Final analysis of the ECOG I-COPA trial (E6484) in patients with non-Hodgkin's lymphoma treated with interferon alfa (IFN-alpha2a) plus an anthracycline-based induction regimen

Apoptosis-inducing factor (AIF) is targeted in IFN-α2a-induced Bid-mediated apoptosis through Bak activation in ovarian cancer cells

Previously we have shown that interferon (IFN)-α induced apoptosis is predominantly mediated by the upregulation of tumor necrosis factor related apoptosis-inducing ligand (TRAIL) via the caspase-8 pathway. It was also shown that recruitment of mitochondria in IFN-α induced apoptosis involves the cleavage of BH3 interacting domain death agonist (Bid) to truncated Bid (tBid). In the present study, we demonstrate that tBid induced by IFN-α2a activates mitochondrial Bak to trigger the loss of mitochondrial membrane integrity, consequently causing release of apoptosis-inducing factor (AIF) in ovarian cancer cells, OVCAR3. AIF translocates from the mitochondria to the nucleus and induces nuclear fragmentation and cell death. Both a small molecule Bid inhibitor (BI-6C9) or Bid-RNA interference (RNAi) preserved mitochondrial membrane potential, prevented nuclear translocation of AIF, and abrogated IFN-α2a-induced cell death. Cell death induced by tBid was inhibited by AIF-RNAi, indicating that caspase-independent AIF signaling is the main pathway through which Bid mediates cell death. This was further supported by experiments showing that BI-6C9 did not prevent the release of cytochrome c from mitochondria to cytosol, while the release of AIF was prevented. In conclusion, IFN-α2a-induced apoptosis is mediated via the mitochondria-associated pathway involving the cleavage of Bid followed by AIF release that involves Bak activation and translocation of AIF from the mitochondria to the nucleus in OVCAR3 cells.

Cancer immunotherapy

Cancer immunotherapy consists of approaches that modify the host immune system, and/or the utilization of components of the immune system, as cancer treatment. During the past 25 years, 17 immunologic products have received regulatory approval based on anticancer activity as single agents and/or in combination with chemotherapy. These include the nonspecific immune stimulants BCG and levamisole; the cytokines interferon-α and interleukin-2; the monoclonal antibodies rituximab, ofatumumab, alemtuzumab, trastuzumab, bevacizumab, cetuximab, and panitumumab; the radiolabeled antibodies Y-90 ibritumomab tiuxetan and I-131 tositumomab; the immunotoxins denileukin diftitox and gemtuzumab ozogamicin; nonmyeloablative allogeneic transplants with donor lymphocyte infusions; and the anti-prostate cancer cell-based therapy sipuleucel-T. All but two of these products are still regularly used to treat various B- and T-cell malignancies, and numerous solid tumors, including breast, lung, colorectal, prostate, melanoma, kidney, glioblastoma, bladder, and head and neck. Positive randomized trials have recently been reported for idiotype vaccines in lymphoma and a peptide vaccine in melanoma. The anti-CTLA-4 monoclonal antibody ipilumumab, which blocks regulatory T-cells, is expected to receive regulatory approval in the near future, based on a randomized trial in melanoma. As the fourth modality of cancer treatment, biotherapy/immunotherapy is an increasingly important component of the anticancer armamentarium.

Twelfth biannual report of the Cochrane Haematological Malignancies Group--focus on tyrosine kinase inhibitors

This 12th biannual report of the Cochrane Haematological Malignancies Group highlights recently published randomized controlled trials in the field of hemato-oncology, covering the publication period from September 1, 2009, through June 30, 2010. Implication for clinical practice and methodological aspects are the main principles used to select trials for this report. Studies on tyrosine kinase inhibitors for patients with chronic myeloid leukemia were identified through electronic search of MEDLINE with a broad search filter that covered all topics in hemato-oncology combined with a highly sensitive search filter for randomized studies as described in the Cochrane Handbook for Systematic Reviews of Interventions.

Identification of potential surrogate end points in randomized clinical trials of aggressive and indolent non-Hodgkin's lymphoma: correlation of complete response, time-to-event and overall survival end points

BACKGROUND

The correlation between efficacy end points in randomized controlled trials (RCTs) of systemic therapy for non-Hodgkin's lymphoma (NHL) was investigated to identify an appropriate surrogate end point for overall survival (OS).

METHODS

RCTs of previously untreated NHL published from 1990 to 2009 were identified. Associations between absolute differences in efficacy end points were determined using nonparametric Spearman's rank correlation coefficients (r(s)).

RESULTS

Thirty-eight RCTs representing 85 treatment arms for aggressive NHL and 20 RCTs representing 42 arms for indolent NHL were included. For aggressive NHL, differences in 3-year progression-free survival (PFS)/event-free survival (EFS) were high correlated with differences in 5-year OS {r(s) of 0.90 [95% confidence interval (CI) 0.73-0.96]} and linear regression determined that a 10% improvement in 3-year EFS or PFS would predict for a 7% ± 1% improvement in 5-year OS. For indolent histology disease, differences in complete response were strongly correlated with differences in 3-year EFS [r(s) 0.86 (95% CI 0.35-0.97)], but there was no correlation between 3-year time-to-event end points and 5-year OS.

CONCLUSIONS

Improvements in 3-year EFS/PFS are highly correlated with improvements in 5-year OS in aggressive NHL and should be explored as a candidate surrogate end point. Definition of these relationships may inform future clinical trial design and interpretation of interim trial data.

Interferon-alpha for maintenance of follicular lymphoma

BACKGROUND

Indolent non-Hodgkin's lymphoma, in particular follicular lymphoma (FL), is characterized by multiple remissions and relapses. Several studies have used interferon-alpha (IFN) to control this disease, both as induction and as maintenance therapy. It is not yet clear whether IFN can be associated with a survival benefit although it may prolong progression-free survival.

OBJECTIVES

To determine the effects of IFN in the maintenance therapy of FL.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 4, 2008), MEDLINE (1966 to 2008), DARE (1990 to 2008), SCOPUS (searched December 2008) and Current Contents (1975 to 2008). .

SELECTION CRITERIA

Randomised controlled trials of IFN versus no intervention or placebo, or IFN plus chemotherapy versus chemotherapy alone, in a maintenance setting in patients with non-Hodgkin's FL. Primary outcomes were overall survival and progression-free survival.

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed trial quality and extracted data. We contacted study authors for additional information. We collected adverse events information from the trials.

MAIN RESULTS

We included eight trials (1563 patients). The drug was IFN alfa-2b in six trials and alfa-2a in two. Trials were heterogeneous in terms of diagnosis of FL, using several classification systems. IFN had been compared with placebo/no intervention in five trials and other chemotherapy in three. The effect of IFN was similar to that of placebo on overall survival (hazard ratio (HR) 0.90, 95% CI 0.61 to 1.34) whereas IFN was more effective when added to chemotherapy (HR 0.68, 95% confidence interval (CI) 0.52 to 0.90). Considering IFN versus all comparators, IFN was effective in prolonging progression-free survival (HR 0.66, 95% CI 0.57 to 0.77) and overall survival (fixed effects HR 0.79, 95% CI 0.67 to 0.94, I(2) = 52%). After adjustment for heterogeneity this statistically significance disappeared (random effects HR 0.82, 95% CI 0.63 to 1.08). Toxicity and patients lost to follow up were significantly higher in the IFN groups.

AUTHORS' CONCLUSIONS

There is evidence that addition of IFN as maintenance therapy for FL improves progression-free survival. A net benefit for overall survival is less evident. In the included studies, IFN was associated with significant toxicities that may have a major impact on a patient's quality of life.

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.

Follicular lymphoma: today's treatments and tomorrow's targets

Over the past two decades, the incidence of follicular lymphoma has increased. Contemporary treatments include combinations of chemotherapy and monoclonal antibodies, radioimmunotherapy, new targeted agents and stem-cell transplantation. Prognostic tools are becoming more important in helping clinicians and patients decide on the most appropriate therapeutic regimens. Gene expression profiling and biomarkers are promising additions to this armamentarium. When patients do require therapy, the addition of rituximab to chemotherapy seems to improve remission duration and may improve overall survival. Radioimmunotherapy capitalises on the capacity to target radiation directly to malignant cells, and is currently approved for the treatment of relapsed/refractory follicular lymphoma. Further investigation is needed to clarify the role of stem-cell transplantation in follicular lymphoma. Only well-designed clinical trials can provide answers to the many questions that remain regarding the optimal treatment and sequence of treatments for patients with follicular lymphoma.

Do recent reports of prolonged survival in patients with follicular lymphoma suggest that deferral of therapy is no longer justifiable?

After an era in which it was unclear whether available systemic therapies for follicular lymphoma (FL) had influenced the survival of patients, several recent reports now suggest that survival of FL patients has improved over the past 25 years, presumably owing to expansion of therapeutic options. Has the pendulum swung so far that it is no longer justifiable to defer therapy in selected patients with FL? To date, the strongest evidence in support of treating all patients comes from randomized studies of different regimens suggesting that one offers a survival advantage over the other. The strongest evidence in support of deferring therapy for select patients comes from a few problematic randomized trials showing no difference between initial therapy and deferred therapy. The subset of patients with early-stage FL presents special but still inconclusive considerations. Accrual to prospective randomized trials is needed to answer the question.

How I treat indolent lymphoma

Despite advances in treatment, there was little evidence until recently that this led to improvement in the survival of patients with indolent lymphoma, with patients continuing to have an unremitting course of relapse of disease. There appears to have been a change in the natural history of these diseases with the introduction of chemoimmunotherapy that may finally result in improvements in survival. With so many agents available for the treatment of indolent lymphomas, questions that have to be addressed include the following: is there still a role for a "watch-and-wait" approach in asymptomatic patients or should they be treated at diagnosis, what are the optimal first-line and salvage treatments, what is the role of maintenance therapy, and is there any role for stem cell transplantation in these diseases? No established treatment of choice has yet emerged, and many of these questions remain unresolved. It is highly likely that our treatment approaches will continue to evolve as the results of ongoing clinical trials are released and that improvement in outcome will result from identification of therapies that target the underlying pathophysiology of the diseases.

Current controversies in follicular lymphoma

Follicular lymphoma (FL) is characterized by its responsiveness to initial therapy, a pattern of repeated relapses, and a tendency for histologic progression to a process resembling diffuse, large B-cell lymphoma. Treatment decisions are complicated by the many effective options now available including combinations of conventional chemotherapy and monoclonal antibody, radioimmunotherapy, new targeted agents, and autologous and allogeneic stem cell transplantation. For selected patients, "watch and wait" or involved field irradiation may still be the most appropriate strategy. When therapy is required, a combination of rituximab and conventional chemotherapy results in improved outcomes compared to chemotherapy alone. Radioimmunotherapy alone or in combination with chemotherapy is an attractive strategy for patients with relapsed disease and may prove to be appropriate first line therapy. The role of stem cell transplant in FL requires further investigation. Novel agents with varied mechanisms of action continue to be developed. Enrollment of patients into clinical trials designed to address the many unanswered questions in FL is essential to improving clinical outcomes.

Meta-Analysis to Evaluate the Role of Interferon in Follicular Lymphoma

Purpose

To determine whether interferon (IFN) -α2, when given with or following chemotherapy, influences response rate, remission duration, and survival in newly diagnosed patients with follicular lymphoma.

Patients and Methods

Ten phase III studies evaluating the role of IFN-α2 in 1,922 newly diagnosed patients with follicular lymphoma were analyzed. Updated individual patient data were used to perform meta-analyses for response, survival, and remission duration.

Results

The addition of IFN-α2 to initial chemotherapy did not significantly influence response rate. An overall meta-analysis for survival showed a significant difference in favor of IFN-α2, but also showed significant heterogeneity between studies. Further analyses were carried out in order to explain this heterogeneity, and to define the circumstances in which IFN-α2 prolonged survival. The survival advantage was seen when IFN-α2 was given: (1) in conjunction with relatively intensive initial chemotherapy (2P = .00005), (2) at a dose ≥ 5 million units (2P = .000002), (3) at a cumulative dose ≥ 36 million units per month (2P = .000008), and (4) with chemotherapy rather than as maintenance therapy (P = .004). With regard to remission duration, there was also a significant difference in favor of IFN-α2, irrespective of the intensity of chemotherapy used, IFN dose, or whether IFN was given as a maintenance strategy or with chemotherapy.

Conclusion

When given in the context of relatively intensive initial chemotherapy, and at a dose ≥ 5 million units (≥ 36 × 106 units per month), IFN-α2 prolongs survival and remission duration in patients with follicular lymphoma.

Advances in follicular lymphoma

Follicular lymphoma is a usually indolent lymphoma that responds well to chemotherapy. While multiple treatments show a good response rate, most patients relapse. Emerging therapies, such as antibody therapy and stem cell transplantation, are increasingly being used to try to lengthen response time. This article will review the available treatments for follicular lymphoma and discuss the studies supporting newer strategies of treatment.

Interferon-alpha-induced apoptosis in U266 cells is associated with activation of the proapoptotic Bcl-2 family members Bak and Bax

We have recently reported that the cytokine interferon-alpha (IFNalpha), commonly used in the treatment of cancer, induced a caspase-dependent apoptosis in tumor cell lines. The signaling mechanisms involved have not been defined. Here, we show that both proapoptotic Bcl-2 family members Bak and Bax were activated by IFNalpha, strictly in correlation with the induction of apoptosis. Using double stainings, we demonstrated that Bak was activated prior to cytochrome c (cyt c) release and caspase-3 activation, whereas activated Bax was only found in cells with released cyt c, mitochondrial depolarization, as well as activated caspase-3. Furthermore, IFNalpha-induced activation of Bak, and to a large extent also of Bax, was dependent on caspase activity. With the use of a panel of specific caspase inhibitors we found, however, that none of caspases-1 to -10 were responsible for this activation. Neither was the Ca(2+)-dependent protease calpain nor the stress-activated p38 SAPK pathway significantly involved. Overexpression of Bcl-2 blocked apoptosis induced by IFNalpha totally abolished Bak activation, as well as decreased the amount of activated Bax. We conclude that IFNalpha induces Bak and Bax activation via distinct mechanisms involving an unknown protease, and that their activation is regulated by Bcl-2.

Minimal residual disease (MRD) in follicular lymphoma in the era of immunotherapy with rituximab

The t(14;18)-translocation can be detected by PCR analysis in more than 90% of cytogenetically t(14;18)-positive follicular lymphomas (FLs), thus providing an easily accessible marker for molecular disease monitoring. Various technical aspects of the detection of residual lymphoma cells as well as the prognostic and clinical significance of the detection of minimal residual disease (MRD) after radiotherapy, chemotherapy and therapy with the monoclonal antibody rituximab are discussed. Up to now the comparability of the different studies investigating minimal residual disease in follicular lymphoma patients is hampered by the use of a variety of PCR techniques. A more standardized quantitative approach based on the real-time PCR technique will provide a powerful tool for the evaluation and optimization of therapy for each individual patient.

Combination of fludarabine and mitoxantrone in untreated stages III and IV low-grade lymphoma: S9501

PURPOSE

To determine the efficacy of combination fludarabine and mitoxantrone (FN) in untreated stages III and IV low-grade lymphoma. The major end point was to estimate progression-free survival (PFS) in all eligible patients.

PATIENTS AND METHODS

Seventy-eight eligible patients were registered. Chemotherapy courses were administered every 4 weeks with mitoxantrone 10 mg/m2 on day 1 and fludarabine 25 mg/m2 on days 1, 2, and 3 for a total of six to eight cycles. Pneumocystis carinii prophylaxis was required.

RESULTS

Seventy-three patients (94%) attained an objective response. Complete remission was demonstrated in 34 patients (44%) and partial remission was demonstrated in 39 patients (50%). With a median follow-up time of 5.5 years, the median PFS was 32 months, with a 4-year PFS rate of 38%. Median survival has not been reached and 88% of all patients are alive at 4 years. The application of the International Prognostic Index and serologic staging showed significant differences in PFS in all risk groups, whereas overall survival was markedly worse for the highest-risk group in either prognostic model. Three prior Southwest Oncology Group trials using a regimen of cyclophosphamide, doxorubicin, vincristine, and prednisone or a combination of prednisone, vincristine, methotrexate, cytarabine, cyclophosphamide, etoposide, nitrogen mustard, vincristine, procarbazine, and prednisone in similar patient populations demonstrated comparable clinical outcome, although the 4-year survival for FN was better. FN was well tolerated, but mild to severe reversible myelosuppression was noted. Other complications were rare.

CONCLUSION

FN is an effective, safe chemotherapy combination for patients with advanced-stage, low-grade lymphoma. Clinical outcomes were comparable to prior published data using anthracycline-based regimens.

[Interferons and hematology]

BACKGROUND

IFN alpha are cytokines used for a number of years in the treatment of certain hemopathies, i.e. of a myeloid and lymphoid etiology. IFN alpha are a family of polypeptides produced by eukaryote cells in response to various stimulant agents. The first trials using this cytokine in humans were carried out by H. Strander in the years 1965-1970. IFN alpha contain anti-viral, anti-proliferative and immunomodulatory properties. The access of clinicians to IFN alpha molecules, in addition to elements produced by genetic engineering for approximately the past 20 years, has permitted a number of therapeutic trials to be carried out. In hematology the clinical interest of IFN alpha was primarily in chronic myeloid and lymphoid proliferating syndromes. Certain indications have to date been well demonstrated. However, the impact of IFN alpha on therapeutic care of certain hemopathies as compared to conventional treatment remains controversial. At the same time, the frequency of side effects from treatment with IFN alpha and its cost should be taken into consideration.

CURRENT POSITION AND MAJOR POINTS

The therapeutic trials carried out over the past ten years have proven the interest of IFN alpha in, essentially, two diseases: on one hand chronic myeloid leukemia with the acquisition of cytogenetic remission and on the other malignant non-Hodgkin's follicular type lymphoma. However, as regards other hemopathies the place of IFN alpha remains debatable.

PERSPECTIVES

The future of IFN alpha use in the treatment of hemopathies appears to be linked to its association with new treatments, an association, however, where its efficacy and superiority should be demonstrated. This is the case in chronic myeloid leukemia where IFN alpha could be associated with aracytine or the inhibitors of tyrosine kinase. Also, in the treatment of malignant non-Hodgkin's lymphomas as well as the studies concerning the association between IFN alpha and monoclonal antibodies, in particular antibody anti-CD 20.

Pegylated interferons for the treatment of chronic hepatitis C infection

BACKGROUND

Interferon (IFN) alfa is a clinically effective therapy used in a wide range of viral infections and cell-proliferative disorders. Combination therapy with IFN alfa-2b and ribavirin is the current standard of care for the treatment of chronic hepatitis C (CHC) infection. However, standard IFN alfa has the drawbacks of a short serum half-life and rapid clearance. To overcome this problem, 2 pegylated forms of IFN have been developed and tested clinically.

OBJECTIVE

This article reviews the development and properties of pegylated IFN alfa-2b and pegylated IFN alfa-2a, and presents safety and efficacy data from recent clinical trials.

METHODS

Relevant clinical studies were identified through a MEDLINE search from 1966 through the present using the key words hepatitis C and interferon. Studies of the pegylated IFNs in humans were then selected.

RESULTS

Pegylated IFN alfa-2b is formed by covalent conjugation of a 12-kd mono-methoxy polyethylene glycol (PEG) molecule to IFN alfa-2b, and pegylated IFN alfa-2a by covalent conjugation of a 40-kd branched mono-methoxy PEG molecule to IFN alfa-2a. The 2 pegylated IFNs differ in the mixture of pegylation isomers resulting from their conjugation chemistry. Pegylated IFN alfa-2b has a prolonged serum half-life (40 hours) relative to standard IFN alfa-2b (7-9 hours). The greater polymer size of pegylated IFN alfa-2a acts to reduce glomerular filtration, markedly prolonging its serum half-life (72-96 hours) compared with standard IFN alfa-2a (6-9 hours). In clinical studies, once-weekly dosing of the pegylated IFNs was associated with a sustained virologic response in patients infected with hepatitis C virus (HCV). Once-weekly dosing with either of the pegylated IFNs was more effective than the respective thrice-weekly regimen of IFN alfa, with a comparable safety profile. The combination of once-weekly pegylated IFN and ribavirin effectively reduced HCV viral load and sustained viral suppression.

CONCLUSIONS

Once-weekly dosing with either pegylated IFN alfa-2b or pegylated IFN alfa-2a has been shown to produce significantly higher rates of viral eradication than standard thrice-weekly IFN alfa therapy without compromising safety. With respect to the treatment of CHC, the greatest anti-HCV efficacy has been achieved with the combination of once-weekly pegylated IFN and ribavirin.