Plasma Cetuximab Concentrations Correlate With Survival in Patients With Advanced KRAS Wild Type Colorectal Cancer.

BACKGROUND: Cetuximab is a standard of care therapy for patients with RAS wild-type (WT) advanced colorectal cancer. Limited data suggest a wide variation in cetuximab plasma concentrations after standard dosing regimens. We correlated cetuximab plasma concentrations with survival and toxicity. METHODS: The CO. 20 study randomized patients with RAS WT advanced colorectal cancer in a 1:1 ratio to cetuximab 400 mg/m2 intravenously followed by weekly maintenance of 250 mg/m2, plus brivanib 800 mg orally daily or placebo. Blood samples obtained at week 5 precetuximab treatment were analyzed by ELISA. Patients were grouped into tertiles based on plasma cetuximab concentrations. Cetuximab concentration tertiles were correlated with survival outcomes and toxicity. Patient demographic and biochemical parameters were evaluated as co-variables. RESULTS: Week 5 plasma cetuximab concentrations were available for 591 patients (78.8%). The median overall survival (OS) was 11.4 months and 7.8 months for patients in the highest (T3) and lowest tertiles (T1) respectively. On multivariable analysis, plasma cetuximab concentration was associated with OS (HR 0.66, 95% confidence interval [CI]: 0.53-0.83, P < .001, T3 vs. T1), and a trend towards progression-free survival (HR 0.82, 95% CI: 0.66-1.02, P = .07, T3 vs. T1). There was no association between cetuximab concentration and skin toxicity or diarrhea. CONCLUSION: The standard cetuximab dosing regimen may not be optimal for all patients. Further pharmacokinetic studies are needed to optimize cetuximab dosing given the potential improvement in OS.

Efficacy and safety of maintenance therapy with pamiparib versus placebo for advanced gastric cancer responding to first-line platinum-based chemotherapy: Phase 2 study results.

BACKGROUND: Poly (ADP-ribose) polymerase (PARP) inhibitors (PARPi) are approved for the treatment of various solid tumors. In gastric cancer, genes commonly harbor mutations in the homologous recombination DNA repair pathway, potentially increasing sensitivity to PARPi. Pamiparib (BGB-290) is a small molecule inhibitor of PARP1 and PARP2. METHODS: The PARALLEL-303 study (NCT03427814) investigated the efficacy and safety of pamiparib 60 mg orally (PO) twice daily (BID) versus placebo PO BID as maintenance therapy in patients with inoperable locally advanced or metastatic gastric cancer that responded to platinum-based first-line chemotherapy. The primary endpoint of this double-blind, randomized, global phase 2 study was progression-free survival (PFS) (RECIST version 1.1; per investigator assessment). Secondary endpoints included overall survival (OS) and safety. RESULTS: In total, 136 patients were randomized 1:1 to receive pamiparib (n = 71) or placebo (n = 65). Median PFS was numerically longer with pamiparib versus placebo but did not reach statistical significance (3.7 months [95% confidence interval (CI): 1.9, 5.3] vs. 2.1 months [95% CI: 1.9, 3.8]; hazard ratio 0.8 [95% CI: 0.5, 1.2]; p = 0.1428). Median OS was 10.2 months (95% CI: 8.7, 16.3) in the pamiparib arm versus 12.0 months (95% CI: 8.2, not estimable) in the placebo arm. Overall, 8 patients (11.3%) in the pamiparib arm and 2 patients (3.1%) in the placebo arm experienced ≥1 TEAE leading to treatment discontinuation. CONCLUSIONS: Maintenance pamiparib did not meet statistical significance for superiority versus placebo for PFS, but was well tolerated with few treatment discontinuations; no unexpected safety signals were identified.

KRAS G12D Mutation Subtype in Pancreatic Ductal Adenocarcinoma: Does It Influence Prognosis or Stage of Disease at Presentation?

Background: KRAS G12D mutation subtype is present in over 40% of pancreatic ductal adenocarcinoma (PDAC), one of the leading global causes of cancer death. This retrospective cohort study aims to investigate whether detection of the KRAS G12D mutation subtype in PDAC patients is a determinant of prognosis across all stages of disease. Methods: We reviewed the medical records of 231 patients presenting with PDAC at a large tertiary hospital, and compared survival using the Kaplan Meier, log-rank test and Cox proportional hazards regression model. Results: KRAS G12D mutation subtype was not significantly associated with poorer survival compared across the whole population of PDAC patients (p = 0.107; HR 1.293 95% CI (0.946-1.767)). However, KRAS G12D patients who were resectable had a shorter median survival time of 356 days compared to all other genotypes (median survival 810 days) (p = 0.019; HR 1.991 95% CI (1.121-3.537)). Conclusions: KRAS G12D patients who were resectable at diagnosis had shorter survival compared to all other PDAC patients. These data suggest that KRAS G12D may be a clinically useful prognostic biomarker of PDAC.

Pituitary function following peptide receptor radionuclide therapy for neuroendocrine tumours.

Peptide receptor radionuclide therapy (PRRT) is an increasingly used treatment for unresectable neuroendocrine tumours (NETs) that express somatostatin receptors. Normal pituitary tissue expresses somatostatin receptors so patients receiving PRRT may be at risk of developing hypopituitarism. The aim was to assess the prevalence of clinically significant hypopituitarism a minimum of 2 years following radioisotope therapy for metastatic NET. This was a multicentre study (Australia and New Zealand). Sixty-six patients with unresectable NETs were included-34 had received PRRT and 32 comparison patients. Median follow-up after PRRT was 68 months. Male hypogonadism was the most common hormonal abnormality (16 of 38 men [42%]) from the total cohort. Of these, seven men had primary hypogonadism (five from PRRT group) and nine had secondary hypogonadism (six in PRRT group). There was no difference in either male hypogonadism or other hormonal dysfunction between patients who had received PRRT and those that had not. Patients who have received PRRT out to 68 months following treatment do not show concerning hypopituitarism although there may be the suggestion of growth hormone deficiency developing. However, hypogonadism is common in men with NETs so the gonadal axis should be assessed in men with suggestive symptoms as the treatment of testosterone deficiency may improve the quality of life.

SIRFLOX: Randomized Phase III Trial Comparing First-Line mFOLFOX6 (Plus or Minus Bevacizumab) Versus mFOLFOX6 (Plus or Minus Bevacizumab) Plus Selective Internal Radiation Therapy in Patients With Metastatic Colorectal Cancer.

PURPOSE: SIRFLOX was a randomized, multicenter trial designed to assess the efficacy and safety of adding selective internal radiation therapy (SIRT) using yttrium-90 resin microspheres to standard fluorouracil, leucovorin, and oxaliplatin (FOLFOX)-based chemotherapy in patients with previously untreated metastatic colorectal cancer. PATIENTS AND METHODS: Chemotherapy-naïve patients with liver metastases plus or minus limited extrahepatic metastases were randomly assigned to receive either modified FOLFOX (mFOLFOX6; control) or mFOLFOX6 plus SIRT (SIRT) plus or minus bevacizumab. The primary end point was progression-free survival (PFS) at any site as assessed by independent centralized radiology review blinded to study arm. RESULTS: Between October 2006 and April 2013, 530 patients were randomly assigned to treatment (control, 263; SIRT, 267). Median PFS at any site was 10.2 v 10.7 months in control versus SIRT (hazard ratio, 0.93; 95% CI, 0.77 to 1.12; P = .43). Median PFS in the liver by competing risk analysis was 12.6 v 20.5 months in control versus SIRT (hazard ratio, 0.69; 95% CI, 0.55 to 0.90; P = .002). Objective response rates (ORRs) at any site were similar (68.1% v 76.4% in control v SIRT; P = .113). ORR in the liver was improved with the addition of SIRT (68.8% v 78.7% in control v SIRT; P = .042). Grade ≥ 3 adverse events, including recognized SIRT-related effects, were reported in 73.4% and 85.4% of patients in control versus SIRT. CONCLUSION: The addition of SIRT to FOLFOX-based first-line chemotherapy in patients with liver-dominant or liver-only metastatic colorectal cancer did not improve PFS at any site but significantly delayed disease progression in the liver. The safety profile was as expected and was consistent with previous studies.

Analysis of KRAS/NRAS Mutations in a Phase III Study of Panitumumab with FOLFIRI Compared with FOLFIRI Alone as Second-line Treatment for Metastatic Colorectal Cancer.

PURPOSE: We evaluated the influence of RAS mutation status on the treatment effect of panitumumab in a prospective-retrospective analysis of a randomized, multicenter phase III study of panitumumab plus fluorouracil, leucovorin, and irinotecan (FOLFIRI) versus FOLFIRI alone as second-line therapy in patients with metastatic colorectal cancer (mCRC; ClinicalTrials.gov, NCT0039183). EXPERIMENTAL DESIGN: Outcomes were from the study's primary analysis. RAS mutations beyond KRAS exon 2 (KRAS exons 3, 4; NRAS exons 2, 3, 4; BRAF exon 15) were detected by bidirectional Sanger sequencing in wild-type KRAS exon 2 tumor specimens. Progression-free survival (PFS) and overall survival (OS) were coprimary endpoints. RESULTS: The RAS ascertainment rate was 85%; 18% of wild-type KRAS exon 2 tumors harbored other RAS mutations. For PFS and OS, the hazard ratio (HR) for panitumumab plus FOLFIRI versus FOLFIRI alone more strongly favored panitumumab in the wild-type RAS population than in the wild-type KRAS exon 2 population [PFS HR, 0.70 (95% confidence interval [CI], 0.54-0.91); P = 0.007 vs. 0.73 (95% CI, 0.59-0.90); P = 0.004; OS HR, 0.81 (95% CI, 0.63-1.03); P = 0.08 vs. 0.85 (95% CI, 0.70-1.04); P = 0.12]. Patients with RAS mutations were unlikely to benefit from panitumumab. Among RAS wild-type patients, the objective response rate was 41% in the panitumumab-FOLFIRI group versus 10% in the FOLFIRI group. CONCLUSIONS: Patients with RAS mutations were unlikely to benefit from panitumumab-FOLFIRI and the benefit-risk of panitumumab-FOLFIRI was improved in the wild-type RAS population compared with the wild-type KRAS exon 2 population. These findings support RAS testing for patients with mCRC. Clin Cancer Res; 21(24); 5469-79. ©2015 AACR.See related commentary by Salazar and Ciardiello, p. 5415.

Hyaluronan-Irinotecan improves progression-free survival in 5-fluorouracil refractory patients with metastatic colorectal cancer: a randomized phase II trial.

PURPOSE: The objective of this study was to conduct a randomised phase II study in second-line metastatic colorectal cancer with the purpose of confirming preliminary clinical data indicating that the formulation of irinotecan with the drug carrier, hyaluronan (HA) reduced toxicity of the drug. METHODS: Irinotecan-naïve patients were randomized to receive either irinotecan (350 mg/m(2)) or HA-Irinotecan (HA 1,000 mg/m(2) and irinotecan at 350 mg/m(2)) every 3 weeks for a maximum of eight cycles. RESULTS: Seventy-six patients (41 HA-Irinotecan and 35 irinotecan-alone) were enrolled. There was no significant difference in any individual, or overall, grade 3 or 4 toxicity. There was a trend for increased diarrhea in the HA-Irinotecan-treated patients (20 versus 9%; P = 21), potentially explained by a disproportionate number of baseline toxicity-associated risk factors in this treatment group. The median number of cycles completed was six for HA-Irinotecan patients and two for irinotecan-alone patients (P = 0.005). When compared to the control arm, HA-Irinotecan patients had a significantly longer median progression-free survival of 5.2 versus 2.4 months (P = 0.017) and time to treatment failure (4 vs. 1.8 months; P = 0.007). Median overall survival was 10.1 months for HA-Irinotecan compared to 8.0 months for irinotecan patients (P = 0.196). CONCLUSION: Further studies are required to define the safety of the formulation of irinotecan with HA. While this study was not adequately powered to demonstrate survival differences, these phase II data indicated HA-Irinotecan to be a promising therapy demonstrating improved efficacy compared to irinotecan-alone.

A phase I and II trial of epirubicin, cisplatin, 24-hour infusion 5 fluorouracil and sodium folinate in patients with advanced esophagogastric carcinomas.

AIM: Advanced esophagogastric carcinoma has a poor prognosis. Palliative chemotherapy provides a survival advantage and improved quality of life. Epirubicin, cisplatin and continuous infusional 5-fluorouracil (5-FU) (ECF) is a well-established chemotherapy regimen but a continuous chemotherapy infusion is not always feasible or acceptable. METHODS: We conducted a phase I and II trial of a modified version of ECF, utilizing 5-FU as a 24-h infusion on day 1 and day 8 of a 21-day cycle, administered with sodium folinate as a modulator of 5-FU (ECSF). In the phase I study the dose of 5-FU was increased in successive cohorts from 1250 mg/m(2) , 1500 mg/m(2) , and 1750 mg/m(2) to 2000 mg/m(2) per 24 h. RESULTS: Dose limiting toxicity of febrile neutropenia was encountered at 2000 mg/m. The recommended dose for 5-FU was 1750 mg/m(2) . Overall 29 patients were treated with ECSF of whom 27 were evaluable for toxicity. The response rate was 45% on an intention-to-treat analysis with a complete response rate of 3%. The median response rate was 4.1 months and the median survival was 10.7 months. A total of 23 patients (72%) obtained clinical benefit with improvement in dysphagia or weight gain. central venous catheter (CVC) complications were observed in 12 (41%) patients. CONCLUSION: ECSF was associated with a response rate and survival similar to that reported with standard ECF. ECSF may provide an alternative regimen to standard ECF when a continuous ambulatory infusion pump is not feasible or not preferred by the patient. CVC complications are a limitation.

Randomized phase III study of panitumumab with fluorouracil, leucovorin, and irinotecan (FOLFIRI) compared with FOLFIRI alone as second-line treatment in patients with metastatic colorectal cancer.

PURPOSE: Panitumumab is a fully human anti-epidermal growth factor receptor (EGFR) monoclonal antibody that improves progression-free survival (PFS) in chemotherapy-refractory metastatic colorectal cancer (mCRC). This trial evaluated the efficacy and safety of panitumumab plus fluorouracil, leucovorin, and irinotecan (FOLFIRI) compared with FOLFIRI alone after failure of initial treatment for mCRC by tumor KRAS status. PATIENTS AND METHODS: Patients with mCRC, one prior chemotherapy regimen for mCRC, Eastern Cooperative Oncology Group performance status 0 to 2, and available tumor tissue for biomarker testing were randomly assigned 1:1 to panitumumab 6.0 mg/kg plus FOLFIRI versus FOLFIRI every 2 weeks. The coprimary end points of PFS and overall survival (OS) were independently tested and prospectively analyzed by KRAS status. RESULTS: From June 2006 to March 2008, 1,186 patients were randomly assigned 1:1 and received treatment. KRAS status was available for 91% of patients: 597 (55%) with wild-type (WT) KRAS tumors, and 486 (45%) with mutant (MT) KRAS tumors. In the WT KRAS subpopulation, when panitumumab was added to chemotherapy, a significant improvement in PFS was observed (hazard ratio [HR] = 0.73; 95% CI, 0.59 to 0.90; P = .004); median PFS was 5.9 months for panitumumab-FOLFIRI versus 3.9 months for FOLFIRI. A nonsignificant trend toward increased OS was observed; median OS was 14.5 months versus 12.5 months, respectively (HR = 0.85, 95% CI, 0.70 to 1.04; P = .12); response rate was improved to 35% versus 10% with the addition of panitumumab. In patients with MT KRAS, there was no difference in efficacy. Adverse event rates were generally comparable across arms with the exception of known toxicities associated with anti-EGFR therapy. CONCLUSION: Panitumumab plus FOLFIRI significantly improved PFS and is well-tolerated as second-line treatment in patients with WT KRAS mCRC.

Sentinel node biopsy: an in depth appraisal.

Sentinel node biopsy (SNB) in primary breast cancer has been taken-up widely to avoid the morbidity attributable to axillary node clearance (ANC). Currently many issues surrounding SNB are undecided. This review summarises why some form of axillary surgery is required and presents data on all aspects of SNB including methodology, clinical results and problems that may delay the introduction of SNB as best practice for all patients with primary breast cancer. There is no long or medium term data relating to the consequences of replacing ANC with SNB, but the mechanisms and probable magnitude of both beneficial and detrimental effects are estimated. A low level of false negative results are inherent to the technique but it is demonstrated that SNB is likely to have an only marginal (0.6%) effect on survival that would be undetectable by clinical trials. Patient sub-groups particularly likely to benefit from SNB are identified.