Combination 13-cis-retinoic acid and interferon alpha-2a in the therapy of solid tumors.

Preclinical data indicate that the combination of retinoids and interferons have synergistic antiproliferative and differentiating effects in some hematologic and solid tumor models. These observations have led to clinical trials in which 13-cis-retinoic acid (13cRA) 1 mg/kg/day was combined with interferon alpha-2a (IFN alpha) 3 or 6 x 10(6) U/day. The first two such trials produced exciting results: 50% response rate in patients with previously untreated stages IB-IVA cervix cancer and 68% in patients with advanced squamous cell skin cancer. These data led to a number of additional trials of the combination, but the high response rates seen in the initial cervix and skin trials have not been duplicated in the other squamous tumors tested (head and neck, lung, pretreated cervix). In addition, trials in two non-squamous histologies were negative (lung and melanoma). However, the regimen was not always studied in an optimal population of previously untreated patients and the negative results in pretreated cervix patients point to the relevance of this consideration. Nevertheless, the observation that the combination of 13cRA and IFN alpha (both of which bind to specific receptors and change gene expression) is able to induce regression in advanced tumors, must be regarded as highly important. Key questions to be addressed include an understanding of the biologic mechanism of specific tumor sensitivity (why some squamous tumors and not others?), and mechanisms of resistance in sensitive tumor types (e.g. cervix). Such data may lead to trials targeted to tumor types with defined biologic features having a high likelihood of clinical benefit. In the meantime, studies integrating this combination with other active treatment modalities such as radiation is warranted in cervix and skin carcinomas.

Combination 13-cis-retinoic acid and interferon alpha-2a in the therapy of solid tumors.

Preclinical data indicate that the combination of retinoids and interferons have synergistic antiproliferative and differentiating effects in some hematologic and solid tumor models. These observations have led to clinical trials in which 13-cis-retinoic acid (13cRA) 1 mg/kg/day was combined with interferon alpha-2a (IFN alpha) 3 or 6 x 10(6) U/day. The first two such trials produced exciting results: 50% response rate in patients with previously untreated stages IB-IVA cervix cancer and 68% in patients with advanced squamous cell skin cancer. These data led to a number of additional trials of the combination, but the high response rates seen in the initial cervix and skin trials have not been duplicated in the other squamous tumors tested (head and neck, lung, pretreated cervix). In addition, trials in two nonsquamous histologies were negative (lung and melanoma). However, the regimen was not always studied in an optimal population of previously untreated patients and the negative results in pretreated cervix patients point to the relevance of this consideration. Nevertheless, the observation that the combination of 13cRA and IFN alpha (both of which bind to specific receptors and change gene expression) is able to induce regression in advanced tumors, must be regarded as highly important. Key questions to be addressed include an understanding of the biologic mechanism of specific tumor sensitivity (why some squamous tumors and not others?), and mechanisms of resistance in sensitive tumor types (e.g. cervix). Such data may lead to trials targeted to tumor types with defined biologic features having a high liklihood of clinical benefit. In the meantime, studies integrating this combination with other active treatment modalities such as radiation is warranted in cervix and skin carcinomas.

Phase II trial of anaxirone (TGU) in advanced colorectal cancer: an EORTC Early Clinical Trials Group (ECTG) study.

Anaxirone, a rationally synthesised triepoxide derivative, was given to 46 patients with metastatic colorectal cancer. Good risk patients received 800 mg/m2 as a rapid intravenous injection every 4 weeks, whereas poor risk patients received 650 mg/m2. Of 46 patients, 45 were evaluable for toxicity and 42 for efficacy analysis. There were 37/45 patients with poor risk, showing no difference in toxicity as compared to good risk patients. The major toxic effect was myelosuppression with 34% of all patients experiencing grade 3 or 4 leucopenia; thrombocytopenia was less frequent. Locoregional phlebitis occurred in 66% of the patients. There was no objective tumour response to anaxirone in 42 evaluable patients. Only 4 patients achieved stabilisation of the disease lasting maximally up to 248 days. Anaxirone is inactive in metastatic colorectal cancer.

Retinoids.

This review highlights recent advances in understanding the mode of action of retinoids at the level of molecular and cellular biology in relation to the new clinical results achieved with retinoids in various malignancies. All-trans-retinoic acid has been established in the clinic as a first-line differentiation therapy for acute promyelocytic leukemia. Other retinoids, as single agents or in combination, generated interesting preliminary results in prevention of or therapy for various precancerous and cancerous lesions. These results are currently being corroborated in ongoing trials. Retinoids are emerging as a new class of anticancer agents with a new molecular target, offering new combination therapies.

Retinoic acid and interferon combination studies in human cancer.

Retinoic acid and interferon-alpha have limited single-agent activity in advanced cancer. Cell culture data indicate that in combination these agents have enhanced activity (modulating growth and differentiation) in a number of malignant cell types. Recent clinical work in advanced squamous cell carcinoma reports major activity with this regimen. This paper reviews the preclinical and clinical data testing retinoic acid in combination with interferons and presents recent work integrating these agents with radiotherapy in locally advanced cervical cancer.

Retinoids in cancer prevention and therapy.

Retinoids are a class of compounds structurally related to vitamin A. In preclinical studies, all-trans retinoic acid (tretinoin), 13-cis retinoic acid (isotretinoin) and the aromatic retinoids etretinate and acitretin have preventive and therapeutic effects on carcinogen-induced premalignant and malignant lesions. Clinically, chemoprevention with isotretinoin and etretinate has been tested with some degree of success in such indications as basal cell carcinomas, squamous cell carcinomas, superficial bladder tumors and second primary tumors in patients with squamous cell carcinoma of the head and neck. Limited therapeutic success has also been achieved with retinoid treatment of precancerous and cancerous conditions of the skin, oral cavity, larynx, lung, bladder and vulva. Dramatic therapeutic effects have been observed in the treatment of acute promyelocytic leukemia with tretinoin, which leads to very high rate of complete remission. Excellent results were recently reported in the treatment of squamous cell carcinomas of the skin and cervix with a combination of isotretinoin and recombinant interferon alfa-2a (rIFN alfa-2a, Roferon-A). The mechanism of action of retinoids is through modulation of cell proliferation and differentiation. Retinoids vary in their capacity to induce differentiation and to inhibit proliferation in a series of human transformed hematopoietic and epithelial cell lines. Some cytokines potentiate the retinoid-induced cell differentiation and act synergistically with retinoids to inhibit cell proliferation. The pattern of synergism is dependent upon the combination and tumor cell line tested. The discovery of nuclear retinoid receptors has contributed substantially to the understanding of the mechanism of action of retinoids at the molecular level. Further understanding of the molecular biology of retinoids is expected to contribute to a rational design of new retinoids in the future, which in turn may result in improvements in the prevention and therapy of cancer.

Recombinant interferon alpha-2A combined with prednisone in metastatic renal-cell carcinoma: treatment results, serum interferon levels and the development of antibodies.

Five partial responses were seen in 23 patients with metastatic renal-cell carcinoma (MRCC) receiving interferon-alpha 2a (IFN)+prednisone (P). Four of 24 subsequent patients responded to IFN+P (combined response rate 19%). The median response duration was 8 months (3 to 30 months). The one-year survival for all eligible patients was 52%. Eight of 26 evaluable patients developed antibodies detected by an enzyme immunoassay. In 2 patients, high levels of neutralizing antibodies were also found, together with particularly low IFN levels. In one patient the development of neutralizing antibodies coincided with the loss of initial response. The treatment was well tolerated by most patients. Premature discontinuation of treatment was necessary in only 2 patients. In MRCC, combination treatment with IFN+P is as effective as IFN monotherapy (response rate 19%), with significantly reduced subjective toxicity. The clinical relevance of the development of antibodies against IFN requires further investigation.

Recombinant interferon alfa-2a with or without vinblastine in metastatic renal cell carcinoma: results of a European multi-center phase III study.

A total of 178 patients with metastatic renal cell cancer were randomized to receive interferon alfa-2a (rIFN alfa-2a) or interferon alfa-2a+vinblastine (VLB). IFN alfa-2a was injected intramuscularly at a dose of 18 MIU 3 times a week and VLB was given intravenously at a dose of 0.1 mg/kg once every 3 weeks. The response rate was 11% for patients on monotherapy and 24% for those on combination treatment. The 5-year survival for 145 eligible patients was 9%, independently from the treatment arm. The performance status was significantly related to long-term prognosis, and 13% of the patients with performance status 0 were alive at 5 years, as compared to 6% and 0% for patients with a WHO grade of 1 and 2, respectively. The most frequent adverse events in both treatment arms were flu-like symptoms (95%), fatigue (70%) and gastrointestinal disturbances (68%). Leukopenia was observed more frequently with combination treatment (53%) than with IFN alfa-2a alone (30%). In conclusion, rIFN alfa-2a monotherapy at this dose and schedule has modest antitumor activity in metastatic renal cell cancer. The combination of rIFN alfa-2a+VLB results in a doubling of the response rate, but this does not translate into prolonged survival. Toxicity (except leukopenia) and tolerance were similar in both treatment arms.

Clinical experience with the combined use of recombinant interleukin-2 (IL2) and interferon alfa-2a (IFN alpha) in metastatic melanoma.

A multicentre study of IL2 and IFN alpha has been performed in 58 patients with metastatic melanoma. The scheme consisted of IL2 3.0 BRMP MU/m2/d as a continuous infusion for 4 d combined with subcutaneous administration of IFN alpha 6 MU/m2/d, day 1 + 4. The cycle was repeated every 2 weeks for a maximum duration of 26 weeks. 54 patients were evaluable for response. One (2%) achieved a complete and 10 (19%) a partial response. 19 (35%) patients were stable and 24 (44%) showed progressive disease. Common side-effects included fever, chills, fatigue, skin rash, anorexia, nausea and diarrhoea. Hypothyroidism was noted in 10% of the patients. These results show that this regimen of IL2 and IFN alpha is active but, in contrast to what could be expected, not superior to IL2 alone possibly due to suboptimal dosing. In an ongoing study in Rotterdam and Nijmegen, a more intense schedule was chosen, consisting of three daily i.v. doses of IL2 4.5 BRMP MU/m2 and IFN alpha 3.0 MU/m2 for 5 d. This regimen is repeated at intervals of 3 weeks for a total of three cycles. Presently, nine patients have been entered. One patient achieved a complete response, four a partial response (overall 56%), three had stable disease and one progressed. Toxicity was severe and treatment was prematurely stopped in five patients: myocardial infarction (one patient), atrial fibrillation (one patient), negative T waves and myocardial hypokinesia (one patient) and psychosis (two patients). This regimen can only be justified if the therapeutic results are superb, which has yet to be awaited.

Improved tolerance of interferon alpha-2a by continuous subcutaneous infusion.

Fifteen patients with progressing melanomas, hypernephromas or B-cell malignancies were treated in a phase I study with Interferon (IFN) alpha-2a by continuous subcutaneous infusion. With the help of a syringe driver pump daily doses of 12-15 MU resulting in median weekly doses of 90 MU could be safely given with little side effects. Flu-like symptoms and side effects from the gastrointestinal tract were mainly of grade 1 or 2 only. The major dose limiting but reversible toxicity was leukopenia. Five patients developed local inflammatory reactions at the infusion site. The pharmacokinetic data demonstrate that by this route of administration median serum levels of 54 IU/ml (range 9.6-192.0 IU/ml) (EIA-F-assay) can be achieved. Antibody formation was observed in 4 patients. - One out of 9 patients evaluable for tumor response demonstrated a partial tumor regression and 4 patients had a stabilisation of their disease. In comparison to intermittent i.m. or s.c. schedules, this novel route of administration by continuous subcutaneous infusion results in significant serum concentrations, biological activity and little clinical side effects. This may facilitate in the future the combination of IFN alpha-2a with other biological response modifiers like interleukin-2 or tumor necrosis factor.

Primary hypothyroidism associated with interleukin-2 and interferon alpha-2 therapy of melanoma and renal carcinoma.

Four patients out of twenty with renal cancer and melanoma undergoing cancer immunotherapy with interleukin 2 (IL-2) and interferon alpha-2 (IFN-alpha 2) had laboratory evidence of hypothyroidism starting at cycle three to six, with a decline in serum thyroxine below normal and, in three cases, a rise in serum thyrotropin and thyroglobulin. One hypothyroid patient had elevated serum antimicrosomal antibody titres before the start of treatment and two others responded similarly during therapy. Three of the sixteen euthyroid patients also developed elevated titres of this antibody. Partial or complete remission was observed in seven of the patients--three of the four with hypothyroidism showed tumour regression. Thus IL-2 and IFN-alpha 2 can cause hypothyroidism, presumably via induction or exacerbation of autoimmune thyroid reactions. The occurrence of hypothyroidism may be mediated by high-dose IL-2 (rather than by LAK cell therapy as previously suggested) and potentiated by IFN-alpha 2.

Responses and toxic deaths in phase I clinical trials.

This review analysis consists of the antitumor activity and toxic deaths reported in single agent Phase I clinical trials using cytotoxic compounds published from 1972 to 1987. A total of 6639 patients with a variety of solid tumors and hematological malignancies were accrued in 211 trials studying 87 compounds. The median number of patients per trial was 28 (range: 7-111) and the median of the median ages reported in the individual trial was 56 (range of individual age: 2 to 93 years). Ten percent of the trials enrolled pediatric patients (less than 18 years), but the exact numbers of children were not always given or separated from the adult patients. Nine percent of the patients had received no prior treatment, 75% were pretreated either with chemotherapy alone (50%) or radio- plus chemotherapy (25%). Radiotherapy alone was administered to 11% of the patients and the remaining 5% of the patients received prior treatments which was not specified. The most frequent tumor types were those of the gastrointestinal tract (22%) and the respiratory tract (19%). The frequency of the remaining malignancies was less than 10% of all patients. There were 23 (0.3%) complete responders and 279 (4.2%) partial responders for an overall response rate of 4.5% among all entries. Toxic deaths were rare and reported in only 31 patients (0.5% of the entire population). Responses were usually observed in chemosensitive tumor types. Despite a low response rate reported during the first phase of cytotoxic drug development, the present analysis shows that some therapeutic benefit can be achieved.

[Therapy of thrombocytosis in myeloproliferative syndromes using recombinant interferon-alpha-2a]. / Therapie der Thrombozytose bei myeloproliferativen Syndromen mit rekombinantem Interferon-alpha-2a.

In a prospective open study 16 consecutive patients with a myeloproliferative syndrome and thrombocytosis were treated with interferon (IFN) alpha-2a. 4 patients had polycythemia vera, 4 essential thrombocythemia, 3 myeloid metaplasia and 5 chronic granulocytic leukemia. Platelet counts decreased in all treated patients within 2 to 12 weeks from a median value of 1010 x 10(9)/l to 350 x 10(9)/l. No primary or secondary resistance was observed. The initial dose of IFN was 9 m U per day. After correction of the thrombocytosis, it was progressively reduced to a minimum dose of 3 m U per week. Despite the good platelet response to IFN, leukocytosis persisted in 3 patients and polycythemia in a further 3. Side effects and poor compliance required discontinuation of therapy in 6 patients. Special attention is focused on the follow-up in 6 patients who have been treated for more than 15 months.

[Rare variants and unusual course of Cushing's syndrome]. / Seltene Varianten und Verlaufsformen des Cushing-Syndroms.

Cushing's syndrome is a rarely observed disease with a poor prognosis when not treated appropriately. Knowledge of clinical features of the different forms of the disease together with a specific and subtle method of cortisol detection is indispensable for an early out-patient diagnostic program. In this study the characteristic features of the rare benign and malignant forms of Cushing's syndrome are presented in typical case-reports. As it has been proven in clinical experience, the necessary diagnostic measures for clarification of the syndrome consists of only few methods reliable concerning their diagnostic validity. The success of any curative treatment of the benign forms or any palliative measure of the malignant forms essentially depends on early diagnosis and differentiation of the various appearances of Cushing's disease.

Inhibited methionine incorporation in human squamous carcinomas of the oral cavity as a measure for response to 5-fluorouracil.

Human epithelial cells and fibroblasts from malignant tumors and healthy tissues of the oral cavity were exposed in vitro to increasing concentrations of 5-fluorouracil. In order to determine whether the two cell types showed a difference in uptake, accumulation was measured over time using tritiated fluorouracil. Maximal drug uptake occurred in highly proliferative epithelial cells from cancerous tissue at 3 h, whereas fibroblasts from the same tissue and other cell types from healthy tissue exhibited a steadily increasing uptake over a long period of time. By use of [3H]methionine, a direct correlation could be demonstrated between the amount of incorporated drug and the fall in the rate of de novo protein synthesis. Furthermore, suppression of protein synthesis was closely related to the inhibition of cell division. These results indicate that the level of de novo protein synthesis can be a direct measure of the anticancer effect of fluorouracil.

Phase II trial of menogaril in advanced colorectal cancer.

Menogaril, a new semisynthetic anthracycline antibiotic, was administered to 35 patients with advanced colorectal cancer. The drug was infused over 2 hr at a dose of 160 mg/sqm or 200 mg/sqm repeated every 4 weeks. Twenty-seven patients were evaluable for response and no objective responses were achieved. Myelosuppression, only leukopenia, was usually of mild-moderate degree and occurred in 63% of the patients. Twenty-seven percent of the patients experienced severe leukopenia. Local erythema and phlebitis were frequently observed and were severe in 13% of the patients. Nausea/vomiting (66%) and alopecia (50%) were. of mild-moderate degree. This study suggests that menogaril at these doses and schedule had no activity in advanced colorectal cancer.

[Malignant pericardial effusion--a sign of unfavorable prognosis?]. / Maligner Perikarderguss--ein prognostisch ungünstiges Zeichen?

Malignant pericardial effusion (MPE) resulting in cardiac tamponade is a rare complication in neoplastic disease. From January 1975 to December 1984 the authors observed 22 patients with cytologically verified malignant pericardial effusion. The most frequent primary tumors were non-small cell lung cancer (6), breast cancer (5), non-Hodgkin lymphoma (4) and mesothelioma (4). 50% of the patients presented with MPE as the initial manifestation of the tumor. In the other group of patients MPE appeared after an average of 11 months following the diagnosis of malignant disease. The most frequent symptoms and clinical findings were dyspnea (100%), jugular venous distention (91%), and tachycardia (82%). During the first 24 hours after pericardiocentesis a median volume of 675 ml of predominantly serosanguinous effusion was drained. Besides intrapericardial drug instillation, patients also received local radiotherapy and systemic chemotherapy. At the time when MPE was diagnosed 77% of the patients exhibited advanced malignant disease. Mean survival time was 140 days. Malignant pericardial effusion is therefore regarded as an unfavorable prognostic factor.