Maintenance Therapy With Panitumumab Alone vs Panitumumab Plus Fluorouracil-Leucovorin in Patients With RAS Wild-Type Metastatic Colorectal Cancer: A Phase 2 Randomized Clinical Trial.

IMPORTANCE: Few studies are available on the role of maintenance strategies after induction treatment regimens based on anti-epidermal growth factor receptors, and the optimal regimen for an anti-epidermal growth factor receptors-based maintenance treatment in patients with RAS wild-type metastatic colorectal cancer is still to be defined. OBJECTIVE: To determine whether maintenance therapy with single-agent panitumumab was noninferior to panitumumab plus fluorouracil and leucovorin after a 4-month induction treatment regimen. DESIGN, SETTING, AND PARTICIPANTS: This open-label, randomized phase 2 noninferiority trial was conducted from July 7, 2015, through October 27, 2017, at multiple Italian centers. Patients with RAS wild-type, unresectable metastatic colorectal adenocarcinoma who had not received previous treatment for metastatic disease were eligible. Induction therapy consisted of panitumumab plus FOLFOX-4 (panitumumab, 6 mg/kg, oxaliplatin, 85 mg/m2 at day 1, leucovorin calcium, 200 mg/m2, and fluorouracil, 400-mg/m2 bolus, followed by 600-mg/m2 continuous 24-hour infusion at days 1 and 2, every 2 weeks). Cutoff date for analyses was July 30, 2018. INTERVENTIONS: Patients were randomized (1:1) to first-line panitumumab plus FOLFOX-4 for 8 cycles followed by maintenance therapy with panitumumab plus fluorouracil-leucovorin (arm A) or panitumumab (arm B) until progressive disease, unacceptable toxic effects, or consent withdrawal. The minimization method was used to stratify randomization by previous adjuvant treatment and number of metastatic sites. MAIN OUTCOMES AND MEASURES: The prespecified primary end point was 10-month progression-free survival (PFS) analyzed on an intention-to-treat basis with a noninferiority margin of 1.515 for the upper limit of the 1-sided 90% CI of the hazard ratio (HR) of arm B vs A. RESULTS: Overall, 229 patients (153 male [66.8%]; median age, 64 years [interquartile range (IQR), 56-70 years]) were randomly assigned to arm A (n = 117) or arm B (n = 112). At a median follow-up of 18.0 months (IQR, 13.1-23.3 months]), a total of 169 disease progression or death events occurred. Arm B was inferior (upper limit of 1-sided 90% CI of the HR, 1.857). Ten-month PFS was 59.9% (95% CI, 51.5%-69.8%) in arm A vs 49.0% (95% CI, 40.5%-59.4%) in arm B (HR, 1.51; 95% CI, 1.11-2.07; P = .01). During maintenance, arm A had a higher incidence of grade 3 or greater treatment-related adverse events (36 [42.4%] vs 16 [20.3%]) and panitumumab-related adverse events (27 [31.8%] vs 13 [16.4%]), compared with arm B. CONCLUSIONS AND RELEVANCE: In patients with RAS wild-type metastatic colorectal cancer, maintenance therapy with single-agent panitumumab was inferior in terms of PFS compared with panitumumab plus fluorouracil-leucovorin, which slightly increased the treatment toxic effects. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02476045.

Effects of Cancer Therapy Targeting Vascular Endothelial Growth Factor Receptor on Central Blood Pressure and Cardiovascular System.

BACKGROUND: In the last 2 decades, new drugs that oppose the effects of vascular endothelial growth factor receptor (VEGFR), and thus angiogenesis, have considerably improved treatment of solid tumors. These anti-VEGFR drugs, however, are burdened by several side effects, particularly relevant on heart and vessels. The aim of this study was to analyze the changes in cardiovascular structure and function associated with use of anti-VEGFR drugs. METHODS: Twenty-nine patients (27 affected by renal and 2 by thyroid cancer), received treatment with anti-VEGFR drugs. Brachial blood pressure (BP), central BP, carotid-femoral pulse wave velocity (cfPWV), augmentation index (Aix), and several echocardiographic markers of systolic and diastolic left ventricular functions including global longitudinal strain were measured before starting treatment (T0), after 2 (T1), and 6 weeks (T2) of treatment. RESULTS: Anti-VEGFR treatment was accompanied by a significant increase of both peripheral (systolic BP +13±15.5mm Hg, diastolic BP +7.1±9.3mm Hg, P < 0.001) and central BP (systolic BP +14±14.2mm Hg, diastolic BP +7.3±10.4mm Hg, P < 0.001) and a significant raise of cfPWV (+1.3±1.8 m/sec, P = 0.003). There was also a significant alteration of markers of diastolic and subclinical left ventricular systolic function, including global longitudinal strain (-19.9±3.8% at T0, -17.8±2.6% at T2, P < 0.05). All the changes were already evident at T1, worsened at T2 in patients who maintained oncological treatment, but disappeared at T2 in patients in whom treatment was stopped. CONCLUSIONS: All the changes regarding BP and cfPWV appear early after treatment initiation and seem to be reversible if treatment is stopped, instead diastolic and systolic left ventricular function are persistently altered by anti-VEGFR drugs.

Epigenetic inactivation of the BRCA1 interactor SRBC and resistance to oxaliplatin in colorectal cancer.

BACKGROUND: A major problem in cancer chemotherapy is the existence of primary resistance and/or the acquisition of secondary resistance. Many cellular defects contribute to chemoresistance, but epigenetic changes can also be a cause. METHODS: A DNA methylation microarray was used to identify epigenetic differences in oxaliplatin-sensitive and -resistant colorectal cancer cells. The candidate gene SRBC was validated by single-locus DNA methylation and expression techniques. Transfection and short hairpin experiments were used to assess oxaliplatin sensitivity. Progression-free survival (PFS) and overall survival (OS) in metastasic colorectal cancer patients were explored with Kaplan-Meier and Cox regression analyses. All statistical tests were two-sided. RESULTS: We found that oxaliplatin resistance in colorectal cancer cells depends on the DNA methylation-associated inactivation of the BRCA1 interactor SRBC gene. SRBC overexpression or depletion gives rise to sensitivity or resistance to oxaliplatin, respectively. SRBC epigenetic inactivation occurred in primary tumors from a discovery cohort of colorectal cancer patients (29.8%; n = 39 of 131), where it predicted shorter PFS (hazard ratio [HR] = 1.83; 95% confidence interval [CI] = 1.15 to 2.92; log-rank P = .01), particularly in oxaliplatin-treated case subjects for which metastasis surgery was not indicated (HR = 1.96; 95% CI = 1.13 to 3.40; log-rank P = .01). In a validation cohort of unresectable colorectal tumors treated with oxaliplatin (n = 58), SRBC hypermethylation was also associated with shorter PFS (HR = 1.90; 95% CI = 1.01 to 3.60; log-rank P = .045). CONCLUSIONS: These results provide a basis for future clinical studies to validate SRBC hypermethylation as a predictive marker for oxaliplatin resistance in colorectal cancer.

Wild-type BRAF is required for response to panitumumab or cetuximab in metastatic colorectal cancer.

PURPOSE Cetuximab or panitumumab are effective in 10% to 20% unselected metastatic colorectal cancer (CRC) patients. KRAS mutations account for approximately 30% to 40% patients who are not responsive. The serine-threonine kinase BRAF is the principal effector of KRAS. We hypothesized that, in KRAS wild-type patients, BRAF mutations could have a predictive/prognostic value. PATIENTS AND METHODS We retrospectively analyzed objective tumor responses, time to progression, overall survival (OS), and the mutational status of KRAS and BRAF in 113 tumors from cetuximab- or panitumumab-treated metastatic CRC patients. The effect of the BRAF V600E mutation on cetuximab or panitumumab response was also assessed using cellular models of CRC. Results KRAS mutations were present in 30% of the patients and were associated with resistance to cetuximab or panitumumab (P = .011). The BRAF V600E mutation was detected in 11 of 79 patients who had wild-type KRAS. None of the BRAF-mutated patients responded to treatment, whereas none of the responders carried BRAF mutations (P = .029). BRAF-mutated patients had significantly shorter progression-free survival (P = .011) and OS (P < .0001) than wild-type patients. In CRC cells, the introduction of BRAF V600E allele impaired the therapeutic effect of cetuximab or panitumumab. Treatment with the BRAF inhibitor sorafenib restored sensitivity to panitumumab or cetuximab of CRC cells carrying the V600E allele. CONCLUSION BRAF wild-type is required for response to panitumumab or cetuximab and could be used to select patients who are eligible for the treatment. Double-hit therapies aimed at simultaneous inhibition of epidermal growth factor receptor and BRAF warrant exploration in CRC patients carrying the V600E oncogenic mutation.

Low doses of subcutaneous interleukin-2 plus interferon-alpha do not induce thyroid function alterations in advanced renal cell carcinoma patients.

The incidence of thyroid function changes among renal cell carcinoma (RCC) patients treated with high-dose IL-2 plus IFN-alpha ranges from 9 to 59%, independently of the administration route (i.v. or s.c.) of IL-2. Although several studies demonstrated a correlation between high-dose IL-2/IFN-alpha regimens and autoimmune thyroid disease, only very limited data are available when low doses of IL-2 plus IFN-alpha are used. We prospectively studied thyroid function in 52 patients with metastatic RCC undergoing immunotherapy with low-dose IL-2 + IFN-alpha. All patients received treatment cycles consisting of both s.c. IL-2 and i.m. IFN-alpha for 4 consecutive weeks; cycles were repeated at 4-month intervals in all patients, irrespectively of their response. Thyroid stimulating hormone (TSH), 3,3',5-triiodo-L-thyronine (T3), thyroxine (T4), human anti-thyroglobulin antibodies (hTg-Ab) and human anti-thyroid peroxidase antibodies (hTPO-Ab) were assayed in all patients before and after each of the first 3 cycles. None of the patients showed clinical signs of dysthyroidism, nor required replacement or suppressive treatment on thyroid function; specifically, no statistically significant differences were found when the median pre- and post-treatment TSH, T3, T4, hTg-Ab and hTPO-Ab levels of each cycle were compared. The median TSH values after the 3 cycles were, respectively, 1.06 [Inter Quartile Range (IQR) 0.58-1.51], 1.21 (IQR 0.58-1.51) and 1.05 micro U/ml (IQR 0.67-1.73). As for thyroid hormones, median values after each of the 3 cycles were: 1.38 (IQR 1.19-1.50), 1.46 (IQR 1.17-1.66) and 1.36 (IQR 1.16-1.46) ng/ml for T3, and 8.74 (IQR 7.26-9.45), 8.67 (IQR 7.12-9.18) and 8.40 (IQR 7.12-9.33) micro g/dl for T4. These data show that a regimen of low-dose IL-2 plus IFN-alpha does not seem to affect thyroid function, neither inducing signs or symptoms of dysthyroidism, nor by causing major biochemical changes in TSH and thyroid hormone levels, or an increase in thyroid-specific auto-antibodies.