Chemotherapy of small cell carcinoma of the lung with V.P. 16-213

Etoposide sensitizes CT26 colorectal adenocarcinoma to radiation therapy in BALB/c mice

AIM: To investigate the combined effect of etoposide and radiation on CT26 colorectal adenocarcinoma implanted into BALB/c mice.

METHODS: We evaluated the radiosensitizing effect of etoposide on CT26 colorectal adenocarcinoma in a syngeneic animal model. BALB/c mice were subcutaneously implanted with CT26 cells and divided into four groups: control (intra-peritoneal saline2) group, etoposide (5 mg/kg intra-peritoneally2) group, radiation therapy (RT 5 Gy2 fractions) group, and combination therapy with etoposide (5 mg/kg intra-peritoneally 1 h before radiation) group.

RESULTS: Tumor growth was significantly inhibited by RT and combination therapy. The effect of combination therapy was better than that of RT. No significant changes were noted in body weight, plasma alanine aminotransferase, or creatinine in any group. The leukocyte count significantly but transiently decreased in the RT and combination therapy groups, but not in the etoposide and control groups. There was no skin change or hair loss in the RT and combination therapy groups.

CONCLUSION: Etoposide can sensitize CT26 colorectal adenocarcinoma in BALB/c mice to RT without significant toxicity.

A phase I/II trial of etoposide and cisplatin in extensive small cell lung cancer: a cancer and leukemia group B study

Patients with untreated extensive small cell lung cancer (SCLC) with CALGB performance scores 0-2 were treated with etoposide 200 mg/m2/day on days 1-3 and cisplatin doses of 20, 30, or 35 mg/m2/day days 1-3 in a Phase I/II format. Of the nine patients treated at the 35 mg/m2/day cisplatin dose in the Phase I portion of the study, Grade 4 leukopenia occurred in five patients and Grade 4 thrombocytopenia in four. There were two deaths due to myelosuppression and sepsis. This dose was thus considered the maximum tolerated dose (MTD), and a Phase II trial was then conducted using this treatment program. In the Phase II trial of 39 patients, the objective response rate was 67% (95% confidence interval, 50-81%) with 21% complete responses (CI 9-36%). Median survival was 10.5 months. Grade 4-5 leukopenia was seen in 57% and Grade 4-5 thrombocytopenia in 56%. The MTD defined by this Phase I trial represents a 67-100% increase in etoposide and a 32-42% increase in cisplatin dosage compared to prior studies. The observed objective response rates with this regimen are comparable to studies using conventional doses, but hematological toxicity was higher.

Etoposide: current status and future perspectives in the management of malignant neoplasms

Etoposide has demonstrated highly significant clinical activity against a wide variety of neoplasms, including germ-cell malignancies, small-cell lung cancer, non-Hodgkin's lymphomas, leukemias, Kaposi's sarcoma, neuroblastoma, and soft-tissue sarcomas. It is also one of the important agents in the preparatory regimens given prior to bone marrow and peripheral stem-cell rescue. Despite its high degree of efficacy in a number of malignancies, the optimal dose, schedule, and dosing form remain to be defined. It is possible that continuous or prolonged inhibition of the substrate, i. e., topoisomerase II, may be the key factor for the cytotoxic effects of etoposide. Clinical studies have shown the activity of etoposide to be schedule-dependent, with prolonged dosing, best accomplished by the oral dosing form, offering a therapeutic advantage. This benefit awaits validation by prospective randomized studies, some of which are in progress. Recent clinical investigations have focused on the use of etoposide in combination with (a) cytokines to ameliorate myelosuppression, the dose-limiting toxicity of etoposide; (b) agents such as cyclosporin A and verapamil to alter the p-glycoprotein (mdr1) function; and (c) topoisomerase I inhibitors to modulate the substrate upon which it acts. There is continued interest in the development of etoposide to its maximal clinical dimensions and in the examination of alternative biochemical and mechanistic approaches to further our understanding of this highly active agent.

Current status of etoposide in the management of small cell lung cancer

Etoposide is a schedule-dependent drug with excellent activity against small cell lung cancer (SCLC). Single-agent etoposide achieves overall response rates ranging from 15% to 84%, depending on the schedule of drug administration and the characteristics of the treated population. The route of etoposide administration (intravenous versus oral) has little impact on response rate, provided appropriate dose adjustments are made for oral therapy. In combination with other active agents, etoposide has proven particularly effective in the management of SCLC. Etoposide can be substituted for doxorubicin or vincristine in the cyclophosphamide, doxorubicin, and vincristine (CAV) regimen without loss of efficacy. The etoposide and cisplatin (EP) combination is thought to be synergistic and has proven to be an effective salvage regimen for CAV failures. A regimen that alternates CAV and EP has been found by some investigators to be modestly more effective against SCLC than CAV alone; however, EP alone may be as useful as an alternating regimen. Most studies to date have demonstrated that EP induction is at least as effective as any other standard induction regimen. However, EP has the potential advantage of being more easily integrated with thoracic radiation therapy (RT). This is particularly important in limited-disease patients: two recent pilot studies employing EP induction with hyperfractionated thoracic RT yielded 2-year survival rates of greater than 50%. These promising results are being evaluated further in an ongoing Phase III trial in the United States. The available data indicate that etoposide is one of the most active agents against SCLC and therefore should be included as a component of induction therapy in all patients. New schedules of etoposide administration warrant further study.

Combination cyclophosphamide and etoposide in treatment of small cell lung cancer

Thirty-one patients with histologically proven small cell lung cancer were treated with cyclophosphamide 1 g m-2 and etoposide (VP16-213) 125 mg m-2 both intravenously on day 1 followed by etoposide 250 mg m-2 orally on days 2-3 for a maximum of six courses at 3 weekly intervals. Fourteen patients had limited and 17 patients had extensive disease. Twenty-five patients were evaluable for response. Objective response was observed in 18 patients (58%) with 6 (19%) complete and 12 (39%) partial responses. Median survival of the entire group of patients was 30 weeks. There was significant survival benefit among the responders (P less than 0.005) when compared with non-responders. One patient (3.3%) developed grade 4 while 60% of patients developed grade 1-2 haematological toxicity. Other side effects were relatively mild. We conclude that combination cyclophosphamide and etoposide was active in small cell lung cancer and relatively well tolerated.

Carboplatin and etoposide in advanced lung cancer:--a phase I study

This phase I study was carried out to determine the maximal tolerated dose of carboplatin (Car) together with a fixed dose of etoposide (E) and to recommend the optimal dose for a phase II study. The dose of E was 100 mg/m2 given i.v. on days 1-3, and the starting dose of Car was 200 mg/m2 given i.v. on day 1. The dose was escalated until WHO grade 4 toxicity developed after two treatment cycles in more than one-third of the patients. A total of 33 patients with advanced lung cancer entered the trial. The maximal tolerated toxicity of the combination was reached at a dose of 500 mg/m2 Car. Myelosuppression was moderate, and hematological toxicity of WHO grade 4 was encountered in one of five patients at 475 mg/m2 and in two out of five patients at 500 mg/m2. The main toxic effects were leucopenia and thrombocytopenia. The frequency of treatment-related infections was low and no deaths were caused by treatment. There was a significant overall correlation between the platelet nadir and creatinine clearance. One complete response and three partial responses were achieved after two treatment cycles. Based on the results of the present study, the dose of carboplatin (combined with 100 mg/m2 eposide given on days 1-3) recommended for phase II studies is 450 mg/m2.

Cisplatin and etoposide as second-line chemotherapy in patients with small cell lung cancer

Twenty-seven evaluable patients with small cell lung cancer (SCLC) resistant to, or relapsed after induction combination chemotherapy (CT) were treated with etoposide (VP16) plus cisplatin (DDP). Previous treatment was: alternating CT with cyclophosphamide (C), adriamycin (A), methotrexate (M), procarbazine (P) (CAMP)/VP16, BCNU (B), hexamethylmelamine (H) (VP16 BH) in 16 patients; C, A, vincristine (CAV) in 6 patients; C, A, and VP16 (CAVP16) in 5 patients. We observed 2 (7%) complete responses (CR) and 9 (33%) partial responses (PR). Duration of CRs was 8 and 14 weeks, respectively. PRs lasted a median of 22 weeks (range 16-44). Seven of 21 (33%) patients previously treated with VP16 responded to DDP plus VP16 (D-V). These results confirm D-V regimen as active in SCLC patients even when heavily pretreated. Our 33% response in patients who had VP16 in their induction treatment regimen provides further evidence of an important potentiating effect of DDP, as reported in animal system.

Etoposide, cisplatin and doxorubicin in patients with small cell lung cancer: tumor response and long term survival

One hundred and fourteen patients with small cell lung cancer received a combination of etoposide 80 mg/m2 IV days 1,2,3,15,16,17, cisplatin 20 mg/m2 IV days 1,2,3 and doxorubicin 40 mg/m2 IV day 1, repeated every 4 weeks. The observation time from the initiation of treatment is longer than 4 years for all patients. An 85% response rate (38% complete response) was obtained after 1-4 cycles in 105 evaluable patients (96 without prior antitumour treatments). The response rate was not influenced by initial performance status and minimally by disease extension, whereas the same prognostic factors correlated significantly with complete responses. For limited disease and WHO performance 0 all responses were complete. For extensive disease and performance 3 no complete response was obtained. Various chemotherapy regimens with or without radiotherapy were used during the maintenance phase. Forty five per cent of first relapses were in the lung or mediastinum and 18% in the nervous system (20% without and 7% with prophylactic cranial irradiation). The median survival was 13.4 months for limited and 8.5 months for extensive disease, and correlated with performance and response. Only 2 patients survived free of disease after 4.8 and 5.5 years. We conclude that the induction treatment as used here produces a high rate of partial and complete responses but a low rate of long survivors.

Clinical pharmacology of intracarotid etoposide

Pharmacokinetics studies were performed in ten patients who received VP-16 by intracarotid infusion at 100-300 mg/m2. VP-16 was analyzed by high-pressure liquid chromatography. ESTRIP and NONLIN were used to characterize VP-16 pharmacokinetics. VP-16 disappeared biphasically, with a t1/2 beta of 6.1 +/- 1.4 h; the total clearance was 26.8 +/- 2.8 ml/min/m2, and the Vss was 8.8 +/- 1.6 l/m2. The pharmacokinetics was not significantly different after administration by the IV route. However, at a lower dosage, less than 140 mg/m2, the half-life appears to be shorter. This may or may not be significant, since VP-16 pharmacokinetics is quite variable and the number of patients studied is relatively small. Overall, the brain and brain tumor do not appear to have any first-pass effect on VP-16 pharmacokinetics.

Combination chemotherapy in small cell lung carcinoma. A randomized study of two intensive regimens

From April, 1979 to November, 1981, 293 patients with small cell lung carcinoma (SCLC) were entered on a randomized, controlled study comparing the two induction regimens of high-dose CAV (HD-CAV) (cyclophosphamide [CTX] 1200 mg/m2, doxorubicin [ADR] 70 mg/m2 and vincristine [VCR] 1 mg/m2 intravenously (IV) on days 1 and 21) versus, conventional-dose CAV + VP-16 (etoposide) (CAV-VP) (CTX 1000 mg/m2, ADR 40 mg/m2, VCR 1 mg/m2 IV on days 1 and 21 with VP-16 100 mg/m2 on days 1-3, and 21-23). Responding and stable patients were continued on conventional-dose CAV for 5 consolidation courses. Prophylactic brain irradiation delivered after the first consolidation course in responders was optional. Patients were included in the study if they had extensive disease (i.e., beyond one hemithorax), no prior chemotherapy, or radiotherapy and performance status of 50 or above. After 2 induction courses, 215 cases are evaluable. Of these, 76 of 106 (72%) patients treated with HD-CAV have responded (greater than 50% regression), including 13 complete responders (CRs) versus 80 of 108 (74%) patients on CAV-VP, including 15 CRs. Of the 130 evaluable patients who have completed consolidation (HD-CAV, 65; CAV-VP, 65), an additional 22 patients achieved CR (HD-CAV, 12; CAV-VP, 10) for an overall CR rate of 24%. Median duration of remission was 33.6 weeks for HD-CAV and 35.6 weeks for CAV-VP (P = 0.61). Median duration of complete response for HD-CAV was 33.8 weeks and for CAV-VP 36.7 weeks (P = 0.81). Survival curves were similar for the two regimens, with medians of 42.1 weeks for HD-CAV and 42.3 weeks for CAV-VP (P = 0.35). Survival correlated with performance status and quality of response. As anticipated, the major toxicity for both induction regimens was leukopenia. During induction, granulocyte nadirs of less than 500/mm3 occurred in 81% of patients on HD-CAV and 77% of patients on CAV-VP. Thus, dose intensification appears to produce high response rates and modest complete response rates in extensive SCLC, but it does not appear to improve materially survival compared to prior reports of conventional-dose therapy.

VP-16 alone and in combination with cisplatin in previously treated patients with small cell lung cancer

Fifty-four patients with small cell cancer of the lung (SCCL) who failed to respond to induction chemotherapy or relapsed within 3 months of its completion were treated either with VP-16 alone or VP-16 and cisplatin. Fifty-two patients were initially treated with cyclophosphamide, doxorubicin (Adriamycin) and vincristine (CAV), and two were treated with cyclophosphamide, methotrexate, and vincristine. Nine patients also received other drug combinations either as maintenance therapy or as treatment for relapse. Fourteen of 18 patients treated with VP-16 alone were evaluable for response, and there was only one partial remission. On the other hand, 15 of the 34 evaluable patients (44%) treated with VP-16 and cisplatin had a partial response, and an additional 11 patients (32%) showed substantial tumor regression and were classified as improved. Two patients had stable disease, and six (18%) progressed. Five of the nine (55.6%) limited-disease patients achieved a partial response compared with 10 of 25 (40%) with extensive disease. The median survival time from the date of first treatment with the combination was 17 weeks (29 weeks for patients achieving a partial response; 19 weeks for those showing improvement; 11 weeks for those with stable disease; and 13 weeks for patients with disease progression). Gastrointestinal toxicity was mild relative to that of CAV-induction therapy but myelosuppression, particularly thrombocytopenia, was common. Mild nephrotoxicity occurred in four patients, but no other important toxicities were identified.

Small cell lung cancer 1973-1983: early progress and recent obstacles

The recognition that the vast majority of patients with small cell lung cancer have distant metastatic disease at the time of diagnosis led to the use of systemic chemotherapy and consequent major improvements in survival in the early to mid-1970's. In the past five years, however, the pace of therapeutic advances has slowed. Recently evaluated treatment strategies, including more intensive induction chemotherapy, "late intensive" therapy of responding patients, alternation of chemotherapeutic regimens, integration of chest irradiation with drug therapy, large field irradiation, and reappraisal of the value of surgical resection, are discussed in this review. Advances in understanding of the cell biology of small cell lung cancer which may eventually lead to new forms of treatment are summarized.

Etoposide: a semisynthetic epipodophyllotoxin. Chemistry, pharmacology, pharmacokinetics, adverse effects and use as an antineoplastic agent

Etoposide (VP 16) is a semi-synthetic derivative of 4'- demethylepipodophyllotoxin , a naturally occurring compound synthesized by the North American May apple (Podophyllum peltatum ) and the Indian species Podophyllum emodi Wallich . Although podophyllotoxins are classical spindle poisons causing inhibition of mitosis by blocking mitrotubular assembly, etoposide inhibits cell cycle progression at a premitotic phase (late S and G2), probably via inhibition of DNA synthesis. There appears to be a selective antileukemic dose response relationship when compared to normal hematopoietic elements. Etoposide is effective when administered orally at about twice the recommended parenteral dosage. Schedule dependency in both animal models and clinical trials has been observed; multiple dosing over three to five consecutive days is superior to weekly single dose administration. Etoposide's dose-limiting toxicity is myelosuppression (leukopenia), which is quite predictable; alopecia and Gl toxicity (nausea, vomiting, stomatitis) occur in about 20-30% of patients given recommended dosages. Etoposide appears to be one of the most active drugs for small cell lung cancer, testicular carcinoma (the Food and Drug Administration approved indication), ANLL and malignant lymphoma. Etoposide also has demonstrated activity in refractory pediatric neoplasms, hepatocellular, esophageal, gastric and prostatic carcinoma, ovarian cancer, chronic and acute leukemias and non-small cell lung cancer, although additional single and combination drug studies are needed to substantiate these data. Its contribution in front-line combination chemotherapeutic regimens for these cancers will be better defined in the forthcoming years. Etoposide appears to have minimal activity in breast cancer and, based on current data, it is inactive against malignant melanoma, colorectal adenocarcinoma and cancer of the head and neck, although the dosage and schedules used in many of the Phase II studies may have been suboptimal.

Treatment of small cell carcinoma of the lung with COPP

The COPP regimen (cyclophosphamide, Oncovin, procarbazine, prednisone) was one of the first chemotherapy programs to prolong survival in small cell lung cancer (SCLC) significantly. Results with this regimen in 50 patients with SCLC show an overall median survival of 10 months. Survival was decreased with more extensive disease. Patients given COPP plus irradiation to the primary lesion lived longer than those given COPP alone, but this difference was not statistically significant. Toxicity was relatively mild. The COPP regimen can be considered, especially in advanced SCLC, if coexisting cardiac or renal disease precludes the use of agents toxic to these organs.

VP16-213 and podophyllotoxin. A study on the relationship between chemical structure and biological activity

VP16-213, a semi-synthetic derivative of podophyllotoxin, is an effective antitumor agent in the treatment of a variety of leukemias and solid tumors. A comparison of the mechanism of action of VP16-213 and podophyllotoxin has revealed that although both drugs inhibit the uptake of nucleosides into HeLa cells, they exhibit other biological properties which are quite distinct. Podophyllotoxin is a potent inhibitor of microtubule assembly in vitro, while VP16-213 has no effect in this system. VP16-213 induces single stranded breaks in HeLa cells DNA, an effect which may be related to its antitumor activity. In contrast to VP16-213 treated cells, podophyllotoxin-treated cells maintain DNA integrity. Structure-activity relationship studies have identified some of chemical sites of VP16-213 and podophyllotoxin responsible for each of their biological properties. These studies illustrate that chemical modification of podophyllotoxin can generate derivatives which possess new and unique biological properties.

The podophyllotoxin derivatives VP16-213 and VM26

VP16-213 and VM26 are compounds with definite anticancer activity in specific tumor types. Despite 10 years of clinical development the full impact of these compounds in current cancer therapy requires further study. There is no conclusive evidence that one compound is superior to the other in any specific tumor type. The composite activities suggest possible differences in certain cancers such as small cell anaplastic lung cancer, lymphoma, leukemia, bladder and ovarian cancer, but sufficiently adequate studies to determine this have not been reported for any tumor. Understanding the basic pharmacology of these compounds should also be considered of high priority since it is obvious that there is much to learn in this area and further clarification should allow improved clinical utilization. It is hoped that the presentations and discussions of the First International Symposium will generate a new wave of interest in future podophyllotoxin research and development.

VP16-213 in combined modality treatment of small cell carcinoma of the lung

Thirty-four previously untreated patients with histologically proven small cell carcinoma of the lung were treated with a combined modality therapy program that incorporated VP16-213, an epipodophyllotoxin derivative, into the chemotherapy regimen. Initial therapy for two cycles was with V-CAM, VP16-213, cyclophosphamide, doxorubicin and methotrexate. Following two cycles of V-CAM each patient received radiation therapy consisting of 4000 rads to the primary site, both hila and the mediastinum, as well as 2000 rads as prophylaxis to the whole brain. After a one-week rest period the patients received monthly cycles of V-CAM until death. Of 10 patients with stage IIIM0 disease, 7 had a complete response (CR), 1 a partial response (PR) and 2 had progressive disease. The median survival was still not reached by approximately 18 months. Of 24 patients with supraclavicular and/or metastatic disease there were only 5 patients with a CR, 11 with a PR and 8 with progressive disease. Their median survival was approximately 9 months. The 70% overall response rate and 9.3-month median survival of the entire group are essentially the same results as those in previously reported studies. There appears to be no additional benefit when VP16-213 is incorporated into our combined modality program.

VP-16-213 (etoposide): the mandrake root from Issyk-Kul

VP-16-213 (etoposide) is an orally and parenterally active antineoplastic agent synthesized from podophyllum extracts of a common North American plant, the May apple or mandrake. The drug delays and kills cells in the G2 phase of the cell cycle and is active in a variety of animal tumors and leukemias. Major therapeutic activity for the drug has been found in small cell bronchogenic carcinoma, germ cell malignancies, acute non-lymphocytic leukemia, Hodgkin's disease and non-HOdgkin's lymphoma. Minor therapeutic activity of the drug occurs in non-small cell bronchogenic carcinoma, pediatric neoplasms, hepatocellular carcinoma and gastric cancer. Toxicity is primarily hematologic, with alopecia, nausea and vomiting occurring less frequently.

[Etoposide VP 16--213)--a podophyllotoxinderivative with high antitumor activity (author's transl)]

Etoposide is a semisynthetic podophyllotoxin derivative with a broad spectrum of antitumor activity and a relatively high therapeutic index. The synergism in animal with cis-platinum, cyclophosphamide, BCNU, and cytosinarabinoside is interesting for combination regimen. Mechanisms of action are inhibition of nucleoside transfer and of DNA and RNA synthesis, single stranded breaks, inhibition of protein synthesis and of microtubular assembly. While in lower concentrations etoposide is acting cell-cycle-dependent with accumulation of cells in the G2-phase it has, in high concentrations, also a cellcycle-phase-unspecific lethal effect. Most suitable is the oral and i.v. application of etoposide in fractionated doses of 80--120 mg/m2 on 3--5 consecutive days and repetition after 21 [14--28] days. Side effects are dose-limiting bone marrow toxicity, nausea, vomiting, fever, hypotension, phlebitis, mucositis, neuropathy, cardiotoxicity, alopecia. Etoposide is one of the most active single agents in small-cell bronchus carcinoma with a remission rate of 37% (10% CR), and is very active in NHL (36%), testicular carcinoma (37%), AMML (35%), choriocarcinoma (35%), and neuroblastoma (29%). The role of etoposide in combination with other active drugs in these tumors is currently investigated in bronchus and testicular carcinoma and NHL, where etoposide will belong to the drugs of the first choice in the future.

Doxorubicin-hexamethylmelamine therapy of small cell carcinoma of the lung

Eighteen patients with small cell carcinoma of the lung treated with doxorubicin hydrochloride and hexamethylmelamine are presented. Fifteen of these patients had extensive disease at presentation. Four patients in this group died after one or fewer courses of chemotherapy. The median duration of survival for the entire group of patients is 15 months. Six patients are alive from 18 to 56 months without evidence of disease. Drug toxicity was minimal and well tolerated, which permitted this regimen to be given in an outpatient setting.

Chemoimmunotherapy of small cell bronchogenic carcinoma with VP-16-213, ifosfamide, vincristine, adriamycin, and Corynebacterium parvum

Thirty-five consecutive patients with small cell bronchogenic carcinoma (SCBC) received chemoimmunotherapy with VP-16-213, Ifosfamide, vincristine, Adriamycin, and Corynebacterium parvum. Of 33 evaluable patients, 26 (79%) responded with complete (55%) or partial (24%) remissions. Complete remissions were more common among patients with limited disease (11/14 patients, 79%) compared with those with extensive disease (7/19 patients, 37%) and among patients (11/14 patients, 79%) compared with those with extensive disease (7/19 patients, 37%) and among patients who were ambulatory prior to therapy (16/25 patients, 64%) compared with those who were nonambulatory (2/8 patients, 25%). Myelosuppression consisted primarily of neutropenia. Eight percent of the treatment courses in 29% of the patients were associated with hematuria and/or documented episodes of infection during neutropenia. There were three deaths possibly related to treatment, in two of which there was no evidence of disease at post-mortem examination. Six patients relapsed in the central nervous system (CNS). In four instances, CNS relapse was the only site of tumor progression. Central nervous system relapse was more common among evaluable patients who did not receive prophylactic brain irradiation (5/17 patients, 29%, vs. 1/15 patients, 7%; P = 0.23). The median survival duration for all patients was 63 weeks, being slightly longer for patients with limited disease than for those with extensive disease (70.9 weeks vs. 56 weeks; P = 0.18). This was also true for patients who achieved complete rather than partial remissions (71 weeks vs. 50 weeks; P = 0.09). Patients receiving prophylactic brain irradiation experienced longer survival (100.8 weeks vs. 48 weeks; P = 0.01).

The epipodophyllotoxin derivatives VM-26 and VP-16-213, 1976-1979, a review

The epipodophyllotoxin derivatives VM 26 and VP 16-213 are currently entering phase III studies. The mechanism of their action is incompletely understood, but the greatest lethal effect is experienced in the late S and G2 phases. In transplanted tumors both drugs have shown marked schedule dependency and human studies also support this. As a single agent VP 16-213 is among the most active drugs in small-cell carcinoma of the lung. Significant clinical activity (> 20% response frequency) has been observed for both drugs in Hodgkin's disease, non-Hodgkin lymphomas and possibly in other more rare tumors (monocytic leukemia, hepatoma and teratoma). Although further clinical studies of both drugs would be ideal, it seems possible at present to justify a discontinuation of VM-26 in order to concentrate the efforts on VP 16-213. Further studies are needed to define optimal dose and schedule and place in combination chemotherapy.