (RIT) protocols in mice models. Here, we summarize the clinical studies that have been performed the last decade, including clinical trials (phases I, II, and III), prospective and retrospective studies, and cases series. We thereby reported 92 clinical studies. Among them, 62 concern the treatment of hematological malignancies, and 30 concern solid tumors. For hematologic diseases, the analysis was complex due to the high discrepancy of therapeutic strategies (first-line therapy, consolidation, stem cell transplantation conditioning) as well as the high variety of malignancies that were treated. The clinical studies from the last decade failed to expand anti-CD20 RIT indications but confirmed that RIT using radiolabeled anti-CD20 remains a pertinent choice for patients with relapse follicular lymphomas. For solid tumors, the positive benefit of RIT is more mitigated, apart for few malignancies that can be treated locally. Clinical trials also demonstrated the potential of some antibody formats, such as F(ab′)₂, which has already been approved by the China State FDA under the trend name Licartin®. Despite disparate results, mAb fragments are an interesting prospect for the improvement of RIT efficiency as well as for pretargeted strategies that delay the injection of radioactive treatments from the mAb ones.

Adverse events of radioimmunotherapy for non-Hodgkin lymphoma: A systematic review and meta-analysis

Non-Hodgkin's lymphoma continues to be a highly prevalent entity in the general population. Currently, there are multiple treatment schemes based on chemotherapeutic agents with a great success rate. However, there is a non-negligible percentage of patients who may relapse or be refractory. In this sense, new therapeutic options have emerged in the search for adequate responses, such as monoclonal antibodies that target the CD20 molecule. Another valid option is radioimmunotherapy (RIT), which combines using monoclonal antibodies for the specific targeting of malignant cells and radiation to destroy these cells. Despite the promising results that favor RIT in several clinical studies in different target populations and types of NHL, one situation to consider is the association of this therapy and second neoplasms (acute myeloid leukemia (AML) or myelodysplastic syndrome (MSD)). In this sense, we have proposed this meta-analysis to analyze the published information and determine the incidence of this association and determine this therapy's safety.

Consolidation with 90 Yttrium-ibritumomab tiuxetan after bendamustine and rituximab for relapsed follicular lymphoma

Bendamustine and rituximab (BR) are widely used in patients with follicular lymphoma (FL) previously treated with conventional immunochemotherapy, but the role of consolidation radioimmunotherapy in these patients is unknown. This study evaluated the efficacy and safety of consolidation with ⁹⁰ Yttrium-ibritumomab tiuxetan (⁹⁰ Y-IT) after re-induction therapy with BR in patients with previously treated FL. This study included adult patients with relapsed FL who had undergone one or two prior therapies. Re-induction therapy with BR was administered every 4 weeks up to 4-6 cycles. If patients achieved at least partial response, ⁹⁰ Y-IT was administered as consolidation therapy. The primary endpoint was 2-year progression-free survival (PFS) after consolidation. A total of 24 FL patients (median age 60 years) who had undergone one (n = 17) or two (n = 7) prior treatments received BR. After BR therapy, 22 patients proceeded to consolidation with ⁹⁰ Y-IT, resulting in an overall 88% response rate to the protocol treatment. Within a median observation period of 46.8 months, the estimated 2-year PFS rate after the consolidation among the 22 patients receiving ⁹⁰ Y-IT was 59% (95% confidence interval [CI], 38%-77%). Patients whose remission after previous treatment had lasted ≥2 years had a significantly higher 2-year PFS rate than patients whose remission after previous treatment had been <2 years (68% vs. 33%, Wilcoxon p = 0.0211). Major adverse events during the protocol treatment and within 2 years after the consolidation were hematological toxicities, but they were generally acceptable. Consequently, the estimated 2-year overall survival after the consolidation was 95% (95% CI, 74%-99%). In conclusion, in a subset of patients with previously treated FL, ⁹⁰ Y-IT consolidation after BR re-induction conferred a durable remission, indicating that consolidation therapy using ⁹⁰ Y-IT may be a novel therapeutic option for patients with relapsed FL (UMIN000008793).

Initial report of a phase II study with R-FND followed by ibritumomab tiuxetan radioimmunotherapy and rituximab maintenance in patients with untreated high-risk follicular lymphoma

R-FND (rituximab, fludarabine, mitoxantrone, and dexamethasone) can induce molecular remissions in indolent lymphoma. The addition of ⁹⁰yttrium ibritumomab tiuxetan (⁹⁰YIT) radioimmunotherapy following first-line induction treatment in patients with advanced follicular lymphoma (FL) may improve remission rates. We now report 10-year follow-up results from our sequential treatment approach with an abbreviated regimen of R-FND followed by ⁹⁰YIT consolidation and rituximab maintenance. Forty-nine patients were enrolled; 47 received treatment. Patients had high-risk (FLIPI score ≥3) FL of grade 1-3A and stage III/IV with adequate hematologic function. Following R-FND, the complete and partial response rates were 91% and 8.5%, respectively. After ⁹⁰YIT consolidation, the CR rate increased to 97%. The 10-year PFS rate was 49%. The most common non-hematologic, grade 3 or 4 adverse events were fatigue, dyspnea, and myalgia. Five developed myelodysplastic syndrome (MDS). This treatment approach is most appropriate in FLIPI-based high-risk patients whose outlook with standard therapy is inadequate.

Clinical pharmacology and clinical trials of ribonucleotide reductase inhibitors: is it a viable cancer therapy?

PURPOSE

Ribonucleotide reductase (RR) enzymes (RR1 and RR2) play an important role in the reduction of ribonucleotides to deoxyribonucleotides which is involved in DNA replication and repair. Augmented RR activity has been ascribed to uncontrolled cell growth and tumorigenic transformation.

METHODS

This review mainly focuses on several biological and chemical RR inhibitors (e.g., siRNA, GTI-2040, GTI-2501, triapine, gemcitabine, and clofarabine) that have been evaluated in clinical trials with promising anticancer activity from 1960's till 2016. A summary on whether their monotherapy or combination is still effective for further use is discussed.

RESULTS

Among the RR2 inhibitors evaluated, GTI-2040, siRNA, gallium nitrate and didox were more efficacious as a monotherapy, whereas triapine was found to be more efficacious as combination agent. Hydroxyurea is currently used more in combination therapy, even though it is efficacious as a monotherapy. Gallium nitrate showed mixed results in combination therapy, while the combination activity of didox is yet to be evaluated. RR1 inhibitors that have long been used in chemotherapy such as gemcitabine, cladribine, fludarabine and clofarabine are currently used mostly as a combination therapy, but are equally efficacious as a monotherapy, except tezacitabine which did not progress beyond phase I trials.

CONCLUSIONS

Based on the results of clinical trials, we conclude that RR inhibitors are viable treatment options, either as a monotherapy or as a combination in cancer chemotherapy. With the recent advances made in cancer biology, further development of RR inhibitors with improved efficacy and reduced toxicity is possible for treatment of variety of cancers.

High ten-year remission rates following rituximab, fludarabine, mitoxantrone and dexamethasone (R-FND) with interferon maintenance in indolent lymphoma: Results of a randomized Study

We report a single-centre, randomized study evaluating the efficacy and safety of concurrent fludarabine, mitoxantrone, dexamethasone (FND) and rituximab versus sequential FND followed by rituximab in 158 patients with advanced stage, previously untreated indolent lymphoma, enrolled between 1997 and 2002. Patients were randomized to 6-8 cycles of FND followed by 6 monthly doses of rituximab or 6 doses of rituximab given concurrently with FND. All patients who achieved at least a partial response received 12 months of interferon (IFN) maintenance. Median ages were 54 and 55 years. The two groups were comparable with the exception of a higher percentage of females (65% vs. 43%) and baseline anaemia (23% vs. 11%) in the FND followed by rituximab group. Complete response/unconfirmed complete response rates were 89% and 93%. The most frequent grade ≥ 3 toxicity was neutropenia (86% vs. 96%). Neutropenic fever occurred in 21% and 16%. Late toxicity included myelodysplastic syndrome (n = 3) and acute myeloid leukaemia (n = 5). With 12·5 years of follow-up, no significant differences based on treatment schedule were observed. 10-year overall survival estimates were 76% and 73%. 10-year progression-free survival estimates were 52% and 51%. FND with concurrent or sequential rituximab, and IFN maintenance in indolent lymphoma demonstrated high response rates and robust survival.

Systemic Front Line Therapy of Follicular Lymphoma: When, to Whom and How

The natural history of follicular lymphoma is usually characterized by an indolent course with a high response rate to the first line therapy followed by recurrent relapses, with a time to next treatment becoming shorter after each subsequent treatment line. More than 80% of patients have advanced stage disease at diagnosis. The time of initiation and the nature of the treatment is mainly conditioned by symptoms, tumor burden, lymphoma grading, co-morbidities and patients preference. A number of clinical and biological factors have been determined to be prognostic in this disease, but the majority of them could not show to be predictive of response to treatment, and therefore can’t be used to guide the treatment choice. CD20 expression is the only predictive factor recognized in the treatment of FL and justifies the use of “naked” or “conjugated” anti-CD20 monoclonal antibodies as a single agent or in combination with chemo- or targeted therapy. Nevertheless, as this marker is almost universally found in FL, it has little role in the choice of treatment. The outcome of patients with FL improved significantly in the last years, mainly due to the widespread use of rituximab, autologous and allogeneic transplantation in young and fit relapsed patients, the introduction of new drugs and the improvement in diagnostic accuracy and management of side effects. Agents as new monoclonal antibodies, immuno-modulating drugs, and target therapy have recently been developed and approved for the relapsed setting, while studies to evaluate their role in first line treatment are still ongoing. Here we report our considerations on first line treatment approach and on the potential factors which could help in the choice of therapy.

90-yttrium-ibritumomab tiuxetan consolidation of fludarabine, mitoxantrone, rituximab in intermediate/high-risk follicular lymphoma: updated long-term results after a median follow-up of 7 years

Radioimmunotherapy (RIT) after an induction phase with conventional chemoimmunotherapy became an attractive strategy of consolidation for patients with advanced follicular lymphoma: in particular, in many studies RIT was represented by yttrium-90-ibritumomab tiuxetan ((90) Y-IT). Independently by the different front-line treatment, updates on the long-term follow-up of these studies are needed because the disease course of follicular lymphoma is characterised by multiple relapses and progressively shorter durations of response. We report updated long-term efficacy and toxicity results of a multicenter phase II study on sequential treatment with four cycles of fludarabine, mitoxantrone, and rituximab followed by (90) Y-IT as front-line therapy for untreated patients with intermediate/high-risk follicular lymphoma. With a median follow-up of 84 months, only 19/49 (38.8%) complete response patients relapsed, yielding an estimated long-term disease-free survival of 62.6%. The 7-year overall survival was 72.7%. Four (7.3%) second acute myeloid leukemia occurred, with a median time following RIT of 42 months. A relevant patients' responsiveness to subsequent therapies occurred: approximately 65% of relapsed patients obtained a good clinical response after the second-line treatment. These data represented the first evidence of a real role even in the long period of 90Y-IT after a fludarabine-containing regimen plus rituximab in the treatment of high-risk follicular lymphoma.

90 Y-ibritumomab tiuxetan: a nearly forgotten opportunityr

Y-ibritumomab tiuxetan (90Y-IT) combines the benefits of a monoclonal antibody with the efficacy of radiation in the treatment of B-cell non-Hodgkin lymphoma (NHL), a remarkably radiosensitive hematologic malignancy. 90Y-IT activity has been well established in the indolent setting, being approved in front-line treatment of follicular lymphoma (FL) patients as well as salvage therapy. However, no advantage in OS was observed with respect to standard treatment. Promising data are available also for aggressive B-cell lymphoma. In particular, the addition of RIT to short-course first line chemotherapy enables reduction of chemotherapy while maintaining cure rates in elderly, untreated diffuse large B-cell lymphoma (DLBCL) patients. Furthermore, 90Y-IT improves response rate and outcomes of relapsed/refractory DLBCL patients, eligible and ineligible for autologous stem cell transplantation (ASCT). Clinical results have shown a role of 90Y-IT even in mantle cell lymphoma (MCL). RIT might improve responses and treat minimal residual disease when used as consolidation after first-line chemotherapy in MCL. Moreover, 90Y-IT has demonstrated its efficacy in combination with high-dose chemotherapies as conditioning regimen for ASCT, with evidence suggesting the ability to overcome chemotherapy resistance. Herein, we review the available evidence for this approved drug and examine the recently published and ongoing trials for potential novel indication in aggressive B-cell NHL.

Advancing radioimmunotherapy and its future role in non-Hodgkin lymphoma

Radioimmunotherapy is an effective treatment modality with an acceptable toxicity profile in both indolent B-cell non-Hodgkin lymphoma and histologic transformation. Its ease of administration from a patient's perspective sets it apart from chemoimmunotherapy regimens. It has demonstrated efficacy in a range of different treatment scenarios. Despite its promise as a treatment modality, radioimmunotherapy has been seldom used, and one of the previously available agents is now off the market. Radioimmunotherapy has shown impressive activity in both the relapsed and upfront settings in follicular lymphoma, histologic transformation, as consolidation after chemotherapy, and in conjunction with high-dose chemotherapy and autologous stem cell support. Future efforts should focus on its optimal employment in the upfront setting for follicular lymphoma as well as further investigation of the promising activity in histologic transformation.

Radioimmunotherapy of human tumours

The eradication of cancer remains a vexing problem despite recent advances in our understanding of the molecular basis of neoplasia. One therapeutic approach that has demonstrated potential involves the selective targeting of radionuclides to cancer-associated cell surface antigens using monoclonal antibodies. Such radioimmunotherapy (RIT) permits the delivery of a high dose of therapeutic radiation to cancer cells, while minimizing the exposure of normal cells. Although this approach has been investigated for several decades, the cumulative advances in cancer biology, antibody engineering and radiochemistry in the past decade have markedly enhanced the ability of RIT to produce durable remissions of multiple cancer types.

Role of consolidation with yttrium-90 ibritumomab tiuxetan in patients with advanced-stage follicular lymphoma

Non-Hodgkin's lymphoma (NHL) accounts for 4% of all cancers diagnosed in the United States. Follicular lymphoma (FL) is the most common type of indolent NHL with a survival from 5 to 15 years. Although it is very sensitive to chemotherapy and radiotherapy, relapses are the main cause of therapeutic failure, and currently there is no consensus on the first-line treatment and optimal therapeutic strategies for patients with FL. Immediate treatment offers any survival benefit for asymptomatic and more indolent disease. In order to improve outcomes in FL, extend the remission, postpone the need for chemotherapy and improve OS, maintenance therapies with rituximab and consolidation treatments represent very attractive strategies. (90)Y-ibritumomab tiuxetan ((90)Y-IT, Zevalin®) is approval as consolidation therapy in previously untreated FL patients who achieve response to first-line chemotherapy. Consolidation therapy with (90)Y-IT after initial induction treatment has shown improved activity compared with induction chemotherapy alone, even in patients previously treated with rituximab, in one phase III and several phase II trials, improving progression-free survival (PFS) and rate of conversion from partial response (PR) to complete response (CR). The phase III international FIT trial shows an improvement in PFS that is maintained after a median follow up of 7.3 years. Several phase II trials show high rate of conversion from PR to CR and a significant improvement in PFS. Treatment is feasible and well tolerated although myelodysplastic syndrome cases has been observed in some trials. (90)Y-IT should be considered for the initial treatment of FL in patients who are unable to tolerate standard chemotherapy, e.g., elderly or frail patients and otherwise in high-risk patients who achieve a PR or CR due to improvements in CR rate and PFS.

Targeting CD19 in B-cell lymphoma: emerging role of SAR3419

Non-Hodgkin lymphoma symbolizes a heterogeneous group of diseases resulting from malignant transformation of lymphocytes with differing patterns of behavior and responses to treatment. The potential curability of non-Hodgkin lymphoma differs among the various histologic subtypes and is associated in part with the stage at presentation. CD19 antigen is a type I transmembrane glycoprotein belonging to the immunoglobulin Ig superfamily. CD19 is specifically expressed in normal and neoplastic B-cells. Recent study showed that in a mouse model, CD19 and c-Myc synergize functionally to accelerate B-cell lymphomagenesis, which is associated with increased disease severity. Specificity is the most important challenge in cancer therapeutics. Antibody–drug conjugates have the prospect of enhancing the therapeutic efficacy over unconjugated monoclonal antibodies through the selective delivery of cytotoxic agents to cancer cells. The ubiquitous expression of CD19 in these tumors, especially at an earlier stage and the property of efficient internalization, makes CD19 an attractive and affective target for antibody–drug conjugate therapy as compared to CD20. SAR3419 (huB4-DM4) is a novel antibody–drug conjugate that is composed of a humanized monoclonal IgG1 anti-CD19 antibody (huB4) attached to the potent cytotoxic drug, a maytansine derivative (DM4), through a cleavable disulfide cross-linking agent N-Succinimidyl-4-2-pyridyldithio butanoic acid (SPDB). The preclinical efficacy of maytansine derivative–anti-CD19 conjugate was demonstrated in our laboratory, and SAR3419 was found to be more effective than CHOP in a xenograft model. Phase I trials have also been conducted on the basis of preclinical studies that demonstrated promising antitumor activity with acceptable safety results in human B-cell lymphoma models. Additional trials are ongoing and will provide additional insight into the full potential of this novel drug.

Bone marrow recovery and subsequent chemotherapy following radiolabeled anti-prostate-specific membrane antigen monoclonal antibody j591 in men with metastatic castration-resistant prostate cancer

Radioimmunotherapy (RIT) has demonstrated efficacy with acceptable toxicity leading to approval in non-Hodgkin’s lymphoma, but has been slower to develop for the treatment of advanced solid tumors. Prostate cancer (PC) represents a good candidate for RIT based upon high exposure to circulating antibodies at common disease sites with a specific, highly expressed cell-surface antigen of prostate-specific membrane antigen. Four phase I and II trials utilizing ¹⁷⁷Lu- or ⁹⁰Y-J591 have been reported. Long-term toxicity and chemotherapy administration was analyzed. As expected, the only serious toxicity observed was myelosuppression. Grade 4 thrombocytopenia occurred in 33.3% without significant hemorrhage and grade 4 neutropenia occurred in 17.3% with 0.07% febrile neutropenia. Nearly all subjects (97.3%) recovered to grade 0 or 1 platelets and all had complete neutrophil recovery. The majority (81.3%) received chemotherapy at any time, with 61.3% receiving chemotherapy following RIT. Ten subjects underwent bone marrow biopsies at some point in their disease course following RIT for low counts; all had diffuse PC infiltration without evidence of myelodysplasia or leukemia. As expected, myelosuppression occurs following therapeutic doses of RIT for men with metastatic castration-resistant PC. However, toxicity is predictable and self-limited, with the majority of patients who do not refuse able to receive cytotoxic chemotherapy following RIT.

SIE, SIES, GITMO revised guidelines for the management of follicular lymphoma

By using the GRADE system, we updated the guidelines for management of follicular cell lymphoma issued in 2006 from SIE, SIES, and GITMO group. We confirmed our recommendation to frontline chemoimmunotherapy in patients with Stage III-IV disease and/or high tumor burden. Maintenance rituximab was also recommended in responding patients. In patients relapsing after an interval longer than 12 months from frontline therapy, we recommended chemoimmunotherapy with non cross-resistant regimens followed by rituximab maintenance. High dose chemotherapy followed by hematopoietic stem cell transplant was recommended for young fit patients who achieve a response after salvage chemoimmunotherapy.

Radioimmunotherapy for B-cell non-hodgkin lymphomas

BACKGROUND

Radioimmunotherapy (RIT) is a safe and effective therapeutic option for patients with indolent B-cell non-Hodgkin lymphomas (NHL), in both up-front and relapsed/refractory settings. Two approved agents (90Y-ibritumomab tiuxetan and 131I-tositumomab) are available in the United States. Both target CD20 with similar clinical outcomes but with unique clinical considerations and radiation precautions due to the use of varying radioisotopes.

METHODS

This paper reviews the available evidence for these approved RIT agents and examines the recently published and ongoing clinical trials of potential novel indications for aggressive B-cell NHL.

RESULTS

A pretreatment biodistribution evaluation required before administering the 90Y-ibritumomab tiuxetan therapeutic dose has been removed, which once limited its usage. The potential clinical applications of RIT include relapsed/refractory indolent B-cell NHL, diffuse large B-cell lymphoma, indolent lymphoma in the front-line setting, and mantle cell lymphoma. Multiple novel RIT agents are in preclinical and clinical development, and the addition of radiosensitizers or external-beam radiotherapy may act in synergy with RIT for both indolent and aggressive lymphomas. The risk of treatment-related myelodysplastic syndrome does not appear to be higher in patients treated with RIT over those receiving chemotherapy alone.

CONCLUSIONS

RIT is a safe, effective, and significantly underutilized therapy for patients with B-cell NHL, and many studies have demonstrated the efficacy of 90Y-ibritumomab tiuxetan and 131I-tositumomab for relapsed/refractory indolent B-cell lymphomas. Continued research to establish its efficacy for other lymphoma subtypes is warranted.