Effect of intramedullary pin size on reducing bone plate strain

The degrees of plate strain, coupled with various diameters of intramedullary pins, is reported. In addition, the fatigue life and stiffness of the plate/pin construct was determined.

Randomized phase II study of perifosine in combination with capecitabine versus capecitabine alone in patients with second- or third-line metastatic colon cancer

4081

Background: Perifosine (Peri), a synthetic alkylphospholipid, inhibits or modifies a number of different signal transduction pathways (AKT, MAPK and JNK). Peri as a single agent or in combination with other cytotoxic agents, has shown clinical benefit with a manageable safety profile. In a phase I solid tumor trial, Peri was safely combined with capecitabine (Cap) and demonstrated interesting activity in patients (pts) with metastatic colorectal cancer (mCRC), with one patient progression-free for 49 weeks (wks). To assess the true effect of Peri, a phase II was initiated as an exploratory randomized double-blind, placebo controlled study where mCRC pts received Cap in combination with Peri or placebo. Methods: Pts with 2nd or 3rd line mCRC, not previously treated with single agent Cap. ECOG PS 0–1, normal organ/marrow function required. Dose for Cap was 825 mg/m2 BID d 1–14 q 3 weeks. Dose for Peri or placebo was 50 mg qd. Primary outcome analyses included median time to progression (TTP) and response rate (CR+PR). Results: 37 pts have been randomized. Median age 68 (range 32–83) and 57% were male. Median prior Rx was 2 (range 1 - 5). For the analyses, 25 pts were unblinded (12 too early) with 22/25 pts evaluable for response (2 pts off for toxicity at d 14, 46 and 1 patient off at d 4 for other disease; all 3 pts were on Cap + placebo). Results in table below. The log-rank p-value comparing active to placebo for TTP is 0.01. As of 12/08, all unblinded pts are off treatment and 11/12 that were too early remain on treatment with enrollment ongoing. Most frequent (>5%) grade 3 /4 adverse events for Cap + Peri was hand/foot syndrome (16%) and anemia (8%); for Cap + placebo was fatigue (8%). Conclusions: Perifosine in combination with capecitabine was well tolerated, clinically active and more than doubled median TTP over capecitabine alone in pts with advanced, metastatic CRC.

[Table: see text]

[Table: see text]

Results of a phase II trial of cetuximab + XELIRI as first-line therapy of patients with advanced and/or metastatic colorectal cancer

4094

Background: We have previously shown that capecitabine/irinotecan (XELIRI) is effective and well-tolerated in metastatic colorectal cancer (mCRC). Cetuximab, a monoclonal IgG1 antibody that binds to the extracellular domain of EGFR, is active in mCRC alone or in combination with chemotherapy. This study was designed to evaluate if cetuximab (Erbitux®) added to XELIRI improves outcome in first-line treatment of mCRC. Methods: Subjects had histologically confirmed colorectal adenocarcinoma with T4 lesions that were unresectable after preoperative chemoradiation therapy and/or metastases. The study regimen was capecitabine 1700 mg/m2 (850 mg/m2 PO BID Days 1–14), irinotecan 200 mg/m2 IV Day 1 every 3 weeks, and weekly cetuximab (initial dose 400 mg/m2 IV over 120 minutes, subsequent doses 250 mg/m2 over 30 minutes). Results: Between February and October 2005, 70 subjects enrolled. Baseline characteristics: 43 males (61%), median age 61.5 years, and ECOG PS 0/1= 66%/34%; 94% of subjects had adenocarcinoma. Prior therapy; surgery (91%), chemotherapy (20%), or radiotherapy (7%). Responses (pts >2 cycles) were; CR (4%), PR (36%), SD (40%) and PD (20%); 15 patients failed treatment; (n=4 allergic reaction, n=2 MD request, n=2 withdrew consent, n=2 Grade 4 neutropenia, and n=5 other AEs). The overall response rate was 40% and the disease control rate was 80%. Median duration of response was 8.8 months (range, 2.6–15.1) and median time to response was 2.0 months (range, 1.2–8.3). 64% of patients remain alive; of the 25 deaths, 84% were due to PD. No death was drug related. The most frequent Grade 3 and 4 treatment-related adverse events (AEs) included: diarrhea (25%), neutropenia (18%), nausea/vomiting (12%), rash and dehydration (9%, each), HFS and fatigue (7%), and allergic reaction (6%). 54% of patients required dose reductions. To date, 64 patients (91%) have gone off study, primarily due to PD (39%) or AE (33%); 3 patients remain on treatment. Conclusions: The combination of cetuximab and XELIRI is feasible and tolerable in first line mCRC. Toxicities are expected and manageable with dose reductions/delay. Funded in part by Bristol-Myers Squibb, Plainsboro, NJ.

No significant financial relationships to disclose.

Results of a phase II trial of cetuximab+XELIRI as first-line therapy of patients with advanced and/or metastatic colorectal cancer

13502

Background: We have previously shown that capecitabine/irinotecan (XELIRI) is effective and well-tolerated in metastatic colorectal cancer (mCRC). Cetuximab targets EGFR and is active in mCRC either alone or combined with chemotherapy. This study evaluated potential improved outcomes with cetuximab+XELIRI in first-line treatment of mCRC. Subjects and Methods: Subjects had histologically confirmed colorectal adenocarcinoma with T4 lesions that were deemed unresectable after preoperative chemoradiation and/or metastatic disease. Treatment: capecitabine 1700 mg/m2 (850 mg/m2 PO BID Days 1–14), irinotecan 200 mg/m2 IV Day 1 every 3 weeks, and weekly cetuximab (initial dose 400 mg/m2 IV over 120 minutes, subsequent doses 250 mg/m2 over 30 minutes). Toxicity was assessed at each visit. Results: Between February and October 2005, 70 subjects enrolled. Baseline characteristics: 43 males (61%), 79% White, median age 61.5 years (range, 32.2 - 85.4), and ECOG PS 0/1= 66%/34%. 63% of subjects had Stage IV disease at diagnosis; 87% of subjects had adenocarcinoma. Prior therapy: surgery (n=60, 86%), chemotherapy (n=14, 20%), and radiotherapy (n=5, 7%). Grade 3–4 treatment-related toxicities in >1 subject included diarrhea (17%); neutropenia and rash (8.5% each); dehydration (7%); nausea/vomiting (5%); and anorexia, dyspepsia, and hypokalemia (3% each). 30 subjects discontinued due to progressive disease (PD) (n=9), toxicity (n=12), MD decision (n=2), patient request/withdrew consent (n=3), death (n=1) and other (n=3; doses delayed >3 weeks). To date 5 subjects have died; no death was treatment-related. Evaluation of tumor responses is ongoing. Conclusions: The combination of cetuximab+XELIRI is feasible and well-tolerated in first-line mCRC. Updated safety and efficacy data will be presented. Funded in part by Bristol-Myers Squibb, Plainsboro, NJ.

[Table: see text]

Cellular immune profile of patients with advanced cancer before and after taxane treatment

The purpose of this study is to determine immune recovery and function after treatment with docetaxel or paclitaxel. Peripheral blood mononuclear cells were harvested before chemotherapy and at weekly times afterwards for cycle 1. Leukocyte subsets ICD45hiCD14lo polymorphonuclear neutrophils, CD45hiCD14hi monocytes, CD45hiCD14- lymphocytes, CD3+CD4/CD8+ T cells, CD3-CD19+ B cells, CD3-CD16/CD56+ natural killer (NK) cells], and circulating cytokine levels [tumor necrosis factor-alpha, gamma-interferon (gamma-IFN), and interleukins (IL-2, IL-10, IL-12)] were followed. In addition, T-cell mitogenic function, NK function, and lymphokine activated killer (LAK) function was assessed. Ten patients were entered in the trial. T-cell frequency, B-cell frequency, and CD4/CD8 ratio did not change. IL-10 serum levels significantly decreased in paclitaxel-treated patients (4.4+/-1.3 pg/ml at week 4 versus 7.8+/-2.1 pg/ml at baseline; p < 0.05). IL-2, IL-12, and gamma-IFN levels were not detectable. NK cytotoxic activity decreased in docetaxel-treated patients. LAK cell activity was not altered. Four patients achieved a partial or complete response. They demonstrated higher than normal CD4:CD8 T-cell ratios and an improved phytohemagglutinin stimulation index (SI = 2.5). In conclusion, our findings suggest that immune function was affected more significantly after docetaxel treatment. Investigational approaches, which enhance cellular immunity, may be of greater relevance after treatment with docetaxel. Additional studies monitoring NK function after chemotherapy are recommended.

Randomized, double-blind, placebo-controlled trial to evaluate the hematopoietic growth factor PIXY321 after moderate-dose fluorouracil, doxorubicin, and cyclophosphamide in stage II and III breast cancer

PURPOSE

To measure the effect of PIXY321 (granulocyte-macrophage colony-stimulating factor/interleukin-3 S. cerevisiae fusion protein) on the incidence, duration, and complications of neutropenia and thrombocytopenia after moderate-dose fluorouracil 600 mg/m(2), doxorubicin 60 mg/m(2), and cyclophosphamide 750 mg/m(2) (FAC) chemotherapy in patients with stage II and III breast cancer.

PATIENTS AND METHODS

In this multicenter, randomized, double-blind placebo-controlled trial, 71 women were to receive four 21-day cycles of treatment with moderate-dose FAC chemotherapy by short intravenous infusion on day 1, followed by either placebo or PIXY321 (375 microg/m(2) subcutaneously twice a day) on days 3 to 15. All patients were to receive prophylactic oral ciprofloxacin when the absolute neutrophil count was less than 1,000/microL.

RESULTS

PIXY321 significantly reduced the incidence and duration of grade 3 and grade 4 neutropenia in cycles 1 and 2 and the duration of grade 3 neutropenia in cycles 1 through 4. In cycles 3 and 4, grade 3 thrombocytopenia was significantly more common with PIXY321 (P <.05). Two patients, both in the PIXY321 group, required platelet transfusions. Fever and hospitalization for intravenous antibiotics were significantly more common in the PIXY321 group during cycle 1 only. More patients in the PIXY321 group achieved hematologic recovery by day 22 in cycles 1 through 3, and time to recovery was significantly shorter with PIXY321 in all cycles. FAC dose intensity was roughly 2% higher in the PIXY321 group (P = NS). Nonhematologic events of any intensity occurring with significantly greater overall frequency in the PIXY321 group included injection-site reactions, fever, chills, abdominal pain, and arthralgia. No patient died on study or within 30 days of her last dose of study drug.

CONCLUSION

PIXY321 decreased the incidence and duration of FAC-induced grade 3 and 4 neutropenia in cycles 1 and 2 and significantly shortened the time to hematologic recovery in all cycles. However, it produced more systemic toxicity as well as thrombocytopenia in cycles 3 and 4.

Reduction in plate strain by addition of an intramedullary pin

OBJECTIVE

The purpose of this study was to determine the strain sparing effect of a bone plate and rod system compared with a bone plate alone.

STUDY DESIGN

Mathematical analysis and in vitro modeling of implant-bone constructs. Implants were instrumented with uniaxial strain gauges. ANIMALS OR SAMPLE PREPARATION: Five pairs of canine femurs.

METHODS

Bone plates were instrumented with two 350-ohm strain gauges. The bone plates were used to bridge a simulated fracture gap in five pairs of canine femurs. In one femur of each pair, a bone plate alone was used to bridge the gap; in the opposite femur, a bone plate and intramedullary rod combination was used. Each specimen was mounted on a custom jig and loaded in an axial servohydraulic testing machine. A constantly increasing compressive load was applied at the rate of 0.7 cm/sec. Strains at 400.5 N were recorded and analyzed using Wilcoxon's signed rank test. Mathematical modeling was done using parallel beam theory.

RESULTS

Stress reduction in the plate and rod system was twofold compared with the plate alone (P = .059). As important, based on stress reduction in the plate, the fatigue life of the plate/rod system increased 10-fold over the plate system alone and was greater than 10-fold at higher absolute stress values. Mathematical analysis of the plate/rod system was similar to that seen with the in vitro analysis.

CONCLUSIONS

The combination of a bone plate and intramedullary pin was superior in reducing plate stress when compared with the plate alone and functioned as two beams acting in concert.

CLINICAL RELEVANCE

Stabilization of comminuted fractures by bridging the zone of fragmentation with a bone plate without anatomic reduction of each fragment is a useful method of managing this type of injury. Addition of an intramedullary pin reduces the stress applied to the plate and thereby extends the fatigue life of the bone plate.

Efficacy and tolerability of oral ondansetron versus prochlorperazine in the prevention of emesis associated with cyclophosphamide-based chemotherapy and maintenance of health-related quality of life

This study compared the efficacy and tolerability of oral ondansetron (8 mg twice daily [BID] for up to 3 days) with those of phenothiazine prochlorperazine (10 mg BID for up to 3 days) in 133 cancer patients receiving cyclophosphamide-based chemotherapy. In addition, the study evaluated the impact of these treatments on patients' health-related quality of life, measured with both the Functional Living Index-Cancer and the Functional Living Index-Emesis questionnaires. The first dose of study drug was administered 30 minutes before initiation of chemotherapy. Patients received a rescue antiemetic at their request or if the investigator deemed it necessary. There was a statistically significant difference in the number of patients with no emetic episodes over the 3-day study period: 60% in the ondansetron group compared with 21% in the prochlorperazine group. Twenty-five percent of ondansetron-treated patients compared with 68% of prochlorperazine-treated patients experienced three or more emetic episodes, rescue medication use, or withdrawal from the study due to emesis or adverse events. Among patients with at least one emetic episode, the mean time to emesis was significantly longer (13 hours and 37 minutes) in the ondansetron group compared with the prochlorperazine group (9 hours and 30 minutes). Nausea and appetite scores did not differ significantly between groups. The score on the vomiting subscale of the Functional Living Index-Emesis was significantly more favorable in the ondansetron group compared with the prochlorperazine group, indicating better maintenance of health-related quality of life in ondansetron-treated patients. Both treatments were well tolerated. The most common potentially drug-related adverse event was headache, which occurred in significantly more (16%) ondansetron-treated patients compared with prochlorperazine-treated patients (3%). The results of this study demonstrate that oral ondansetron 8 mg BID for up to 3 days is more effective than prochlorperazine 10 mg BID for up to 3 days in the prevention of emesis associated with moderately emetogenic chemotherapy.

Efficacy and tolerability of oral ondansetron versus prochlorperazine in the prevention of emesis associated with cyclophosphamide-based chemotherapy and maintenance of health-related quality of life

This study compared the efficacy and tolerability of oral ondansetron (8 mg twice daily [BID] for up to 3 days) with those of phenothiazine prochlorperazine (10 mg BID for up to 3 days) in 133 cancer patients receiving cyclophosphamide-based chemotherapy. In addition, the study evaluated the impact of these treatments on patients' health-related quality of life, measured with both the Functional Living Index--Cancer and the Functional Living Index--Emesis questionnaires. The first dose of study drug was administered 30 minutes before initiation of chemotherapy. Patients received a rescue antiemetic at their request or if the investigator deemed it necessary. There was a statistically significant difference in the number of patients with no emetic episodes over the 3-day study period: 60% in the ondansetron group compared with 21% in the prochlorperazine group. Twenty-five percent of ondansetron-treated patients compared with 68% of prochlorperazine-treated patients experienced three or more emetic episodes, rescue medication use, or withdrawal from the study due to adverse events or lack of efficacy of the study drug. Among patients with at least one emetic episode, the mean time to emesis was significantly longer (13 hours and 37 minutes) in the ondansetron group compared with the prochlorperazine group (9 hours and 30 minutes). Nausea and appetite scores did not differ significantly between groups. The score on the vomiting subscale of the Functional Living Index--Emesis was significantly more favorable in the ondansetron group compared with the prochlorperazine group, indicating better maintenance of health-related quality of life in ondansetron-treated patients. Both treatments were well tolerated. The most common potentially drug-related adverse event was headache, which occurred in significantly more (16%) ondansetron-treated patients compared with prochlorperazine-treated patients (3%). The results of this study demonstrate that oral ondansetron 8 mg BID for up to 3 days is more effective than prochlorperazine 10 mg BID for up to 3 days in the prevention of emesis associated with moderately emetogenic chemotherapy.

Simulation of human gait with the aid of a simple mechanical model

A simple mechanical model was used in this study to simulate the stance phase of human locomotion. The model consists of a concentrated mass supported by two elastic and viscous straight legs. The model is provided with a set of initial conditions at the instant of "heel strike" and then continues to move due to its inertia and the action of gravity. The simulation results were compared with the corresponding experimental data and have shown agreeable similarity. The model was also used to study the effect of some body features on the resulting walking pattern and to explain the generation of the ground reaction force characteristics.