The efficacy of adjunctive N-acetylcysteine in major depressive disorder: a double-blind, randomized, placebo-controlled trial.

OBJECTIVE: Major depressive disorder (MDD) is one of the most common psychiatric disorders, conferring considerable individual, family, and community burden. To date, treatments for MDD have been derived from the monoamine hypothesis, and there is a paucity of emerging antidepressants, especially with novel mechanisms of action and treatment targets. N-acetylcysteine (NAC) is a redox-active glutathione precursor that decreases inflammatory cytokines, modulates glutamate, promotes neurogenesis, and decreases apoptosis, all of which contribute to the neurobiology of depression. METHOD: Participants with a current episode of MDD diagnosed according to DSM-IV-TR criteria (N = 252) were treated with NAC or placebo in addition to treatment as usual for 12 weeks and were followed to 16 weeks. Data were collected between 2007 and 2011. RESULTS: The omnibus interaction between group and visit for the Montgomery-Asberg Depression Rating Scale (MADRS), the primary outcome measure, was not significant (F1,520.9 = 1.98, P = .067), and the groups did not separate at week 12 (t360.3 = -1.12, P = .265). However, at week 12, the scores on the Longitudinal Interval Follow-Up Evaluation-Range of Impaired Functioning Tool (LIFE-RIFT) differed from placebo (P = .03). Among participants with a MADRS score ≥ 25, NAC separated from placebo at weeks 6, 8, 12, and 16 (P < .05). Additionally, the rate of change between baseline and week 16 was significant (t221.03 = -2.11, P = .036). NAC treatment was superior to placebo at week 16 for secondary readouts of function and clinical impression. Remission and response were greater in the NAC group at week 16, but not at week 12. The NAC group had a greater rate of gastrointestinal and musculoskeletal adverse events. CONCLUSIONS: Being negative at the week 12 end point, and with some positive secondary signals, the study provides only limited support for the role of NAC as a novel adjunctive therapy for MDD. These data implicate the pathways influenced by NAC in depression pathogenesis, principally oxidative and inflammatory stress and glutamate, although definitive confirmation remains necessary. TRIAL REGISTRATION: www.anzctr.org.au Identifier: ACTRN12607000134426.

Maintenance N-acetyl cysteine treatment for bipolar disorder: a double-blind randomized placebo controlled trial.

BACKGROUND: N-acetyl cysteine (NAC) is a glutathione precursor that has been shown to have antidepressant efficacy in a placebo-controlled trial. The current study aimed to investigate the maintenance effects of NAC following eight weeks of open-label treatment for bipolar disorder. METHOD: The efficacy of a double blind randomized placebo controlled trial of 2 g/day NAC as adjunct maintenance treatment for bipolar disorder was examined. Participants (n = 149) had a Montgomery Asberg Depression Rating Score of ≥12 at trial entry and, after eight weeks of open-label NAC treatment, were randomized to adjunctive NAC or placebo, in addition to treatment as usual. Participants (primarily outpatients) were recruited through public and private services and through newspaper advertisements. Time to intervention for a mood episode was the primary endpoint of the study, and changes in mood symptoms, functionality and quality of life measures were secondary outcomes. RESULTS: There was a substantial decrease in symptoms during the eight-week open-label NAC treatment phase. During the subsequent double-blind phase, there was minimal further change in outcome measures with scores remaining low. Consequently, from this low plateau, between-group differences did not emerge on recurrence, clinical functioning or quality of life measures. CONCLUSIONS: There were no significant between-group differences in recurrence or symptomatic outcomes during the maintenance phase of the trial; however, these findings may be confounded by limitations. TRIAL REGISTRATION: The trial was registered with the Australian New Zealand Clinical Trials Registry (ACTRN12607000074493).

The efficacy of N-acetylcysteine as an adjunctive treatment in bipolar depression: an open label trial.

BACKGROUND: Evidence is accumulating to support the presence of redox dysregulation in a number of psychiatric disorders, including bipolar disorder. This dysregulation may be amenable to therapeutic intervention. Glutathione is the predominant non-enzymatic intracellular free radical scavenger in the brain, and the most generic of all endogenous antioxidants in terms of action. N-acetylcysteine (NAC) is a glutathione precursor that effectively replenishes brain glutathione. Given the failure of almost all modern trials of antidepressants in bipolar disorder to demonstrate efficacy, and the limited efficacy of mood stabilisers in the depressive phase of the disorder, this is a major unmet need. METHOD: This study reports data on the treatment of 149 individuals with moderate depression during the 2 month open label phase of a randomised placebo controlled clinical trial of the efficacy of 1g BID of NAC that examined the use of NAC as a maintenance treatment for bipolar disorder. RESULTS: In this trial, the estimated mean baseline Bipolar Depression Rating Scale (BDRS) score was 19.7 (SE=0.8), and the mean BDRS score at the end of the 8 week open label treatment phase was 11.1 (SE=0.8). This reduction was statistically significant (p<0.001). Improvements in functioning and quality of life were similarly evident. CONCLUSION: These open label data demonstrate a robust decrement in depression scores with NAC treatment. Large placebo controlled trials of acute bipolar depression are warranted.

Association of clinical status of follicular lymphoma patients after autologous stem cell transplant and quantitative assessment of lymphoma in blood and bone marrow as measured by SYBR Green I polymerase chain reaction.

Molecular remission in the autograft and bone marrow after transplant are predictive of durable clinical remission in relapsed follicular lymphoma. Thus, a simple reliable method to quantify minimal residual disease (MRD) would improve prognostication in these patients. Fluorescent hybridization probes have been used in real-time quantitative polymerase chain reaction (RQ-PCR) to monitor MRD with a reproducible sensitivity of 0.01%; however, these techniques are expensive and require additional experiments to examine clonality. We describe a SYBR Green I detection method that is more universal, checks clonal identity, yields the same sensitivity for monitoring MRD, and is more economically attractive. Using this method to follow 14 follicular lymphoma patients treated with autologous stem cell transplantation, molecular markers were successfully defined for 12 patients. Median contamination of stem-cell grafts was 0.1% (range, 0 to 13%). Six patients with measurable graft contamination became PCR-negative in blood and bone marrow within 12 months after autologous stem cell transplantation. Three patients free of disease progression (median follow-up of 75 months) are in molecular remission. Increasing fractions of RQ-PCR-positive blood and bone marrow cells reliably predicted morphological and clinical relapse. In one case, both clinical relapse and spontaneous regression were reflected by changes in MRD levels. Thus, our RQ-PCR method reproducibly distinguishes different levels of MRD.

Immunotherapy with rituximab following high-dose therapy and autologous stem-cell transplantation for mantle cell lymphoma.

Advanced-stage mantle cell lymphoma (MCL) is a disease for which no curative treatment strategy exists. Results with standard combination chemotherapy, with or without an anthracycline, are disappointing, and new and better therapies are needed. High-dose therapy and autologous stem-cell transplantation (ASCT) have been performed in patients with MCL both up front and at relapse with varying degrees of success. Rituximab (Rituxan; Genentech, Inc, South San Francisco, CA, and IDEC Pharmaceuticals, San Diego, CA) has shown moderate response rates in patients with MCL. It has also been used safely and effectively as an in vivo purge during ASCT for patients with lymphoma. We are currently investigating an aggressive protocol in patients with newly diagnosed, untreated MCL using a combination of two promising therapeutic modalities, high-dose therapy-ASCT and rituximab. Since 1999, 13 patients with newly diagnosed MCL have been enrolled in this phase II clinical trial. CHOP (cyclophosphamide/prednisone/vincristine/doxorubicin) is used as debulking chemotherapy. Stem cells are mobilized with 5 days of granulocyte colony-stimulating factor 10 microg/kg/d, with a single infusion of rituximab 375 mg/m(2) used as an in vivo purge before stem-cell collection by large-volume leukapheresis. The transplant conditioning regimen is cyclophosphamide/carmustine/etoposide. Post-transplant consolidative immunotherapy consists of rituximab 375 mg/m(2), administered as two 4-week cycles at 2 and 6 months post-transplant. So far, 12 patients (7 men/5 women) with a median age of 55 years (range, 41 to 65 years) have been transplanted. Patients were first assessed and then transplanted a median of 40 and 201 days, respectively, from diagnosis. International Prognostic Index at diagnosis was low (n = 3), low-intermediate (n = 8), and high-intermediate (n = 1). A median of six cycles of CHOP was required to debulk tumor sufficiently for transplant. Response to CHOP was 100% with six complete responses, one complete response unconfirmed, and five partial responses. Transplantation was well tolerated. Patients engrafted quickly, with a median of 11.5 days to neutrophil engraftment and 10 days to platelet independence. Patients had modest transfusion requirements, requiring a median of four units of packed red blood cells and two and a half platelet transfusions. Six to 8 weeks post-transplant, six patients were in complete response, four in complete response unconfirmed, and two in partial response. Eight patients have received all eight maintenance rituximab treatments, and four have received only their first cycle. Following rituximab, the two patients in partial response and two in complete response unconfirmed converted to complete response. With a median follow-up of 239 days from transplant (range, 61 to 727 days), all patients remain alive and well with no documented relapses. Samples for molecular monitoring have been drawn from the stem-cell graft, and serially from the peripheral blood and bone marrow of patients at baseline, preapheresis, pretransplant, and post-transplant at 3-month intervals. This data shows that ASCT followed by rituximab immunotherapy is feasible and safe in patients with MCL. Although patient numbers are low and follow-up time is short, preliminary results are encouraging. Rituximab may convert partial responders to complete responders. The durability of responses will be determined with longer follow-up.

T-cell analysis in identical twins reveals an impaired anti-follicular lymphoma immune response in the patient but not in the healthy twin.

In lymphomas an innate defect in the T-cell repertoire could account for the impaired tumour-specific immune response; alternatively, the tumour itself could exert an inhibitory effect on the immune system. To address this issue we analysed the T-cell responses against follicular lymphoma (FL) in identical twins as it can be postulated that their overall T-cell repertoire is identical. While differences between the T-cell response of the patient and the healthy twin would point to a tumour-induced T-cell unresponsiveness, impaired responses in both would point to a defective T-cell repertoire. We demonstrated an impaired tumour-specific proliferation (P = 0.035 and P = 0.013) and cytokine release (P = 0.004 and P = 0.0008) of both peripheral blood and tumour-derived T-cells, respectively, in the FL patient compared with the T-cell response of the healthy twin. Moreover, only syngeneic primed T cells were able to directly lyse unmodified FL cells of the patient. These data support previous findings in murine lymphomas and suggest that inhibitory mechanisms during tumour growth, rather than a defective T-cell repertoire, are responsible for the insufficient T-cell response in lymphoma.

Immunotherapy with rituximab following high-dose therapy and autologous stem-cell transplantation for mantle cell lymphoma.

Advanced-stage mantle cell lymphoma (MCL) is a disease for which no curative treatment strategy exists. Results with standard combination chemotherapy, with or without an anthracycline, are disappointing, and new and better therapies are needed. High-dose therapy and autologous stem-cell transplantation (ASCT) have been performed in patients with MCL both up front and at relapse with varying degrees of success. Rituximab (Rituxan; Genentech, Inc, South San Francisco, CA, and IDEC Pharmaceuticals, San Diego, CA) has shown moderate response rates in patients with MCL. It has also been used safely and effectively as an in vivo purge during ASCT for patients with lymphoma. We are currently investigating an aggressive protocol in patients with newly diagnosed, untreated MCL using a combination of two promising therapeutic modalities, high-dose therapy-ASCT and rituximab. Since 1999, 13 patients with newly diagnosed MCL have been enrolled in this phase II clinical trial. CHOP (cyclophosphamide/prednisone/vincristine/doxorubicin) is used as debulking chemotherapy. Stem cells are mobilized with 5 days of granulocyte colony-stimulating factor 10 µg/kg/d, with a single infusion of rituximab 375 mg/m2 used as an in vivo purge before stem-cell collection by large-volume leukapheresis. The transplant conditioning regimen is cyclophosphamide/carmustine/etoposide. Post-transplant consolidative immunotherapy consists of rituximab 375 mg/m2, administered as two 4-week cycles at 2 and 6 months post-transplant. So far, 12 patients (7 men/5 women) with a median age of 55 years (range, 41 to 65 years) have been transplanted. Patients were first assessed and then transplanted a median of 40 and 201 days, respectively, from diagnosis. International Prognostic Index at diagnosis was low (n = 3), low-intermediate (n = 8), and high-intermediate (n = 1). A median of six cycles of CHOP was required to debulk tumor sufficiently for transplant. Response to CHOP was 100% with six complete responses, one complete response unconfirmed, and five partial responses. Transplantation was well tolerated. Patients engrafted quickly, with a median of 11.5 days to neutrophil engraftment and 10 days to platelet independence. Patients had modest transfusion requirements, requiring a median of four units of packed red blood cells and two and a half platelet transfusions. Six to 8 weeks post-transplant, six patients were in complete response, four in complete response unconfirmed, and two in partial response. Eight patients have received all eight maintenance rituximab treatments, and four have received only their first cycle. Following rituximab, the two patients in partial response and two in complete response unconfirmed converted to complete response. With a median follow-up of 239 days from transplant (range, 61 to 727 days), all patients remain alive and well with no documented relapses. Samples for molecular monitoring have been drawn from the stem-cell graft, and serially from the peripheral blood and bone marrow of patients at baseline, preapheresis, pretransplant, and post-transplant at 3-month intervals. This data shows that ASCT followed by rituximab immunotherapy is feasible and safe in patients with MCL. Although patient numbers are low and follow-up time is short, preliminary results are encouraging. Rituximab may convert partial responders to complete responders. The durability of responses will be determined with longer follow-up. Semin Oncol 29 (suppl 2):56-69. Copyright © 2002 by W.B. Saunders Company.