Positive autoregulation of the glial promoting factor glide/gcm

Fly gliogenesis depends on the glial-cell-deficient/glial-cell-missing (glide/gcm) transcription factor. glide/gcm expression is necessary and sufficient to induce the glial fate within and outside the nervous system, indicating that the activity of this gene must be tightly regulated. The current model is that glide/gcm activates the glial fate by inducing the expression of glial-specific genes that are required to maintain such a fate. Previous observations on the null glide/gcmN7-4 allele evoked the possibility that another role of glide/gcm might be to maintain and/or amplify its own expression. Here we show that glide/gcm does positively autoregulate in vitro and in vivo, and that the glide/gcmN7-4 protein is not able to do so. We thereby provide the first direct evidence of both a target and a regulator of glide/gcm. Our data also demonstrate that glide/gcm transcription is regulated at two distinct steps: initiation, which is glide/gcm-independent, and maintenance, which requires glide/gcm. Interestingly, we have found that autoregulation requires the activity of additional cell-specific cofactors. The present results suggest transcriptional autoregulation is a mechanism for glial fate induction.

Phase I and pharmacologic study of continuous infusion topotecan in combination with cisplatin in patients with advanced cancer: a Cancer and LeukemiaGroup B study

PURPOSE

Preclinical and clinical data suggest that topotecan may be more effective, and perhaps less toxic, when administered as a continuous intravenous infusion (CIVI). A previous Cancer and Leukemia Group B (CALGB) trial of topotecan, given on a daily bolus schedule in combination with cisplatin, produced more hematologic toxicity than expected with either drug alone. Therefore, we designed this phase I trial to define the dose-limiting toxicities (DLTs) and the recommended phase II doses of cisplatin in combination with topotecan administered as a CIVI. Population pharmacodynamic models for the combination also were investigated.

PATIENTS AND METHODS

Patients with advanced solid tumors and a maximum of one prior chemotherapy regimen for metastatic disease were eligible if they had a performance status of 0 to 1 and adequate renal, hepatic, and bone marrow function. Prior treatment with camptothecins or platinum compounds and prior pelvic irradiation were not allowed. The initial schedule consisted of a fixed dose of topotecan 0.4 mg/m2/d administered as a CIVI for 21 days and escalating doses of cisplatin administered on days 1, 8, and 15 of a 28-day schedule, until the maximum tolerated dose (MTD) was achieved. After severe hematologic toxicity was observed in the first two patients, the topotecan infusion was shortened to 14 days, and the total dose of cisplatin was administered on day 1 in all subsequent patients. After the MTD was defined, that cohort was expanded to include a total of 12 assessable patients. Hematopoietic growth factors were not allowed. For the pharmacologic studies, total topotecan plasma concentrations were measured by high-pressure liquid chromatography (HPLC) during infusion on days 3, 8, and 11 on the first cycle, and the median steady-state concentration (Tss) was determined. Platinum plasma concentrations on day 3 were measured by atomic absorption spectrometry.

RESULTS

Of the 32 patients enrolled, 28 were assessable for toxicity and 24 for response. The primary toxicity was hematologic, with both neutropenia and thrombocytopenia being dose-limiting. The MTD of cisplatin was 75 mg/m2 on day 1 in combination with topotecan 0.4 mg/m2/d for 14 days. At this dose level, three of a total of 12 assessable patients had DLT. The pharmacodynamic relationship between Tss and the absolute neutrophil count at the nadir (ANCn) was described by the following equation: log10 (ANCn)=4.23 - 0.47 x Tss - 0.01 x cisplatin dose (P < .0001; R2=0.64). The substitution of platinum concentration for cisplatin dose in this model did not result in a significant improvement. Three patients had a partial response: one with duodenal carcinoma; a second with small-cell lung cancer; and a third with melanoma.

CONCLUSION

Cisplatin can be given safely in combination with CIVI topotecan. However, toxicity was still substantial. Based on the current results and our previous trial of this combination, we conclude that, when combined with cisplatin, CIVI topotecan does not seem to be advantageous compared with the more traditional daily bolus schedule.

Glial differentiation does not require a neural ground state

Glial cells differentiate from the neuroepithelium. In flies, gliogenesis depends on the expression of glial cell deficient/glial cell missing (glide/gcm). The phenotype of glide/gcm loss- and gain-of-function mutations suggested that gliogenesis occurs in cells that, by default, would differentiate into neurons. Here we show that glide/gcm is able to induce cells even from a distinct germ layer, the mesoderm, to activate the glial developmental program, which demonstrates that gliogenesis does not require a ground neural state. These findings challenge the common view on the establishment of cell diversity in the nervous system. Strikingly, ectopic glide/gcm overrides positional information by repressing the endogenous developmental program. These findings also indicate that glial differentiation tightly depends on glide/gcm transcriptional regulation. It is likely that glide/gcm homologs act similarly during vertebrate gliogenesis.

Therapeutic drug monitoring of 21-day oral etoposide in patients with advanced non-small cell lung cancer

The purpose of this study was to prospectively test a pharmacodynamic model for therapeutic drug monitoring of 21-day oral etoposide. In our previous studies, etoposide trough concentrations on this schedule were related to the hematological toxicity, expressed as WBC and neutrophil counts at the nadir. The following pharmacodynamic model estimated the absolute neutrophil count at the nadir (ANCn) based on the etoposide concentration (Ec) and the pretreatment count (ANCp): ANCn=0.32(1 + ANCp x e(-2.47 x Ec)). Patients were treated with 40 mg/m2/day etoposide p.o. x 21 days and 100 mg/m2 cisplatin i.v. on day 1. All patients had non-small cell lung cancer stage IIIB or IV, had a performance status of 0-2, and had a median age of 66 (range, 42-80). Etoposide was measured in the plasma on day 8 by high-performance liquid chromatography, and dosage adjustments were made for the remainder of the course. We targeted for grade 3 neutropenia (ANCn, 500 to 999/microl) and attempted to avoid grade 4 neutropenia (ANCn, <500/microl). Of 25 patients entered, 22 were evaluable for therapeutic drug monitoring in the first course. Three patients developed grade 3 neutropenia, and seven patients developed grade 4 neutropenia. Etoposide concentrations were significantly correlated with ANCn in the first course (r=-0.50, P < 0.02). For those patients whose dosages were not changed, the estimated correlation between predicted and actual ANCn was 0.77 (P < 0.01). No evidence of significant bias of the pharmacodynamic model was detected. The etoposide dosages were increased in 12 patients and were not changed in the remaining patients. The precision of the model was good in patients whose dosages were not changed but poor in patients whose dosages were increased. The actual observed ANCn was compared with the predicted ANCn based on the pharmacodynamic model. The prediction was considered accurate if the predicted and actual ANCn values were within 500/microl of each other. Using this margin, the ANCn was accurately predicted in 10 of 22 patients. Etoposide concentrations >0.3 microg/ml on this schedule were significantly correlated with combined grades 3 and 4 neutropenia (P < 0.0001). In conclusion, the pharmacodynamic model is statistically sound when applied to a population of patients. However, when applied to individual patients for therapeutic drug monitoring, the model lacks precision and accuracy.

[Features of surface architectonics and ultrastructure of peripheral blood in children with insulin-dependent diabetes mellitus]

Electron microscopic study of the surface architectonics and ultrastructure of the peripheral blood erythrocytes in 25 children with insulin-dependent diabetes mellitus (IDDM) revealed that the decrease of the count of disk-shaped cells, increased count of transitional and degenerative forms, and alteration of their ultrastructure. Traditional therapy failed to completely normalized these characteristics over the entire follow-up.

A phase II study evaluating the efficacy of carboplatin, etoposide, and paclitaxel with granulocyte colony-stimulating factor in patients with stage IIIB and IV non-small cell lung cancer and extensive small cell lung cancer

We initiated a phase II pilot study to determine whether adding paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) to combination carboplatin/etoposide is tolerable and active in patients with advanced non-small cell lung cancer and extensive small cell lung cancer. Patients were given carboplatin (area under the concentration-time curve of 6) followed by etoposide 80 to 100 mg/m2 intravenously on days 1 through 3 followed by paclitaxel 200 mg/m2 intravenously over 3 hours on day 3. On days 4 through 18, granulocyte colony-stimulating factor 5 microg/kg was administered subcutaneously. Each cycle was repeated every 21 days. Fourteen patients have been accrued to the study and 12 were evaluated for toxicity, the first 10 of whom were treated with 80 mg/m2 etoposide. Among the first 10 evaluable patients, significant grade 4 neutropenia occurred in one patient, grade 4 thrombocytopenia in three patients, grade 2 neuropathy in two patients, and grade 3 neurotoxicity in two patients. None of the four patients with non-small cell lung cancer responded to treatment, while six of seven small cell lung cancer patients have obtained major responses to therapy. We have increased the etoposide dose to 100 mg/m2 in subsequent patients. The combination chemotherapy regimen of carboplatin, etoposide, and paclitaxel is tolerable and active in patients with small cell lung cancer.

Pharmacology of 21-day oral etoposide given in combination with i.v. cisplatin in patients with extensive-stage small cell lung cancer: a cancer and leukemia group B study (CALGB 9062)

This was a pharmacological companion study to a randomized Phase III trial comparing 21-day oral versus 3-day i.v. etoposide in combination with i.v. cisplatin in patients with extensive-stage small cell lung cancer. Etoposide plasma concentrations were measured in patients randomized to the 21-day schedule and correlated with toxicity and tumor response. Patients were treated with etoposide (50 mg/m2/day) orally for 21 days and cisplatin (33 mg/m2/day) i.v. for 3 consecutive days every 28 days for 6 courses. Plasma samples before the daily etoposide dose (trough concentrations) and complete blood counts were obtained weekly during treatment. The average of three etoposide concentrations (EC) per course was calculated. Of 158 patients registered to this schedule of the study, 150 were eligible. In 106 patients, etoposide samples were obtained at least in the first course in which the mean EC was 0.39 microgram/ml (SD = 0.29). In 102 patients (missing albumin values in 4 of 106 patients), the concentration of etoposide not bound to protein (Efree) was estimated based on the following equation: percentage unbound = (1.4 x total bilirubin) - (6.8 x albumin) + 34.4. Regression analysis revealed that increasing age was correlated with higher EC (r = 0.27; two-tailed P < 0.01) and Efree (r = 0.31; two-tailed P < 0.01). Higher EC and Efree values were associated with lower WBC counts and absolute neutrophil counts after the first treatment course in 83 patients with nadir counts. Using multiple linear regression, a pharmacodynamic model was developed that included EC or Efree, age, and alkaline phosphatase. An interaction with bone marrow results at diagnosis was found, indicating a sharper decline in nadir counts with increasing EC or Efree when the marrow was involved with small cell lung cancer. This model explained 29% of the variation for WBC nadirs (P < 0.001) and 31% of the variation for absolute neutrophil count nadirs (P < 0. 001). Neither EC nor Efree showed a significant correlation with tumor response. A pharmacokinetic relationship between EC or Efree and age was found. A pharmacodynamic model could be developed for toxicity but not for tumor response.

Prolonged infusion of etoposide in patients with advanced non-small cell lung cancer

We assessed the efficacy and toxicity of two etoposide infusional schedules in patients with advanced non-small cell lung cancer (NSCLC). Twenty-six patients were treated with a 21-day infusion every 28 days at a dose of 25-40 mg/m2/d, and six patients with a 7-day infusion every 21 days at a dose of 45-75 mg/m2/d. Sixty-three percent of patients had a Karnofsky status of 80% or better, and only five (15%) patients had prior chemotherapy. Plasma etoposide concentrations were determined in 26 patients. Sixty-nine treatment cycles were administered. Two patients (6.3%; 90% confidence interval, 1.1-18.4%) had partial responses; with response durations of 2 and 7 months, respectively. The median survival was 4 months. Grade 3 or 4 neutropenia occurred in 13 of 69 cycles (19%) and was associated with three toxic deaths. Ten patients required RBC transfusions. Nausea was common, but was associated with vomiting in only 7% of all cycles. The interpatient variability of etoposide concentrations at steady state was significant. We conclude that the antitumor activity of prolonged infusion of etoposide is not superior to standard dose and schedule in advanced NSCLC.

Fadrozole hydrochloride in postmenopausal patients with metastatic breast carcinoma

BACKGROUND

Fadrozole hydrochloride (CGS-16949A) belongs to the class of aromatase inhibitors that lowers circulating estrogen levels by inhibiting the conversion of androgens to estrogens, thereby causing tumor regression in patients with breast carcinoma.

METHODS

This was a prospective, randomized, Phase II study of fadrozole hydrochloride in postmenopausal patients with metastatic breast carcinoma. The three treatment groups received, respectively, fadrozole hydrochloride 0.6 mg three times daily, 1 mg twice daily, and 2 mg twice daily orally.

RESULTS

Fifty-six patients were entered on protocol and 54 were eligible (2 patients were perimenopausal). Eight patients had received no prior therapy, 15 patients had received prior hormonal therapy, 5 patients had received prior chemotherapy, and 28 patients had received both. After 12 weeks of treatment, 2 complete and 3 partial responses were observed. Forty patients continued treatment beyond 12 weeks, and 3 additional responses were achieved. Thus, 8 of 56 patients responded (14% overall response rate). Responses did not appear to be dose-related. The median duration of response was 36 months (range, 8-45 months). Subjective toxicity was mild to moderate and appeared more frequent on the 2 mg twice daily dosing schedule. No objective toxicity in laboratory parameters was observed. No patient had severe or life-threatening toxicity. Fadrozole hydrochloride plasma concentrations (obtained every 2 weeks for 12 weeks) appeared to be dose-dependent and noncumulative.

CONCLUSIONS

This study confirms modest activity of fadrozole hydrochloride in a heterogeneous group of patients with breast carcinoma treated at three different dose levels.

Phase I and pharmacologic study of 7- and 21-day continuous etoposide infusion in patients with advanced cancer

PURPOSE

This phase I study was undertaken to evaluate the safety and tolerability of prolonged infusional etoposide, and to evaluate its pharmacokinetic/pharmacodynamic profile in patients with advanced cancer.

METHODS

A group of 17 patients received a 7-day infusion of etoposide (schedule A) every 21 days at doses from 30 to 75 mg/m2 per day, and a second group of 37 patients a 21-day infusion (schedule B) every 28 days at doses from 18 to 40 mg/m2 per day. Patients had a median Karnofsky performance status (PS) of 80%, and 34 patients had no prior chemotherapy. Etoposide concentrations at steady state (Css) and other pharmacokinetic parameters (plasma clearance, CLp; area under the curve, AUC) were determined during the first treatment cycle. Correlation coefficients were calculated to measure the relationship between variables.

RESULTS

Myelosuppression was the major toxicity, and was associated with three deaths. The maximum tolerated dose due to neutropenia was 75 mg/m2 per day for schedule A and 40 mg/m2 per day for schedule B. There was significant interpatient pharmacokinetic variability in both infusional schedules. Even though etoposide dose levels did not significantly correlate with plasma levels, the Css was > or = 1 microgram/ml in the majority of the patients. A significant correlation between AUC and neutrophil absolute decrease was noted only in schedule B (r = 0.56, P = 0.003). There were several marginal relationships in schedule B: PS versus Css (r = 0.31, P = 0.058), PS versus AUC (r = -0.38; P = 0.058) and age versus CLp (r = -0.31, P = 0.057).

CONCLUSION

Overall, significant correlations were found for several hematologic variables and etoposide dose levels, but not with the Css values. One major problem with the application of pharmacodynamic models to predict hematologic toxicity in clinical practice is the presence of significant interpatient variability.

Guidelines for radiation oncology registrar training. Royal North Shore Hospital

Radiation oncology registrar training varies between centres, reflecting to some extent the varied training experiences of specialists. The attempts of one department to formalize the philosophy, aims and structure of its training are described and illustrated.

Phase I study of paclitaxel and topotecan in patients with advanced tumors: a cancer and leukemia group B study

PURPOSE

To define the dose-limiting toxicities (DLTs) and the recommended phase II doses of paclitaxel combined with topotecan, without and with filgrastim support.

PATIENTS AND METHODS

Patients with advanced solid tumors and a maximum of one prior chemotherapy regimen for metastatic disease were eligible if they had a performance status of 0 to 1 and normal renal, hepatic, and bone marrow function. Prior treatment with taxanes or comptothecin analogs, and prior pelvic irradiation were not allowed. Patients with a history of cardiac disease or on medications known to affect cardiac conduction were excluded. The dose of topotecan was fixed at 1.0 mg/m2/d for 5 days. The dose of paclitaxel was escalated until the maximum-tolerated dose (MTD), without and with filgrastim 5 micrograms/kg subcutaneously (SC) on days 6 to 14, was reached. Paclitaxel was administered over 3 hours on day 1 before topotecan. Treatment cycles were repeated every 21 days.

RESULTS

Of 46 patients entered, 45 were assessable for toxicity and 34 for response. The principal toxicity was neutropenia. Without filgrastim, the MTD of paclitaxel was 80 mg/m2 on day 1 in combination with topotecan 1.0 mg/m2/d for 5 days. With filgrastim, the dose of paclitaxel was escalated to 230 mg/m2 in combination with the same dose of topotecan. At this dose level, one patient had hematologic DLT and a second patient developed neuromuscular DLT. Three patients had a partial response (PR): one with head and neck cancer, a second with non-small-cell lung cancer, and the third with colon cancer.

CONCLUSION

We conclude that paclitaxel can be given at clinically relevant doses in combination with topotecan and filgrastim. The recommended dose for phase II studies is paclitaxel 230 mg/m2 on day 1 and topotecan 1.0 mg/m2/day for 5 days with filgrastim 5 micrograms/kg on days 6 to 14.

Schedule dependency of 21-day oral versus 3-day intravenous etoposide in combination with intravenous cisplatin in extensive-stage small-cell lung cancer: a randomized phase III study of the Cancer and Leukemia Group B

PURPOSE

This was a randomized phase III study to test the schedule dependency of etoposide given as a conventional 3-day intravenous (IV) regimen versus a prolonged 21-day oral regimen for extensive-stage small-cell lung cancer (SCLC). Both regimens contained IV cisplatin. The objectives were to compare survival (primary end point) and to establish response rates, failure-free survival, and toxicity (secondary end points).

PATIENTS AND METHODS

Patients with untreated measurable or assessable disease and normal organ function were eligible. Randomization was stratified according to performance status 0 versus 1 or 2. Treatment consisted of etoposide 130 mg/m2/d IV for 3 days and cisplatin 25 mg/m2/d IV for 3 days every 21 days for eight courses (schedule 1) versus etoposide 50 mg/m2/d orally for 21 days and cisplatin 33 mg/m2/d IV for 3 days every 28 days for six courses (schedule 2). In 1990, bioavailability of oral etoposide was assumed to be 50%, and the study was designed to deliver the same total doses of etoposide and cisplatin on both regimens over 24 weeks without the use of growth factors.

RESULTS

Between December 1990 and October 1993, 306 eligible patients were entered. Of these, 69% were male and 66% were > or = 60 years of age; 21% had a performance status of 0, 47% a performance status of 1, and 32% a performance status of 2; 156 were randomized to receive schedule 1 and 150 to receive schedule 2. Overall median survival estimates were 9.5 and 9.9 months (difference not significant) for schedule 1 and schedule 2, respectively. The 95% confidence interval (CI) for overall survival, 8 to 11 months, was the same for both schedules, with 126 and 117 deaths on schedule 1 and 2, respectively. Both schedules also resulted in the same median failure-free survival estimate of 7 months (95% CI, 6 to 8 months on either schedule). Complete and partial responses were observed in 15% and 42% of patients on schedule 1 and 14% and 47% on schedule 2, respectively. The overall maximal hematologic toxicities grade 3 and 4 for leukocytes, neutrophils, platelets, and hemoglobin were, respectively, as follows: schedule 1, 62%, 85%, 32%, and 32%; schedule 2, 83%, 83%, 52%, and 53%. Lethal toxicity due to neutropenia and infection occurred in 4% of patients on schedule 1 and 10% on schedule 2 (difference not statistically significant).

CONCLUSION

The two schedules of etoposide in combination with cisplatin did not result in differences in treatment outcome with respect to tumor response and survival. However, a significantly greater rate of severe or life-threatening hematologic toxicity was noted on the 21-day oral etoposide treatment schedule.

A phase I study of etoposide phosphate administered as a daily 30-minute infusion for 5 days

PURPOSE

To determine the maximum tolerated dose, toxicities, kinetics, and disposition of etoposide phosphate when administered as a daily 30-minute infusion for 5 days.

PATIENTS AND METHODS

Twenty-eight patients were enrolled in this phase I dose-escalation trial. Cohorts of patients received etoposide phosphate in etoposide equivalent doses of 50, 75, 100 and 125 mg/m2 intravenously for 30 minutes each day for 5 days. Pharmacokinetic sampling of both blood and urine was performed and concentrations of etoposide and etoposide phosphate were determined on day 1 of study for each patient and on day 4 of study for three patients receiving the 100 mg/m2 dose.

RESULTS

The dose-limiting toxicity was reversible myelosuppression as evidenced by leukopenia and neutropenia. Toxicities seen were comparable to those expected from etoposide administration. With this schedule, the 100 mg/m2 dose was the maximum tolerated dose. Nonhematologic toxicities were generally mild. Two patients had major responses and three others had minor responses. Pharmacokinetic analyses revealed rapid (< 15 minutes) extensive conversion of etoposide phosphate to etoposide. Peak plasma etoposide concentrations and etoposide areas under the curve were proportional to the dose of etoposide phosphate administered. Etoposide kinetics were similar to those expected after a comparable dose of etoposide.

CONCLUSIONS

Etoposide phosphate is a water-soluble pro-drug of etoposide that is rapidly converted to etoposide in vivo with a toxicity profile similar to etoposide. Etoposide generated from etoposide phosphate exhibits linear kinetics over a dose range of 50 to 125 mg/m2. When administered as a daily 30-minute infusion for 5 days, the dose-limiting toxicity is myelosuppression and 100 mg/m2 daily is the maximum tolerated dose.

Phase II study of prolonged oral etoposide in combination with intravenous cisplatin in advanced non-small cell lung cancer

The objectives of the study were to evaluate the combination of cisplatin and prolonged oral etoposide for response rate, survival, and toxicity. The treatment regimen consisted of etoposide (50 mg/m2/day) p.o. for 21 consecutive days and cisplatin (100 mg/m2) i.v. on day 1 every 28 days for up to six courses. Patients with Stage IIIB or IV non-small cell lung cancer who had not received prior chemotherapy and had an ECOG performance status of 0-2 were eligible if they had normal bone marrow, liver and renal functions. Patients were followed weekly for toxicity including complete blood counts. The total number of patients entered in the study was 60, of whom 56 were male and four female, 40 white and 20 African Americans. Median age was 64 years (range, 39-77). Performance status 0, 1, and 2 was present in five, 39, and 16 patients, respectively. Fourteen patients had Stage IIIB and 46 Stage IV disease. A total of 142 treatment courses were administered (median 2, range 1-6). Three patients had a complete response and 19 patients had a partial response for an objective response rate of 37% (95% confidence interval, 31-43%). Median survival was 5 months (range, 1-39+). Neutropenia was the major toxicity with Grade 4 occurring in 25 patients after the first course. The following percent of patients experienced severe or life-threatening hematologic toxicity (Grade 3 and 4 combined) over all courses: leukopenia, 73%; neutropenia, 73%; anemia, 42%; and thrombocytopenia, 37%. Three patients died of neutropenic sepsis.(ABSTRACT TRUNCATED AT 250 WORDS)

Dosing of oral etoposide normalized for body surface area

The objective of this clinical and pharmacological study was to determine whether any pretreatment parameters were associated with pharmacological or toxicity parameters after prolonged oral etoposide. Therefore, the relationships between patient characteristics and etoposide concentrations and hematological toxicity were evaluated. Sixty patients with advanced non-small cell lung cancer were treated with etoposide 50 mg/m2/day p.o. for 21 consecutive days and cisplatin 100 mg/m2 i.v. on day 1. Complete blood counts and etoposide plasma concentrations were obtained weekly. Etoposide was measured by high-performance liquid chromatography. The input variables were age, gender, race, weight, weight0.66, weight0.75, height, body surface area, performance status, albumin concentration; and total etoposide dose. The outcome measures were etoposide concentration; nadir values (white blood cells, neutrophils, hemoglobin, and platelets); the absolute decrease, relative decrease, and survival fraction of blood cells; and graded toxicity. No significant correlations were found in 49 fully evaluable patients between any of the input and outcome variables. Among the outcome variables, significant correlations were found between etoposide concentration and the logarithmic transformation of the nadir blood counts. If any of the input variables were significantly correlated to etoposide concentrations or toxicity variables, it would be possible to suggest another predictor variable besides body surface area. As long as treatment is not modified for etoposide concentrations, dosing of oral etoposide must still rely on estimates of body surface area.

Phase I study of topotecan and cisplatin in patients with advanced solid tumors: a cancer and leukemia group B study

PURPOSE

The objectives of this phase I trial were to determine the dose-limiting toxicities (DLTs) of the novel topoisomerase I inhibitor topotecan combined with cisplatin, to define the maximum-tolerated doses (MTDs) of the combination without and with the use of filgrastim, and to define recommended doses for phase II trials.

PATIENTS AND METHODS

Patients with advanced solid tumors were eligible if they had normal bone marrow, renal, and hepatic function and had not previously been treated with platinum compounds. Topotecan was administered intravenously on days 1 through 5 and cisplatin was administered intravenously on day 1 of a 21-day cycle. The topotecan dose was fixed at 1.0 mg/m2/d on the first four dose levels, and cisplatin was escalated in 25-mg/m2 increments from 25 to 100 mg/m2 without filgrastim. After encountering DLT, the dose of cisplatin was decreased by one level and topotecan dose escalation was attempted. After defining the MTD without growth factor, the study proceeded with escalating cisplatin doses to define the MTD with filgrastim 5 micrograms/kg subcutaneously (SC) daily starting on day 6 of treatment. Priming with filgrastim 5 micrograms/kg SC on days -6 to -2 before the first course was explored last.

RESULTS

Of 38 patients entered, 37 were eligible, 35 assessable for toxicity in the first course, and 28 assessable for response. The principal toxicity was grade 4 neutropenia, which had to last more than 7 days to be considered dose-limiting. No DLT was observed at the starting cisplatin dose of 25 mg/m2 (dose level 1). On level 2 (cisplatin 50 mg/m2, one patient had dose-limiting neutropenia and one patient had grade 3 renal toxicity. On level 3 (cisplatin 75 mg/m2), two patients had dose-limiting neutropenia. Therefore, cisplatin dose escalation was stopped. On dose level 5 (cisplatin 50 mg/m2 and topotecan 1.25 mg/m2/d), one patient had grade 4 neutropenia that lasted more than 7 days and one patient died of neutropenic sepsis. The remaining dose levels used topotecan 1.0 mg/m2/d plus cisplatin 75 mg/m2 (level 6) and 100 mg/m2 (levels 7 and 8) with filgrastim. No DLT was observed on level 6. On level 7, two patients had dose-limiting neutropenia and one patient had grade 3 hyperbilirubinemia. Priming with filgrastim on level 8 demonstrated no obvious advantage over level 7, and one patient had grade 4 thrombocytopenia that lasted more than 7 days. Three patients with non-small-cell lung cancer achieved a partial response and one patient with breast cancer had a complete response.

CONCLUSION

Topotecan and cisplatin in combination cause more neutropenia than expected from either drug given alone at the same dosage. The recommended phase II doses are topotecan 1.0 mg/m2/d for 5 days in combination with cisplatin 50 mg/m2 on day 1 without filgrastim or cisplatin 75 mg/m2 on day 1 with filgrastim support.

Intravenous pamidronate disodium treatment of bone metastases in patients with breast cancer. A dose-seeking study

BACKGROUND

Treatment of the symptoms of bone metastases currently involves the use of narcotic medication, radiation therapy, or hormonal therapy. Pamidronate disodium, a bisphosphonate, may prove helpful in the palliative treatment of bone metastases in patients with breast cancer as demonstrated in this multicenter, dose-ranging trial.

METHODS

Ambulatory female patients age 18 years or older with breast cancer metastatic to bone and a life expectancy of at least 3 months were eligible for the study. Bone metastases were confirmed by bone scan or bone survey within 6 months of enrollment. Sixty-one patients were treated as outpatients and were randomized to receive one of four intravenous pamidronate regimens for 12 weeks: 30 mg administered every 2 weeks, 60 mg every 4 weeks, 60 mg every 2 weeks, or 90 mg every 4 weeks. The primary efficacy parameter for this study was pain score. The change from baseline in pain score was determined for each patient at each study visit and at endpoint, defined as the last postbaseline evaluation for each patient before or at week 12. Secondary efficacy variables included narcotic scores, urinary calcium/creatinine and hydroxyproline/creatinine ratios, serum osteocalcin and bone alkaline phosphatase concentrations, and bone lesion (radiologic) response.

RESULTS

At 3 months, the regimens of 60 mg every 4 weeks, 60 mg every 2 weeks, and 90 mg every 4 weeks resulted in significant reduction in bone pain beginning by week 6 of treatment. The regimen of 30 mg every 2 weeks was not effective. Narcotic use, as reflected by narcotic scores, did not parallel the pain scores, because there was little evidence of any effect for any of the treatment groups. Reduction in bone pain was accompanied by decreases in urinary calcium/creatinine and hydroxyproline/creatinine ratios, and bone alkaline phosphatase concentrations. Side effects of pamidronate were mild and transient. Radiographic changes consistent with healing of lytic lesions were observed in 15 patients (25%).

CONCLUSION

Intravenous pamidronate is a well tolerated treatment that produced significant relief of bone pain in the majority of patients with metastatic breast cancer at the three highest doses tested.

Predictive performance of a pharmacodynamic model for oral etoposide

The objective of this work was to prospectively validate a pharmacodynamic model for 21-day oral etoposide. The model had been developed in 27 untreated patients with stage IIIB or IV non-small cell lung cancer. Treatment consisted of 50 mg/m2/day, p.o., etoposide for 21 days in combination with 100 mg/m2, i.v., cisplatin on day 1 every 28 days for up to 6 courses. Weekly evaluations included etoposide plasma concentrations (Ec, microgram/ml) before the daily dose and WBC and neutrophil counts (ANC, 10(3)/microliters). The relationship between Ec and the pretreatment (WBCp, ANCp) and nadir counts (WBCn, ANCn) in the first course was described as follows: WBCn = 0.35 (1 + WBCp x e-1.12 x Ec)) ANCn = 0.32 (1 + ANCp x e-2.47 x Ec) The same study criteria were used to enter 26 additional patients, and 21 were evaluable for pharmacodynamics (5 had incomplete data). Predicted nadir counts were not significantly different from observed nadir counts (paired t test, P > 0.4). There were 12 and 7 patients correctly predicted to be above and below, respectively, the clinically important ANCn of 0.5 x 10(3)/microliters. The model performed reliably, and therapeutic drug monitoring appears warranted in future studies.

Miller-Dieker syndrome. Detection of a cryptic chromosome translocation using in situ hybridization in a family with multiple affected offspring

OBJECTIVE

To describe a family in whom fluorescence in situ hybridization allowed for accurate diagnosis of Miller-Dieker syndrome in an at-risk pregnancy and determination of parental carrier status.

DESIGN

Retrospective case analysis and application of a new molecular tool to evaluate the family.

SETTING

Health maintenance organization. The family was followed up by the Departments of Medical Genetics, Pediatrics, and Obstetrics and Gynecology, Kaiser Permanente Medical Center, Panorama City, Calif.

PARTICIPANTS

Members of a single family.

INTERVENTIONS

Clinical evaluation and neuroimaging studies of the proband. Prenatal diagnosis via ultrasonography and amniocentesis. Chromosomal evaluation of the couple and their offspring. In situ hybridization studies in both parents and an affected fetus.

MEASUREMENTS/MAIN RESULTS

We describe a family in whom fluorescence in situ hybridization detected a submicroscopic deletion of the Miller-Dieker syndrome critical region 17p13.3 arising from a cryptic translocation in one of the parents. The proband was determined at birth owing to the presence of multiple congenital anomalies, including low birth weight, microcephaly, agenesis of the corpus callosum, lissencephaly, cerebral atrophy, unilateral ptosis, polydactyly, and omphalocele. High-resolution chromosome-banding analysis findings were normal in the parents and proband, who died at age 4 years. There were four subsequent pregnancies: two ended in first-trimester spontaneous abortion, and in the other two, large omphaloceles were detected in fetuses at 15 and 13 weeks' gestation. Both pregnancies were terminated. Fluorescence in situ hybridization probes for 17p13.3 had become available before the most recent pregnancy and were used to study parental and fetal cells. As a result, a balanced cryptic translocation between chromosome 17 and chromosome 19 was identified in the father: 46,XY,t(17;19)(p13.3q13.33). An unbalanced form of the translocation, involving a deletion of 17p13.3, was detected with fluorescence in situ hybridization in the fetus. This finding was in accordance with a clinical diagnosis of Miller-Dieker syndrome.

CONCLUSIONS

Molecular cytogenetic technology should be used in cases of suspected Miller-Dieker syndrome when high-resolution cytogenetic analysis fails to detect del(17) (p13.3). Positive findings should be followed up with parental studies. In addition, omphalocele should be included among the list of malformations that make up the Miller-Dieker syndrome.

Role of fetal breathing movements in control of fetal lung distension

Our aim was to determine the role of fetal breathing movements (FBM) in the maintenance of fetal lung liquid volume. Experiments were performed in 14 chronically catheterized fetal sheep. FBM were selectively abolished for 48 h by the infusion of tetrodotoxin (TTX) onto the phrenic nerves of five fetuses. Lung liquid volumes and secretion rates were measured before each treatment, 46-48 h after the start of the TTX infusion, and 22-24 h after the end of the infusion. Blockade of the phrenic nerves reduced fetal lung liquid volumes from 27.6 +/- 1.9 to 21.8 +/- 2.6 ml/kg and increased lung liquid secretion rates from 3.8 +/- 0.6 to 6.2 +/- 1.1 ml.h-1.kg-1. Control experiments confirmed the lack of effect of TTX infused intravenously and saline infused intrapleurally on changes in fetal lung liquid volume and secretion rate. To measure the static relaxation volume of the fetal lung, in six fetuses we combined skeletal muscle paralysis with bypass of the upper airway for 48 h. This reduced fetal lung liquid volume from 39.1 +/- 3.1 to 23.0 +/- 2.5 ml/kg and increased lung liquid secretion rates from 4.1 +/- 0.7 to 5.8 +/- 0.9 ml.h-1.kg-1. This experiment demonstrates that the fetal lung is normally maintained at a level of expansion that is much greater than its static relaxation volume. We conclude that the volume of luminal liquid in the fetal lungs is dependent on the diaphragmatic contractions associated with FBM. Their effect is to resist the elastic recoil of the fetal lungs, thereby reducing the loss of liquid from the lungs via the trachea.

Pharmacodynamics of prolonged oral etoposide in patients with advanced non-small-cell lung cancer

PURPOSE

This study was undertaken to investigate the pharmacodynamic relationship between etoposide drug levels on 21-day oral treatment courses and hematologic toxicities in patients with advanced non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

Thirty-two patients with stage IIIB or IV NSCLC were treated with oral etoposide 50 mg/m2/d for 21 consecutive days in combination with cisplatin 100 mg/m2 on day 1. Treatment was repeated every 28 days for up to six courses. Patients had not received previous chemotherapy and had a performance status of 0 to 2. Patients were monitored weekly while on treatment for compliance with oral etoposide and toxicity, including complete blood cell counts, and a blood sample before the daily etoposide dose (drug trough levels). Etoposide concentrations were measured in the plasma by high-performance liquid chromatography (HPLC).

RESULTS

Three patients achieved a complete response (CR) and 10 patients a partial response for an objective response rate of 41% (95% confidence interval, 24% to 58%). The median survival was 4 months (range, 1 to 23). Neutropenia was dose-limiting, and two patients died of neutropenic sepsis. Pharmacodynamic correlations for drug concentrations and hematologic toxicities were available for 27 patients and a total of 76 treatment courses, and correlations were significant for graded hematologic toxicity and nadir counts of leukocytes, neutrophils, hemoglobin, and platelets. The grade of infection (77 courses) was also related to drug levels. Using data from 27 initial courses, a pharmacodynamic model was developed to estimate the nadir leukocyte or neutrophil count (WBCn, ANCn) based on the pretreatment count (WBCp, ANCp) and the etoposide concentration (Ec) as follows: WBCn = 0.35 (1 + WBCp x e-1.12 x Ec) and ANCn = 0.32 (1 + ANCp x e-2.47 x Ec).

CONCLUSION

Etoposide concentrations are related to the resulting hematologic toxicities. It is possible to predict nadir counts in the first course by a pharmacodynamic model. The above equations need to be validated prospectively and may be useful in future studies of prolonged oral etoposide.