Two different kinds of key peck in the pigeon: some properties of responses maintained by negative and positive response-reinforcer contingencies

Pigeons emitted almost exclusively short-duration key pecks (shorter than 20 msec) when on negative automaintenance procedures, in which pecks prevented reinforcement. Peck durations under fixed-interval and fixed-ratio reinforcement schedules were generally two to five times longer than pecks under a negative automaintenance schedule. However, initial key pecks were of short duration, independent of procedure. The frequency of short-duration pecks was insensitive to differential reinforcement, while the frequency of long-duration pecks was sensitive to differential reinforcement. It is proposed that short-duration pecks arise from the pigeon's normal feeding pattern and are directly enhanced by food presentation, while long-duration pecks are controlled by the contingent effects of food presentation. The implications of the existence of two classes of pecks for the functional definition of operants and the separation of phylogenetic and ontogenetic sources of control of key pecking are discussed.

Maintenance of key pecking by response-independent food presentation: the role of the modality of the signal for food

Three pigeons were exposed to a series of procedures in which periods of response-independent food presentation, on a variable-time schedule, alternated with periods in which food was never presented. The stimuli that signalled periods of food availability or non-availability varied from one procedure to the next, and were sometimes key colors, sometimes tones, and sometimes compounds of both. Key pecking was initiated and maintained when key color was a signal for food; key pecking was not initiated when a tone was the signal for food. However, control of key pecking that was already established could be transferred from key color to tone, and subsequently, initiated by the tone. It is suggested that for pigeons, pre-experimental relationships exist among food, visual stimuli, and pecking, and that a similar relationship, which includes auditory stimuli, must be induced in the laboratory.

THE EFFECT OF TEMPERATURE ON THE RATE OF HYDROLYSIS OF TRIGLYCERIDES BY PANCREATIC LIPASE

1. The temperature characteristics for the hydrolysis of various concentrations of tributyrin, trivalerin, tricaproin, triheptylin, and tricaprylin have been determined. 2. The micro values for the hydrolysis of all concentrations of tributyrin by pancreatic lipase, except the most dilute, were found to be constant within the experimental error, 8,500 +/- 1,000. 3. The temperature characteristics for the hydrolysis of trivalerin, tricaproin, triheptylin, and tricaprylin varied from approximately 8,500 +/- 1,000 for the high concentrations to 12,400, 20,000, 22,400, and 23,700 respectively for the most dilute concentration of each. 4. An interpretation of these results was presented.

Retinal blood vessel width measured on color fundus photographs by image analysis

The purpose of this paper was to develop a technique using computerized image analysis to measure the width of retinal arteries and veins on color fundus photographs. The width of the retinal vessel was determined from digitized fundus photographs by programs based on edge detection and boundary tracing. The average vessel width was determined at different distances or eccentricities from the center of the optic disc and using various lengths of vessel segment. Measurements of superior and inferior temporal vessel width for 20 eyes by 2 operators showed that about 75% of the measurements could be obtained without the use of plan points. The average percent coefficient of variation of the measurements was 2.17% for 3 measurements of each vessel. This technique provides a reproducible and objective method for obtaining the following parameters: the edges of the vessel, the length of the vessel segment to be measured, location of the measurement along the vessel and subsequent retinal vessel width. This technique is readily suitable for application to clinical studies particularly clinical trials.

Decrease of optic disc cupping and pallor of ocular hypertensives with timolol therapy

PURPOSE

The purpose of this study was to determine whether timolol drops compared to placebo drops had a significant effect on optic disc cupping and pallor in ocular hypertensives.

METHODS

Thirty-seven ocular hypertensives were randomly assigned to placebo or 0.5% timolol drops to both eyes in a double masked clinical trial. Measurements of ocular pressure and photographs of the optic disc for cupping by photogrammetry and pallor by computerized image analysis were made at about 3 month intervals, for 18 to 24 months of follow-up.

RESULTS

None of the subjects developed visual field loss when tested with the Goldmann perimeter by kinetic and static means at six month intervals. Subjects treated with timolol developed a significant decrease in ocular pressure and a significant decrease in optic disc cupping with a smaller decrease in pallor compared to subject treated with placebo. Multivariate analyses indicated that the decrease of optic disc cupping and pallor was not associated with the ocular pressure on treatment or the decrease in ocular pressure during the trial.

CONCLUSION

Timolol treatment was associated with a decrease in optic disc cupping and pallor. The effect of timolol appears to be related to mechanisms other than the decrease in ocular pressure.

Increase of retinal nerve fiber layer thickness in ocular hypertensives with timolol therapy

PURPOSE

The purpose of this study was to determine whether timolol drops compared to placebo drops had a significant effect on retinal nerve fiber layer thickness in ocular hypertensives.

METHODS

Thirty-seven ocular hypertensives were randomly assigned to receive placebo or 0.5% timolol drops to both eyes for 18 to 24 months in a double masked clinical trial. Measurements of ocular pressure and photographs of retinal nerve fiber layer using stereophotogrammetric techniques were made at about 3 month intervals for 18 to 24 months of follow-up.

RESULTS

None of the subjects developed visual field loss when tested with the Goldmann perimeter by kinetic and static means at six month intervals. Subjects treated with timolol had a significant decrease in ocular pressure and developed a significant increase in retinal nerve fiber layer thickness compared to subjects treated with placebo. Multivariate analyses indicated that the increase of retinal nerve layer thickness was not associated either with the ocular pressure on treatment or the decrease in ocular pressure on treatment.

CONCLUSION

Timolol treatment was associated with an increase of retinal nerve fiber thickness. The effect of timolol appears to be related to mechanisms other than the decrease in ocular pressure.

Increase of retinal vessel width in ocular hypertensives with timolol therapy

PURPOSE

The purpose of this study was to determine whether timolol drops compared to placebo drops had a significant effect on retinal vessel width in ocular hypertensives.

METHODS

Thirty-seven ocular hypertensives were randomly assigned to receive placebo or 0.5% timolol drops to both eyes for 18 to 24 months in a double masked clinical trial. Measurements of ocular pressure and retinal vessel width by computerized image analysis from fundus photographs were made at about 3 month intervals for 18 to 24 months of follow-up.

RESULTS

None of the subjects developed visual field loss when tested with the Goldmann perimeter by kinetic and static means at six month intervals. Subjects treated with the placebo showed no change in ocular pressure and a significant decrease in retinal vessel width over time especially in the right eye. Subjects treated with timolol had an increase in retinal vessel width compared to the placebo group significant especially for the superior temporal vein. Multivariate analyses indicated that the increase of retinal vessel width was not associated mainly with the ocular pressure on treatment or decrease in ocular pressure on treatment.

CONCLUSION

Timolol treatment was associated with an increase of retinal vessel width. The effect of timolol appears to be related primarily to mechanisms other than the decrease in ocular pressure.

Phase I dose escalation trial (ARQ 197–111) evaluating combination of selective c-Met inhibitor ARQ 197 and erlotinib

3549

Background: ARQ197 (A) is a selective, non-ATP competitive inhibitor of c-Met, a receptor tyrosine kinase implicated in tumor cell migration, invasion, and proliferation. Phase I data for ARQ 197 monotherapy is previously reported. Recent evidence suggests c-Met promotes resistance to EGFR-inhibition by driving ERBB3 (HER3)-dependent PI3K activation. Dual EGFR-Met inhibition is now proposed as a strategy for overcoming resistance to EGFR-inhibition. Methods: Patients (pts) were enrolled in a sequential-cohort dose-escalation trial seeking to define safety, tolerability, pharmacokinetics (PK), and preliminary anti-tumor activity of A in combination with 150 mg daily oral erlotinib (E). Oral A was administered at escalating doses of 120, 240, and 360 mg bid. Intra-patient dose escalation was allowed in the absence of dose-limiting toxicity (DLT) through 1 cycle of therapy (21 days). Results: 25 pts (10 F/15 M; mean 60.5 yrs) received EA combination with starting A dose of 120 (8 pts), 240 (4 pts), and 360 (13 pts) mg bid. PK data reveal linear kinetics through 360 bid and no evidence of drug-drug interaction. Adverse events (AEs) considered related to combination therapy were reported in 13 (52%) of pts incl.sinus bradycardia (5 pts), fatigue (5 pts), rash (4 pts), itching (3 pts), and diarrhea (3 pts). 2 pts experienced related serious AEs incl. neutropenia (360 bid) and sinus bradycardia (240 bid). 1 death occurring on-study was considered unrelated to study drug. 9/10 evaluable pts demonstrated disease stabilization (SD) as their best RECIST response (5.9–27.1+ wks). Tumor regressions (2.3%-19.4%) were observed in 4/10 evaluable pts. Of note, 3/3 evaluable pts with NSCLC achieved SD for durations (14–32 wks) exceeding median PFS in BR.21 (9.7 wks). Conclusions: Continuous therapy with EA combination appears well tolerated and without drug-drug interaction. While no formal MTD was identified, a phase 2 combination dose (R2PD) of 360 mg bid A + 150 mg daily E is recommended. This RP2D is currently being investigated in an ongoing randomized trial comparing EA to E monotherapy in 2nd/3rd line NSCLC.

[Table: see text]

A novel stone retrieval basket for more efficient lithotripsy procedures

This paper presents the development of an improved stone retrieval device that uses a newly designed cage of Nitinol wires encompassing a mesh basket made of a material that is laser resistant. Current methods to extract large stones involve imaging, using a laser to fragment the stones and then using existing cage-like baskets to trap the fragments individually and extracting them one at a time. These procedures are tedious, and may result in leaving some fragments behind that can reform causing the need for another procedure. The device presented in this paper will have a mesh-like sack which will consist of a laser resistant material of polytetrafluoroethylene (PTFE) enclosed within a newly designed Nitinol cage. Two alternate designs are provided for the cage in this paper. The handle of the device is revised to allow for a 3 Fr (1 mm) opening such that a laser's fiber optic cable can enter the device. Using this device a laser can be used to fragment the stone, and all the fragments are retained in the basket in both the design options. The basket can then be retracted allowing for the retrieval of all the fragments in one shot. The stone retrieval basket presented in this paper will significantly improve the efficiency and effectiveness of lithotripsy procedures for removal of large kidney and biliary tract stones.

Acute promyelocytic leukaemia and acquired alpha-2-plasmin inhibitor deficiency: a retrospective look at the use of epsilon-aminocaproic acid (Amicar) in 30 patients

Bleeding diathesis and a hyper-fibrinolytic state often accompany a diagnosis of Acute Promyelocytic Leukaemia (APML). This complication can have grave effects if not successfully treated, with a 10-20% incidence of haemorrhagic death. We hypothesized that alpha-2-antiplasmin levels would correlate with the risk for bleeding, and that administration of epsilon-aminocaproic acid (EACA) would attenuate that risk. To assess this, we conducted a retrospective chart review analyzing 30 APML patients, 17 of whom were treated with EACA. Thirty patients were treated, 21 with primary induction therapy. Patients with low alpha-2-antiplasmin levels were treated with a coagulopathy protocol consisting of low-dose heparin, EACA and blood product support. Seventeen patients (57%) developed haemorrhagic complications during their treatment. The presence and grade of haemorrhage appeared to be associated with the alpha-2-antiplasmin level. There were no grade IV haemorrhages or episodes of haemorrhagic death. One episode of central venous catheter associated thromboembolism and three deaths from infection during chemotherapy were observed. alpha-2-Antiplasmin levels are a reliable surrogate for fibrinolysis and haemorrhagic risk in patients with APML. Treatment with EACA is a rational way to pharmacologically inhibit fibrinolysis, is associated with a low incidence of severe haemorrhagic events, and appears to be safe with a low risk of thrombosis. Randomized clinical trials further assessing the efficacy and potential toxicity of EACA in inhibiting fibrinolysis in patients with APML are needed.

Organic arsenic in patients (pts) with advanced solid tumors: Phase-1 results of zio-101 (s-dimethylarsino-glutathione)

3554

Background: ZIO-101(S-dimethylarsino-glutathione), a novel organic arsenic, is active against multiple cancers in vitro and in animal models. Anti-cancer activity is multifaceted and is mediated by disrupted mitochondrial function, increased reactive oxygen species (ROS) production, modified signal transduction and anti-angiogenesis. Methods: Phase-1 dose finding study to determine maximum tolerated dose (MTD), dose-limiting toxicity (DLT), pharmacokinetics (PK), and toxicities of ZIO-101 in patients with advanced solid tumors. Results: 34 pts (18 M/16 F) received 78–588 mg/m2/d IV for 5 consecutive days every 4 weeks. Median age was 61 (range, 42–79 y). Median N prior regimens was 3 (1–5). Pts had colorectal (N=17; 12 evaluable), renal (N=4), lung (N=3), melanoma (N=2), pancreas (N=2) and others (N=6). Median N of cycles was 2 (range, 1–12). MTD is 420 mg/m2/d and DLT was transient confusion, and ataxia. Fatigue, nausea and emesis were = grade-2. ZIO-101 was otherwise well-tolerated: There are no hematological toxicities and no QTc- prolongation. Five patients had stable-disease 4–12 mo (colorectal [N=3], renal [N=2],). PK studies at 420 mg/m2/d: tmax = 1 h (SD + 0.9), Cmax = 1.06 μg/L (SD ± 0.07 μg/mL), t1/2 = 17.8 h (SD ± 1.4 h) and AUC0- 8 = 25.9 mg·h/L (SD ± 0.8mg.h/L). 1 pt had complete resolution of a brain metastasis (renal) and 1 patient had a substantial decrease of a liver metastasis (pancreas). Conclusions: ZIO-101 was well tolerated. MTD is 420 mg/m2/d and DLT is transient confusion and ataxia. There was observed clinical benefit in five patients. Expansion cohort is ongoing to further test toxicities and antitumor activity. Phase II studies are ongoing.

[Table: see text]

ZIO-101 (S-dimethylarsino-glutathione): Phase I/II trials in advanced/progressive multiple myeloma

8109

Background: ZIO-101(S-dimethylarsino-glutathione), a novel organic arsenic, is active against multiple cancers including myeloma in vitro and in animal models. In vitro, it is active at low concentrations in cancers resistant to arsenic trioxide. Anti-cancer activity is multifaceted and is mediated by disrupted mitochondrial function, increased reactive oxygen species (ROS) production, modified signal transduction and anti-angiogenesis. Methods: (1) Phase I/II study to determine maximum tolerated dose (MTD), dose- limiting toxicity (DLT), safety-profile and preliminary efficacy in patients with advanced/progressive myeloma receiving ZIO-101 daily for 5 consecutive d every 4 w; (2) comparison of this schedule at MTD with a schedule of 420 mg/me2/d twice/w for 3 w every 4 w. Results: (1) phase I/ II: 19 patients have been treated so far. Median age is 61 y (range, 41–84 y). Median N prior therapies was 8 (range, 4–10). ZIO-101 was well-tolerated; MTD was 420 mg/me2/d for the 5 d schedule, and DLT was transient confusion /ataxia. No clinically- important biochemical, bone marrow, or cardiac toxicities were seen and there was neither neuropathy nor QTc-prolongation. Pain during peripheral infusion was reported in some patients. Anemia was the only adverse event = grade-3 in 25% of subjects. 6 of 14 evaluable subjects had stable disease (SD) =8 w and 2, SD > 6 mo. Accrual to the phase II portion continues. Conclusions: ZIO-101 was well- tolerated. In the daily for 5 consecutive d every 4 w schedule, the MTD is 420 mg/me2/d and DLT, transient confusion /ataxia. There was SD in 43% of patients with advanced/progressive myeloma, of whom half are beyond 6 months. Accrual into the phase II part of this study continues.

No significant financial relationships to disclose.

Phase I and pharmacological study of orally administered indibulin in advanced solid tumors

2565

Background: Indibulin (ZIO-301/D-24851) (N-(pyridin-4-yl)-[1-(4-chlorbenzyl)-indol-3-yl]-glyoxyl-amid) a novel, oral, synthetic, anti-mitotic drug is widely active against human tumor cell lines and xenografts, including multidrug resistant and taxane refractory tumors. Indibulin destabilizes microtubule polymerization; its tubulin binding site is distinct from taxanes and vinca alkaloids. In preclinical studies indibulin lacks neurotoxicity typically associated with other tubulin binding drugs. Methods: Phase I study to evaluate safety, pharmacokinetics (PK), maximum tolerated dose (MTD) and dose limiting toxicity (DLT) in patients with advanced solid tumors. Initial dosing was in lactic acid drinking solution, which later was converted to a capsule formulation. Administration was po daily for 14 consecutive days at 21 day intervals at pre-determined dose increases between cohorts. Results: 31 patients (20 M, 11F) with advanced refractory cancers were treated; 14 received 20–80 mg/dose po in lactic acid solution and 17 po capsules 100–600 mg/dose. Median age was 60 y (29–72 y); median number of prior therapies was 4 (1–8); ECOG PS = 2. Median number of cycles was 2 (1–14). Patients continued on study until disease progression or significant toxicity. DLT for solution was nausea and emesis, ascribed to lactic acid. To date, no MTD or DLT observed with oral capsules at 600 mg daily; dose escalation continues using a twice daily schedule. No neurotoxicity has been observed. There was a disproportionate increase of the AUC with dose, with declining AUC corrected for dose starting at the 250 mg dose-level. The terminal half-life at the 600 mg dose was 25.2 ± 2.4 h. Prolonged disease stabilization was seen in 2 adenoid cystic carcinoma patients for 3 and 14 months and in one prostate cancer patient for 5 months. The latter patient went off study after 5 months due to liver function disorder (ALT CTC grade 2 and AST grade 3). Conclusions: Indibulin was well tolerated at doses showing preliminary clinical activity. Target plasma concentrations above the IC50 have been achieved. Dose escalation twice daily continues. Prolonged disease stabilization was noted in adenoid cystic carcinoma and prostate cancer.

[Table: see text]

Loss of AP-2alpha results in deregulation of E-cadherin and MMP-9 and an increase in tumorigenicity of colon cancer cells in vivo

Activator protein-2 (AP-2) is a transcription factor that regulates proliferation and differentiation in mammalian cells and has been implicated in the acquisition of the metastatic phenotype in several types of cancer. Herein, we examine the role of AP-2alpha in colon cancer progression. We provide evidence for the lack of AP-2alpha expression in the late stages of colon cancer cells. Re-expression of the AP-2alpha gene in the AP-2alpha-negative SW480 colon cancer cells suppressed their tumorigenicity following orthotopic injection into the cecal wall of nude mice. The inhibition of tumor growth could be attributed to the increased expression of E-cadherin and decreased expression and activity of matrix-metalloproteinase-9 (MMP-9) in the transfected cells, as well as a substantial loss of their in vitro invasive properties. Conversely, targeting constitutive expression of AP-2alpha in AP-2-positive KM12C colon cancer cells with small interfering RNA resulted in an increase in their invasive potential, downregulation of E-cadherin and increased expression of MMP-9. In SW480 cells, re-expression of AP-2alpha resulted in a fourfold increase in the activity of E-cadherin promoter, and a 5-14-fold decrease in the activity of MMP-9 promoter, indicating transcriptional regulation of these genes by AP-2alpha. Chromatin immunoprecipitation assay showed that re-expressed AP-2alpha directly binds to the promoter of E-cadherin, where it has been previously reported to act as a transcriptional activator. Furthermore, chromatin immunoprecipitation assay revealed AP-2alpha binding to the MMP-9 promoter, which ensued by decreased binding of transcription factor Sp-1 and changes in the recruitment of transcription factors to a distal AP-1 element, thus, contributing to the overall downregulation of MMP-9 promoter activity. Collectively, our data provide evidence that AP-2alpha acts as a tumor suppressor gene in colon cancer..

Mass vaccination for annual and pandemic influenza

Influenza virus causes annual epidemics and occasional pandemics. Frequent mutations in circulating influenza strains ("antigenic drift") result in the need for annual vaccination. More than two-thirds of persons in the U.S. are recommended for annual vaccination. Because influenza vaccine is available seasonally, mass vaccination strategies are well suited to its delivery. Although doctors offices are the most frequent setting for influenza vaccination overall, workplaces, clinics, and community sites (retail stores and pharmacies) also are common vaccination settings. Influenza vaccination also is delivered in mass vaccination clinics to health care workers and military personnel. Universal influenza vaccination, which has been recommended as a strategy to improve prevention by increasing vaccination coverage and providing indirect protection of adults by decreasing infection and transmission among children, would require expanded use of mass vaccination, for example in schools, as well as in the community. Influenza pandemics occur when a new influenza A subtype is introduced into the population ("antigenic shift"). Most or all of the population is susceptible to the pandemic virus and two doses of vaccine may be needed for protection. U.S. pandemic preparedness and response plans indicate that the entire population should be vaccinated beginning with defined priority groups including those who provide essential services including healthcare and those at highest risk of severe illness and death. Pandemic influenza vaccination will occur primarily through the public sector in mass clinic settings. Vaccination program planning must consider issues including coordination, staffing, clinic location and lay-out, security, record keeping, and communications. Exercising vaccination clinics is important for preparedness and can be done in the context of annual influenza vaccination.

Sorafenib in advanced melanoma: a Phase II randomised discontinuation trial analysis

The effects of sorafenib – an oral multikinase inhibitor targeting the tumour and tumour vasculature – were evaluated in patients with advanced melanoma enrolled in a large multidisease Phase II randomised discontinuation trial (RDT). Enrolled patients received a 12-week run-in of sorafenib 400 mg twice daily (b.i.d.). Patients with changes in bi-dimensional tumour measurements <25% from baseline were then randomised to sorafenib or placebo for a further 12 weeks (ie to week 24). Patients with ⩾25% tumour shrinkage after the run-in continued on open-label sorafenib, whereas those with ⩾25% tumour growth discontinued treatment. This analysis focussed on secondary RDT end points: changes in bi-dimensional tumour measurements from baseline after 12 weeks and overall tumour responses (WHO criteria) at week 24, progression-free survival (PFS), safety and biomarkers (BRAF, KRAS and NRAS mutational status). Of 37 melanoma patients treated during the run-in phase, 34 were evaluable for response: one had ⩾25% tumour shrinkage and remained on open-label sorafenib; six (16%) had <25% tumour growth and were randomised (placebo, n=3; sorafenib, n=3); and 27 had ⩾25% tumour growth and discontinued. All three randomised sorafenib patients progressed by week 24; one remained on sorafenib for symptomatic relief. All three placebo patients progressed by week-24 and were re-started on sorafenib; one experienced disease re-stabilisation. Overall, the confirmed best responses for each of the 37 melanoma patients who received sorafenib were 19% stable disease (SD) (ie n=1 open-label; n=6 randomised), 62% (n=23) progressive disease (PD) and 19% (n=7) unevaluable. The overall median PFS was 11 weeks. The six randomised patients with SD had overall PFS values ranging from 16 to 34 weeks. The most common drug-related adverse events were dermatological (eg rash/desquamation, 51%; hand-foot skin reaction, 35%). There was no relationship between V600E BRAF status and disease stability. DNA was extracted from the biopsies of 17/22 patients. Six had V600E-positive tumours (n=4 had PD; n=1 had SD; n=1 unevaluable for response), and 11 had tumours containing wild-type BRAF (n=9 PD; n=1 SD; n=1 unevaluable for response). In conclusion, sorafenib is well tolerated but has little or no antitumour activity in advanced melanoma patients as a single agent at the dose evaluated (400 mg b.i.d.). Ongoing trials in advanced melanoma are evaluating sorafenib combination therapies.

Randomized phase III trial of sorafenib in advanced renal cell carcinoma (RCC): Impact of crossover on survival

4524

Background: Sorafenib was approved for advanced RCC in the USA December 2005. A Phase III randomized double-blind, placebo-controlled trial demonstrated an estimated 39% improvement in survival for patients receiving sorafenib versus placebo (HR= 0.72, p = 0.018) (ECCO 2005). These data supported independently reviewed doubling of PFS to 24 weeks in RCC patients receiving sorafenib compared with placebo (12 weeks) (p < 0.000001) (ASCO 2005). Based on the statistical significance and magnitude of PFS benefit, patients were unblinded and placebo patients allowed to crossover to sorafenib in April 2005. A prospectively planned interim OS analysis reflecting impact of crossover of placebo patients is presented. Methods: OS data up to November 30, 2005, were analyzed in this interim analysis using a stratified log-rank test comparing the two treatment groups. In order to examine the effect of crossover on OS, a secondary analysis was performed censoring data from patients randomized to placebo at June 30, 2005. Results: A total of 903 patients were randomized (451 to sorafenib, 452 to placebo) and >200 placebo patients crossed over to sorafenib. Baseline characteristics were similar between treatment arms. There were 367 deaths. The median OS was 19.3 months for sorafenib versus 15.9 months for placebo (HR = 0.77; 95% CI 0.63, 0.95; p = 0.015); although this did not attain the level of significance specified for the interim analysis (α = 0.009), a continued favorable trend in survival benefit was observed. With censoring of crossover data, the median OS was 19.3 months for sorafenib versus 14.3 months for placebo (HR = 0.74, 95% CI 0.58, 0.93; p = 0.010). Conclusion: Sorafenib is the first novel, oral approved treatment for advanced RCC in more than a decade. Previous information on the effect of crossover on OS in randomized oncology studies is limited. The lower HR observed after censoring placebo patients crossed over to sorafenib suggests a continued beneficial effect of sorafenib. Final results await more mature data.

[Table: see text]