Phase II trial of imatinib mesylate in patients with metastatic melanoma.

Metastatic melanoma cells express a number of protein tyrosine kinases (PTKs) that are considered to be targets for imatinib. We conducted a phase II trial of imatinib in patients with metastatic melanoma expressing at least one of these PTKs. Twenty-one patients whose tumours expressed at least one PTK (c-kit, platelet-derived growth factor receptors, c-abl, or abl-related gene) were treated with 400 mg of imatinib twice daily. One patient with metastatic acral lentiginous melanoma, containing the highest c-kit expression among all patients, had dramatic improvement on positron emission tomographic scan at 6 weeks and had a partial response lasting 12.8 months. The responder had a substantial increase in tumour and endothelial cell apoptosis at 2 weeks of treatment. Imatinib was fairly well tolerated: no patient required treatment discontinuation because of toxicity. Fatigue and oedema were the only grade 3 or 4 toxicities that occurred in more than 10% of the patients. Imatinib at the studied dose had minimal clinical efficacy as a single-agent therapy for metastatic melanoma. However, based on the characteristics of the responding tumour in our study, clinical activity of imatinib, specifically in patients with melanoma with certain c-kit aberrations, should be examined.

Noncytotoxic suramin as a chemosensitizer in patients with advanced non-small-cell lung cancer: a phase II study.

BACKGROUND: The purpose of this study was to evaluate the potential of noncytotoxic doses of suramin to reverse chemotherapy resistance in advanced chemonaive and chemoresistant non-small-cell lung cancer patients. PATIENTS AND METHODS: Patients received paclitaxel (Taxol) (200 mg/m(2)) and carboplatin (area under the concentration-time curve 6 mg/ml/min) every 3 weeks. The total suramin per cycle dose was calculated using a nomogram derived from the preceding phase I trial to obtain the desirable plasma concentration range of 10-50 microM. RESULTS: Thirty-nine response-assessable chemonaive patients (arm A) received 213 cycles. Thirty-eight cycles were administered to 15 patients with demonstrated resistance to paclitaxel and carboplatin (arm B). The pattern/frequency of toxic effects was similar to those expected for paclitaxel/carboplatin, and pharmacokinetic analyses (199 cycles) showed suramin plasma concentrations maintained between 10 and 50 microM in 94% of cycles. In arm A, response evaluation criteria in solid tumors (RECIST) response rate was 36% (95% confidence interval 22% to 54%; two complete, 12 partial); 15 patients (38%) had disease stabilization for > or =4 months; median progression-free survival (intention to treat) was 6.4 months; median overall survival (OS) 10.4 months and 1-year survival rate 38%. In arm B, no RECIST responses occurred; four patients had disease stabilization for > or =4 months; median OS was 132 days and 1-year survival rate 7%. Plasma basic fibroblast growth factor levels were higher in chemopretreated/refractory patients compared with chemonaive patients (P = 0.05). Sequence analysis of the EGFR tyrosine kinase domain in a long-term disease-free survivor revealed an ATP-binding pocket mutation (T790M). CONCLUSIONS: Noncytotoxic suramin did not increase paclitaxel/carboplatin's toxicity and the suramin dose was predicted from clinical parameters. No clinically significant reversal of primary resistance was documented, but a modulatory effect in chemotherapy-naive patients cannot be excluded. Controlled randomization is planned for further evaluation of this treatment strategy.

Inhibition of B16-BL6 melanoma growth in mice by methionine-enkephalin.

The antitumor effect of methionine-enkephalin [( Met]enkephalin) was demonstrated in C57BL/6J mice inoculated with B16-BL6 melanoma cells. Local subcutaneous tumor growth was inhibited with a 50-micrograms dose daily for 7 or 14 days. The antitumor effect of [Met]enkephalin was inhibited by the administration of the opioid receptor antagonist naloxone. Naloxone alone had no significant effect on tumor growth.

Chemotherapy for breast cancer decreases plasma protein C and protein S.

An increased incidence of thromboembolic events has been described in women receiving chemotherapy for breast cancer. The etiology of this enhanced thrombotic state has not been defined. We performed serial coagulation studies in 15 women during 1 monthly cycle of cyclophosphamide, methotrexate, and fluorouracil (CMF) chemotherapy for breast cancer; seven adjuvant and eight metastatic. Plasma protein C levels were measured by anticoagulant, amidolytic, and antigenic techniques. Antigen levels of both total and free plasma protein S were quantitated by immunoelectrophoresis. Plasma levels of protein C, an important vitamin K-dependent inhibitor of blood coagulation and a profibrinolytic agent, and protein S, a cofactor for protein C, decreased 1 and 2 weeks after initiation of chemotherapy compared with pretreatment values. Plasma levels of factor VII and fibrinogen also decreased. The changes in protein C and protein S may contribute to the enhanced thrombotic tendency described in this setting. Possible mechanisms for the decreases in plasma protein C, protein S, factor VII, and fibrinogen are discussed.

Acute lymphoblastic leukemia with chromosomal 5;14 translocation and hypereosinophilia: case report and literature review.

A 19-year-old man with acute lymphoblastic leukemia (ALL) presented with 82,000 WBC/microL, 57% eosinophils, and cardiorespiratory symptoms. Lymphoblast infiltration of the meninges and testes developed without eosinophil infiltration at these sites and peripheral blood and marrow lymphoblast counts progressively increased, while blood eosinophilia disappeared. The patient's bone marrow cells had a clonal cytogenetic abnormality--t(5;14), (q?,q32)--which disappeared during remission and reappeared during disease relapse. Including this case, three patients with ALL and hypereosinophilia have had cytogenetic studies with G-banding. All three had 14q + chromosomal abnormalities and two had a similar translocation t(5,14), (q?,q32). Survival of the 26 ALL patients with hypereosinophilia reported since 1973 was similar to that of 52 age- and sex-matched historical-control patients without hypereosinophilia treated during the same time interval.

Lactate dehydrogenase values and bone scans as predictors of bone marrow involvement in small-cell lung cancer.

The value of serum lactate dehydrogenase (LDH) levels and bone scan results in predicting marrow involvement in small-cell carcinoma of the lung (SCCL) was studied. Records of 79 patients with SCCL who had undergone 92 bone marrow examinations were reviewed. None of 25 patients with marrow involvement had a normal LDH and a negative bone scan, compared with 23 of 59 in the uninvolved group. We conclude that patients with SCCL with both negative bone scans and normal LDH values have a less than 5% chance of marrow involvement.

Promising new agents under development by the Division of Cancer Treatment, Diagnosis, and Centers of the National Cancer Institute.

The Division of Cancer Treatment, Diagnosis and Centers of the National Cancer Institute (NCI) has a large program in clinical cancer therapeutics development. It currently holds investigational new drug applications for nearly 200 agents with which it sponsors clinical trials. In addition, it has a major preclinical development program. With the tremendous advances in our understanding of molecular and tumor biology during the past decade, the NCI's portfolio of agents has expanded beyond classical cytotoxic agents to include a wide variety of new molecular and therapeutic targets. In addition to agents with more conventional mechanisms of action, the NCI has targeted therapeutics programs that focus on tumor vasculature, cell cycle control and cell signaling, mechanisms of apoptosis, invasion and metastasis, and immunological recognition and response. Each of these focused areas includes agents of different classes and modes of action that are all directed at the target of interest. The scope of the NCI's program allows it to respond to incorporate promising new agents or targets as they arise and to prioritize them for use of preclinical and clinical resources. Agents in development through the NCI are derived from a number of diverse sources including its own screening efforts, academia, and numerous collaborations with the pharmaceutical and biotechnology industries. NCI works closely with collaborators to ensure complementary, non-duplicative clinical development and attempts to ensure that the full potential of promising agents is explored. A number of compounds in early clinical development or about to enter the clinic are discussed briefly in this manuscript.

Modulation of murine melanoma growth by naloxone.

The present study was undertaken to determine the effect of the opioid receptor antagonist, naloxone, on the growth of B16 melanoma, a murine tumor known to possess opioid receptors. Naloxone inhibited the growth of B16 melanoma in vitro when monolayer cultures were continuously exposed to concentrations of greater than or equal to 0.25 mg/ml. Tumor cell proliferation as measured by [3H]thymidine ([3H]Tdr) incorporation is reduced by a continuous 48-h treatment with greater than or equal to 0.025 mg/ml but slightly enhanced by a 6-h treatment. The administration of naloxone to mice caused a transient inhibition of subcutaneous local tumor growth at doses of 0.1, 1 and 10 mg/kg daily. At a dose of 10 mg/kg daily, naloxone caused a slight reduction in the number of pulmonary metastases following the intravenous inoculation of tumor cells. The mechanism by which naloxone inhibits tumor growth in vivo is not clear, but factors other than direct cytotoxicity may also be involved. The results further support the role of the endogenous opioid system in the modulation of tumor growth.

Enhancement of host resistance to viral and tumor challenge by treatment with methionine-enkephalin.

Host resistance to disease is dependent upon a number of factors. Recent evidence indicates that natural killer (NK) cells play an important role in resistance to both neoplastic and virally induced disease. Treatment of C57Bl/6 mice with methionine-enkephalin (1, 3, 10, or 30 mg/kg body weight) results in significant increases in NK activity of splenic lymphocytes 20 hours after injection of the enkephalin. Enkephalin treatment also enhances host resistance. The short-term survival of A/J female mice after HSV-2 infection was significantly increased by daily subcutaneous injections (3 mg/kg body weight) of methionine-enkephalin. Similarly, daily doses of 50 micrograms of methionine-enkephalin for 7 to 14 days inhibit the local subcutaneous tumor growth of B15 melanoma in C57Bl/6 mice.

Effect of methionine-enkephalin plus ZnCl2 on active T cell rosettes.

Methionine-enkephalin (Met-Enk) and ZnCl2 in combination enhances active T cell rosette formation of human peripheral blood lymphocytes to a greater degree than either of the agents used separately. Enhancement of rosette formation by Met-Enk plus ZnCl2 was not inhibited by the opiate receptor antagonist naloxone but was completely blocked by the zinc chelator 1,10-phenanthroline. The results suggest a relationship between zinc and Met-Enk and that zinc may be a modulator of enkephalin binding and function in the immune system as well as the nervous system.

Vitamin B6 and cancer: a novel pyridoxal 5-phosphate conjugate in tumor cells and blood of cancer patients.

Studies on the metabolic transformations of labeled pyridoxine showed that its utilization by tumor animals and tumor cells differs greatly from that seen in control animals. When [3,4-14C] and/or tritium labeled pyridoxine at the 6th ring carbon is administered i.p. to tumor-bearing animals and its fate is subsequently determined at different time intervals (using HPLC separation of the labeled metabolites following acid extraction from tissues), in addition to other differences, synthesis of a novel labeled product occurs which begins with the onset of tumor growth. It is either absent or present only at minimal levels in normal animals and regenerating rat liver. It is present in all tumor sources examined to date, i.e. serum of tumor rats, a spectrum of rat hepatomas, solid human tumors, tumor cells in culture and plasma of cancer patients. The novel product is a conjugate of pyridoxal 5'-phosphate with the structure Adenosine-N6-Diethylthioether-N1- Pyridoximine-5'-phosphate. This communication reports on the occurrence and distribution of the novel product in different tumor tissues and cells as well as the blood of cancer patients with active disease and in remission, and in normal volunteers. The results show significantly higher levels of this product in the blood of patients with different malignancies and in the active state. The novel vitamin B6 compound may be a good candidate as a marker for tumor presence and/or metastasis.

The role of the FDA in new drug development and availability.

During the last decade, the process by which the FDA regulates investigational new drugs has become a renewed focus of national attention. The ability of the FDA to maintain a balance between accelerating the availability of new drugs and ensuring that patients do not receive unsafe or ineffective treatments has been particularly challenged by the AIDS crisis. In response to this crisis, the FDA has revised its regulations and created various formal mechanisms for expediting the development and accessibility of promising new therapies to treat AIDS and other serious illnesses. Regulatory requirements have been reduced and consultation with the FDA to discuss the planning and design of clinical research is encouraged.

Immunological approaches to cancer treatment.

A better understanding of cellular immunology and advances in recombinant DNA technology have led to a new dimension in the immunological treatment of cancer in which the potential for success is greatly increased. The number of biological agents with the ability to enhance the host's anti-tumor defense mechanisms has markedly increased during the last decade. The development of clinical trials with these biological response modifiers is an area of intense research. As a result of these investigations, a variety of malignancies now can be treated successfully by immunological approaches.