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J A Ledermann

Publications and source records attributed to J A Ledermann.

14 recordsLinked to original sources
PubMed1992

Factors influencing variability of localisation of antibodies to carcinoembryonic antigen (CEA) in patients with colorectal carcinoma--implications for radioimmunotherapy.

Tumour localisation of anti-tumour antibodies varies greatly between patients. Factors which may be responsible for this have been investigated in 56 patients with colorectal carcinoma with a view to improving radioimmunotherapy. Thirty-seven to seventy-four MBq of 125-I labelled mouse monoclonal antibody to CEA, was given intravenously and tumour resected 70-480 h later. Percentage injected activity kg-1 (% inj.act kg-1) in tumour, was inversely correlated with the time interval between injection and operation (P = 0.004). To assess the influence of other parameters on localisation, patients were divided into two time groups according to time interval between injection and operation, 70-120 h (n = 33) and 144-480 h (n = 23). In neither group was there a significant correlation of % inj.act kg-1 with time. The % inj.act kg-1 in tumour showed a significant correlation with that in the blood for both groups (P = 0.005 and P = 0.01). There was no significant correlation for either time group between % inj.act kg-1 in tumour and serum CEA values, the per cent of tumour cells positive for CEA and vascularity. Tumour to blood ratios varied considerably (range 0.3-28.5:1) suggesting that factors other than time and persistence of activity in the blood contribute to efficient targeting. Tumour to blood ratios were inversely correlated with % inj.act kg-1 in blood for the 70-120 h group (P = 0.007), and were positively correlated with % inj.act kg-1 in tumour (P = 0.012). Autoradiography showed that antibody localised predominantly on tumour cells but was distributed heterogeneously, was not solely related to the expression of antigen and in some cases accumulated in necrotic more than viable areas of tumour. Penetration of antibody into malignant acinar structures was poor and CEA-positive cells closer to the blood supply were targeted to a greater extent than distant cells. Preoperative administration of radiolabelled antibody to CEA may be helpful in selecting patients with favourable localisation for radioimmunotherapy.

Antibodies, Monoclonal↗
PubMed1991

A phase-I study of repeated therapy with radiolabelled antibody to carcinoembryonic antigen using intermittent or continuous administration of cyclosporin A to suppress the immune response.

The anti-mouse antibody response was examined in patients receiving repeated i.v. therapy with radiolabelled mouse monoclonal antibody (MAb) to carcinoembryonic antigen (CEA): 131I anti-CEA was given approximately every 2 weeks with cyclosporin A, to suppress the anti-mouse antibody response. Two schedules of cyclosporin A--intermittent therapy for 6 days with each course of anti-CEA and continuous therapy--were compared. Suppression of the immune response in the intermittent high-dose (3 patients) and continuous low-dose groups (4 patients) was equivalent, but the latter regimen was less toxic. Repeated therapy led to the formation of small amounts of anti-mouse antibody, but provided that cyclosporin A was continued it did not prevent further therapy or lead to an increase in the rate of clearance of anti-CEA from blood. Without cyclosporin A no more than 2 courses of antibody therapy could be given. Patients received up to 4 doses of 131I anti-CEA. The nadir platelet count was related to the half-life of 131I anti-CEA in blood. Thrombocytopenia limited the amount of 131I anti-CEA that could be given and determined the interval between treatments. Effective suppression of the anti-antibody response is possible and this study has determined that myelosuppression is the principal obstacle to repeated therapy with radiolabelled antibody.

Adult↗
PubMed1991

Outcome of patients with unfavorable optimally cytoreduced ovarian cancer treated with chemotherapy and whole abdominal radiation.

There is a subgroup of patients with Stage II or III ovarian cancer whose survival is poor despite optimal cytoreduction of tumor and abdominopelvic radiation. This study examined whether the survival of these patients, who have tumor with unfavorable histopathological characteristics and/or small residual disease, could be improved by giving chemotherapy before radiation. Forty-four out of fifty-one eligible patients, seen between 1981 and 1985, with Stage II or III disease were entered into the study. Following six courses of cisplatin-based chemotherapy, 33 (75%) received abdominopelvic radiotherapy. Survival was compared to that of 48 eligible matched control patients, treated with radiation between 1978 and 1981. The median follow-up is 6.6 years. The median survival was extended from 2.4 to 5.7 years (P = 0.13), and 42.6% of patients receiving combined therapy were free of relapse at 5 years, compared to 21.6% (P = 0.03) in the historical control group, treated with abdominopelvic irradiation alone. Only 2 of 44 patients in the combined group required surgery for bowel obstruction, as did 1 of 48 in the control group. Tolerance and toxicity of the combined approach were acceptable. Although we cannot be certain that the entire benefit we observed was not attributable to the chemotherapy alone, there is evidence that the radiotherapy may have been additive. Chemotherapy followed by abdominopelvic radiotherapy seems a reasonable management policy in these patients.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

Weekly etoposide, methotrexate and actinomycin D, alternating with cyclophosphamide plus vincristine (EMA/CO): a phase II study in advanced gastric carcinoma.

A total of 27 patients with measurable/evaluable metastatic or locally advanced gastric carcinoma were given combination chemotherapy comprising etoposide, methotrexate, actinomycin D, cyclophosphamide and vincristine (EMA/CO). Ten achieved partial remission, giving a response rate of 37% (95% CI; 21.7%-66.3%), 12 attained stable disease, whereas five had disease progression despite treatment. Drug toxicity was moderate to severe. Five of those who achieved partial remission underwent an attempt to resect residual disease which was successful in only three patients.

Adenocarcinoma↗
PubMed1991

Results of the central data analysis.

This chapter presents the results of blind serological studies carried out by workshop participants on 87 monoclonal antibodies (mAbs) supplied to them as a coded panel. Twenty six mAbs had been studied in the first workshop. Participants were asked to carry out immunohistochemical, immunocytological or flow cytometric analysis on a mandatory panel of target tissues or cells. Central computer analysis and other supporting data allowed the assignment of 33 mAbs to seven clusters. Two of the antigens identified have been cloned while two more have been defined as carbohydrate epitopes. The results allow comparison of new mAbs against lung cancer with existing ones and are beginning to provide a description of the antigenic structure of the SCLC cell surface.

Antibodies, Monoclonal↗
PubMed1989

EMOP/CA chemotherapy for the treatment of aggressive non-Hodgkin's lymphomas.

From October 1983 to June 1987, 32 patients with aggressive non-Hodgkin's lymphomas (diffuse centroblastic, lymphoblastic and Burkitt type) were treated with the weekly alternating EMOP/CA schedule, total duration 12 weeks. There were six bulky stage II, nine stage III and 17 stage IV patients, median age 54 years (range 19-75). The complete remission rate was 59% (95% confidence limits 40-76%) and the partial remission rate 28% providing an overall response rate of 87%. With a median follow up time of 33 months (range 18-56) the relapse-free survival of those patients achieving a complete remission is 52% and the overall survival for the 32 patients treated is 27%. The CR rate for patients with stage IV disease was 47% and for those with stage II and III disease was 73% of whom 81% remain in remission. EMOP/CA chemotherapy produces acceptable results in stage II and III aggressive non-Hodgkin's lymphomas but is inadequate therapy for stage IV disease.

Adult↗
PubMed1989

Antibody distribution and dosimetry in patients receiving radiolabelled antibody therapy for colorectal cancer.

The distribution of iodine-131 (131I) labelled antibody to carcinoembryonic antigen (CEA) has been studied in 16 patients with colorectal cancer. Levels of tumour and normal tissue radioactivity were measured by serial gamma-camera imaging and counting of blood and urine. Maximum concentrations were found in tumour 8 h after administration and varied up to 9-fold in different patients. Higher levels were found on average in tumour than in any other tissue. Liver, lung and blood were the other tissues in which antibody was concentrated relative to the rest of the body. Antibody cleared from all these tissues over 1 week. Second antibody directed against the antitumour (first) antibody was given 24 h after first antibody in order to accelerate clearance from the blood. This increased the tumour to blood ratio but had little effect on other tissues. Cumulative radiation dose to tumour and normal tissue was estimated. In patients with the most efficient localisation the tumour to body ratio was 20:1 and tumour to blood ratio 5:1. This may be sufficient for effective therapy of cancer in patients selected for efficient antibody localisation. The data may be used to estimate the effect of different therapeutic strategies. For instance, in the time after second antibody administration the average tumour to blood ratio of radiation dose was 11:1, suggesting that two phase systems in which the therapeutic modality is given after a good tumour to normal tissue ratio is obtained may be effective for the majority of patients.

Antibodies, Neoplasm↗
PubMed1988

Cyclosporin A prevents the anti-murine antibody response to a monoclonal anti-tumour antibody in rabbits.

Repeated therapy of cancer with mouse monoclonal antibodies frequently produces antibodies directed against the administered antibody. We have investigated the ability of cyclosporin A (CsA) and the use of ultracentrifuged antibody to prevent the formation of anti-antibodies in rabbits. Courses of CsA, 20 mgkg-1 day-1, were given intramuscularly for 6 days to rabbits and a mouse monoclonal anti-human chorionic gonadotrophin antibody was given intravenously on day 2 with or without ultracentrifugation to remove microaggregates. The whole course was repeated after an interval of two weeks. Rabbit anti-mouse antibody production was prevented in all 8 animals that were given CsA and ultracentrifuged preparation (non UC-W14). Anti-mouse antibody was produced by all the animals that were not given CsA. A further dose of mouse antibody eight weeks after CsA demonstrated that immunological recovery had occurred in all four animals re-challenged with non UC-W14 but only 3/7 animals given an UC-W14 preparation. This suggests that CsA and ultracentrifugation facilitate the induction of immunological tolerance. The complete suppression of antibody production which could be achieved justifies a clinical trial of CsA and ultracentrifugation of antibody.

Animals↗
PubMed1988

Repeated antitumour antibody therapy in man with suppression of the host response by cyclosporin A.

Antibody targeted therapy of cancer results in anti-antibody production which prevents repeated treatment. Cyclosporin A (CsA) has been used to suppress this response in patients treated with a radiolabelled antibody to carcinoembryonic antigen (CEA). Patients with CEA producing tumours received a minimum of two courses consisting of an injection of radiolabelled antibody and CsA, 24 mg kg-1 day-1, for 6 days; each course was given at 2 week intervals. Two weeks after the completion of the second course the mean human antimouse antibody (HAMA) levels were 3.5 micrograms ml-1 (s.d. 2.7) in 3 patients receiving CsA and 1,998 micrograms ml-1 (s.d. 387) in 3 patients not receiving the drug. Clearance of antitumour antibody was accelerated and tumour localisation absent when HAMA levels exceeded 30 micrograms ml-1. With lower levels of HAMA in the CsA-treated patients, further antitumour antibody accumulated in the tumour after each dose. Further therapy with antitumour antibody and CsA lead to the development of HAMA, but this was less than 25% of the amount in patients not given CsA. In this preliminary study up to 4 times as many doses of antitumour antibody could be usefully given when CsA was used. This increases the potential for effective antibody targeted therapy of cancer.

Adult↗
PubMed1986

Is ectopic production of human chorionic gonadotrophin (hCG) or alpha fetoprotein (AFP) by tumours a marker of chemosensitivity?

We have treated eight patients with various tumours producing hCG or AFP with the high risk gestational choriocarcinoma regimen EMA/CO. Marker response was seen in two of three tumours producing AFP and in all of five tumours producing hCG. Three further patients were treated with EpPt/OMB, a regimen used in relapsed germ cell tumors. All responded biochemically. All complete biochemical responses were accompanied by anatomical response. These responses may reflect particular sensitivity in the marker producing tumours and marker measurements would identify this subgroup. These findings do not preclude the possibility that these cytotoxic regimens may have activity against a wide range of solid tumours.

Antineoplastic Combined Chemotherapy Protocols↗