Safety and efficacy of first-line XELIRI with or without bevacizumab in patients with metastatic colorectal cancer: Analysis of two phase II studies

560

Background: The safety and efficacy of first-line XELIRI (capecitabine in combination with irinotecan) and XELIRI plus bevacizumab (BEV) have been evaluated in patients with metastatic colorectal cancer (mCRC). To date, however, no randomized studies comparing these regimens have been performed. This retrospective analysis compared efficacy and safety data for the two regimens from separate phase II studies performed at a single institution.

Methods: Patients with histologically documented metastatic or recurrent CRC and no prior treatment for advanced disease received irinotecan 175 mg/m2 on day 1 and oral capecitabine 1,000 mg/m2 twice daily on days 2-8 every 2 weeks (XELIRI study). For patients age ≥65 years, the starting doses of irinotecan and capecitabine were reduced to 140 mg/m2 and 750 mg/m2, respectively. In the second study, patients received the same regimen plus BEV 5 mg/kg on day 1 (XELIRI + BEV study).

Results: A total of 53 and 46 patients were entered into the XELIRI and XELIRI + BEV studies, respectively. Patient characteristics were generally similar in both groups. Efficacy results for the ITT populations are summarized in the Table. Patients treated with XELIRI + BEV had a significantly higher ORR and longer median TTP vs. XELIRI alone and a numerically longer median OS was observed (p=NS). The overall incidence of adverse events (all grades or grade 3/4) was similar in the two groups, although alopecia, mucositis, hand–foot syndrome, and haemorrhage were more common with XELIRI + BEV vs. XELIRI alone (all p<0.05).

Conclusions: In this retrospective comparison of two studies, the addition of BEV to XELIRI appeared to improve outcome relative to XELIRI alone in the first-line treatment of patients with mCRC. The overall incidence of adverse events was similar in the two groups.

[Table: see text]

No significant financial relationships to disclose.

[HIV-1 neuropathogenesis: therapeutic strategies against neuronal loss induced by gp120/Tat glycoprotein in the central nervous system]

Neuroinflammation is a key process in the neuropathogenesis of AIDS virus since as a result of the aberrant activation of the chemokine receptors (CXCR4, CX3CR1 and CR5) produces proinflammatory cytokine release by infected cells, increases microglial neurotoxicity and generates lipoperoxides and reactive oxygen species (ROS) that eventually damage the neuron. Moreover, the neurotoxin Tat produces dendritic loss by interacting with the low-density lipoprotein receptor (LRP) and also overstimulates N-methyl D-aspartate receptors (NMDA). Furthermore, the aberrant interaction of glycoprotein gp120 with the CXCR4 chemokine receptor causes caspase-3-dependent apoptosis (ceramide is also released) activating apoptotic proteins (p53 and retinoblastoma), which are part of the neurotoxic mechanisms associated to neuronal dysfunction in neuroAIDS. Similarly, gliosis/microglial activation and the release of neurotoxic factors by infected monocytes with elevated amounts of certain chemokines in the cerebrospinal fluid (MCP-1 and fractalkine, among others) contribute to the neuropathogenesis of HIV-1. Alpha-synuclein and beta amyloid deposits have also been detected in post mortem brains of seropositives patients. In addition, there are studies have detected several systemic markers related with the degenerative effects of the virus and its neurotoxins on the central nervous system; such as osteopontin, CD163 and fractalkine, among others. Lastly, clinical trials have been conducted using protective strategies related that attempt to inhibit apoptotic proteins (GSK-3 beta), microglial activation inhibitors (minocycline), antioxidants (selegiline) or trophic factors (IGF-1, growth hormone or erythropoietin). These trials have shown that their treatments are beneficial and complementary to treat complications of HIV/AIDS.

The effect of dentine-bonding agents on substance P release in human dental pulp

AIM

To quantify the effect of dentine-bonding agents on Substance P (SP) release in healthy human dental pulp tissue.

METHODOLOGY

Forty pulp samples were obtained from healthy pre-molars where extraction was indicated for orthodontic reasons. In thirty of these pre-molars, a standardized Class V cavity preparation was performed, and teeth were divided equally into three groups: (i) Unetched-cavity control group: Class V cavities only; (ii) Experimental Group I: 'One-step' self-etch bonding agent was placed in the cavity; and (iii) Experimental Group II: 'Two-step' total-etch bonding agent was placed in the cavity. The remaining ten healthy pre-molars where extracted without treatment and served as an intact-teeth control group. SP was measured by radioimmunoassay.

RESULTS

Greater SP release was found in the 'one-step' bonding agent group, followed by the 'two-step' bonding agent group and the unetched-cavity control group. The lower SP values were for the intact-teeth control group. anova showed statistically significant differences between groups (P = 0.0001). Tukey HSD post hoc tests showed statistically significant differences in SP release between the intact-teeth control group and the three other groups (P < 0.01) and between the unetched-cavity control group and the 'one-step' bonding agent group (P < 0.05). No significant difference was found between the 'two-step' bonding agent and the unetched-cavity control group.

CONCLUSION

Dentine-bonding agents placed over Class V cavity preparations increased SP release. One-step dentine-bonding agents increased SP release most.

Hemodynamic changes during reperfusion of the graft in an animal model of liver xenotransplantation

Our goal was to determine the hemodynamic changes that are witnessed during the initial minutes of reperfusion of the graft in liver xenotransplantation from pig to baboon.

METHOD

We studied a group of 12 baboons undergoing transplantation of a pig liver via the classic technique with arterial anastomosis to the aorta. The anesthesia technique was similar to that used in humans. Hemodynamic monitoring, due to the size of the recipient, consisted of heart rate (HR), mean arterial pressure (MAP), and central venous pressure (CVP) recorded at the beginning and end of each of the three phases: preanhepatic (A1, A2), anhepatic (B1, B2), and neohepatic (C1 and C2). We aimed to maintain the following values by means of crystalloids, colloids, and blood derivates: HR >50 beats/minute; MAP >60 mm Hg; and CVP >10 mm Hg.

RESULTS

Both HR and CVP remained unchanged throughout the procedure. MAP droped briefly after vascular clamping (B1) but not on reperfusion (C1).

CONCLUSION

In cirrhotic patients there is an autonomic dysfunction, demonstrated as cardiovascular instability at times like the clamping of major vessels and reperfusion of the graft. On the other hand, the intact baboon has an intact nervous system. After vascular clamping, the sharp decrease in venous return lead to an adequate vasopressor response. Likewise, the extreme vasodilatation involved with reperfusion managed to maintain MAP above 70 mm Hg.

Treatment of locally advanced esophageal carcinoma with induction cisplatin-paclitaxel-5FU (PTF) before local therapy

15174

Background: We analyse induction therapy with PTF before local definitive therapy in terms of response, resectability, toxicity and survival. Methods: Patients (pts) with locally advanced esophageal carcinoma were included. Treatment: Paclitaxel 175 mg/m2 and CDDP 75 mg/m2 on day 1 and 5FU 800 mg/m2/day, days 1–4, every 21 days. After 2–3 cycles surgery is considered. If unresectable, Radiotherapy (64 Gy) and concomitant Carboplatin (60 mg/m2, d 1–5 during 1st and 4th week of RT) are planned. Results: From May-02 to October-06 31 pts were treated (28M, 3F) Age: 55 (32–70) PS 0–1: 6–25. Location: Upper 10, Middle 13, Distal 7, Whole 1. Pathology: Squamous 29, Adenocarcinoma 2. T3/4:14/17 N0/1:8/23 M1a: 3. Weight loss >10 kg 12 pts. 87 cycles have been delivered. Range: 2–4. Mean 2,83. Median 3. Toxicity (episodes): hematological 3/4: no episodes. Emesis 3: 2. Mucositis 3: 2. Asthenia 2/3: 8. 2 pts died in remission due to gastrostomy complications and esophago-tracheal fistula, treatment related. Response: CR 5, PR 9, SD 13, PD 4. Treatment after PTF: Surgery 10 pts (1 upper, 5 middle, 4 distal). 1 distal unresectable at surgery, 2 middle not resected because of liver cirrhosis and liver metastases at surgery. pCR: 1. pPR 6 (R0: 3, R1: 3) Chemoradiation with concomitant Carboplatin: 19, making 3 SD in PR, 2 PR in CR and 1 SD in CR. One PR and 4 SD progressed after chemoradiation. Progression: 21 (local 7, systemic 7, both 7). Died: 19 (16 of disease, 2 of complications of gastrostomy, 1 unrelated) Median PFS: 48,28 weeks (95% CI 32,80 - 63,77). Median OS: 51,14 weeks (95% CI 28,81 - 73,47). Conclusions: This schedule has a good toxicity profile. Surgical rescue is possible in almost a half of middle and distal tumours. Chemoradiation is the best approach for unresectable tumours. Considering stage at diagnosis, survival curves are promising.

No significant financial relationships to disclose.