ALBERT

Description: Chimeric anti-CD4 monoclonal antibody was administered intravenously as a single dose to eight patients with mycosis fungoides. The dose was escalated throughout the study between patients groups, and individual patients received 50, 100, or 200 mg per dose. Seven of eight patients responded to treatment with an average freedom from progression of 25 weeks (range, 6 to 52 weeks). The treatment was well tolerated, and there was no clinical evidence of immunosuppression. Following treatment, there was significant suppression of peripheral blood CD4 counts in all patients for 1 to 22+ weeks. Only one patient made a very low titer human antichimeric antibody response. All but two patients made primary antibody and T-cell proliferative responses to a foreign antigen administered 24 hours after antibody infusion. However, there was generally marked, but temporary suppression of T-cell proliferative responses in vitro to phytohemagglutinin (PHA), tetanus toxoid, and normal donor lymphocytes. We conclude that at the dose levels studied, this antibody (1) had clinical efficacy against mycosis fungoides; (2) was well tolerated; (3) had a low level of immunogenicity; (4) decreased T-cell proliferative responses in vitro, and (5) did not induce tolerance to a foreign antigen.

Description: Chimeric (murine/human) anti-CD4 monoclonal antibody was infused into seven patients with mycosis fungoides. Successive patients received doses of 10, 20, 40, and 80 mg of antibody twice a week for 3 consecutive weeks. All patients had some clinical improvement, but responses were of relatively short duration. Serum levels of chimeric antibody varied as a function of dose. At the 80-mg dose level, antibody was readily observed in biopsied skin lesions. Although there was coating by antibody of most CD4 positive cells in the blood, there was no significant depletion of CD4 positive cells. Low-level antibody responses against the mouse Ig variable region and human Ig allotypic constant region determinants were observed in several patients, but none were of clinical significance. All but two patients made primary antibody and T-cell proliferative responses to a simultaneously administered foreign protein test antigen. However, there was marked suppression of the mixed lymphocyte reaction. We conclude that at the dose levels studied, a chimeric anti-CD4 monoclonal antibody (1) had some clinical efficacy against mycosis fungoides; (2) was well tolerated; (3) had a low level of immunogenicity; (4) had immediate immunosuppressive effects; and (5) did not induce tolerance to a co- injected antigen.

Description: Patients with non-Hodgkin's B-cell lymphoma who received an antitumor vaccine of idiotypic ig protein showed humoral and proliferative immune responses. Because immunity to some antigens, including tumor antigens and human pathogenic viruses, may be better correlated with the cytolytic cellular immune response, we evaluated 16 non-Hodgkin's lymphoma patients immunized with autologous idiotypic ig molecules for changes in tumor-specific cytotoxic T-lymphocyte precursor (CTLp) frequency using limiting dilution analysis. Eleven patients had a significant increase in tumor-specific CTLp. Eight of these 11 patients remain without evidence of disease or with stable minimal disease. In contrast, all five patients who did not have a significant change in tumor-specific CTLp have developed progressive disease. Patient vaccination with tumor associated protein antigens can increase tumor- specific CTLp frequencies. The correlation of increased tumor specific CTLp with freedom from progression is significant at P = .002. This study indicates that measurement of CTLp frequencies are relevant to the clinical evaluation of human tumor vaccines and suggests that cell- mediated cytolytic immune responses may be an important determinant of vaccine efficacy.

Description: The Ig idiotype of B-cell lymphoma can be used as a tumor-specific target. Prior trials with monoclonal anti-idiotype antibodies alone and combined with alpha-interferon have shown significant antitumor activity. In some patients, idiotype-negative tumors emerged after treatment. In this trial, patients with relapsed non-Hodgkin's lymphoma were treated with two identical courses of monoclonal anti-idiotype anti-body therapy. Concurrent with the second course, at a time when idiotype-negative cells were suspected to be proliferating, a pulse dose of chlorambucil was administered. Tumor biopsies obtained before the first and second courses of treatment and at relapse were analyzed for idiotype expression and proliferation. Thirteen patients received 24 courses of antibody with minimal toxicity. Eleven had tumor regression, with 1 complete remission, 8 partial remissions, and 2 minor remissions, with freedom from progression lasting a median of 7 months in responding patients. Idiotype-negative tumor cells appeared in some relapse specimens despite the use of chlorambucil. In retrospect, this was not surprising because there was no increase in the proliferative rate of these tumors at the time the drug was used. Anti-idiotype antibodies continue to demonstrate antitumor activity against B-cell lymphoma with minimal toxicity. The mechanism of the effect is presumed to involve both direct antiproliferative effects of the antibody on the tumor cells as well as indirect, more long-lasting effects on the host. The addition of a mild chemotherapeutic agent in the dose and schedule used here to the second cycle of antibody therapy did not interfere with the antitumor effect, nor did it decrease the emergence of idiotype-negative cells.

Description: Custom-made monoclonal anti-idiotype antibodies (anti-Id MoAbs) have been tested as a treatment modality in 34 non-Hodgkin's lymphoma (NHL) patients. Partial or complete tumor remissions have been induced with this treatment in 68% of these patients. One mechanism by which anti- idiotype antibodies may have induced these tumor responses is via a direct antiproliferative effect on the tumor cells, resulting in apoptosis. Primary NHL cells do not proliferate well enough in vitro to test this hypothesis directly. Therefore, we studied the effect of anti-idiotype antibodies on signal transduction through the surface Ig receptor as measured by the induction of cellular protein tyrosine phosphorylation. To assess whether bcl-2 protein could protect lymphoma cells from death induced by anti-Id MoAb, we also measured the level of bcl-2 protein in the same tumor cells. We found a strong correlation between the ability of an anti-Id MoAb to induce an increase in tyrosine phosphorylation in vitro and its ability to induce a tumor regression in the patient. By contrast, the level of bcl-2 expressed by the tumor cells was not correlated with clinical response to anti-Id MoAb treatment.

Description: A randomized comparison of the relative efficacy and toxicity of daunorubicin (DNR) at 30 or 45 mg/sq m or adriamycin (ADM) at 30 mg/sq m, given on the first 3 days of a 7-day continuous infusion of cytosine arabinoside (ara-C) at 100 mg/sq m/day, shows the outcome to be dependent on anthracycline, dose, and patient age. DNR 45 is significantly better than DNR 30 or ADM 30 for inducing complete remissions (CR) in patients younger than 60 yr, (72%, 59%, 58% CRs, respectively). DNR 30 is better than DNR 45 or ADM 30 for inducing CR in patients older than 60 yr (47%, 31%, 35%, respectively). There was a corresponding shift in the induction mortality for the age, dose, and anthracycline groups. Adriamycin was significantly more toxic to the gastrointestinal tract than daunorubicin. The duration of complete remission, with cyclic courses of maintenance therapy, was independent of the patient's age, the dose, or choice of anthracycline used in induction, and of whether the maintenance courses were given every 4 wk or every 8 wk.

Description: Background: Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous entity which necessitates the characterization of prognostic markers to better define risk groups. Previously, we showed that the expression of LMO2 mRNA was a strong predictor of superior outcome in patients with DLBCL in a multivariate model of six genes (Lossos et al, NEJM 2004). Subsequently, using a novel monoclonal anti-LMO2 antibody, we showed that LMO2 protein expression predicted outcome in DLBCL patients treated with anthracyline-based chemotherapy with and without rituximab (Natkunam et al, JCO 2008). For validation of our prior findings we analyzed an independent cohort of DLBCL patients treated with RCHOP that had not been included in our previous study. Methods: 106 patients with de novo DLBCL treated with RCHOP and followed for clinical outcome were included. Immunohistochemistry (IHC) for LMO2 was performed on tissue microarrays containing cores of biopsies obtained at initial diagnosis. Specimens expressing LMO2 in more than 30% of neoplastic cells were defined as positive. LMO2 expression was correlated with the international prognostic index (IPI), overall survival (OS) and progression free survival (PFS). Results: The median age of the study population was 58.5 years (24–85). The distribution of patients according to the IPI was 47% low risk (0–1 factors), 24% low intermediate (2 factors), 14% high intermediate (3 factors) and 15% high risk disease (〉=4 factors). 70 patients (66%) were LMO2 positive (compared to 55% in our original study). 18 patients (17%) have died and the median survival has not been reached. At a median follow-up of 32 months the 2 year OS for LMO2 positive versus negative cases was 91% (95% confidence interval [CI] 0.84, 0.98) versus 70.8% (95% CI 0.558, 0.875) respectively, p=0.04. No significant difference was observed in the 2 year PFS between LMO2 positive versus negative cases. A multivariate Cox regression analysis that included IPI scores and LMO2 expression as dependent variables for OS demonstrated a trend for LMO2 (p=0.07) and significance for the IPI (p=0.046) as independent predictors for OS. For PFS only the IPI remained statistically significant (p=0.03). Conclusions: This study validates the prognostic impact of LMO2 protein expression in the RCHOP treatment era in an independent cohort of DLBCL patients. Despite the higher proportion of LMO2 positive cases in the current cohort, a relatively short follow-up and few adverse events, LMO2 protein expression was associated with improved OS. Continued clinical follow-up of this cohort is ongoing to fully assess the impact on outcome. Assessment of LMO2 protein expression by routine IHC in biopsy samples of newly diagnosed DLBCL may help identify patients with different outcomes. Clinical trials will be necessary to assess the optimal therapy for patients based on LMO2 status.

Description: The presence of circulating tumor idiotype interferes with the in vivo effectiveness of anti-idiotype antibodies. We developed two assays that permit identification of patients with high levels of serum idiotype without the need for first producing an anti-idiotype antibody. A cell suspension made from the tumor was cultured for seven days with or without phytohemagglutin (PHA) and/or phorbol myristic acetate (PMA). Ig secretion in vitro by patients' tumor cells varied. In 4 patients, no secretion in vitro occurred, 5 patients had low levels, and 5 patients had high levels of Ig secretion. In three patients, Ig secretion occurred only after stimulation with PHA, PMA, or both. Spontaneous or induced immunoglobulin secretion in vitro is related to the levels of tumor idiotype secretion that exist in vivo. Eight patients with serum idiotype levels greater than 100 micrograms/mL (mean 265 micrograms/mL), had a minimum of 1.0 microgram/10(6) cells of idiotype secretion in vitro. Nine patients with serum idiotype levels less than 30 micrograms/mL (mean 3.7 micrograms/mL), had less than or equal to 0.5 microgram/10(6) cells of idiotype secretion in vitro. In another assay, the levels of IgM kappa and IgM lambda in patients' sera were compared with those in normal serum. An imbalance in the relative amounts of IgM kappa and IgM lambda indicated high levels of circulating idiotype in the serum, but this assay was less sensitive than the in vitro secretion assay and limited to IgM-secreting tumors. These assays will be useful for future clinical studies using anti- idiotype antibodies.

Description: Gaucher disease patients are occasionally affected by chronic or fulminant infections. Since Gaucher cells originate from tissue phagocytes, we studied the functional implications of glucocerbroside accumulation on phagocytes in Gaucher disease patients. Circulating monocytes and granulocytes from nine type I Gaucher disease patients, and matched controls, were studied. Evaluation of phagocytic activity included (1) maximal superoxide generation rates following stimulation by phorbol 12-myristate 13-acetate (PMA), opsonized zymosan (OZ), or formyl-methionyl-leucylphenylalanine (FMLP); (2) nitroblue tetrazolium reduction test (NBT); (3) chemotaxis toward FMLP; (4) phagocytosis of OZ particles; and (5) killing activity against Staphylococcus aureus. Superoxide generation in monocytes following PMA, OZ, and FMLP stimulation was significantly suppressed at 52% +/- 15%, 39% +/- 8%, and 51% +/- 11% of control, respectively. Superoxide generation in granulocytes was normal. NBT reduction, staphylococcal killing, and phagocytosis were also markedly decreased in monocytes, and normal in granulocytes. Mean chemotaxis rates were normal in both monocytes and granulocytes; however, decreased chemotactic rates were observed in some patients. The abnormality of superoxide generation could be reproduced in a dose- and time-dependent manner in normal circulating monocytes incubated with glucocerebroside. Superoxide generation in glucocerebroside-conditioned normal monocytes in a cell-free system showed normal superoxide generation, reflecting the integrity of the NADPH oxidase complex itself. These results demonstrate markedly compromised phagocytic functions in circulating monocytes in Gaucher disease patients. These abnormalities can be attributed to accumulation of glucocerebroside, since it could be reproduced in normal monocytes incubated with glucocerebroside. Similar abnormalities in Gaucher cells throughout the reticuloendothelial system could impair host defense, and may be of particular importance in the pathogenesis of osteomyelitis in Gaucher disease patients.