Immunochemotherapy in indolent non-Hodgkin's lymphoma

Clinical and economic aspects of the use of rituximab in non-Hodgkin's lymphoma

Non-Hodgkin's lymphoma (NHL) consists of a group of neoplasias involving mainly B cells and represents 90% of all lymphomas. The current available therapy is based on chemotherapy associated with the monoclonal antibody rituximab (Mab Thera(r)), which targets the CD20 protein, present in over 80% of NHL mature B cells. Recent clinical reports show a preference for combining the benefits of immunotherapy and adjuvant chemotherapy, thus generating safe and effective alternative treatments. The current review aimed at evaluating various aspects related to the use of rituximab for NHL, highlighting the possible inhibitory mechanisms of cell proliferation, the achieved clinical results, and the expected clinical and economic outcomes of treatments. The results from clinical tests indicate the need for a better understanding of the critical mechanisms of action of this antibody, which may maximize its therapeutic efficacy. This therapy not only represents a viable option to treat most types of NHLs, especially when associated with conventional chemotherapy, but also offers cost-utility and cost-effectiveness advantages.

Volume and attenuation computed tomography measurements for interim evaluation of Hodgkin and follicular lymphoma as an additional surrogate parameter for more confident response monitoring: a pilot study

Purpose: To retrospectively determine the potential role of additional computed tomography (CT) attenuation measurements for interim response evaluation in residual masses of patients with Hodgkin disease (HD) and follicular non-Hodgkin lymphoma (NHL). Materials and methods: In this retrospective study, 39 patients with HD and 35 patients with NHL presented with residual masses at mid-treatment CT (after 2–4 cycles of chemotherapy) and were assessed via contrast-enhanced CT at baseline, mid-treatment and post-treatment. Volume was recorded as whole-tumour volume. A tumour attenuation ratio (TAR) was calculated as the quotient of attenuation between tumour and muscle at the respective point in time versus baseline. The standard deviation of attenuation values within the tumour volume was recorded to estimate tumour heterogeneity. Results were correlated with relapse-free survival determined at a minimum of 12 months after end-treatment CT. Results: Tumour volume and TAR at interim versus baseline control were significantly reduced in responders compared with non-responders, even after controlling for age, stage, treatment regimen, and baseline tumour volume. No significant differences with respect to the standard deviation of attenuation values within the tumour volumes (tumour heterogeneity) were observed. The volume and attenuation CT (VACT) criteria yielded the highest sensitivities and specificities for the identification of non-response at a threshold of a >20% increase in volume and an increase in TAR at interim control, i.e. 88% (NHL 80%, HD 100%) and 98% (NHL 97%, HD 100%), respectively. The negative predictive values reached by VACT analysis were ≥97%, according to both parameters. Conclusion: Mid-treatment response assessment of residual masses in patients with HD and NHL using VACT may aid in the risk stratification as an additional surrogate parameter.

Immunotherapy combined with chemotherapy in the treatment of tumors

This article provides a broad overview of the data, including laboratory and clinical studies, currently available on the combination of immunotherapy and chemotherapy for treating cancer. The various forms of immunotherapy combined with chemotherapy include monoclonal antibodies, adoptive lymphocyte transfer, or active specific immunotherapy, such as tumor proteins, irradiated tumor cells, tumor cell lysates, dendritic cells pulsed with peptides or lysates, or tumor antigens expressed in plasmids or viral vectors. This discussion is not limited to malignant brain tumors, because many of the studies have been conducted on various cancer types, thereby providing a comprehensive perspective that may encourage further studies that combine chemotherapy and immunotherapy for treating brain tumors.

Combination immunotherapy with anti-CD20 and anti-HLA-DR monoclonal antibodies induces synergistic anti-lymphoma effects in human lymphoma cell lines

Rituximab is effective in about one half of patients with indolent lymphoma. Even these patients relapse and develop rituximab resistance. To increase potency and circumvent resistance, the anti-lymphoma effects of rituximab, an anti-CD20 MAb(1), combined with chLym-1(2), an anti-HLA-DR MAb, were assessed in human lymphoma cell lines by examining growth inhibition and cell death, apoptosis induction, ADCC(3) and CDC(4). There were additive effects in all assays and synergism in cell lines, such as B35M, which displayed resistance to either MAb alone. In B35M cells, combined rituximab and chLym-1 induced a 27-fold direct reduction in viable cells, whereas equivalent concentrations of rituximab or chLym-1 alone induced only a 1-fold and 10-fold reduction in viable cells, respectively. Because these results occurred at MAb concentrations readily achievable in patients, they suggest that this combination immunotherapy regimen may increase the potency and range of effectiveness of these MAbs in lymphoma patients.

Combination of active specific immunotherapy or adoptive antibody or lymphocyte immunotherapy with chemotherapy in the treatment of cancer

Successful treatment of cancer patients with a combination of monoclonal antibodies (mAb) and chemotherapeutic drugs has spawned various other forms of additional combination therapies, including vaccines or adoptive lymphocyte transfer combined with chemotherapeutics. These therapies were effective against established tumors in animal models and showed promising results in initial clinical trials in cancer patients, awaiting testing in larger randomized controlled studies. Although combination between immunotherapy and chemotherapy has long been viewed as incompatible as chemotherapy, especially in high doses meant to increase anti-tumor efficacy, has induced immunosuppression, various mechanisms may explain the reported synergistic effects of the two types of therapies. Thus direct effects of chemotherapy on tumor or host environment, such as induction of tumor cell death, elimination of regulatory T cells, and/or enhancement of tumor cell sensitivity to lysis by CTL may account for enhancement of immunotherapy by chemotherapy. Furthermore, induction of lymphopenia by chemotherapy has increased the efficacy of adoptive lymphocyte transfer in cancer patients. On the other hand, immunotherapy may directly modulate the tumor's sensitivity to chemotherapy. Thus, anti-tumor mAb can increase the sensitivity of tumor cells to chemotherapeutic drugs and patients treated first with immunotherapy followed by chemotherapy showed higher clinical response rates than patients that had received chemotherapy alone. In conclusion, combination of active specific immunotherapy or adoptive mAb or lymphocyte immunotherapy with chemotherapy has great potential for the treatment of cancer patients which needs to be confirmed in larger controlled and randomized Phase III trials.

Monoclonal antibodies as therapeutic agents in oncology and antibody gene therapy

Antibodies as therapeutic agents are mostly used in oncology, as illustrated by their applications in lymphoma, breast cancer or colorectal cancer. This review provides a brief historical sketch of the development of monoclonal antibodies for cancer treatment and summarizes the most significant clinical data for the best-established reagents to date. It also discusses strategies to improve the anti-tumor efficacy of antibody therapy, including antibody gene therapy and exploitation of bone marrow derived primary mesenchymal stem cells as the antibody gene transporter.

Combined cyclophosphamide, vincristine, doxorubicin, and prednisone (CHOP) improves response rates but not survival and has lower hematologic toxicity compared with combined mitoxantrone, chlorambucil, and prednisone (MCP) in follicular and mantle cell lymphomas

BACKGROUND

In patients with advanced-stage follicular lymphoma (FL) and mantle cell lymphoma (MCL), conventional chemotherapy remains a noncurative approach, and no major improvement in overall survival has been achieved in recent decades.

METHODS

The German Low-Grade Lymphoma Study Group performed a randomized trial comparing combined cyclophosphamide, vincristine, doxorubicin, and prednisone (CHOP) chemotherapy with combined mitoxantrone, chlorambucil, and prednisone (MCP) chemotherapy as first-line therapy for patients with advanced-stage FL or MCL.

RESULTS

Three hundred sixty-three patients with advanced-stage FL (n = 277 patients) or MCL (n = 86 patients) entered the trial and were evaluable fully. CHOP resulted in a significantly higher overall response rate in patients with FL (91% vs. 82%; P = .026) and a similar tendency in patients with MCL (87% vs. 73%; P = .080). However, no significant differences were observed in the time to treatment failure or in overall survival. CHOP produced significantly more nonhematologic toxicities, whereas MCP was associated with more severe hematologic side effects. The proportion of patients who successfully underwent peripheral blood stem cell collection was significantly lower after MCP (44% vs. 93% after CHOP; P = .0003).

CONCLUSIONS

Taking into account that, currently, chemotherapy regularly is combined with rituximab as first-line therapy for FL and MCL, the data from this study may have an impact on the type of chemotherapy to be applied in such combinations. Particularly in younger, high-risk patients who are candidates for autologous stem cell transplantation, CHOP should be preferred over MCP.

Immunochemotherapy with Rituximab, Vincristine and 5-Day Cyclophosphamide for Heavily Pretreated Follicular Lymphoma

PURPOSE

Therapeutic options for relapsed or refractory follicular lymphoma include combination chemotherapy, immunotherapy and, for selected patients, autotransplant. Because of the different mechanisms of action and non-overlapping toxicities, combination of rituximab with chemotherapy is a rational approach.

METHODS

30 patients with follicular non-Hodgkin's lymphoma with advanced-stage disease were treated with four cycles of immunochemotherapy with rituximab 375 mg/m2 on day 1, vincristine 2 mg i.v. on day 2 and cyclophosphamide 400 mg/m2 i.v. from days 2 to 6, repeated at 3-week intervals. All patients had received multiple lines of therapy (median 3); 9 (30%) had relapses (2 after high-dose therapy with autologous transplant), and 21 (70%) were in relapse and refractory to salvage treatment (with an anthracycline-containing regimen in 19).

RESULTS

Of 29 patients evaluable for response, 16 (55 %) obtained a complete response (CR) and 3 (10%) a partial response (PR), with an overall response rate of 65% (19/29); 10 patients (35%) achieved less than PR. The median event-free survival was 16.1 months for all patients, being 22.8 months for responders. After a median follow-up of 2 years from the start of therapy (range 6 months to 3.8 years), of 16 patients who achieved CR, 10 remain free of disease.

CONCLUSION

The combination of rituximab with vincristine and 5-day cyclophosphamide is able to produce CR in patients with advanced follicular lymphoma, even in patients resistant to third-generation regimens. The regimen designed on the basis of pharmacokinetics of the chimeric antibody seemed important for the clinical efficacy of the combination.

Overview of monoclonal antibodies in cancer therapy: present and promise

After 30 years of development, therapy with monoclonal antibodies has started to realize its promise. Clinical use is most widespread in the field of oncology, where half of the agents approved for routine clinical use are employed and a large number of molecules are currently undergoing clinical trials. In the past 2 years alone, three new compounds-the radiolabeled antibody (131)I-tositumomab and two antibodies targeting growth factor receptors (bevacizumab and cetuximab)-have received FDA approval for indications in oncology. This review summarizes the development of this exciting treatment modality over the last three decades, examines the outcome of treatment with these new antibodies and others available for routine clinical use (i.e. rituximab, trastuzumab, alemtuzumab, gemtuzumab ozogamicin, (90)Y-ibritumomab tiuxetan) in standard indications and in experimental settings, and gives a brief outlook on possible future developments.

Non-Hodgkin lymphoma: an update

Non-Hodgkin lymphoma (NHL) causes many deaths worldwide, and its incidence is increasing. Although some cases are associated with immunodeficiency, autoimmunity, or viral infections, in most cases the causes of NHL are not understood. However, there have been some important advances in our understanding of the development of healthy lymphocytes and the pathogenesis of NHL over the past 10 years. These advances have been accompanied by an improvement in treatment for NHL. Before the late 1990s, the only treatment option available was cytotoxic chemotherapy. In the past 10 years, however, high-dose chemotherapy and autologous stem-cell reconstitution have become established parts of treatment for aggressive lymphoma. Furthermore, monoclonal antibodies have become another therapeutic option. Rituximab (an anti-CD20 monoclonal antibody) is the most advanced monoclonal antibody in clinical trials and has become part of standard treatment for some lymphomas. Rituximab, and many other monoclonal antibodies, continue to be assessed in clinical studies. Monoclonal antibodies can be used alone or in combination with standard-dose or high-dose chemotherapy, and they can also be conjugated to radionuclides to enhance cytotoxicity. Here, we review advances in the treatment of NHL that have occurred over the past 10 years.

Safety of rituximab in the treatment of B cell malignancies: implications for rheumatoid arthritis

The chimeric anti-CD20 monoclonal antibody rituximab has been used extensively in the treatment of B cell malignancies, and more recently it has emerged as a potential treatment for rheumatoid arthritis (RA), via selective B lymphocyte depletion. Experience in oncology shows that rituximab is well tolerated in a variety of settings, with mild-to-moderate infusion related reactions following the first infusion being the most common adverse event. Current data suggest that the safety profile of rituximab in patients with RA is similar to that in oncology, but that the adverse events are less frequent and less severe in patients with RA.

New strategies in radioimmunotherapy for lymphoma

Treatment options for patients with indolent non-Hodgkin's lymphoma historically involved radiation or chemotherapy. Although initial response rates are excellent, treatment is increasingly less effective with each successive relapse. The advent of immunotherapy heralds a new era for the treatment of these patients. Radioimmunotherapy adds the benefits of cytotoxic radiation to immunotherapy and represents a significant addition to the treatment armamentarium. Various antigens for lymphoma have been targeted, of which anti-CD20 antibodies are the furthest in development. Ibritumomab tiuxetan (Zevalin; IDEC Pharmaceuticals, San Diego, CA), a (90)yttrium-labeled agent, and (131)iodine-labeled tositumomab (Bexxar; Corixa, Seattle, WA) are approved by the US Food and Drug Administration. Both agents have shown utility in therapy for relapsed and refractory low-grade and transformed lymphomas. This review highlights features of radioimmunotherapy that are relevant to non-Hodgkin's lymphoma, focusing on the two anti-CD20 antibodies.

Monoclonal antibody therapy for lymphoma

Monoclonal antibodies are an exciting advance in the treatment of lymphoma. They are safe and well-tolerated, and exhibit little cross-resistance with conventional chemotherapeutic agents. In indolent lymphomas, antibody therapy has shown useful response rates, both as first-line therapy and in relapsed disease. Follicular lymphomas appear to be particularly sensitive to rituximab, and chronic lymphocytic leukaemia to alemtuzumab. In aggressive lymphomas, the addition of rituximab to CHOP chemotherapy significantly lengthens disease-free and overall survival compared to CHOP alone as first-line therapy. Newer agents, including radiolabelled antibodies, immunotoxin-linked antibodies and antibodies against novel target antigens are showing promise in phase I and II trials in a variety of clinical settings.

Long-term effect of a watch and wait policy versus immediate systemic treatment for asymptomatic advanced-stage non-Hodgkin lymphoma: a randomised controlled trial

BACKGROUND

Neither chemotherapy with a single-alkylating agent nor aggressive combination chemotherapy cures advanced stage low-grade non-Hodgkin lymphomas, even when combined with radiotherapy. Our aim was to compare administration of immediate chlorambucil treatment with a policy of delaying chlorambucil until clinical progression necessitated its use, in asymptomatic patients with advanced-stage, low-grade non-Hodgkin lymphoma.

METHODS

309 patients with asymptomatic, advanced-stage, low-grade non-Hodgkin lymphomas were recruited from 44 UK centres between Feb 1, 1981, and July 31, 1990. 158 patients were randomised to receive immediate systemic therapy with oral chlorambucil 10 mg per day continuously. The remaining 151 were randomised to an initial policy of observation, with systemic therapy delayed until disease progression. In both groups, local radiotherapy to symptomatic nodes was allowed.

FINDINGS

Median length of follow-up was 16 years. Overall survival or cause-specific survival did not differ between the two groups (median overall survival for oral chlorambucil 5.9 [range 0-17.8] years and for observation 6.7 [0.5-18.9] years, p=0.84; median cause-specific survival 9 [0-17.8] years and 9.1 [0.67-18.9] years, respectively p=0.44). In a multivariate analysis, age younger than 60 years, erythrocyte sedimentation rate (ESR) 20 mm/h or less, and stage III disease, conferred significant advantages in both overall survival (p<0.0001, 0.03, and 0.03, respectively) and cause-specific survival (p=0.002, 0.008, and 0.001, respectively). In the observation group, at 10 years' follow-up, 19 patients were alive and had not received chemotherapy. The actuarial chance of not needing chemotherapy (non-lymphoma deaths censored) at 10 years was 19% (40% if older than 70 years).

INTERPRETATION

An initial policy of watchful waiting in patients with asymptomatic, advanced stage low-grade non-Hodgkin lymphoma is appropriate, especially in patients older than age 70 years.

Lymphomas

Hodgkin's and non-Hodgkin's lymphomas are an important part of the differential diagnosis of head and neck tumors. Their diagnosis begins with a complete history and physical examination and is confirmed with an appropriately obtained and prepared pathologic specimen. Prognosis and therapy of the lymphomas vary depending on stage and the characteristics of each particular subtype of lymphoma. Low-grade lymphomas and chronic lymphocytic leukemia are characterized by long survival times and are most often treated with palliative intent. More aggressive high-grade lymphomas are treated for cure. Although chemotherapy and radiotherapy remain the mainstays of treatment, immunotherapy demonstrates increasing promise.

Immunological evaluation of CTL precursor-oriented vaccines for advanced lung cancer patients

Recent clinical trials of peptide vaccine for cancer patients have rarely resulted in tumor regression. One of the reasons for this failure could be an insufficient induction of anti-tumor responses in these regimens, in which peptide-specific memory cytotoxic T lymphocytes (CTLs) were not measured prior to vaccination. We investigated in this study whether pre-vaccination measurement of peptide-specific CTLs can provide any advantages in lung cancer patients receiving peptide vaccination with regard to safety and immunological responses. Ten patients with advanced lung cancer received vaccination with peptides under a regimen of CTL precursor-oriented vaccination, in which pre-vaccination peripheral blood mononuclear cells (PBMCs) were at first screened for reactivity in vitro to each of 14 peptides, followed by in vivo administration of only the reactive peptides. Profiles of the vaccinated peptides varied markedly among the 10 patients. This regimen was generally well-tolerated, although local skin reactions, diarrhea, and colitis were observed in 8, 2, and 1 patient, respectively. Increased CTL responses against the immunized peptides and tumor cells were observed in the post-vaccination PBMCs from 4 of 8 and 3 of 10 patients tested, respectively. Peptide-specific IgG became detectable in post-vaccination sera in 4 of 10 patients tested, and these 4 patients had a long progression-free survival. Furthermore, the median survival time of 9 patients with non-small cell lung cancer was 668.0 +/- 164.2 days. These results encourage further development of CTL precursor-oriented peptide vaccination for lung cancer patients.

Small Bowel Lymphoma

Treatment of small bowel lymphoma requires the expertise of medical and surgical subspecialists. The two most important factors that determine the optimal treatment are histology and staging of small bowel lymphoma. Other factors that may affect treatment include age, multiple areas of involvement, tumor size, and perforation. At present, the best treatment for gastrointestinal lymphoma (stage IE disease) is limited resection of the tumor, followed by postoperative radiotherapy. The cure rate is approximately 75% for stage IE patients, even for those with aggressive histologic types. Chemotherapy is reserved for advanced-staged tumors. In patients with regional nodal involvement or extranodal involvement confined to one side of the diaphragm (pathologic stage IIE disease), chemotherapy should be combined with radiation therapy. The best chemotherapy regimen depends on the histology of the tumor. For diffuse large B-cell lymphoma, the most frequently diagnosed subtype of non-Hodgkin's lymphoma (NHL), the CHOP regimen (cyclophosphamide, doxorubicin, vincristine, and prednisone) is still the gold standard. Clinical trials have been conducted evaluating the new monoclonal antibody rituximab, along with the CHOP regimen for primary NHL. Results have been promising. The use of rituximab in the treatment of extranodal lymphoma is still being evaluated. Low-grade lymphomas have a more indolent course and do not respond as well to combination chemotherapy agents as the high-grade tumors. Fludarabine alone or in combination with cyclophosphamide is effective as a first-line agent for patients with low-grade NHL. It has also been used to treat relapsed or refractory low-grade NHL. Some promising results have been reported using the chemoimmunotherapy agent rituximab alone or in combination with fludarabine for the treatment of low-grade NHL. However, clinical trials are still needed. In patients with nodal involvement on both sides of the diaphragm or other extranodal involvement such as bone marrow or liver (pathologic stages IIIE and IVE), the disease is managed primarily with combination chemotherapy. Radiation therapy is reserved for treatment of initially bulky tumor sites, treatment of residual disease following chemotherapy, or serious local problems. The disease can be controlled in 25% to 40% of patients with stage IIIE or IVE disease. As with stage IIE disease, the optimal chemotherapy regimen depends on the histologic subtype of NHL.

Beyond immunochemotherapy: combinations of rituximab with cytokines interferon-alpha2a and granulocyte colony stimulating factor [corrected]

Monotherapy with the human-mouse chimeric anti-CD20 monoclonal antibody rituximab is effective and well tolerated in the treatment of indolent non-Hodgkin's lymphoma, but the majority of patients relapse. The combination of chemotherapeutic agents with rituximab results in greater efficacy, but at the cost of the increased toxicity associated with chemotherapy. To increase the efficacy of rituximab without compromising tolerability, the cytokines interferon-alpha2a, which has multiple immunomodulatory effects and enhances antibody-dependent cell-mediated cytotoxicity, and the granulocyte-colony stimulating factor, which enhances antibody-dependent cell-mediated cytotoxicity by neutrophils, have been combined with rituximab. In a randomized comparative study in patients with relapsed or untreated indolent non-Hodgkin's lymphoma, the addition of interferon-alpha2a significantly increased responsiveness to a second course of rituximab in patients with a partial response or minor response to an initial course of rituximab monotherapy. In a single-arm study in 20 patients with relapsed disease, the combination of granulocyte-colony stimulating factor with rituximab resulted in a longer duration of response than normally seen with rituximab monotherapy. In both studies, no significant increase in adverse events compared with rituximab monotherapy was reported. Currently available data suggest that the combination of rituximab with immunomodulatory cytokines result in increased efficacy without compromising tolerability.

Increasing treatment options in indolent non-Hodgkin's lymphoma

There is currently no standard first-line treatment for indolent non-Hodgkin's lymphoma (NHL) because there is no curative treatment. In asymptomatic patients, treatment with chemotherapy does not improve survival compared with a "watch and wait" approach. Improved treatment strategies, with curative intent, are thus required for indolent NHL. Rituximab is effective and well tolerated in the treatment of indolent NHL and can be considered for asymptomatic patients, where the side effects of chemotherapy may outweigh the benefits. In addition, rituximab does not compromise the use of subsequent chemotherapy in patients who relapse. A study of rituximab monotherapy in patients with low-tumor-burden follicular lymphoma has shown high rates of both clinical remission and molecular remission (clearance of bcl-2-positive cells from blood and/or bone marrow). After 2 years, half the patients relapsed, indicating that improved strategies are still required. Efforts to improve the efficacy of rituximab have included repeated administrations of the antibody and combined administration with chemotherapy or interferon-alpha2a. The optimal role of rituximab in first-line therapy for indolent NHL will be determined through randomized clinical trials.