Thrombocytosis in patients with pancreatic cancer treated with gemcitabine - does it have clinical significance? Description of 6 cases.

Gemcitabine is a cytostatic drug from the pyrimidine antimetabolite group. It is used in treatment of some neoplasms, among them inoperable pancreatic cancer. The most common undesirable effects of gemcitabine include pancytopenia, with thrombocytopenia associated with gemcitabine's myelosuppressive activity. This study contains a description of six cases of patients with pancreatic cancer treated with gemcitabine, who - contrary to expectations - showed increased levels of thrombocytes. The number of thrombocytes ranged from 424 to 1059 × 109 (mean 470 × 109). It was highest during the 2(nd) and 3(rd) chemotherapy cycles and it normalized after completion of treatment. One patient suffered from a cardiac infarction on the 15(th) day of the 3(rd) cycle of treatment, despite a normal level of thrombocytes on the day; however, the patient indicated thrombocytosis on the 1(st) day of the cycle. No thromboembolic complications were observed in the remaining patients. These patients were not subjected to any antithrombotic prophylaxis. The mechanism by which thrombocytosis occurs after administration of gemcitabine and the clinical significance of this fact remain unknown.

Randomized phase Ib/II trial of rilotumumab or ganitumab with panitumumab versus panitumumab alone in patients with wild-type KRAS metastatic colorectal cancer.

PURPOSE: Panitumumab, a fully human anti-epidermal growth factor receptor monoclonal antibody (mAb), has demonstrated efficacy in patients with wild-type KRAS metastatic colorectal cancer (mCRC). Rilotumumab and ganitumab are investigational, fully human mAbs against hepatocyte growth factor (HGF)/scatter factor and IGF1R, respectively. Here we evaluate combining rilotumumab or ganitumab with panitumumab in previously treated patients with wild-type KRAS mCRC. EXPERIMENTAL DESIGN: Part 1 was a phase Ib dose-finding study of panitumumab plus rilotumumab. The primary endpoint was the incidence of dose-limiting toxicities (DLT). Part 2 was a randomized phase II trial of panitumumab in combination with rilotumumab, ganitumab, or placebo. The primary endpoint was objective response rate (ORR); safety, progression-free survival (PFS), and overall survival (OS) were secondary endpoints. Archival tissue specimens were collected for exploratory correlative work. RESULTS: In part 1, no DLTs were reported. A recommended phase II dose of 10 mg/kg rilotumumab was selected. In part 2, for the panitumumab plus rilotumumab (n = 48), panitumumab plus ganitumab (n = 46), and panitumumab plus placebo arms (n = 48), the ORRs were 31%, 22%, and 21%, respectively. The median PFS was 5.2, 5.3, and 3.7 months and median OS 13.8, 10.6, and 11.6 months, respectively. Adverse events were tolerable. Exploratory biomarker analyses, including MET and IGF-related protein expression, failed to indicate conclusive predictive evidence on efficacy endpoints. CONCLUSIONS: Panitumumab plus rilotumumab met the prespecified criterion for improvement in ORR whereas ganitumab did not. This is the first study to suggest a benefit for combining an HGF inhibitor (rilotumumab) with panitumumab in previously treated patients with wild-type KRAS mCRC.

Axitinib or bevacizumab plus FOLFIRI or modified FOLFOX-6 after failure of first-line therapy for metastatic colorectal cancer: a randomized phase II study.

OBJECTIVE: Axitinib, a potent and selective second-generation inhibitor of vascular endothelial growth factor receptors 1, 2, and 3, shows activity in multiple tumor types, including those refractory to previous antiangiogenic therapy. This randomized, multicenter, parallel-group, open-label phase II trial compared axitinib with bevacizumab each in combination with 5-fluorouracil/leucovorin/oxaliplatin (FOLFOX) or 5-fluorouracil/leucovorin/irinotecan (FOLFIRI) for second-line treatment of metastatic colorectal cancer. METHODS: Patients were randomized 1:1 to axitinib 5 mg twice daily or bevacizumab 5 mg/kg every 2 weeks plus modified FOLFOX-6 (if previously treated with irinotecan) or FOLFIRI (if previously treated with oxaliplatin) and were stratified by performance status and prior bevacizumab therapy. Primary endpoint was progression-free survival. RESULTS: In 171 patients, progression-free survival was 7.6 months with axitinib/FOLFOX vs. 6.4 months with bevacizumab/FOLFOX (hazard ratio [HR], 1.04; 95% confidence interval [CI], 0.55-1.96; 1-sided P = .55) and 5.7 months with axitinib/FOLFIRI vs. 6.9 months with bevacizumab/FOLFIRI (HR, 1.27; 95% CI, 0.77-2.11; 1-sided P = .83). Overall survival was 17.1 vs. 14.1 months with axitinib/FOLFOX and bevacizumab/FOLFOX (HR, 0.69; 95% CI, 0.37-1.27; 1-sided P = .12) and 12.9 vs. 15.7 months with axitinib/FOLFIRI and bevacizumab/FOLFIRI (HR, 1.36; 95% CI, 0.82-2.24; 1-sided P = .88). More grade ≥ 3 adverse events (eg, diarrhea, fatigue, decreased appetite) and treatment discontinuations due to adverse events occurred with axitinib. CONCLUSIONS: Compared with bevacizumab, axitinib did not improve outcomes when added to second-line chemotherapy for metastatic colorectal cancer. With current dosing regimens, axitinib plus FOLFOX or FOLFIRI seems to be less well tolerated than bevacizumab-based regimens.

Fluorouracil, leucovorin, and irinotecan plus either sunitinib or placebo in metastatic colorectal cancer: a randomized, phase III trial.

PURPOSE: This double-blind, phase III study aimed to demonstrate that sunitinib plus FOLFIRI (fluorouracil, leucovorin, and irinotecan) was superior to placebo plus FOLFIRI in previously untreated metastatic colorectal cancer (mCRC). PATIENTS AND METHODS: Patients were randomly assigned to receive FOLFIRI and either sunitinib (37.5 mg per day) or placebo (4 weeks on treatment, followed by 2 weeks off [schedule 4/2]) until disease progression. The primary end point was progression-free survival (PFS). Secondary end points included overall survival, safety, and patient-reported outcomes. The correlation between genotype and clinical outcomes was also analyzed. RESULTS: In all, 768 patients were randomly assigned to sunitinib plus FOLFIRI (n = 386) or placebo plus FOLFIRI (n = 382). Following a second prespecified interim analysis, the study was stopped because of potential futility of sunitinib plus FOLFIRI. Final results are reported. The PFS hazard ratio was 1.095 (95% CI, 0.892 to 1.344; one-sided stratified log-rank P = .807), indicating a lack of superiority for sunitinib plus FOLFIRI. Median PFS for the sunitinib arm was 7.8 months (95% CI, 7.1 to 8.4 months) versus 8.4 months (95% CI, 7.6 to 9.2 months) for the placebo arm. Sunitinib plus FOLFIRI was associated with more grade ≥ 3 adverse events and laboratory abnormalities than placebo (especially diarrhea, stomatitis/oral syndromes, fatigue, hand-foot syndrome, neutropenia, thrombocytopenia, anemia, and febrile neutropenia). More deaths as a result of toxicity (12 v four) and significantly more dose delays, dose reductions, and treatment discontinuations occurred in the sunitinib arm. CONCLUSION: Sunitinib 37.5 mg per day (schedule 4/2) plus FOLFIRI is not superior to FOLFIRI alone and has a poorer safety profile. This combination regimen is not recommended for previously untreated mCRC.