Treatment of advanced pancreatic carcinoma with a combination of protracted infusional 5-fluorouracil and weekly carboplatin: a Mid-Atlantic Oncology Program Study.

BACKGROUND: Advanced pancreatic cancer is a rapidly fatal disease whose course has been little influenced by chemotherapy. Earlier studies have shown some modest promise for the combination of protracted infusional 5-fluorouracil (PIF) and cisplatin. We sought to evaluate a regimen of possibly lesser toxicity, PIF plus weekly carboplatin. PATIENTS AND METHODS: Fifty-four patients with advanced adenocarcinoma of the pancreas were treated with a regimen of protracted infusional fluorouracil 300 mg/m2/day for 70 days and carboplatin 100 mg/m2/weekly on weeks 1 through 10 of a 12-week cycle. After a two-week rest, cycles were repeated until progression. RESULTS: Median duration on treatment was 82 days (range 4-490 days). Toxicity was mild. Grade 3-4 toxicities were anemia 11%, leukopenia 6%, thrombocytopenia 2%, nausea/ vomiting 7%, diarrhea 9%, mucositis 9%, and renal 2%. Response was evaluable in 47 patients. There were two complete and seven partial responses (17% overall objective response rate among all patients). Stable disease for greater than 12 weeks was seen in 19 patients (40%) and progression in 19 (40%). The median overall survival was 22 weeks (1-99), with 61 weeks median survival in responders (22-99). One-year survival was 13%. CONCLUSIONS: Response and survival results with this regimen are at least equal to the best combination regimens reported, and were obtained with a low overall rate of serious toxicity.

Phase II randomized study of cisplatin plus etoposide phosphate or etoposide in the treatment of small-cell lung cancer.

PURPOSE: This randomized phase II study evaluated the efficacy and toxicity of etoposide phosphate when used in combination with cisplatin in the treatment of small-cell lung cancer. PATIENTS AND METHODS: Patients with previously untreated small-cell lung cancer were randomized to receive cisplatin in combination with either etoposide or etoposide phosphate. Molar-equivalent doses of etoposide and etoposide phosphate were used. Response rate, time to progression, survival, and toxicity were compared. RESULTS: Major response rates with etoposide phosphate and etoposide were 61% (95% confidence interval, 55% to 67%) and 58% (95% confidence interval, 52% to 64%), respectively (P = .85). No significant differences in median time to progression or survival were observed in patients who received etoposide phosphate versus etoposide. Grade 3 and 4 leukopenia occurred in 63% of patients who received etoposide phosphate compared with 77% who received etoposide (P = .16). CONCLUSION: The combination of etoposide phosphate and cisplatin is effective in the treatment of small-cell lung cancer, and can be administered with acceptable toxicity. Although this study was not designed to be a formal comparative trial, the efficacy and toxicity observed with this regimen were found to be similar to a standard etoposide/cisplatin regimen, using molar-equivalent etoposide doses. Because of its greater ease of administration, etoposide phosphate is preferable to etoposide for routine clinical use.

Hormonal palliation of chemoresistant ovarian cancer: three consecutive phase II trials of the Mid-Atlantic Oncology Program.

PURPOSE: To evaluate the efficacy of three hormonal manipulations in the palliation of chemoresistant ovarian cancer, and to analyze the results in the light of other clinical trials. PATIENTS AND METHODS: Three sequential phase II trials were performed in patients with refractory epithelial ovarian carcinoma, using high-dose megestrol acetate (800 mg/d for 30 days, then 400 mg/d), high-dose tamoxifen (80 mg/d for 30 days, then 40 mg/d), and aminoglutethimide (1 g/d plus tapering doses of hydrocortisone). Results were compared with those described in the world literature from trials of the same or similar agents. RESULTS: No responses were seen among 30 assessable patients treated with megestrol acetate, and most (but not all) similar trials have reported low response rates. Five responses (17%) were seen among 29 patients treated with tamoxifen. Two responses exceeded 5 years in duration. No responses were seen among 15 patients treated with aminoglutethimide. CONCLUSION: Antiestrogen therapy may offer the possibility of useful and, occasionally, long-term palliation of refractory epithelial ovarian carcinoma, with little toxicity. There may be a trend toward a dose-response effect, which represents a suitable topic for a future prospective trial.

A study of oral etoposide, infusional cisplatin, and infusional 5-fluorouracil for locally advanced or metastatic non-small-cell lung cancer. A Mid-Atlantic Oncology Program study.

A combination of oral etoposide, infusional cisplatin (24-hr) and infusional 5-fluorouracil (5-day) was used to treat 87 patients with non-small-cell lung cancer in a Phase II trial. Twenty-six patients were Stage IIIB, and 61 patients were Stage IV (new international classification). The regimen was well tolerated, with 49% grade 3 or 4 toxicities of all types. Response rates, partial and complete, were 40%, (95% confidence interval: 30%, 51%) for Stage IV patients and 20% (95% confidence interval: 10%, 32%), in Stage IIIB. An additional 68% of patients in Stage IIIB and 45% of patients in Stage IV achieved stable disease and had a median survival of 8.8 months, similar to that of patients in partial remission. Median survival was 5.6 months (95% confidence interval: 4.4 months, 10.8 months) for Stage IV patients and 11.0 months (95% confidence interval: 8.8 months, 12.4 months), for Stage IIIB. Of interest was the finding of a higher response rate in patients with a shorter duration of symptoms (less than 6 months versus greater than 6 months).

Relationships between various uses of antineoplastic drug-interaction terms.

In in vitro testing, no pharmacologic synergism has been found for the combination of cisplatin and etoposide in P388 leukemia in contrast to the demonstration of therapeutic synergism in the same model. No pharmacologic synergism has been found for the same combination in the treatment of four small-cell lung-cancer cell lines, although clinical results obtained using this combination in small-cell lung cancer and other cancers suggest a therapeutic advantage. The popular concept of synergy, implying a therapeutic advantage, is different from the pharmacologic meaning, which generally implies that less drug is required in a combination for an equal effect. Therapeutic advantage may be obtained regardless of whether drugs are synergistic in the pharmacologic sense in the treatment of a tumor. To gain a more comprehensive insight into concepts of drug interaction, it is important to recognize that the type of drug interaction seen is dependent on the drug doses used and may vary with the treatment of different cell lines. All of these factors complicate the use of the word synergism, or any associated term, in a categorical manner to describe the effects of combinations of antineoplastic drugs.

A pilot study of intensive weekly chemotherapy for extensive disease small-cell lung carcinoma.

An intensive weekly chemotherapeutic treatment for extensive disease small-cell lung cancer was piloted in 14 patients. The regimen consisted of 6 drugs. Two drugs were given each week for a total of 12 weeks of treatment. Modifications were required in the protocol to attempt to overcome excessive toxicity. Unexpected toxicity included anemia requiring transfusions in 8 of 10 patients completing treatment, sepsis in 8 of 14 with 3 related deaths, and prolonged grade III motor neurotoxicity in 2 patients. All 3 patients who died of sepsis had shown evidence of response, and 8 of the remaining 11 had 90% or greater tumor shrinkage. Two others had a partial response. Median survival time for all patients was 9.3 months.

Calculation of received dose intensity for combinations of drugs using small-cell lung carcinoma treatment regimens as examples.

Programs are presented for the calculation of received dose intensity in combination chemotherapy regimens. These provide methods for determining the final dose intensity, the mean cumulative dose intensity together with its standard error, and other tabular and graphic summaries. Two ways of dividing patients into high and low received-dose-intensity groups are proposed. Methods are illustrated using data from Mid-Atlantic Oncology Program (MAOP) 2183, a phase III evaluation of a six-drug alternating combination vs a three-drug "standard" combination treatment for extensive small-cell lung cancer. Comparisons of received dose intensity with demographic and outcome variables are presented.

A study of infusional cisplatin and infusional fluorouracil for locally advanced or metastatic non-small-cell lung cancer: a Mid-Atlantic Oncology Program study.

A combination of cisplatin administered as a 24-hour infusion and fluorouracil administered as a 5-day infusion was used to treat 97 patients with non-small-cell lung (NSCLC) cancer in a phase II trial. Thirty patients had stage IIIB disease; 67 patients, stage IV disease (new international classification). Patients with stage IIIB disease also received thoracic radiation after chemotherapy. The regimen was well tolerated, with 24% or less grade 3 or greater toxicities of all types. One toxic death was attributed to fluid overload. The response rate, partial and complete, was 43% (95% confidence interval, 27% to 63%), and median survival was 13.8 months for patients with stage IIIB disease. Response rates refer to the chemotherapy response. For patients with stage IV disease, the response rate was 34% (95% confidence interval, 24% to 47%), and median survival was 6.2 months. On this regimen, stable-disease patients with stage IV disease had survivals at least equal to responders.

Dichloromethotrexate, infusional cisplatin, and infusional 5-fluorouracil for locally advanced or metastatic non-small cell lung cancer. A MAOP study.

The combination of dichloromethotrexate, cisplatin, and infusional 5-fluorouracil was evaluated as treatment for non-small-cell lung cancer in a phase II trial using 43 evaluable patients. Grade III or IV toxicity included thrombocytopenia (21%), leukopenia (14%), nausea/vomiting (14%), mucositis (9%), infection (5%), and other (16%). There were six responders (14%), with a 95% confidence interval of [5%, 28%]. Two additional patients achieved a 50% reduction in cross-sectional tumor size that was not documented twice. Median survival time was 6.5 months. This combination is not considered sufficiently active for further evaluation in this disease.

Comparison of cyclophosphamide, doxorubicin, and vincristine with an alternating regimen of methotrexate, etoposide, and cisplatin/cyclophosphamide, doxorubicin, and vincristine in the treatment of extensive-disease small-cell lung carcinoma: a Mid-Atlantic Oncology Program study.

An alternating regimen for the treatment of extensive-disease small-cell lung cancer (SCLC) was compared with standard treatment with cyclophosphamide, doxorubicin, and vincristine (CAV) in 170 patients. Overall severity of toxicity was similar in both arms, with four toxic deaths in each arm (4.7%). Response results were also similar, with 54% complete and partial responses with the standard regimen and 53% complete and partial responses with the alternating regimen. Median survival time was 6.9 months with the standard regimen and 9.2 months with the alternating regimen (P = .078). The 2-year survival rate was 1.2% for the standard regimen and 4.7% for the alternating regimen. Survival benefit for treatment with the alternating regimen reached statistical significance only in those subsets of patients with poorer prognosis (male sex, performance status 3, liver metastases, bone marrow metastases, and oat cell histologic subtype).

Synthesis of potential dual-acting radiation sensitizer antineoplastic agents: 2,2-dimethylphosphoraziridines containing 2-nitroimidazoles or other electron-affinic moieties.

In view of the in vivo demonstrated radiation-potentiating activities of several previously studied 2,2-dimethylphosphoraziridines, six new compounds incorporating the bis(2,2-dimethyl-1-aziridinyl)phosphinyl moiety, together with an electron-affinic group such as 2-nitroimidazole or nitrobenzyl, have been synthesized and tested (1) in vitro for ability to increase the effect of X-irradiation under hypoxic conditions on V-79 Chinese hamster lung fibroblast cells, (2) in vivo for antitumor activity in the absence of radiation against P388 leukemia in mice, and (3) in a preliminary experiment with compound 10 only, in combination with whole-body gamma-radiation, using the P388 leukemia mouse model for in vivo radiation-potentiating activity. The chemical-alkylating activities and hydrolytic behavior of these compounds, as well as their antitumor activities without radiation, were found to be comparable to those of other 2,2-dimethylphosphoraziridines, while their in vitro radiosensitizing activities were at low concentrations generally comparable to that of misonidazole, with compound 8 showing superior activity. At higher concentrations, only compound 10 was sufficiently soluble and nontoxic to the cells for evaluation in this assay. Thus, the bis(2,2-dimethyl-1-aziridinyl) phosphinyl moiety does not seem to have contributed to the hypoxic radiosensitizing activities (only to the cytotoxicities) of the electron-affinic moieties in this in vitro assay. In comparison, the prototype 2,2-dimethylphosphoraziridine, ethyl [bis(2,2-dimethyl-1-aziridinyl) phosphinyl]carbamate (AB-132), showed at nontoxic doses no radiosensitizing activity in this assay, and at cytotoxic doses increased the cell-killing effect of each given dose of X-radiation additively under both hypoxic and oxic conditions. Conversely, only the 2,2-dimethylphosphoraziridine moiety appeared to participate in the moderate "therapeutic radiation-potentiating" activity indicated by compound 10 in the in vivo experiment using the P388 leukemia model (on day 1), as the misonidazole standard was inactive in this nonhypoxic system. Clearly, the mechanism of the in vivo observed radiation-potentiating effect of AB-132 and other 2,2-dimethylphosphoraziridines is different from that of the hypoxic radiosensitizers, but the possible synergism between the two biologically active moieties of the new compounds could not be demonstrated with the experimental models so far employed.

A prospective randomized comparison of protracted infusional 5-fluorouracil with or without weekly bolus cisplatin in metastatic colorectal carcinoma. A Mid-Atlantic Oncology Program study.

One hundred eighty-four patients with advanced measurable colorectal cancer not previously treated with chemotherapy were entered into a prospective randomized clinical trial by the Mid-Atlantic Oncology Program (MAOP) to assess the value of weekly cisplatin (20 mg/m2) when added to a protracted schedule of 5-fluorouracil (5-FU) infusion (PIF) at 300 mg/m2/d for 10 weeks of every 12 weeks. The liver was the primary indicator lesion in approximately 75% of the study group. All tumor measurements required radiographic confirmation. The response rate in the PIF alone arm was 35% (29 of 83; 95% confidence interval [CI], 25% to 46%) compared with 33% (28 of 85; 95% CI, 23% to 44%) for the arm in which weekly cisplatin was added to PIF. The median survival times were 11.8 and 11.2 months in the two groups. Weekly cisplatin does not appear to add to the effectiveness of PIF in colorectal carcinoma.

Case report of metastatic familial pheochromocytoma treated with cisplatin and 5-fluorouracil.

We report on a rare case of malignant pheochromocytoma in a patient with a family history of this disease. After three cycles of treatment with cisplatin and 5-fluorouracil, a decrease in the need for antihypertensive treatment occurred, which lasted almost 2 years despite the discontinuation of chemotherapy. The patient showed an objective response, which was technically a minor response, although in this slow-growing tumor it was of major clinical significance. This chemotherapy regimen may play a role in the management of malignant pheochromocytoma.

A method for determining schedule dependency in tissue culture.

A dual-exposure drug treatment of cell lines in tissue culture provides a possible method for determining schedule dependency. This is suggested by results of treatment of human small cell lung carcinoma NIH H209 and murine L1210 leukemia cell lines with cisplatin, a non-schedule-dependent drug, and etoposide, a schedule-dependent drug. Nonlinear least squares was used to estimate the dose-response surface. The estimated regression coefficients for the effect of the first dose compared to that of the second dose support the premise that cisplatin is not schedule dependent. Unlike cisplatin, the second dose of etoposide was shown to be more effective than the first dose in the human small cell carcinoma line. This agrees with known clinical results where multiple etoposide dosing has been shown to be more effective and confirms schedule dependency. This methodology, or a refinement, may offer another tool for studying schedule dependency of drugs using tissue culture methods.

Demonstration of a schedule-dependent therapeutic synergism utilizing the interacting drugs methotrexate and teniposide in L1210 leukemia.

When three variables require simultaneous adjustment for treatment optimization, the experimental determination of the optimum treatment becomes more complicated than generally appreciated, especially when one variable is the interval between drug administrations. Molecular pharmacological studies at this institution suggest that teniposide, in doses that are achievable in vivo, blocks methotrexate efflux from cells, enhancing formation of methotrexate polyglutamates which are active retentive forms of the drug. Hence, the combination might show a synergistic effect if teniposide is given at an appropriate time in relation to administration of methotrexate. This paper considers the problem of estimating the optimal dose levels and timing of administration of these drugs in B6D2F1 mice bearing L1210 leukemia in vivo as a model for the analysis of multidrug regimens when time and dose are variables. Because of the complexity of these experiments, an adaptive approach was applied. Three cycles of treatment were given using methotrexate at 0-400 mg/kg, teniposide at 0-60 mg/kg, and an interval of 0-54 hours between the two drugs. The single drugs prolonged median survival up to 24 days under the conditions of these experiments. The combination given simultaneously resulted in median survival of up to 33.5 days, while use of an appropriate interval between drugs prolonged median survival to greater than 50 days. An analysis of the underlying dose-time response gives a much better appreciation of the relationships among the variables. The concept that optimal doses included less methotrexate and more teniposide as the interval between drugs is increased was developed only through modeling. This finding is critical in demonstrating the importance of including all nonnegligible variables in the experimental design if the results are to be considered valid. Confidence regions about the optimum dose and about the response at the optimum provide a sound basis for a claim of therapeutic synergism as demonstrated by use of a scheduling variable in the experiment design. A nonproportional hazards analysis permits the conclusion of nonproportionality and emphasizes the contribution of methotrexate to optimal short-term survival (15-24 days) and teniposide to long-term survival (24-39 days).

Combination of 5-fluorouracil and cyclophosphamide in L1210 and P388 leukemias with changes in optimum treatments as a function of the age of the L1210 tumor at first treatment.

The interaction of 5-fluorouracil and cyclophosphamide in the treatment of L1210 and P388 leukemias was studied using response surface methodology. Single dose treatment of each drug was administered simultaneously or with a 24-hr interval between 5-fluorouracil and cyclophosphamide to the advanced tumors or at various times after L1210 inoculation. While at low doses the action of the combination of the two drugs was greater than expected, there was no therapeutic synergism if the drugs were given together (optimum doses cyclophosphamide 366 mg/kg and 364 mg/kg, respectively, in advanced L1210 and P388 leukemias) or in the early tumor when cyclophosphamide was given 24 hours after 5-fluorouracil. In the advanced tumor, using the regimen employing a 24-hr interval between drugs, therapeutic synergism could be demonstrated (optimum doses 5-fluorouracil 130 mg/kg followed by cyclophosphamide 248 mg/kg in advanced L1210 leukemia and 5-fluorouracil 110 mg/kg followed by cyclophosphamide 263 mg/kg in advanced P388 leukemia). The evidence generated suggested that improved therapy could be found in two separate regions of the treatment space, raising the possibility of more than one mechanism of drug interaction. The location of the optimal treatment depended on the tumor burden at the time treatment was initiated. A shift from one region to the other occurred after 4-6 days of tumor growth when the original inoculum was 10(5) i.p. L1210 cells. Another more obvious conclusion that can be drawn is that treatment was less effective as the tumor became more advanced. The notion that different tumor stages may require different ratios of drugs in a clinically useful combination should receive attention.

Antitumor activity and toxicity of peroxo heteroligand vanadates(V) in relation to biochemistry of vanadium.

A selected set of 14 V(V) complexes was tested for toxicity and antitumor activity against L1210 murine leukemia, to examine the biological properties of peroxoheteroligand vanadates(V) of the formula (NH4)4[O(VO(O2)2)2], M3I[VO(O2)2C2O4], and MI[VO(O2)L], L = malate, citrate, iminodiacetate, nitrilotriacetate, and EDTA. The x-ray structure is known for five of these compounds. A relationship has been found between the chemical composition and the biological activity (antitumor activity-toxicity) of these complexes. Activity in the L1210 system is defined as greater than or equal to 25% increase in life span, and this was seen with (NH4)4[O(VO(O2)2)2]; M3[VO(O2)2(C2O4)]2H2O, M = K, NH4; and NH4[VO(O2)Malato]H2O. These observations are important for the biochemistry of vanadium. The special nature of electron transfer within the V(V)-peroxo moiety is proposed to be responsible for this phenomenon. Peroxo heteroligand vanadates(V) therefore represent a model system for studying some biochemical interactions of vanadium in living matter.

Analysis of "early" thymidine/inosine protection as an adjunct to methotrexate therapy.

The feasibility of "early" thymidine and inosine protection of methotrexate (MTX) toxicity is evaluated in this paper. This approach is based on the proposition that the most vulnerable period for susceptible host cells to MTX toxicity is an interval following a pulse of MTX when the MTX monoglutamate level is high. In contrast, tumor cells that accumulate active MTX polyglutamyl derivatives are exposed to the cytotoxic effects of MTX, not only when the monoglutamate levels are high, but also over the much longer interval during which polyglutamyl derivatives are retained within these cells. The protecting agents employed, thymidine and inosine, circumvent the antipurine and antipyrimidine effects of MTX, but neither agent inhibits the transport or the polyglutamylation of MTX. Nucleoside protection given over 6 hours after MTX markedly decreased toxicity to normal BDF1 mice at MTX doses up to 150 mg/kg/day for 3 consecutive days. The LD10 for unprotected mice was 14 mg/kg/day, while the LD10 for the protected mice was 114 mg/kg/day, a greater than eightfold increase in the drug dose delivered. MTX with early nucleoside protection produced a 50% increase in median life span in tumor-bearing mice at doses of drug that were toxic to unprotected mice. Flow cytometric analyses indicated that consecutive daily pulses of MTX with early nucleoside protection alter the cell cycle distribution. By 24 hours after the last of three daily pulses of MTX, the G1 component was maximal (80% of the cell population), with less than 2% of the cells in G2M and 17% of the cells in S phase. This distribution persisted for 24 hours, after which a normal pattern emerged, a process that was accelerated by neither thymidine/inosine nor leucovorin. These studies support the concept that toxicity to the host is initiated largely in the interval shortly after MTX administration. The data indicate that early nucleoside protection permits the repetitive administration of much higher doses of MTX than can be given with MTX alone. This approach may be useful not only in the treatment of human neoplasms but in the treatment of other disorders, such as rheumatoid arthritis, psoriatic arthritis, or psoriasis. Finally, this paper considers the potential advantages of early thymidine/inosine protection in comparison to leucovorin rescue with the administration of low or moderate doses of MTX.