A Multicenter, Open-Label Phase II Clinical Trial of Combined MEK plus EGFR Inhibition for Chemotherapy-Refractory Advanced Pancreatic Adenocarcinoma.

PURPOSE: On the basis of preclinical evidence of synergistic activity between MEK and EGFR inhibitors in pancreatic ductal adenocarcinoma (PDAC), we evaluated the safety and efficacy of selumetinib, a MEK1/2 inhibitor, plus erlotinib in patients with previously treated advanced PDAC. EXPERIMENTAL DESIGN: In this single-arm phase II trial, eligible patients received the combination of erlotinib 100 mg plus selumetinib 100 mg daily in 3-week cycles. Study assessments included measurement of clinical outcomes, with a primary endpoint of overall survival, and exploration of potential molecular predictors of treatment benefit. RESULTS: Forty-six patients were enrolled and received a median of two cycles (range, 1-7). Although no objective responses were observed, 19 patients (41%) showed evidence of stable disease for ≥6 weeks, and 13 of 34 patients (38%) had a CA19-9 decline ≥50%. Median progression-free survival was 1.9 months [95% confidence interval (CI), 1.4-3.3 months], with a median overall survival of 7.3 months (95% CI, 5.2-8.0 months). Common adverse events included rash, diarrhea, and nausea/vomiting. Patients with tumors exhibiting an epithelial phenotype (demonstrated by a high level of E-cadherin expression) were more likely to be sensitive to study treatment. Tumor-derived DNA was detectable in plasma from the majority of patients using next-generation digital DNA sequencing, and its relative abundance correlated with tumor burden. CONCLUSIONS: A therapeutic strategy of dual targeted inhibition of the MEK and EGFR pathways shows modest antitumor activity in pancreatic cancer. Specific molecular subtypes may derive greatest benefit from this combination. Further exploration, both with more potent MEK inhibitors and in molecularly enriched patient subsets, is warranted.

A phase I trial of nab-paclitaxel, gemcitabine, and capecitabine for metastatic pancreatic cancer.

BACKGROUND: Substantial antitumor activity has previously been demonstrated with the addition of nab-paclitaxel (Abraxane [Celgene, Summit, NJ]), an albumin-bound formulation of paclitaxel, to gemcitabine in patients with advanced pancreatic cancer. Given preclinical evidence of synergy when a fluoropyrimidine is added to gemcitabine plus a taxane in a sequence-specific schedule, we conducted a phase I study to evaluate the combination of nab-paclitaxel, gemcitabine, and capecitabine administered biweekly in patients with metastatic pancreatic adenocarcinoma. MATERIALS AND METHODS: Patients with previously untreated metastatic pancreatic cancer and an ECOG performance status of 0-1 were eligible to participate. Study design utilized a 3 + 3 dose-escalation schema, with expanded cohort at maximum-tolerated dose (MTD). Treatment was administered in 14-day cycles, with capecitabine given on days 1-7 and both gemcitabine (at fixed-dose rate infusion) and nab-paclitaxel on day 4 of each cycle. Dose-limiting toxicity (DLT) definitions included grade 3-4 hematologic toxicities and grade 2-4 hand-foot syndrome, neuropathy, or diarrhea. RESULTS: Fifteen patients were enrolled across two dose levels. Final MTD was established at nab-paclitaxel 100 mg/m(2), gemcitabine 750 mg/m(2), and capecitabine 750 mg/m(2) twice daily. Patients received a median of four treatment cycles (range 1-16). The most frequent adverse events (any grade) for the entire study cohort included fatigue, rash/hand-foot syndrome, nausea/vomiting, diarrhea, neuropathy, and elevated liver function tests. Ten patients (66.7 %) experienced at least one grade 3-4 adverse event. Grade 3-4 hematologic toxicities were uncommon. Two of 14 evaluable patients (14.3 %) exhibited a partial response, and 6 of 12 patients (50 %) with elevated CA19-9 at baseline had a ≥50 % biomarker decline. CONCLUSION: While well tolerated overall, this regimen demonstrated only modest antitumor activity in patients with metastatic pancreatic cancer. Recognizing the limits of cross-study comparisons and small sample size, these results do not match those reported at MTD in the phase I/II trial of gemcitabine/nab-paclitaxel. The lower doses used in the current study suggest that dose intensity may be a critical aspect to optimize multidrug regimens.

Optimizing the administration of fixed-dose rate gemcitabine plus capecitabine using an alternating-week schedule: a dose finding and early efficacy study in advanced pancreatic and biliary carcinomas.

OBJECTIVES: This multisite study sought to optimize the dosing, schedule, and administration of fixed-dose rate (FDR) gemcitabine plus capecitabine for advanced pancreatic and biliary tract cancers using an alternating-week dose schedule of both agents. METHODS: Patients with previously untreated advanced pancreatic and biliary tract cancers with Eastern Cooperative Oncology Group performance status of 0 or 1 were eligible. For the dose-finding portion, a standard 3+3 dose-escalation schema was used, with the gemcitabine dose kept at 1000 mg/m(2) administered by FDR (10 mg/m(2)/min) on day 1 of each 14-day cycle, and capecitabine given on days 1 to 7 at doses ranging from 800 to 1500 mg/m(2) twice daily. Primary study objective was determination of maximum tolerated dose (MTD). The cohort at MTD was expanded for further efficacy assessment. RESULTS: A total of 45 patients (median age 61 y; 93% pancreatic/7% biliary; 84% with metastatic disease) were enrolled. Median number of cycles received was 11.5. The MTD using this dose schedule was FDR gemcitabine 1000 mg/m(2) plus capecitabine 1000 mg/m(2) bid, due to a high incidence of late hand-foot syndrome observed at the next higher dose level. Most common nonhematologic adverse events related to treatment included nausea/vomiting (overall rate, 64%; all grade 1/2) and hand-foot syndrome (overall rate, 60%; grade 3, 22%). The incidence of grade 3/4 hematologic adverse events was 24%. Six of 41 evaluable patients (14.6%) had a partial response; 18 of 31 patients (58%) with elevated baseline CA 19-9 level had ≥50% biomarker decline during treatment. Estimated median time to tumor progression and overall survival were 5.5 and 9.8 months, respectively (5.5 and 10.1 mo in the metastatic pancreatic cancer cohort). CONCLUSIONS: This dosing schedule of FDR gemcitabine plus capecitabine is active in patients with advanced pancreatobiliary cancers. Given its favorable toxicity profile and convenience, this regimen represents an appropriate front-line option for this patient population and may serve as the foundation on which new investigational agents are added in future trial design.

A phase II study of bevacizumab plus erlotinib for gemcitabine-refractory metastatic pancreatic cancer.

PURPOSE: No standard of care exists for patients with metastatic pancreatic cancer following progression on first-line chemotherapy. Based on potential for additive or synergistic activity by concurrent inhibition of VEGF and EGFR, we conducted a phase II study evaluating the combination of bevacizumab plus erlotinib in this patient population. METHODS: Patients with metastatic pancreatic adenocarcinoma, ECOG performance status 0-1, and previous exposure to 1-3 systemic therapies (at least one gemcitabine-based) were eligible. Treatment consisted of bevacizumab 15 mg/kg every 21 days plus erlotinib 150 mg daily. RESULTS: Thirty-six patients were enrolled, including eight who had previously received VEGF-targeted therapy and nine prior erlotinib. Median number of treatment cycles was 2 (range, 1-7). Common toxicities included rash (72%), diarrhea (25%), venous thromboembolic events (15%), and hypertension (11%). One patient demonstrated partial response and seven others stable disease for >2 cycles. CA19-9 decline ≥25% was observed in 4/26 patients with baseline levels >2x ULN. Estimated median time to progression was 40 days (95% CI, 35-41 days) and median survival 102 days (95% CI, 74-117 days), with a 6-month survival rate of 22%. Baseline concentration of circulating endothelial cells (CD45(-)/CD34(+)/CD31(+)) was inversely associated with overall survival. CONCLUSIONS: The combination of bevacizumab and erlotinib is safe but relatively ineffective in patients with gemcitabine-refractory metastatic pancreatic cancer. Future studies should focus on refining subsets of patients in this challenging population likely to benefit from treatment beyond first-line.

A phase II study evaluating bevacizumab in combination with fixed-dose rate gemcitabine and low-dose cisplatin for metastatic pancreatic cancer: is an anti-VEGF strategy still applicable?

BACKGROUND: The role of bevacizumab, a recombinant humanized monoclonal antibody directed against vascular endothelial growth factor, in the treatment of pancreatic cancer remains unclear. The objectives of this study were to determine safety and efficacy in chemotherapy-naive patients with metastatic pancreatic cancer receiving bevacizumab in combination with fixed-dose rate (FDR) gemcitabine and low-dose cisplatin. METHODS: Eligible patients received gemcitabine 1,000 mg/m2 at FDR infusion (10 mg/m(2) per minute), cisplatin 20 mg/m(2), and bevacizumab 10 mg/kg, on days 1 and 15 of a 28-day cycle. Patients were monitored by computed tomography scans every two cycles and monthly serum CA19-9 measurements. RESULTS: Of 52 patients eligible for analysis, ten (19.2%) had an unconfirmed response and 30 (57.7%) had stable disease. Of 35 patients with elevated baseline CA19-9 levels, 20 (57.1%) had > or = 50% biomarker decline during treatment. Median time to tumor progression was 6.6 months and median survival was 8.2 months (estimated 1-year survival, 36%). Grade 3/4 toxicities possibly related to bevacizumab included thromboembolic events (15.1%), hypertension (13.2%), gastrointestinal bleeding (9.4%), cardiac events (7.5%), and bowel perforation (5.7%). Plasma vascular endothelial growth factor and basic fibroblast growth factor levels and circulating tumor cell concentration did not correlate with overall survival, either at baseline or after 2 months of therapy. CONCLUSIONS: This bevacizumab-containing study regimen is modestly effective in patients with metastatic pancreatic cancer, although occasional serious complications may occur. Given the negative results of CALGB 80303, future efforts should be focused on identifying those specific patients who are most likely to benefit from bevacizumab-based therapy.

Excess toxicity associated with docetaxel and irinotecan in patients with metastatic, gemcitabine-refractory pancreatic cancer: results of a phase II study.

BACKGROUND: No therapeutic standard of care exists for patients with advanced pancreatic cancer who progress following first-line treatment with a gemcitabine-based regimen. There is evidence of synergistic activity between docetaxel and irinotecan, and the combination of these two agents has shown promising efficacy in the first-line setting for advanced pancreatic cancer. We, therefore, evaluated this regimen in patients with gemcitabine-refractory disease. METHODS: Eligible patients with metastatic pancreatic adenocarcinoma were required to have an elevated serum CA19-9 (> 2x ULN) and exposure to one or two prior chemotherapy regimens, including one gemcitabine-based. Treatment consisted of docetaxel 65 mg/m2 and irinotecan 160 mg/m2, both administered every 21 days. Serum CA19-9 levels were measured at the start of each treatment cycle and CT scans performed after every two cycles. RESULTS: Fourteen patients were enrolled before the study was closed due to excess toxicity. The most common grade 3/4 toxicities included neutropenia/leukopenia, nausea and vomiting, and diarrhea. Fully half of patients received only 1 treatment cycle, with a median time to treatment failure of 36 days. No objective responses were observed, although 3 patients had stable disease for at least 6 cycles. Overall survival for the entire cohort was 134 days, with a 6-month survival rate of 36%. CONCLUSIONS: The combination of docetaxel and irinotecan given on a 21-day cycle is associated with excess toxicity in gemcitabine-refractory patients with advanced pancreatic cancer. Although select patients may benefit from treatment, the overall risk:benefit ratio is unfavorable, and other dosing regimens and therapeutic options should be explored in this setting.

A phase II study of fixed-dose rate gemcitabine plus low-dose cisplatin followed by consolidative chemoradiation for locally advanced pancreatic cancer.

PURPOSE: The optimal strategy for treating locally advanced pancreatic cancer remains controversial, including the respective roles and timing of chemotherapy and radiation. We conducted a Phase II nonrandomized trial to evaluate sequential chemotherapy followed by chemoradiation in this patient population. METHODS AND MATERIALS: Chemotherapy naive patients with locally advanced pancreatic adenocarcinoma were treated with fixed-dose rate gemcitabine (1,000 mg/m(2) at 10 mg/m(2)/min) plus cisplatin 20 mg/m(2) on Days 1 and 15 of a 28-day cycle. Those without evidence of extrapancreatic metastases after six cycles of chemotherapy received radiation (5,040 cGy over 28 fractions) with concurrent capecitabine (800 mg/m(2) orally twice daily on the day of radiation) as a radiosensitizer. RESULTS: A total of 25 patients were enrolled with a median follow-up time of 656 days. Twelve patients (48%) successfully received all six cycles of chemotherapy plus chemoradiation. Eight patients (32%) progressed during chemotherapy, including 7 with extrapancreatic metastases. Grade 3/4 hematologic toxicities were uncommon. Two patients sustained myocardial infarctions during chemotherapy, and 4 were hospitalized for infectious complications, although none in the setting of neutropenia. Median time to progression was 10.5 months and median survival was 13.5 months, with an estimated 1-year survival rate of 62%. Patients receiving all components of therapy had a median survival of 17.0 months. CONCLUSIONS: A strategy of initial fixed-dose rate gemcitabine-based chemotherapy, followed by chemoradiation, shows promising efficacy for treatment of locally advanced disease. A substantial proportion of patients will be identified early on as having extrapancreatic disease and spared the potential toxicities associated with radiation.

Phase II study of fixed dose rate gemcitabine with cisplatin for metastatic adenocarcinoma of the pancreas.

PURPOSE: Although gemcitabine remains the standard of care for patients with advanced pancreatic cancer, additional improvements may be realized by combining therapeutic agents with synergistic activity, and optimizing drug delivery using pharmacokinetic principles such as fixed dose rate (FDR) infusion. The objectives of this study were to determine safety and efficacy in patients with metastatic pancreatic cancer treated with FDR gemcitabine in combination with low-dose cisplatin. PATIENTS AND METHODS: Chemotherapy-naive patients with metastatic pancreatic adenocarcinoma were treated with a combination of gemcitabine 1,000 mg/m2 at 10 mg/m2/min together with cisplatin 20 mg/m2 on days 1 and 8 of a 21-day cycle. Patient follow-up was performed using computerized tomographic scans and serial CA 19-9 measurements. RESULTS: A total of 51 patients were enrolled onto the study, with a median follow-up time of 215 days. Twenty-two of 40 patients (55.0%) with a baseline serum CA 19-9 level > or = 2x the upper limit of normal demonstrated a > or = 50% biomarker decline during treatment. Nine of 47 patients (19.1%) with measurable disease achieved a partial response, and 28 patients (59.6%) had disease stabilization for at least two treatment cycles. Median time to progression was 3.9 months and median survival was 7.1 months, with an estimated 1-year survival rate of 29%. The most frequently reported grade 3 or 4 adverse events were neutropenia (52.9%) and thrombocytopenia (15.7%). Most patients were switched to an every-other-week dosing schedule. CONCLUSION: The combination of FDR gemcitabine and cisplatin is well tolerated and appears to be an acceptable, albeit not clearly superior, alternative to other gemcitabine/platinum regimens for the treatment of metastatic pancreatic cancer.