[Chemotherapy for pancreatic cancer]

Chemotherapy is expected to play an important role in the treatment of pancreatic cancer because most of pancreatic cancers are being discovered at locally advanced or metastatic stages and recurrence rate is high even after the curative resection. Gemcitabine is a key agent for the first-line therapy of advanced pancreatic cancer. It can enhance the quality of life and prolong the survival of patients. Combination of erlotinib or capecitabine with gemcitabine showed a marginal survival benefit over single-agent gemcitabine. If patient's performance state is good, gemcitabine-based platinum combination therapy showed overall survival benefit compared with gemcitabine monothrapy. If the first-line palliative chemotherapy fails, 5-FU, capcitabine, or tegafur with or without combination can be used as the second-line agents. Adjuvant chemotherapy using 5-FU or gemcitabine after curative resection has overall survival benefit. However, neoadjuvant chemotherapy has not been proven to be effective in the treatment of pancreatic cancer.

Pooled analysis of diarrhea events in patients with cancer treated with lapatinib

PURPOSE

To characterize diarrhea events in patients with cancer treated with lapatinib as monotherapy or in combination with capecitabine or taxanes.

PATIENTS AND METHODS

Eleven clinical trials (phase I, II, or III) in patients with metastatic cancer were analyzed. Lapatinib was administered at doses ranging from 1,000 to 1,500 mg/day as monotherapy (n = 926) or in combination with capecitabine (n = 198) or taxanes (n = 687). Diarrhea events were characterized based on severity, time to onset, duration, required interventions, and clinical outcomes.

RESULTS

In the pooled analysis of nine studies, diarrhea occurred in 55% of lapatinib-treated patients and 24% of patients not receiving lapatinib. All grade diarrhea occurred in 51% of patients treated with lapatinib monotherapy and 65% treated with lapatinib plus capecitabine. In a separate analysis, 48% of patients treated with lapatinib plus a taxane experienced diarrhea. Overall, most diarrhea events were grade 1/2. Grade 3 events occurred in <10% of patients and grade 4 events were rare (<or=1%). Most diarrhea events resolved with conventional approaches and without dose modification. Approximately 40% of patients treated with lapatinib monotherapy or combination therapy experienced a first diarrhea event within 6 days of treatment initiation, with a median duration of 7-9 days. Lapatinib-containing chemotherapy regimens do not cause severe diarrhea when proactive monitoring and intervention is introduced.

CONCLUSION

Most diarrhea events in lapatinib-treated patients are low grade, requiring infrequent lapatinib dose modification or interruption. Proactive management of diarrhea is crucial to prevent more serious complications in lapatinib-treated patients.

A phase II study of capecitabine plus gemcitabine in patients with locally advanced or metastatic pancreatic cancer

PURPOSE

This open-label, multicenter phase II study was conducted to investigate the efficacy and safety of capecitabine plus gemcitabine combination chemotherapy as first-line treatment in patients with locally advanced or metastatic pancreatic cancer.

PATIENTS AND METHODS

We enrolled 63 patients who received capecitabine 830 mg/m(2) orally twice daily on days 1-21 plus gemcitabine 1000 mg/m(2) as a 30-min infusion on days 1, 8 and 15 every 4 weeks for up to six cycles.

RESULTS

A total of 14 patients had partial responses giving an overall response rate of 22% (95% confidence interval [CI] 13-34%) in the intent-to-treat population. The median time to progression and overall survival were 3.9 months (95% CI 3.5-5.7) and 7.5 months (95% CI 5.0-10.0), respectively, and 1-year survival rate was 27.1% in the intent-to-treat population. Capecitabine plus gemcitabine was well tolerated. Grade 3 hematological adverse events were neutropenia (21%) and thrombocytopenia (2%); the only grade 4 hematological events were anemia (2%) and neutropenia (6%). Non-hematological adverse events were mainly gastrointestinal events and hand-foot syndrome, which affected 16% of patients. Grade 3/4 non-hematological events were infrequent.

CONCLUSION

The combination of capecitabine plus gemcitabine appears to be active and well tolerated as first-line treatment in patients with advanced/metastatic pancreatic cancer.

Capecitabine and oxaliplatin for advanced esophagogastric cancer

BACKGROUND

We evaluated capecitabine (an oral fluoropyrimidine) and oxaliplatin (a platinum compound) as alternatives to infused fluorouracil and cisplatin, respectively, for untreated advanced esophagogastric cancer.

METHODS

In a two-by-two design, we randomly assigned 1002 patients to receive triplet therapy with epirubicin and cisplatin plus either fluorouracil (ECF) or capecitabine (ECX) or triplet therapy with epirubicin and oxaliplatin plus either fluorouracil (EOF) or capecitabine (EOX). The primary end point was noninferiority in overall survival for the triplet therapies containing capecitabine as compared with fluorouracil and for those containing oxaliplatin as compared with cisplatin.

RESULTS

For the capecitabine-fluorouracil comparison, the hazard ratio for death in the capecitabine group was 0.86 (95% confidence interval [CI], 0.80 to 0.99); for the oxaliplatin-cisplatin comparison, the hazard ratio for the oxaliplatin group was 0.92 (95% CI, 0.80 to 1.10). The upper limit of the confidence intervals for both hazard ratios excluded the predefined noninferiority margin of 1.23. Median survival times in the ECF, ECX, EOF, and EOX groups were 9.9 months, 9.9 months, 9.3 months, and 11.2 months, respectively; survival rates at 1 year were 37.7%, 40.8%, 40.4%, and 46.8%, respectively. In the secondary analysis, overall survival was longer with EOX than with ECF, with a hazard ratio for death of 0.80 in the EOX group (95% CI, 0.66 to 0.97; P=0.02). Progression-free survival and response rates did not differ significantly among the regimens. Toxic effects of capecitabine and fluorouracil were similar. As compared with cisplatin, oxaliplatin was associated with lower incidences of grade 3 or 4 neutropenia, alopecia, renal toxicity, and thromboembolism but with slightly higher incidences of grade 3 or 4 diarrhea and neuropathy.

CONCLUSIONS

Capecitabine and oxaliplatin are as effective as fluorouracil and cisplatin, respectively, in patients with previously untreated esophagogastric cancer. (Current Controlled Trials number, ISRCTN51678883 [controlled-trials.com].).

Capecitabine as salvage treatment in relapsed nasopharyngeal carcinoma: a phase II study

PURPOSE

To evaluate the efficacy of capecitabine (Xeloda) as rescue treatment (2nd, 3rd and 4th line) in patients with relapsed nasopharyngeal carcinoma (NPC) in a phase II study.

PATIENTS AND METHODS

Between 5/2002-11/2005, 23 relapsed NPC patients (17 locoregional relapse, 3 metastatic, 3 locoregional + metastatic) received capecitabine 2500 mg/m(2)/d, days 1-14 every 3 weeks, until progression or for a maximum of 6 cycles.

PATIENT CHARACTERISTICS

23 patients (14 men, 9 women) with median age 46 years (range 15-59); ECOG performance status 1 n=21, 2 n=2; histology: undifferentiated carcinoma (WHO type III) n=21, non-keratinizing epidermoid carcinoma (WHO type II), n=2. Capecitabine was given as 2nd--(13 patients), 3rd--(7 patients), and 4th--(3 patients) line chemotherapy. Previous chemotherapy regimes were epirubicin + cisplatin, paclitaxel + carboplatin, paclitaxel + 5-fluorouracil and leucovorin (5-FU/LV) or methotrexate. 104 cycles were given (median 5, range 2-6). Two (9%) patients achieved complete response (CR); 9 (39%) partial response (PR); 9 (39%) stable disease (SD) and 3 (13%) progressed (PD). Toxicity was mild without toxic deaths or grade 4 toxicities. The most frequent toxicities (grades 1-3) were anemia (38%), hand-foot syndrome (23%), leukopenia (13%) and diarrhea (7%). Median follow-up was 10 months (range 2-44). Median overall survival was not reached at 18 months and actuarial one-year survival was 62% (95% confidence interval/CI: 41-80). Median progression-free survival was 14 months.

CONCLUSION

Capecitabine is active in relapsed NPC patients, achieving 48% objective responses, with mild toxicity. It is an attractive therapy to be administered in an outpatient setting.

Chemotherapy side-effect management using mobile phones

Colorectal cancer is a major health problem in developed countries, accounting for a significant proportion of deaths in the population. Advances in chemotherapy treatment have led to therapy being delivered in the home-setting, which presents challenges in ensuring that treatment-related side-effects are detected and reported to clinical staff in an appropriate time-frame. A telemedicine system has been developed using a mobile-phone platform to allow patients to complete symptom diaries which trigger alerts paged to their nurse in the event of severe side-effects. Six patients used this system for two cycles of oral chemotherapy. Two cases of moderate symptoms deteriorating to more severe conditions were observed, and individual self-care and treatment advice were presented to these patients.

[Possibilities of resistance prediction to neoadjuvant concomitant chemoradiotherapy in the treatment algorithm of patients with rectal carcinoma]

BACKGROUNDS

Neoadjuvant concomitant chemoradiotherapy has become a standard treatment of locally advanced rectal adenocarcinomas (LARA). It leads to shrinkage of the tumor mass and subsequently to an increase in complete resections (R0 resections), increasing a feasibility of sphincter-sparing intervention avoiding colostomy. It is based on concurrent application of fluoropyrimidines (5-fluorouracil, capecitabine) and radiotherapy (45 - 50,4 Gy). It shows less acute toxicity and improves local control rate in comparison to adjuvant treatment. Unfortunately, neoadjuvant chemoradiotherapy is not beneficial for all patients. The treatment response ranges from a complete pathological remission (pCR, ypT0ypN0) to a resistance. It is reported that cca 15 percent of patients with advanced rectal cancer show pCR which is indicative of improved long-term prognosis.

DESIGN

The following is a review of the significance of neoadjuvant concomitant chemoradiotherapy in the treatment algorithm of patients with LARA and summary of potentional clinical-pathological and molecular markers of response prediction to neoadjuvant therapy. The most important clinical studies concern serum tumor markers levels, clinical lymph node classification. The components of the carcinogenic pathways are explored, including oncogenes, tumor supressor genes, microsatellite instability (MSI) and potentional markers involved in apoptosis, angiogionesis, proliferation as well as metastasis and invasion, are reviewed. Finally, the role of specific enzymes associated with the metabolism of fluoropyrimidines are examined.

CONCLUSIONS

No one marker has been consistently identified as clinically applicable. Studies designed to determine the potentional markers are hampered by various techniques as well as tumor heterogenity and recent scientific approach--studying individual molecular markers. Gene expression profiling analysis of multiple genes from the same tumor is becoming reality. We suppose that this assessment will lead in future in finding combination of markers for predicting prognosis and response to therapy in rectal cancer.

Capecitabine and docetaxel combination for the treatment of breast cancer

The management of breast cancer depends on the tumor and patient's characteristics. Anthracycline-based regimens have been proven to decrease the risk of relapse and prolong survival time in breast cancer. Taxanes have been incorporated not only into metastatic breast cancer but also into adjuvant regimens. Capecitabine, an oral fluoropyrimidine carbamate, has good single-agent activity and, together with docetaxel, demonstrated preclinical synergy and a survival benefit in metastatic breast cancer. Recent analyses show that capecitabine/docetaxel dosing flexibility for managing side effects does not compromise efficacy, and define this combination regimen as an important treatment option for its efficacy, tolerability and cost-effectiveness.

Integrating microarray and proteomics data to predict the response on cetuximab in patients with rectal cancer

To investigate the combination of cetuximab, capecitabine and radiotherapy in the preoperative treatment of patients with rectal cancer, fourty tumour samples were gathered before treatment (T0), after one dose of cetuximab but before radiotherapy with capecitabine (T1) and at moment of surgery (T2). The tumour and plasma samples were subjected at all timepoints to Affymetrix microarray and Luminex proteomics analysis, respectively. At surgery, the Rectal Cancer Regression Grade (RCRG) was registered. We used a kernel-based method with Least Squares Support Vector Machines to predict RCRG based on the integration of microarray and proteomics data on To and T1. We demonstrated that combining multiple data sources improves the predictive power. The best model was based on 5 genes and 10 proteins at T0 and T1 and could predict the RCRG with an accuracy of 91.7%, sensitivity of 96.2% and specificity of 80%.

Neoadjuvant chemotherapy and radiation for patients with locally unresectable pancreatic adenocarcinoma: feasibility, efficacy, and survival

BACKGROUND

We evaluated the feasibility and efficacy of neoadjuvant chemotherapy and radiation for patients with locally unresectable pancreatic cancer.

MATERIALS AND METHODS

From October 2000 to August 2006, 245 patients with pancreatic adenocarcinoma underwent surgical exploration at our institution. Of these, 78 patients (32%) had undergone neoadjuvant therapy for initially unresectable disease, whereas the remaining patients (serving as the control group) were explored at presentation (n=167). All neoadjuvant patients received gemcitabine-based chemotherapy, often in conjunction with docetaxal and capecitabine in a regimen called GTX (81%). Seventy-five percent of neoadjuvant patients also received preoperative abdominal radiation (5,040 rad).

RESULTS

Neoadjuvant patients were younger than control-group patients (60.8 vs 66.2 years, respectively, p<0.002). Seventy-six percent of neoadjuvant patients were resected as compared to 83% of control patients (NS). Concomitant vascular resection was required in 76% of neoadjuvant patients but only 20% of NS (p<0.01). Complications were more frequent in the neoadjuvant group (44.1 vs 30.9%, p<0.05), and mortality was higher (10.2 vs 2.9%, p<0.03). Among the neoadjuvant patients, all but one of the deaths were in patients that underwent arterial reconstruction. Mortality for patients undergoing a standard pancreatectomy without vascular resection was 0.8% in this series. Of patients resected, negative margins were achieved in 84.7% of neoadjuvant patients and 72.7% of NS. Within the cohort of neoadjuvant patients, radiation significantly increased the complication rate (13.3 vs 54.6%, p<0.006), but did not affect median survival (512 vs 729 days, NS). Median survival for patients who received neoadjuvant therapy (503 days) was longer than NS that were found to be unresectable at surgery (192 days, p<0.001) and equivalent to NS that were resected (498 days).

CONCLUSIONS

Resection rate, margin status, and median survivals were equivalent when neoadjuvant patients were compared to patients considered resectable by traditional criteria, demonstrating equal efficacy. Surgical resection with venous reconstruction following neoadjuvant therapy for patients with locally advanced pancreatic cancer can be performed with acceptable morbidity and mortality. This approach extended the boundaries of surgical resection and greatly increased median survival for the "inoperable" patient with advanced pancreatic cancer.

Xelox (capecitabine plus oxaliplatin) as neoadjuvant chemotherapy of unresectable liver metastases in colorectal cancer patients

Complete resection of liver metastasis may provide long term survival in patients with colorectal cancer. Increased number of studies on successful resection after neoadjuvant chemotherapy with initially unresectable liver metastasis has been reported. We evaluated retrospectively the results of 35 patients with unresectable liver only metastases from colorectal cancer treated with capecitabine plus oxaliplatin combination (XELOX). Treatment consisted of IV oxaliplatin 130 mg/m2 day 1 and oral capecitabine 1000 mg/m2 day twice daily on days 1 to 14 followed by 7 days of rest repeated every 3 weeks. After chemotherapy, 13 (37, 2 %) patients showed partial clinical response. Among them, 7 patients were considered suitable for surgery but 2 patients refused the surgery. While one of 5 patients had unresectable disease at surgery, the remaining 4 patients (11, 4 %) had a complete resection. There was one postoperative mortality due to sepsis within 2 months after surgery. Our data suggests that XELOX regimen seems to be useful in unresectable liver only metastases from colorectal cancer because of its activity, feasibility and tolerability. Further studies of XELOX in combination with bevacizumab and/ or cetuximab are warranted in this setting.

Low-dose capecitabine in breast cancer patients with symptomatic bone marrow infiltration: a case study

BACKGROUND

The prognosis of patients with metastatic breast cancer and symptomatic bone marrow involvement is poor. The aim of treatment to these patients is palliation. In this study, we sought to determine the efficacy of therapy with low doses of capecitabine in this subgroup of patients.

PATIENTS AND METHODS

Five consecutive breast cancer patients with overt bone marrow involvement were treated by low doses of capecitabine in our department. Four out of five patients also received bisphosphonates to palliate skeletal symptoms. The influence of this therapeutic regimen on tumor response, blood count normalization and overall survival was analysed.

RESULTS

All patients except one responded in terms of their haematological profile within two months of the initiation of treatment. Duration of haematological response was 8+ months for all patients. In two of them, tumor response in other sites was evaluated as stable disease, in one as partial remission and in one as progressive disease. Two patients survived more than 22 months without bone marrow failure.

CONCLUSION

These initial results are very encouraging for this subset of patients with poor prognosis and limited life expectancy. The administration of capecitabine might be an efficient alternative treatment option. Our results merit further investigation.

Interferon-alpha plus capecitabine and thalidomide in patients with metastatic renal cell cancer

Thirty patients with progressive metastatic renal cell carcinoma were treated. Eleven patients received 2 or more prior systemic therapies; 2 had a complete response, 7 had a partial response, and 11 had stable disease. The complete responders are off therapy and remain without disease recurrence. The median duration of response was 3.8 months (range 1 - 48+ months). Therapy was well tolerated; predominant toxicities were fatigue, paraesthesias and hand/foot syndrome. The data suggest that the combination of interferon-alpha, thalidomide and capecitabine has anti-tumor activity in previously treated patients with progressive metastatic renal cell carcinoma. A prospective investigation of this combination warranted.

Impact of celecoxib on capecitabine tolerability and activity in pretreated metastatic breast cancer: results of a phase II study with biomarker evaluation

BACKGROUND

Preclinical evidence suggests that the cyclo-oxygenase-2 (COX-2) enzyme plays an important role in breast cancer progression. The aim of the present phase II study was to determine the activity and safety of the combination of the COX-2 inhibitor celecoxib with capecitabine in metastatic breast cancer (MBC) patients pretreated with anthracyclines and/or taxanes.

METHODS

Eligible patients received capecitabine 1,000 mg/m(2) twice daily on days 1-14 every 21 days and celecoxib 200 mg twice daily, continuously, until disease progression or unacceptable toxicity.

RESULTS

About 42 pretreated MBC patients were enrolled into the study. Median number of previous chemotherapy lines for metastatic disease was 2 (0-3). Seven patients (19%) responded to treatment while disease stabilization occurred in 17 patients (40.5%). Overall, 20 patients (47.5%) achieved clinical benefit [objective responses (CR) plus stable disease (SD) >/=6 months]. Median time to progression (TTP) and median overall survival (OS) were 5.2 and 17.8 months, respectively. Treatment was very well tolerated: grade 3 toxicities were observed in only five patients, respectively, and no grade 4 adverse events were reported. Celecoxib was never discontinued for toxicity. Analysis of COX-2 expression in the 22 patients with available tissue revealed a significantly longer TTP and OS for patients whose tumors over-expressed COX-2.

CONCLUSIONS

The combination of capecitabine and celecoxib is active and safe in far advanced MBC patients. Interestingly, this association resulted in a lower-than-expected toxicity, as compared to single-agent capecitabine. The clinical relevance of COX-2 as determinant of sensitivity to treatment with celecoxib should be further evaluated in larger series of patients.

Histopathologic evidence of capecitabine corneal toxicity in dogs

In an experimental model of transplant rejection, renal transplants were performed on 6 mixed-breed dogs. Capecitabine (CPC) was administered as an oral immunosuppressive agent. All recipients received systemic CPC, cyclosporine (CSA), prednisolone, and famotidine throughout the study. Two dogs developed superficial keratitis, which was characterized by multifocal geographic erosions, superficial corneal epithelial pigmentation, and corneal neovascularization. These clinical signs correlated with the dose of CPC given, whereas other drug doses remained unchanged. After euthanasia, routine histologic sections were stained with hematoxylin and eosin and with alcian blue periodic acid-Schiff for light microscopic evaluation. Ocular histopathologic abnormalities were limited to neovascularization and inflammatory infiltrate of the anterior corneal stroma and abnormal basal cell morphology, disorganization, thinning, and pigmentation of the corneal epithelium. The purpose of this communication is to describe the clinical and histopathologic evidence of CPC corneal toxicity in dogs.

Capecitabine for treatment of advanced hepatocellular carcinoma

BACKGROUND/AIMS

Patients with advanced hepatocellular carcinoma (HCC) face a dismal prognosis, as no effective palliative chemotherapy exists. Moreover, treatment of patients with hepatocellular carcinoma presents a major challenge, because associated cirrhosis limits the choice of chemotherapeutic agents. We evaluated the activity and toxicity of capecitabine in patients with advanced hepatocellular carcinomas.

METHODOLOGY

The authors performed a retrospective analysis of all patients with HCC who were treated with capecitabine. The medical records of patients with HCC who were treated at our institution between October 2002 and July 2005 were reviewed.

RESULTS

A total of eleven patients were treated with capecitabine. Eight patients had liver cirrhosis and Child-Pugh scores of A and B. Capecitabine was administered twice daily for 14 days at a total daily dose of 2000 mg/m2. Treatment was repeated every 21 days. Each patient received 2-16 treatment cycles. One partial response was observed (9%; 95% confidence interval (CI) 0.2-41.3%) and 3-month progression free survival rate was 27%. The median time to tumor progression and median overall survival were 2.2 months (95% CI 1.7-2.7 months) and 10.1 months (95% CI 3.0-17.2 months), respectively. The therapy was well tolerated, with hand-foot syndrome as the main toxicity. Grade 3 diarrhea occurred in one patient. Grade 3/4 hyperbilirubinemia was seen in five patients, but was mainly due to tumor progression. No other significant toxicities were observed.

CONCLUSIONS

Capecitabine was found to be safe for treatment of patients with HCC, including those with compensated cirrhosis. However, the objective response rate was limited.

Treatment of advanced colorectal cancer in the elderly

The recent improved survival in advanced colorectal cancer, owing in a large part to advances in adjuvant treatment, has mainly been reported in studies of younger patient groups. Less is known about outcome in elderly patients, the fastest growing cohort of cancer patients. The antimetabolite capecitabine used sequentially or concomitantly with the topoisomerase 1 inhibitor irinotecan or the DNA cross linking agent oxaliplatin are now considered to be the standard first line chemotherapy regime. The role of surgery in advanced colorectal cancer in the elderly is restricted to the relief of bowel obstruction and where appropriate resection of hepatic metastasis. Advanced chronological age has not been shown to be a contraindication to the consideration of these interventions. Indeed, chronological age alone does not provide sufficient guidance when considering the appropriateness of any palliative treatment regime in the elderly.

Docetaxel, capecitabine and carboplatin in metastatic esophagogastric cancer: a phase II study

PURPOSE

A Phase I investigation of docetaxel, carboplatin, and capecitabine at our institution demonstrated the safety and tolerability of this regimen in patients with metastatic esophagogastric cancer. The objectives of this Phase II study were to determine the response rate, toxicity, and survival for patients with metastatic esophagogastric cancer treated with this regimen.

MATERIALS AND METHODS

Chemotherapy naïve patients with metastatic esophageal or gastric cancer received a regimen comprised of docetaxel 40 mg/m(2), days 1 and 8, carboplatin AUC = 2, Days 1 and 8, and capecitabine 2000 mg/m(2), Days 1-10 in 21-Day cycles. Patients were treated until disease progression or unacceptable toxicity.

RESULTS

Twenty-five patients were treated with a median of 4 cycles of chemotherapy. Twelve of 25 patients (48 percent) had a Grade 3/4 toxicity. There were no Grade 4 nonhematologic toxicities, and 1 patient (4 percent) had neutropenic fever. There were 3 complete responses, and 9 partial responses, for an overall response rate of 48 percent. The median survival was 8 months (95% confidence interval, 5.5-13 months), and the 1-year survival was 36 percent.

CONCLUSIONS

Weekly docetaxel and carboplatin with capecitabine was an easily administered outpatient regimen. The response rate and 1-year survival were similar to more complex regimens. Future trials may investigate the substitution of carboplatin with more active agents.

Long-term survival on capecitabine in two gemcitabine refractory pancreatic cancer patients. Is there a pharmacogenetic explanation?

CONTEXT

Capecitabine has shown efficacy in treatment of metastatic pancreatic cancer. Several researchers have identified thymidine phosphorylase, dihydropyrimidine dehydrogenase, or their ratio as indicators of response to capecitabine in various cancers.

CASE REPORT

We report two patients with metastatic pancreatic carcinoma who had long-term survivals on capecitabine after gemcitabine failure. These two cases prompted us to measure thymidine phosphorylase and dihydropyrimidine dehydrogenase levels to facilitate discourses regarding their relationship with efficacy of capecitabine. We also describe a novel method of measuring thymidine phosphorylase level from serum without an invasive tissue biopsy. One patient is alive as of today, with improved performance status, 50 months after capecitabine was started. CA 19-9 and CT scans remained stable during 57 cycles. Her thymidine phosphorylase level was 1.77 compared to a control level of 1.00. Dihydropyrimidine dehydrogenase level was 4.14 compared to a control level of 1.00. Their ratio was 0.43. The other patient was alive on capecitabine for 24 months. His performance status, bilirubin, AST, and ALT improved on capecitabine. CT scans and CA 19-9 remained stable during this period. He had thymidine phosphorylase level of 5.56, dihydropyrimidine dehydrogenase level of 2.74, and their ratio of 2.03.

CONCLUSION

Capecitabine resulted in long term survivals in two patients with metastatic pancreatic cancer after gemcitabine failure. The use of capecitabine as second-line treatment in metastatic pancreatic cancer should be further explored along with the role of thymidine phosphorylase and dihydropyrimidine dehydrogenase levels in its activity. A non-invasive method of thymidine phosphorylase measurement we described should be validated in larger trials.

Development and validation of a drug activity biomarker that shows target inhibition in cancer patients receiving enzastaurin, a novel protein kinase C-beta inhibitor

PURPOSE

To evaluate the effects of the novel protein kinase C (PKC) inhibitor enzastaurin on intracellular phosphoprotein signaling using flow cytometry and to use this approach to measure enzastaurin effects on surrogate target cells taken from cancer patients that were orally dosed with this agent.

EXPERIMENTAL DESIGN

The activity of PKC was assayed in intact cells using a modification of published techniques. The U937 cell line and peripheral blood mononuclear cells were stimulated with phorbol ester, fixed, permeabilized, and reacted with an antibody specific for the phosphorylated forms of PKC substrates. The processed samples were quantitatively analyzed using flow cytometry. The assay was validated for selectivity, sensitivity, and reproducibility. Finally, blood was obtained from volunteer cancer patients before and after receiving once daily oral doses of enzastaurin. These samples were stimulated ex vivo with phorbol ester and were assayed for PKC activity using this approach.

RESULTS

Assay of U937 cells confirmed the selectivity of the antibody reagent and enzastaurin for PKC. Multiparametric analysis of peripheral blood mononuclear cells showed monocytes to be the preferred surrogate target cell. Day-to-day PKC activity in normal donors was reproducible. Initial results showed that five of six cancer patients had decreased PKC activity following enzastaurin administration. In a following study, a group of nine patients displayed a significant decrease in PKC activity after receiving once daily oral doses of enzastaurin.

CONCLUSION

An inhibition of surrogate target cell PKC activity was observed both in vitro and ex vivo after exposure to the novel kinase inhibitor, enzastaurin.