Mechanistic investigation of adult myotube response to exercise and drug treatment in vitro using a multiplexed functional assay system.

The ability to accurately measure skeletal muscle functional performance at the single-cell level would be advantageous for exercise physiology studies and disease modeling applications. To that end, this study characterizes the functional response of individual skeletal muscle myotubes derived from adult rodent tissue to creatine treatment and chronic exercise. The observed improvements to functional performance in response to these treatments appear to correlate with alterations in hypertrophic and mitochondrial biogenesis pathways, supporting previously published in vivo and in vitro data, which highlights the role of these pathways in augmenting skeletal muscle output. The developed system represents a multiplexed functional in vitro assay capable of long-term assessment of contractile cellular outputs in real-time that is compatible with concomitant molecular biology analysis. Adoption of this system in drug toxicity and efficacy studies would improve understanding of compound activity on physical cellular outputs and provide more streamlined and predictive data for future preclinical analyses.

A multiplexed chip-based assay system for investigating the functional development of human skeletal myotubes in vitro.

This report details the development of a non-invasive in vitro assay system for investigating the functional maturation and performance of human skeletal myotubes. Data is presented demonstrating the survival and differentiation of human myotubes on microscale silicon cantilevers in a defined, serum-free system. These cultures can be stimulated electrically and the resulting contraction quantified using modified atomic force microscopy technology. This system provides a higher degree of sensitivity for investigating contractile waveforms than video-based analysis, and represents the first system capable of measuring the contractile activity of individual human muscle myotubes in a reliable, high-throughput and non-invasive manner. The development of such a technique is critical for the advancement of body-on-a-chip platforms toward application in pre-clinical drug development screens.

Correlation of embryonic skeletal muscle myotube physical characteristics with contractile force generation on an atomic force microscope-based bio-microelectromechanical systems device.

Rigorous analysis of muscle function in in vitro systems is needed for both acute and chronic biomedical applications. Forces generated by skeletal myotubes on bio-microelectromechanical cantilevers were calculated using a modified version of Stoney's thin-film equation and finite element analysis (FEA), then analyzed for regression to physical parameters. The Stoney's equation results closely matched the more intensive FEA and the force correlated to cross-sectional area (CSA). Normalizing force to measured CSA significantly improved the statistical sensitivity and now allows for close comparison of in vitro data to in vivo measurements for applications in exercise physiology, robotics, and modeling neuromuscular diseases.

Paclitaxel by 1-h infusion in combination with carboplatin in advanced non-small cell lung carcinoma (NSCLC).

In our previous study, FCCC 93-024, paclitaxel by 24-h infusion combined with carboplatin yielded a response rate of 62% and median survival of 54 weeks in advanced non-small cell lung cancer (NSCLC). Myelosuppression proved dose-limiting, requiring the routine use of granulocyte-colony stimulating factor (G-CSF). Based on the reported activity of 1-h paclitaxel infusion in NSCLC and minimal myelosuppression at doses of 135 and 200 mg/m2 every 3 weeks and the suggestion of a dose-response relationship, we launched an intrapatient dose escalation trial of combination carboplatin and 1-h paclitaxel. Chemotherapy-naïve patients with advanced NSCLC received paclitaxel 175 mg/m2 1-h and carboplatin dosed to a fixed targeted area under the concentration-time curve (AUC) of 7.5 at three weekly intervals for six cycles. In the absence of grade 4 myelosuppression, paclitaxel was escalated by 35 mg/m2/cycle on an intrapatient basis to a maximum dose of 280 mg/m2 by cycle 4. G-CSF was not routinely used. 57 patients (pts) were accrued from November 1994 through to April 1996. 44 pts (77%) had Eastern Cooperative Oncology Group (ECOG) performance status 1. Median age was 64 (range: 34-80) years. Cumulative peripheral sensory neuropathy proved dose-limiting and prohibitive in the first 20 evaluable patients (cohort A): grade > or = 1 in 15 patients (75%), grade 3 in 6 (30%), generally occurring at paclitaxel doses > or = 215 mg/m2 and obligating 3 patients to have treatment halted in the absence of disease progression. The protocol, therefore, was revised and the initial paclitaxel dose reduced to 135 mg/m2 with intrapatient dose escalation of 40 mg/m2/cycle to a maximum dose of 215 mg/m2, recapitulating the original dosing schema used in FCCC 93-024. 35 patients were enrolled in this second cohort (B); 33 proved evaluable. Whilst 17 (52%) experienced peripheral sensory neuropathy, grade 3 neurotoxicity developed in only 3 (9%). Myelosuppression also was less pronounced, with 42% exhibiting grade 4 granulocytopenia and 30% grade > or = 3 thrombocytopenia in cohort B compared with 70% and 50%, respectively in cohort A. Of the first 22 patients accrued to cohort A, 12 (55%) had major objective responses. Median survival was 48.5 weeks, 1-year survival rate 45% and 2-year survival rate 18%. Of 33 evaluable patients in cohort B, 9 (27%) had major objective responses. Median survival was 46 weeks, 1-year survival rate 47% and 2-year survival rate 12%. Combination paclitaxel by 1-h infusion and carboplatin at a fixed targeted AUC of 7.5 is active in advanced NSCLC. Neurotoxicity, not myelosuppression, proved dose-limiting at paclitaxel doses exceeding 215 mg/m2. Lower doses may be associated with lower response rates, but do not appear to compromise survival.

Superantigen-targeted therapy: phase I escalating repeat dose trial of the fusion protein PNU-214565 in patients with advanced gastrointestinal malignancies.

Antibody-directed, superantigen-induced cytotoxicity has been shown to have potent in vitro and in vivo antitumor effects in preclinical models. In the present study, PNU-214565, a recombinant fusion protein consisting of the Fab of the monoclonal antibody C242 and staphylococcal enterotoxin A (SEA), was used in an escalating repeat dose Phase I clinical trial in patients with advanced gastrointestinal malignancies. A prior single-dose Phase I clinical trial had demonstrated safety at doses of 1.5 ng/kg with toxicities of fever and hypotension that were not dose related. Twenty-seven patients (age range, 36-75 years; median, 62; 14 males and 13 females; 23 colorectal and 4 pancreatic) were treated in the present study with one cycle of four consecutive daily 3-h infusions of PNU-214565 at doses of 0.15 ng/kg (n = 3); 0.5 ng/kg (n = 3), 1.5 ng/kg (n = 4), 2.75 ng/kg (n = 12), and 3.5 ng/kg (n = 5). All patients had a good performance status [Eastern Cooperative Oncology Group: PS = 0 (n = 15), PS = 1 (n = 12)]. As in the single-dose trial, fever and hypotension were the most common toxicities. Dose-limiting toxicity (DLT), consisting of transient hypotension responsive to dopamine, was experienced by one patient treated at the 2.75 ng/kg dose level. One patient with pancreatic cancer metastatic to the liver experienced a partial response of hepatic metastases with stable pancreatic head abnormalities by computed tomography scan. Further dose escalation was suspended when two patients treated in a companion repeat dose Phase I study experienced DLT at the 4 ng/kg dose level. Multiparameter analyses on all patients treated in the two companion single-dose and two-repeated-dose Phase I trials revealed that the levels of patients' pretreatment anti-SEA antibodies protected against toxicity at a given drug dose. By jointly considering weight and the baseline anti-SEA concentration in a patient, it is possible to assign a PNU-214565 dose that will induce systemic cytokine release (a surrogate test to assess for the presence of uncomplexed drug and its ability to induce systemic cellular activation) without DLT. This pharmacodynamically based dosing scheme will be tested in future repeated-dose clinical trials and will define maximally tolerated doses of this powerful new immunotherapy approach.

Phase II trial of 96-hour paclitaxel plus oral estramustine phosphate in metastatic hormone-refractory prostate cancer.

PURPOSE: To evaluate the antitumor activity of 96-hour paclitaxel and daily oral estramustine phosphate (EMP) in patients with metastatic hormone-refractory prostate cancer (HRPC). PATIENTS AND METHODS: Thirty-four patients with adenocarcinoma of the prostate that progressed after one or more hormonal therapies and a trial of antiandrogen withdrawal were enrolled onto this phase II trial. Patients received paclitaxel 120 mg/m2 by 96-hour intravenous (i.v.) infusion on days 1 through 4 of each 21-day cycle, together with daily oral EMP 600 mg/m2/d, continuously. RESULTS: Four of nine patients with measurable disease had objective responses (one complete response [CR] and three partial responses [PRs]) in liver (two patients) or nodes (two patients) of 2, 6, 8, and 20 months' duration. Of 25 assessable patients with metastases limited to bone, 14 had a > or = 50% decline in pretreatment prostate-specific antigen (PSA) level sustained for at least 6 weeks and seven had a > or = 80% decline. Overall, 17 of 32 patients (53.1%) with elevated pretreatment PSA levels had a > or = 50% decline of PSA and nine (28.1%) had a > or = 80% decrease. The main toxicities (> or = grade 2) were nausea, fluid retention, and fatigue, which occurred in 33%, 33%, and 24.2% of patients. Median time to progression, based on increasing PSA level and other clinical criteria, was 22.5 weeks. The estimated median overall survival time is 69 weeks. CONCLUSION: The combination of EMP and 96-hour paclitaxel is an active regimen for patients with HRPC. These results further support the therapeutic strategy of combining agents that impair microtubule function by complementary mechanisms.

Paclitaxel (1-hour) and carboplatin (area under the concentration-time curve 7.5) in advanced non-small cell lung cancer: a phase II study of the Fox Chase Cancer Center and its network.

We previously reported a 62% response rate and 54% 1-year survival rate for paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) administered by 24-hour infusion in combination with fixed-dose carboplatin to treat patients with advanced non-small cell lung cancer (NSCLC). Myelosuppression proved dose limiting, but was substantially reduced by the routine use of granulocyte colony-stimulating factor during the second and subsequent cycles. Activity for paclitaxel 135 mg/m2 and 200 mg/m2 by 1-hour infusion every 3 weeks in patients with NSCLC, with minimal myelosuppression and the suggestion of a dose-response relationship, has been reported. In November 1994, we initiated a phase II trial in patients with advanced, measurable, chemotherapy-naive NSCLC using paclitaxel 175 mg/m2 given in 1 hour, and carboplatin dosed to a fixed target area under the concentration-time curve of 7.5 every 3 weeks. In the absence of grade 4 myelosuppression, paclitaxel was escalated on an intrapatient basis by 35 mg/m2 per cycle to a maximum dose of 280 mg/m2 by cycle 4. Granulocyte colony-stimulating factor was not routinely used. Of the 57 patients accrued, 44 (81%) are Eastern Cooperative Oncology Group performance status 1. The median patient age is 64 years. To date, 54 patients are fully evaluable for toxicity. In the first 20 evaluable patients accrued (cohort A), myelosuppression was tolerable, but cumulative peripheral sensory neuropathy proved dose limiting: grade > or = 1 in 15 (75%) patients and grade 3 in six (30%), generally occurring at paclitaxel doses > or = 215 mg/m2 and obligating at least three patients to be removed from study despite absence of disease progression. The protocol was consequently revised. The starting dose of paclitaxel was reduced to 135 mg/m2 with intrapatient dose escalations of 40 mg/m2 per cycle, to a maximum paclitaxel dose of 215 mg/m2, recapitulating the original dosing schema used in Fox Chase Cancer Center study 93-024. For the 35 patients enrolled in the second cohort (cohort B), treatment has been better tolerated. Of 21 evaluable patients, 13 (62%) have experienced peripheral sensory neuropathy, grade 3 in only one (5%) patient. Myelosuppression also has been less pronounced, with 44% grade 4 granulocytopenia and 38% grade > or =3 thrombocytopenia in cohort B compared with 70% and 50%, respectively, in cohort A. Of the first 22 patients accrued to cohort A, 12 (55%) had major objective responses. Median event-free survival is 24 weeks and median survival is 47 weeks. Of the 35 evaluable patients in cohort B, nine (26%) have had major objective responses. Median event-free survival is 22 weeks. It is too early to report median survival. Paclitaxel given by 1-hour infusion in combination with carboplatin at a fixed target area under the concentration-time curve of 7.5, although active in advanced NSCLC, is associated with problems that compromise its efficacy. Higher dose levels yield intolerable toxicity, evidenced by the incidence of neurotoxicity (rather than myelosuppression) that was dose and protocol limiting at paclitaxel doses exceeding 215 mg/m2. Lower doses, while more tolerable, appear to be associated with lower response rates.

Superantigen-based immunotherapy: a phase I trial of PNU-214565, a monoclonal antibody-staphylococcal enterotoxin A recombinant fusion protein, in advanced pancreatic and colorectal cancer.

PURPOSE: To establish the maximum-tolerated dose (MTD) and define the toxicities of a single-dose infusion of PNU-214565, a recombinant Escherichia coli-derived fusion protein of Staphylococcal enterotoxin A (SEA) and the Fab-fragment of the C242 monoclonal antibody in patients with advanced colorectal and pancreatic carcinomas. To investigate the capability of PNU-214565 to induce a superantigen (SAg) response resulting in cytokine production and tumor regression. PATIENTS AND METHODS: Twenty-one patients (age range, 39 to 76 years; median, 64; 12 men, nine women; 18 colorectal, three pancreatic cancers) were treated with a single 3-hour infusion of PNU-214565, with doses ranging from 0.01 to 1.5 ng/kg. All patients had prior chemotherapy and a good performance status Eastern Cooperative Oncology Group [ECOG] performance status [PS] = 0 [n = 10]; PS = 1 [n = 11]), 10 had prior radiation, and 18 had prior surgery. RESULTS: Fever and hypotension were the most common toxicities. Fever of any grade occurred in 16 of 21 patients (76%): four of 21 (19%) with grade 2 and two of 21 (9.5%) with grade 3. Hypotension of any grade occurred in 13 of 21 (62%): four of 21 with grade 2 and one of 21 (5%) with grade 3. Interleukin-2 (IL-2) and tumor necrosis factor alpha (TNF alpha) induction correlated with toxicity. In the two patients with grade 3 fever, peak IL-2 and TNF alpha levels were 2.9 IU/mL and 165 pg/mL, and 8.3 IU/mL and 245 pg/mL, respectively. Transient, > or = 50% decreases in circulating monocytes were observed in 17 of 21 patients as early as 0.5 hours (median time, 2 hours) from the start of infusion. Decreases (mean 33%) in circulating lymphocytes were observed in seven of 21 patients. All three patients with grade 3 toxicity were treated at the 0.5-ng/kg dose. The significance of baseline anti-SEA, human antimouse antibody (HAMA), CA242-soluble antigen levels, and T-cell receptor variable beta region (TCR V beta) subsets and histocompatibility leukocyte antigen-DR (HLA-DR) genotypes was assessed as possible predictors of toxicity. All toxicities were transient and easily managed. No grade 3 toxicity occurred at the higher dose levels. CONCLUSION: PNU-214565, a SAg-based tumor targeted therapy, is safe when given as a single 3-hour infusion at doses up to 1.5 ng/kg. The MTD for a single dose was not determined. The safety of a repeated dose schedule is currently under investigation, beginning with doses determined to be safe in this trial.

Combination paclitaxel (1-hour) and carboplatin (AUC 7.5) in advanced non-small cell lung cancer: a phase II study by the Fox Chase Cancer Center Network.

We have previously reported a 62% response rate and 54% 1-year survival rate for patients with advanced non-small cell lung cancer (NSCLC) treated with paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) by 24-hour infusion in combination with carboplatin, using area under the concentration-time curve dosing (FCCC 93-024). Myelosuppression proved dose limiting, but was substantially reduced by the routine use of granulocyte colony-stimulating factor during the second and subsequent cycles. Antitumor activity has been reported with minimal myelosuppression, with paclitaxel 135 and 200 mg/m2 given every 3 weeks by 1-hour infusion to patients with NSCLC. In November 1994, we initiated a phase II trial of paclitaxel 175 mg/m2 given over 1 hour, with carboplatin dosed to a fixed, targeted area under the concentration-time curve of 7.5 every 3 weeks. In the absence of grade 4 myelosuppression, paclitaxel was escalated on an intrapatient basis by 35 mg/m2 per cycle to a maximum dose of 280 mg/m2 by cycle 4. Granulocyte colony-stimulating factor was not routinely used. Eligibility stipulated advanced, measurable, chemotherapy-naive NSCLC. Of 47 patients accrued, 39 (83%) had Eastern Cooperative Oncology Group performance status 1. The median age was 64 years; 40 patients were evaluable for toxicity. Of the first 20 evaluable patients accrued (cohort A), myelosuppression was tolerable. Cumulative peripheral sensory neuropathy grade > or = 1 in 15 (75%) patients and grade 3 in six (30%), however, generally occurring at paclitaxel doses greater than 215 mg/m2, obligated removal from study of at least three patients, despite the absence of disease progression, and proved to be dose-limiting. Consequently, the protocol was revised: the starting dose of paclitaxel was reduced to 135 mg/m2, with intrapatient dose escalation of 40 mg/m2 per cycle to a maximum dose of 215 mg/m2, thus recapitulating the original dosing schema used in FCCC 93-024. To date, 25 patients have been enrolled in this second cohort (cohort B) and treatment has been better tolerated. Of 21 evaluable patients, 13 (62%) have experienced peripheral sensory neuropathy, but only one (5%) has been grade 3. Myelosuppression also has been less pronounced, with 33% grade 4 granulocytopenia and 13% grade > or = 3 thrombocytopenia in cohort B compared with 70% and 50%, respectively, in cohort A. Of the first 22 patients accrued to cohort A, 12 (55%) had major objective responses. Median event-free survival is 23 weeks and median survival is 47 weeks. Of 15 evaluable patients in cohort B, five (33%) have had major objective responses. It is too early to report survival data. In conclusion, paclitaxel by 1-hour infusion in combination with carboplatin at a fixed targeted area under the concentration-time curve of 7.5 is an active regimen in advanced NSCLC. Neurotoxicity, rather than myelosuppression, is dose and protocol limiting at paclitaxel doses exceeding 215 mg/m2.

Paclitaxel plus estramustine in metastatic hormone-refractory prostate cancer.

Combination antimicrotubule therapy with estramustine phosphate (EMP) and vinblastine has reproducible activity in metastatic hormone-refractory prostate cancer (HRPC) with an objective response rate of 31%. Although paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) by 24-hour infusion was inactive in HRPC, 0.5 to 1.0 nmol/L concentrations of paclitaxel combined with EMP exerted synergistic cytotoxicity in DU-145 androgen-independent human prostate cancer cell lines. Based on these results, we treated 24 patients with HRPC using the combination of paclitaxel 120 to 140 mg/m2 by 96-hour intravenous infusion every 3 weeks plus daily oral EMP at 600 mg/m2/d. Of seven patients with measurable soft tissue metastases, three have attained partial responses and a fourth patient is nearing partial response status. Of 16 patients with bone-only disease evaluated by change in serum prostate-specific antigen levels, 11 patients (68.8%) have had decreases of > or = 50% from pretreatment baseline. The prostate-specific antigen decrease has exceeded 80% in six of 16 (37.5%) patients. For all 23 evaluable patients, the prostate-specific antigen has decreased by > or = 50% in 15 (65.2%) and by > or = 80% in eight (34.7%). Grade 4 leukopenia occurred in one of 21 patients treated at the paclitaxel dose of 120 mg/m2/96 hr and one of three patients treated at 140 mg/m2/96 hr. The incidence of nausea (50%) and peripheral edema (37.5%) was similar to that associated with single-agent EMP. These results demonstrate that 96-hour paclitaxel plus EMP is active in HRPC and provide further evidence that the rational combination of antimicrotubule agents leads to synergistic antitumor activity in HRPC.

Paclitaxel and carboplatin in combination in the treatment of advanced non-small-cell lung cancer: a phase II toxicity, response, and survival analysis.

PURPOSE: To determine the activity and toxicity of combination paclitaxel (24 hours) and carboplatin in advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: Eligibility required measurable disease (stage IV or stage IIIB with malignant pleural effusion), Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1, absolute neutrophil count > or = 2,000/microL, platelet count > or = 100,000/microL serum creatinine concentration < or = 1.5 mg/dL, and bilirubin level < or = 2 mg/dL. Paclitaxel was initially administered at a dose of 135 mg/m2/d, followed by carboplatin on day 2 at a targeted area under the concentration-time curve (AUC) of 7.5 using the Calvert formula. Granulocyte colony-stimulating factor (G-CSF) 5 micrograms/kg subcutaneously (SC) on days 3 to 17 was introduced during the second and subsequent cycles. In patients who sustained less than grade 4 myelosuppression, the paclitaxel dose was sequentially escalated 40 mg/m2 per cycle to a maximum of 215 mg/m2. Treatment was repeated at 3-week intervals for six cycles. RESULTS: From June 1993 through February 1994, 54 patients were enrolled; 53 are assessable for toxicity and response. The median age was 62 years (range, 34 to 84). Sixty-nine percent were male, 65% had adenocarcinoma, and 93% had stage IV disease. Two hundred sixty-eight cycles were administered; 32 patients (59%) completed all six cycles. Twenty-five unanticipated hospitalizations occurred during treatment (9.3% of cycles) in 20 patients (37%). Myelosuppression was the principal toxicity; grade 3 or 4 granulocytopenia occurred in 57% of patients after the first cycle, but decreased to 35% during the second cycle after introduction of G-CSF and consistently remained < or = 22% during subsequent cycles. Seven episodes of neutropenic fever occurred, all during the first cycle. Grade 3 or 4 thrombocytopenia and anemia occurred in 47% and 33% of patients, respectively. Eight patients (15%) required platelet transfusions and 16 (30%) required packed RBC support. Neuropathy, myalgias/arthralgias, and thrombocytopenia, although generally mild, were cumulative. The paclitaxel dose was boosted to 215 mg/m2 in > or = 70% of patients who received three or more cycles. At an AUC of 7.5, the median first-cycle carboplatin dose was 424 mg/m2 (range, 273 to 709 mg/m2). The objective response rate was 62%, with five (9%) complete responses and 28 (53%) partial responses. The median progression-free survival time was 28 weeks and the median survival time 53 weeks. The 1-year survival rate is 54%. CONCLUSION: The paclitaxel-carboplatin combination is active in advanced NSCLC and may enhance survival; it merits further investigation in phase III trials.

Paclitaxel by 24- or 1-hour infusion n combination with carboplatin in advanced non-small cell lung cancer: the Fox Chase Cancer Center experience.

A phase II trial of combination paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) and carboplatin included 54 chemotherapy-naive patients with advanced non-small cell lung cancer. Eligibility mandated Eastern Cooperative Oncology Group performance status of 0 or 1 and adequate hematologic, renal, and hepatic function. Paclitaxel 135 mg/m2 over 24 hours preceded carboplatin dosed to an area under the concentration-time curve of 7.5. Six planned courses were given every 3 weeks. Granulocyte colony-stimulating factor was introduced during the second and subsequent cycles, and paclitaxel increased 40 mg/m2/cycle (maximum, 215 mg/m2) in patients with absolute neutrophil and platelet nadirs exceeding 500/microL and 50,000/microL, respectively. Grade 3 or 4 neutropenia, observed in 54% of patients during cycle 1, declined to 35% during cycle 2 and to 22% or less during cycles 3 through 6. Neuropathy, myalgias/arthralgias, and thrombocytopenia were mild but cumulative. In 53 evaluable patients, the objective response rate was 62%, with 9% complete remissions and a median response duration of 6 months (range, 1 to 19+ months). At median potential follow-up of 16 months, 9% of patients remain progression free (52+ to 80+ weeks). Median survival is 12.5 months; 1-year survival is 54%. Paclitaxel/carboplatin is highly active in advanced non-small cell lung cancer; granulocyte colony-stimulating factor abrogates neutropenia as the dose-limiting toxicity, but has no effect on the cumulative incidence of thrombocytopenia or treatment delays. One-hour paclitaxel infusion is minimally myelosuppressive, logistically easier, and less costly. A follow-up study combined paclitaxel (175 mg/m2) over 1 hour followed by carboplatin (area under the concentration-time curve, 7.5). In the absence of grade 4 myelosuppression, paclitaxel was increased 35 mg/m2/cycle (maximum, 280 mg/m2). Granulocyte colony-stimulating factor was implemented only after neutropenic fever or grade 4 neutropenia. Of 17 patients entered, 13 are evaluable for toxicity and seven for response. Four patients have sustained a partial response, two a minor response, and one stable disease. The incidence of grade 3 or 4 neutropenia, thrombocytopenia, and anemia in cycle 1 was 38%, 16%, and 0%, respectively, and 72%, 28%, and 28%, respectively, during cycle 2. Major nonhematologic toxicities include myalgias and arthralgias (54%) and fatigue and neuropathy (78%), the latter cumulative and progressive over successive cycles. Preliminary data suggest comparable activity for the 1- and 24 hour paclitaxel infusions in combination with carboplatin. The more severe neuropathy of the 1-hour paclitaxel/carboplatin combination may be related to the paclitaxel dosing schema (175 mg/m2 to as high as 280 mg/m2).(ABSTRACT TRUNCATED AT 400 WORDS)

Phase I study of paclitaxel and estramustine: preliminary activity in hormone-refractory prostate cancer.

Estramustine phosphate is a unique antimitotic agent that binds to tubulin and microtubule-associated proteins. Preclinically, estramustine combined with other microtubule inhibitors, like vinblastine or paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ), produced additive or greater antimitotic and cytotoxic effects. Clinically, the estramustine/vinblastine combination has significant activity in hormone-refractory prostate cancer. We have begun a phase I study of paclitaxel by 96-hour continuous infusion every 3 weeks combined with daily oral estramustine (600 mg/m2). Eighteen patients with refractory solid tumors have received paclitaxel doses ranging from 80 to 140 mg/m2. Grade 3 or 4 granulocytopenia occurred in one of seven and two of four patients treated at the 120- and 140-mg/m2 dose levels, respectively. The latter two patients experienced grade 3 mucositis and had mean plasma paclitaxel levels exceeding 0.1 mumol/L. Other toxicities, principally nausea and hepatic function abnormalities, have been mild. The apparent steady-state concentrations of paclitaxel 100 and 120 mg/m2 administered with estramustine are similar to those reported for single-agent paclitaxel administered as a 96-hour infusion at doses of 100 and 120 mg/m2. In contrast, at the 140 mg/m2 dose level, paclitaxel concentrations increased throughout the infusion, and steady state was not reached in three of the four patients treated. Objective responses have been observed in two of three patients with adenocarcinoma of the esophagus and in two patients with hormone-resistant prostate cancer and measurable soft tissue metastases. Two additional patients with prostate cancer have been treated with the estramustine/paclitaxel combination, one achieving a major response and the other stable disease. The recommended phase II dose for 96-hour infusional paclitaxel with daily oral estramustine is at least 120 mg/m2. Studies to determine the effect of estramustine on paclitaxel pharmacokinetics are continuing. The antitumor activity observed merits phase II studies of this combination in hormone-resistant prostate cancer and other malignancies.

Paclitaxel and carboplatin in the treatment of advanced non-small cell lung cancer.

Based on the superior response rates (21% to 24%) of patients treated with single-agent paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) in Eastern Cooperative Oncology Group and M.D. Anderson Cancer Center trials in non-small cell lung cancer (NSCLC) and on the superior 1-year survival rates of NSCLC patients treated with carboplatin in a randomized study of cisplatin combination and analogues, we initiated a phase II trial of paclitaxel/carboplatin in patients with stage IV or effusion-positive stage III NSCLC. Eligibility stipulated chemotherapy-naive patients with measurable disease, good performance status, and adequate hematologic, hepatic, and renal function. Previous radiotherapy was restricted to < or = 30% of marrow-bearing bone. Paclitaxel was initially given at 135 mg/m2 over 24 hours followed by carboplatin dosed to a targeted area under the concentration versus time curve (AUC) of 7.5, with treatment repeated at 3-week intervals for six cycles. Granulocyte colony-stimulating factor was introduced during the second and subsequent cycles, with the paclitaxel dose sequentially escalated in 40 mg/m2 increments to a maximum dose of 215 mg/m2 in patients with less than grade 4 granulocytopenia and less than grade 3 thrombocytopenia. Of 54 patients enrolled, 30 currently are evaluable for response, 23 for toxicity. Myelosuppression has been the principal toxicity, with grade 3 or 4 granulocytopenia occurring in 70% of patients after the first cycle. After the introduction of granulocyte colony-stimulating factor, granulocytopenia decreased to 37% during the second cycle and then consistently to 20% or lower during subsequent cycles. Only 22% of cycles have been delayed for 1 week or more. Neutropenic fever has occurred in five (5%) of 100 evaluable cycles. Other grade 3 or 4 toxicities include thrombocytopenia (13%), anemia (9%), fatigue (9%), and hemorrhagic cystitis (1%). The paclitaxel dose was boosted to 215 mg/m2 in 12 (70%) of 17 patients by cycle 3 or 4. At an AUC of 7.5, the median first-cycle carboplatin dose was 434 mg/m2 (range, 293 to 709 mg/m2). The objective response rate is 50%, with three complete, 12 partial, and five minor responses. We conclude that the paclitaxel/carboplatin combination is active in advanced NSCLC and, with AUC-based dosing of carboplatin, can be given at 3-week intervals. Although dose limiting at a paclitaxel dose of 135 mg/m2, granulocytopenia can be reduced substantially with granulocyte colony-stimulating factor, allowing sequential dose escalation of paclitaxel to 175 mg/m2 and 215 mg/m2 in 70% of patients receiving three or more cycles.

Phase I study of phosphonacetyl-L-aspartate, 5-fluorouracil, and leucovorin in patients with advanced cancer.

Low-dose phosphonacetyl-L-aspartate (PALA) may potentiate both 5-fluorouracil (5-FU) incorporation into RNA and thymidylate synthase inhibition by 5-fluorodeoxyuridylate (5-FdUMP). The gastrointestinal toxicity of 5-FU is not increased by PALA administration. Exogenous leucovorin, on the other hand, which enhances thymidylate synthase inhibition, appears to increase the clinical toxicity of 5-FU in a dose-dependent manner. As a result, the clinical use of high-dose leucovorin requires a marked dose reduction of 5-FU. Extracellular leucovorin levels of 1 microM suffice to maximize the enhancement of thymidylate synthase inhibition in several models. We conducted a trial to add leucovorin to the PALA/5-FU regimen. We chose a leucovorin dose that was predicted to yield end-infusion total reduced folate concentrations of 1 microM. The major endpoint was to determine the maximum tolerated dose of 5-FU in this combination. The regimen consisted of 250 mg/m2 PALA given on day 1 and, 24 h later, escalating 5-FU doses ranging from 1,850 to 2,600 mg/m2 admixed with 50 mg/m2 leucovorin and given by 24-h infusion. Courses were repeated weekly. A total of 24 patients with a median performance status of 1 were entered at three dose levels. Diarrhea was dose-limiting; 6/13 patients had grade II or worse diarrhea at 2,600 mg/m2. Dose modification resulted in a mean dose intensity of 2,300 mg/m2 at both the 2,600- and 2,300-mg/m2 dose levels. The 2,300-mg/m2 dose is suitable for phase II testing of this regimen. Three patients (two with breast cancer and 1 with sarcoma) had a partial remission. We measured steady-state concentrations (Css) of 5-FU in 23 patients. The mean Css increased with dose from 0.738 to 1.03 micrograms/ml. Total body clearance did not vary with dose in this range. Patients with grade II or worse diarrhea had a higher mean Css (1.10 +/- 0.19) than those with grade O or I toxicity (0.835 +/- 0.25, P < 0.02). Total bioactive folates (bound and free) were measured using a biological assay. Pretreatment values ranged from 2 to 52 nM and were not predictive of toxicity. End-infusion (23-h) values were somewhat lower than predicted and ranged from 400 to 950 nM. The risk of diarrhea was positively correlated with end-infusion total folate values. In a logistic regression analysis, total folate values obtained at 23 h were a more powerful predictor of diarrhea than were 5-FU Css values.(ABSTRACT TRUNCATED AT 400 WORDS)

Phase I trial of ilmofosine as a 24 hour infusion weekly.

Ilmofosine, an ether lipid derivative of lysophosphatidylcholine has antineoplastic activity in vitro and in vivo. Maximum efficacy in preclinical models is associated with prolonged exposure to the drug. In a Phase I trial of a weekly 2 hour infusion schedule of ilmofosine, a syndrome of lethargy, diminished performance status, and mild hepatotoxicity was dose-limiting at 550 mg/m2. To avoid the higher drug concentrations associated with a brief infusion, a Phase I study of a weekly 24 hour infusional schedule was undertaken in an attempt to maximize dose-intensity. Doses were escalated from 550 to 800 mg/m2. Toxicities included nausea, anorexia, fatigue, and minor elevations of liver function tests. The dose limiting toxicity at 800 mg/m2 was a syndrome of severe abdominal pain. No neutropenia or thrombocytopenia was observed except in one patient who was found to have a myelodysplastic syndrome, thought not to be related to drug therapy. The more prolonged infusion schedule of ilmofosine did not result in a substantial increase in the tolerable dose.

Phase II study of topotecan in metastatic hormone-refractory prostate cancer.

Systemic chemotherapy with currently available agents has not improved survival for patients with hormone refractory prostate cancer (HRPC), consequently, the evaluation of new agents is warranted. Topotecan is a specific inhibitor of topoisomerase I with broad antitumor activity in preclinical studies. The purpose of this phase II trial was to determine the objective response rate of topotecan administered as a 30 minute infusion for five consecutive days in men with metastatic HRPC. Thirty-four evaluable patients were treated with topotecan 1.1-1.5 mg/m2 as a 30 minute infusion daily for five days, repeated every three weeks until disease progression or unacceptable toxicity. Response was assessed with a combination of standard solid tumor response criteria and the serum prostate specific antigen (PSA) for patients with bidimensionally measurable disease, and by serial measurements of the PSA in patients with bone only (evaluable) disease. One of 13 patients (7.6%) with measurable soft tissue disease had a PR in nodal sites. Of 21 patients with only osseous metastases, 1 (4.7%) had improvement in bone scan. Six of the 34 evaluable patients (17.6%) had the serum PSA decrease by > or = 50% and 2 (5.8%) had PSA decreases of > or = 75%. Toxicity was chiefly hematologic with 66% of patients experiencing Grade 3 or 4 granulocytopenia. Thirty-nine percent of cycles required a delay to allow for hematologic recovery and ten patients required red cell transfusions. Non-hematologic toxicity, mainly nausea and alopecia, was mild. Topotecan administered at this dose and schedule has limited activity in patients with HRPC. Further trials of topo I inhibition in HRPC should utilize alternative schedules of topotecan (e.g., prolonged infusion) or other camptothecin analogs with more potent topo I inhibitory activity.

Phase I study of etoposide phosphate (etopophos) as a 30-minute infusion on days 1, 3, and 5.

Etoposide phophate is a phosphate ester prodrug of etoposide designed to improve the pharmaceutical characteristics of the parent compound. A Phase I dose-escalating study of etoposide phosphate was conducted concurrently at two institutions to determine its toxicity, pharmacokinetics, and maximum tolerated dose. Etoposide phosphate was administered i.v. for 30 min on days 1, 3, and 5 every 21 days or on recovery from toxicity. Cohorts of at least three patients received etoposide phosphate at dose levels from 50 mg/m2 to 150 mg/m2 expressed as molar equivalents of etoposide. Blood and urine samples were obtained from all patients during the first cycle of treatment and the concentrations of etoposide phosphate and etoposide were measured. Thirty-nine patients with documented cancers received a total of 75 cycles of etoposide phosphate. The dose-limiting toxicity was myelosuppression which occurred at the 150-mg/m2 etoposide equivalent dose. Etoposide phosphate was rapidly and extensively converted to etoposide. No measurable etoposide phosphate was detectable in the plasma by 15-60 min after the end of the infusion. The mean half-life of etoposide at the different dose levels ranged from 5.5 to 9.3 h. The pharmacokinetics of etoposide, generated from etoposide phosphate, was linear over the dose range studied and was comparable to results reported in the literature for i.v. etoposide. In summary, i.v. etoposide phosphate is rapidly and extensively converted to etoposide. The maximum tolerated dose of etoposide phosphate when given on days 1, 3, and 5 is 150 mg/m2/day. The dose-limiting toxicity is myelosuppression. The maximum tolerated dose and adverse event profile are consistent with those of etoposide.

Phase I and pharmacokinetic study of ormaplatin (tetraplatin, NSC 363812) administered on a day 1 and day 8 schedule.

Ormaplatin (tetraplatin, NSC 363812) is a platinum(IV) analogue that is active against cisplatin-resistant cell lines in preclinical models. A schedule previously shown to be active and well tolerated for cisplatin was evaluated in 26 patients. Ormaplatin was administered over a dose range of 4.4-60.8 mg/m2 i.v. given over 30 min on a day 1 and day 8 schedule every 28 days. Twenty-three patients had received prior chemotherapy, and the median performance status was 1. Nausea/vomiting (> or = grade 2) occurred in 40% of patients but was well controlled with standard antiemetic therapy. One patient had grade 2 renal toxicity and 1 patient had grade 3 hepatotoxicity (grade 2 pretreatment). No toxicity limited the dose given during the first course. With repeated drug administration delayed severe neurotoxicity developed in 4 patients, manifested as a sensory polyneuropathy in 3 patients and a possible autonomic neuropathy in one. Prospective nerve conduction studies did not detect subclinical neuropathy prior to the onset of symptoms. Patients who received cumulative doses above 200 mg/m2 were at increased risk for developing neurotoxicity. Plasma elimination of ultrafilterable platinum (measured by atomic absorption spectrometry) was biphasic with a harmonic mean terminal half-life of 15.8 h. The mean total body clearance and renal clearance of ultrafilterable platinum were 173 and 29.8 ml/min/m2, respectively. Thus, renal clearance accounted for 16% of total clearance suggesting that extensive protein/tissue binding was responsible for the majority of platinum clearance. Approximately 60% of the platinum is protein bound (one-half irreversibly) at the end of the infusion. Pharmacokinetic parameters were not dose dependent. No pharmacokinetic parameters were more predictive of neurotoxicity than the cumulative ormaplatin dose. A phase II dose cannot be recommended on this schedule because severe and unpredictable neurotoxicity precludes the administration of more than three cycles at the three highest doses levels tested.

Phase I trial of thiotepa in combination with recombinant human granulocyte-macrophage colony-stimulating factor.

PURPOSE: The ability of growth factors to stimulate marrow recovery suggests their potential for use in dose intensification of cytotoxic drugs. We performed a phase I study of the alkylating agent thiotepa in combination with granulocyte-macrophage colony-stimulating factor (GM-CSF), with the goal of dose-escalation of thiotepa. Thiotepa was selected based on its capacity for dose escalation to more than 1 g/m2 in the marrow transplantation setting. PATIENTS AND METHODS: The starting dose of thiotepa (75 mg/m2) was the highest dose evaluated in our previous phase I trial. Thirteen patients received 22 courses of thiotepa and GM-CSF. The dose of GM-CSF was 10 micrograms/kg subcutaneously daily in six patients and 5 micrograms/kg in seven patients. RESULTS: Three patients (23%) developed grade 3 to 4 neutropenia on the first course, with a recovery to more than 1000/mm3 in 4.7 days (mean). Recovery was as rapid with the 5 micrograms/kg as it was with the 10 micrograms/kg GM-CSF dose. Thrombocytopenia grade 3 to 4 affected seven of 13 (54%) patients in the first course; counts recovered to more than 50,000/mm3 in a median of 15 days. GM-CSF at either dose did not influence markedly the severity or duration of thrombocytopenia, and did not permit dose escalation of thiotepa. Among the seven patients who received a second cycle of treatment, six of seven experienced grade 3 or 4 thrombocytopenia that lasted a median of 15.5 days. Five had thrombocytopenia that lasted more than 35 days after one to three cycles of treatment. Plasma concentrations of thiotepa and tepa were measured by gas chromatography in eight patients. The plasma elimination of thiotepa fit a two-compartment open model with a harmonic mean terminal half-life of 2.44 hours. The mean total body clearance was 217.9 mL/min/m2, and the mean steady-state volume of distribution (Vdss) was 36.8 L/m2. The half-life of tepa was 7.98 hours, and the ratio of the area under the plasma concentration versus time curve (AUC) of tepa to that of thiotepa was 0.79. CONCLUSIONS: These data were consistent with our previous observations at this dose, and indicated that the severity of toxicity in these patients was not explained by aberrant pharmacokinetic indices. We conclude that, independent of effects on neutropenia, severe and cumulative platelet toxicity precludes further escalation of thiotepa dose despite the use of GM-CSF.