Burden of illness analysis of renal cell carcinoma

14548

Background: There were over 36,000 new cases of kidney cancer reported in the US in 2004, the most common being renal cell carcinoma (RCC). RCC patients have limited treatment options and low survival rates, particularly for advanced-staged patients. Despite the growing importance of RCC, data on its economic burden are limited. Methods: A prevalence-based approach was used to estimate the aggregate annual cost burden from a societal perspective, including costs of medical treatment and lost productivity, due to RCC in the U.S. Key relationships represented in the model include the annual number of patients treated for RCC by age group and cancer stage; utilization of cancer specific treatments; unit costs of these treatments; work-days missed by these patients, and wage rates. Data sources included the linked Surveillance, Epidemiology, and End Results (SEER)-Medicare database, the Bureau of Labor Statistics, and the published literature. Results: The annual prevalence of RCC in the US was estimated to be 109,500 cases. The associated annual burden of RCC (US $2005) was approximately $4.8 billion ($43,749 per patient). Healthcare costs and lost productivity accounted for 84.9% ($4.1 billion) and 15.1% ($726 million) of the total, respectively. Reflecting its higher prevalence, the total cost associated with localized RCC accounted for the greatest share (78.2%) followed by regional, distant and unstaged RCC, which accounted for 18.3%, 2.8% and 0.7%, respectively. Sensitivity analyses resulted in a range in the estimated annual burden from $3.9 to $5.2 billion. Focusing only on newly diagnosed RCC cases (approximately 25,000 per year), the annual burden was estimated at $1.5 billion, with a per-patient cost of $62,340. Conclusions: The economic burden of RCC in the US is substantial. New therapies for RCC have the potential to yield considerable economic and societal benefits.

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Anti-proliferative effects of sorafenib in clear cell renal cell carcinoma (CCRCC) cell lines: Relationship to von Hippel Lindau protein (pVHL) expression and hypoxia

4601

Background: Sorafenib, a multikinase inhibitor targeting raf kinase and several receptor tyrosine kinases including VEGFR-2 and PDGFR, has demonstrated clinical activity in the treatment of metastatic CCRCC. To further characterize the molecular basis of response to this agent, we tested the functional role of pVHL and hypoxia in the anti-tumor activity of sorafenib in a panel of CCRCC cell lines. Methods: CCRCC cell lines CAKI-1 (wild-type pVHL), CAKI-2 (mutant VHL) and the isogenic pair, 786–0-neo (vector control) and 786–0-VHL (pVHL expressing) cells were treated with sorafenib (2.5 - 20 μM) for 24 - 96 hours at 37°C in a atmosphere of either normoxia (21% oxygen) or hypoxia (1% oxygen), 5% carbon dioxide and remainder nitrogen. Gene expression analysis of control and sorafenib treated CCRCC cell lines was carried out using a custom cancer cDNA array containing probes to 9240 cDNA clones corresponding to 4900 Unigenes or unclustered ESTs relevant to cancer or kidney development. Results: Anti-proliferative effects of sorafenib were both concentration and time of treatment dependent; the IC50 of sorafenib (inhibitory concentration for 50% cell kill) ranged from 7.5-10 μM and required continuous treatment for at least 48-72 hours for maximal cell kill. In contrast to CAKI-2 and 786–0-neo cells harboring mutant VHL, both CAKI-1 and 786–0-VHL cells expressing wild type VHL were ∼2-fold more resistant to the anti-proliferative effects of sorfaenib when treated under hypoxic conditions. No difference in resistance was observed under normoxic conditions. In contrast to 786–0-neo cells, there were ∼40 genes overexpressed (>5-fold) under hypoxia in control 786–0-VHL cells, that were predominantly related to anti-apoptosis (e.g. bcl2-associated athanogene) or angiogenesis (e.g. PDGF beta). Bcl2-associated athanogene and PDGF beta were down regulated >2-fold in hypoxia with sorafenib treatment. Conclusions: CCRCC with wild type VHL under hypoxic conditions can promote overexpression of anti-apoptotic and angiogenesis genes that attenuate the anti-proliferative effects of sorafenib. pVHL and hypoxia related genes may be important biomarkers for assessing the clinical efficacy of sorafenib in CCRCC.

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Randomized phase II trial of the multi-kinase inhibitor sorafenib versus interferon (IFN) in treatment-naïve patients with metastatic renal cell carcinoma (mRCC)

4501

Background: Sorafenib, an oral multi-kinase inhibitor that targets tumor growth and vascularization, significantly prolonged PFS in a Phase III trial with previously treated mRCC patients. This randomized Phase II trial investigated the efficacy and tolerability of sorafenib compared with IFN in first-line therapy of patients with clear-cell RCC. Methods: Untreated patients with mRCC were stratified by MSKCC prognostic score and randomized to receive continuous oral sorafenib 400 mg bid or IFN 9 million units tiw, with an option of dose escalation (600 mg bid sorafenib) or crossover from IFN to sorafenib upon disease progression. The study assessed PFS at 99 events as primary objective, best response (RECIST), overall survival, health-related quality of life, and adverse events (AEs). Results: Baseline characteristics of 188 patients (sorafenib n=97; IFN n = 91) were: median age 62.0 years; MSKCC score: 57% low, 41% intermediate, 1% high; prior nephrectomy: 82%; ECOG 0:1, 55.3%:44.7%. As of January 6, 2006, PFS events have been reported for 64 (34%) patients. Preliminary data showed drug-related AEs of any severity (sorafenib vs IFN) in 50.5% vs 51.6% of patients (≥grade 3: 8.2% vs 11.0%), including diarrhea (24.7% vs 5.5%), fatigue (14.4% vs 20.9%), fever (2.1% vs 18.7%), hypertension (13.4% vs 0%), nausea (5.2% vs 13.2%), flu-like syndrome (1.0% vs 6.6%), hand-foot skin reaction (6.2% vs 0%), and rash/desquamation (4.1% vs 0%). Drug-related metabolic/laboratory abnormalities at grade 3 (no grade 4) comprised hypophosphatemia (21.7% vs. 0%), lipase elevation (5.6% vs. 11.1%), anemia (0% vs. 5.3%) and hypoalbuminemia (0% vs. 3.6%). Five patients receiving IFN withdrew from treatment due to AEs, whereas only one patient withdrew from sorafenib. Conclusions: Sorafenib was generally well tolerated in RCC patients in the first-line setting, with relatively infrequent drug-related AEs ≥grade 3. Full PFS data will be presented at the meeting.

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Results of a Phase I trial of sorafenib (BAY 43-9006) in combination with doxorubicin in patients with refractory solid tumors

BACKGROUND

Sorafenib (BAY 43-9006), a novel, oral multi-kinase inhibitor, blocks serine/threonine and receptor tyrosine kinases in the tumor and vasculature. Sorafenib demonstrated single-agent activity in Phase I studies, and was tolerated and inhibited tumor growth in combination with doxorubicin in preclinical studies. This Phase I dose-escalation study determined the safety, pharmacokinetics and efficacy of sorafenib plus doxorubicin.

PATIENTS AND METHODS

Thirty-four patients with refractory, solid tumors received doxorubicin 60 mg/m(2) on Day 1 of 3-week cycles, and oral sorafenib from Day 4 of Cycle 1 at 100, 200 or 400 mg bid.

RESULTS

Common drug-related adverse events were neutropenia (56%), hand-foot skin reaction (44%), stomatitis (32%), and diarrhea (32%). The maximum tolerated dose was not reached. One patient with pleural mesothelioma achieved a partial response (modified WHO criteria) and remained on therapy for 39.7 weeks. Fifteen patients (48%) achieved stable disease for >/=12 weeks. Doxorubicin exposure increased moderately with sorafenib 400 mg bid. The pharmacokinetics of sorafenib and doxorubicinol were not affected.

CONCLUSION

Sorafenib 400 mg bid plus doxorubicin 60 mg/m(2) was well tolerated. The increased doxorubicin exposure with sorafenib 400 mg bid did not result in significantly increased toxicity; low patient numbers make the clinical significance of this unclear. These promising efficacy results justify further clinical investigation.

A phase III randomized trial of BAY 12-9566 (tanomastat) as maintenance therapy in patients with advanced ovarian cancer responsive to primary surgery and paclitaxel/platinum containing chemotherapy: a National Cancer Institute of Canada Clinical Trials Group Study

OBJECTIVE

BAY 12-9566 (tanomastat) is a biphenyl matrix metalloprotease inhibitor (MMPI) with antiangiogenic and antimetastatic properties in vivo. The objective of the study was to determine whether the addition of BAY 12-9566 after optimal response to chemotherapy could improve time to progression (TTP).

PATIENTS AND METHODS

Patients enrolled in the study had received 6-9 cycles of platinum/paclitaxel containing chemotherapy for stage III or IV ovarian carcinoma, with a response of no evidence of disease, or complete or partial response with residual disease < 2 cm. Patients were then randomized to BAY 12-9566 800 mg p.o. b.i.d. or placebo. The primary endpoint was progression-free survival (PFS); secondary endpoints were quality of life, toxicity, changes in CA 125 levels, response, and overall survival (OS). The total planned sample size was 730.

RESULTS

The study was closed after 243 patients had been randomized because of Bayer's decision to close all ongoing trials due to negative results from other phase III trials in pancreatic and small cell lung cancer. The final analysis was performed in August 2000 after the requisite number of events for the first planned interim analysis had occurred; 54% of patients had progressed and 18% had died.

PATIENT CHARACTERISTICS

performance status was ECOG 0/1/2 in 65/33/2%; median age 57 years; 79% of patients were FIGO stage III; 41% were optimally debulked; 76% had serous histology, and 67% had > or = grade 3 histology. Toxicity was generally grade 1 or 2 in severity, with the most common (BAY 12-9566 vs. placebo) being nausea (26% vs. 13%), fatigue (24% vs. 12%), diarrhea (14% vs. 10%), rash (12% vs. 7%), grade 3/4 thrombocytopenia (3% vs. 1%), and grade 3/4 anemia (5% vs. 1%). Median time to progression (TTP) was 10.4 months (8.5-11.5) for BAY 12-9566 and 9.2 months (7.2-13.9) for placebo (P = 0.67). Median overall survival (OS) was 13.9 months (12.9-infinity) for BAY 12-9566 and 11.9 months (10.5-16.5) for placebo (P = 0.53).

CONCLUSION

We conclude that BAY 12-9566 was generally well tolerated and at the time of the final analysis, there was no evidence of an impact of BAY 12-9566 on PFS or OS.

Pooled safety analysis of BAY 43-9006 (sorafenib) monotherapy in patients with advanced solid tumours: Is rash associated with treatment outcome?

In this analysis of the safety and efficacy of BAY 43-9006 (sorafenib) -- a novel, oral multi-kinase inhibitor with effects on tumour and its vasculature -- pooled data were obtained from four phase I dose-escalation trials. Time to progression (TTP) was compared in patients with/without grade 2 skin toxicity/diarrhoea. Grade 3 hand-foot skin reactions (HFS; 8%) and diarrhoea (6%) were common. At the recommended 400mg bid dose for phase II/III trials (RDP), 15% of patients experienced grade 2/3 HFS, and 24% experienced grade 2/3 diarrhoea. Sorafenib induced stable disease for 6 months in 12% of patients (6% stabilized for 1 year). Patients receiving sorafenib doses at or close to the RDP, who experienced skin toxicity/diarrhoea, had a significantly increased TTP compared with patients without such toxicity (P < 0.05). Sorafenib was well tolerated at the RDP, and induced sustained disease stabilization, particularly in patients with skin toxicity/diarrhoea.

How often should a port-A-cath be flushed?

While it is important during treatment to flush the port-A-cath (PAC) with heparin regularly, catheter maintenance needs to be evaluated in those patients who, after completion of therapy, retained their ports for extended periods of time. The manufacturer has recommended monthly accession to maintain catheter patency and function. Our objective is to demonstrate that a longer interval between maintenance accessions of PACs still may be medically safe, convenient, and more efficient. We performed a retrospective review of all patients who had undergone PAC insertion from 1988 to 1993 at the Albert Einstein College of Medicine, and from 1997 to 2002 at the New York Hospital Medical Center of Queens. An adequate maintenance time is defined as a period of at least 6 months without chemotherapy or total parenteral nutrition. Data collected included date and location of PAC insertion, date of PAC accessions, PAC complications, and results of attempts at flushing the catheters with no venous blood return. All data were entered into an Excel spreadsheet and analyzed. The difference in interval accessions in patients without any complication to patients with complication was calculated using the Mann-Whitney "U" test. A total of 73 patients were included in the study. Compliance with visits for PAC maintenance varied considerably with the individual median accession times varying between 28 and 262 days with an overall median of 42 days. The individual means ranged from 29.5 to 244 days with an overall mean of 53.6 days. Seven patients in the group had episodes where the provider was unable to draw blood from the port during routine accession. The average intervals between accessions for each of these patients ranged from 38 to 244 days. The average intervals of accession among those patients who had no blood return during PAC accession was 79 days, versus 63 days for those without any difficulty. The difference was not statistically significant (p>0.05). Monthly maintenance of PAC is excessive, inconvenient for the patients, and expensive. Extending the interval of PAC maintenance proves to be medically safe and beneficial to the patients, the physicians and the health care system. Our clinical experience suggests that less frequent accessions of PACs is safe and feasible. We strongly advocate future prospective investigation of alternative PAC maintenance protocols in gynecologic cancer patients.

Phase I study to determine the safety and pharmacokinetics of the novel Raf kinase and VEGFR inhibitor BAY 43-9006, administered for 28 days on/7 days off in patients with advanced, refractory solid tumors

BACKGROUND

BAY 43--9006, an oral multi-kinase inhibitor, targets serine-threonine kinases and receptor tyrosine kinases, and affects the tumor and vasculature in preclinical models. Based on its pharmacologic effect, it may be a useful cancer treatment. This study determined the maximum tolerated dose (MTD) of BAY 43-9006 in 42 patients with advanced, refractory metastatic or recurrent solid tumors. Dose-limiting toxicities (DLTs), safety, pharmacokinetics and tumor response were also evaluated.

PATIENTS AND METHODS

In this open-label, phase I, dose-escalation study, BAY 43--9,006 was administered orally in repeated cycles of 35 days (28 days on/7 days off). Eight doses were investigated: from 50 mg every fourth day to 600 mg twice daily. Treatment continued until unacceptable toxicity, tumor progression or death.

RESULTS

The MTD was 400 mg twice daily. BAY 43-9006 was well tolerated, with mild to moderate toxicities; only six patients discontinued study therapy due to adverse events. DLTs consisted of hand-foot skin reaction in three of seven patients receiving 600 mg twice daily. Stable disease was achieved in 22% of patients; median duration of stable disease was 7.2 months. Consistent with its observed half-life of approximately 27 h, BAY 43-9, 006 accumulated on multiple dosing. Increases in exposure were less than proportional to the increases in dose.

CONCLUSIONS

Results indicate that further clinical investigation of BAY 43--9006 is warranted, and suggest it could be a promising future therapy for patients with cancer.

An NCIC-CTG phase I dose escalation pharmacokinetic study of the matrix metalloproteinase inhibitor BAY 12-9566 in combination with doxorubicin

BACKGROUND

This phase I study was performed to evaluate the safety, tolerability, and efficacy of the oral matrix metalloproteinase inhibitor BAY 12-9566 in combination with doxorubicin in patients with advanced solid tumours, and to identify the maximum tolerated dose of these agents in combination and the dose for use in subsequent studies.

PATIENTS AND METHODS

14 patients were entered onto 3 dose levels consisting of escalating doses of doxorubicin (50 mg/m(2), 60 mg/m(2) and 70 mg/m(2)) with 800 mg po bid BAY 12-9566. At all three dose levels, patients received doxorubicin alone in cycle one on day 1. Daily oral dosing with BAY 12-9566 was started on day 8 of cycle 1, and thus doxorubicin was given concurrently with BAY 12-9566 in cycle 2. Patients were continued on treatment until a dose limiting toxicity or tumour progression occurred.

RESULTS

Pharmacokinetic studies from cycles 1 and 2 from the patients treated in the first three dose levels demonstrated that the addition of BAY 12-9566 increased the AUC(0-12h) levels of doxorubicin by a median of 48%. No effects were seen on the BAY 12-9566 pharmacokinetic values. Two dose limiting toxicities were seen at the third dose level. One patient experienced grade 3 stomatitis in cycle 2, and another patient experienced grade 4 granulocytopenia in cycle 1 and grade 4 thrombocytopenia in cycle 2. Thus the maximum tolerated dose of 60 mg/m(2) was declared. These toxicities were those that would have been expected from doxorubicin alone.

CONCLUSIONS

BAY 12-9566 can be safely administered with full doses of doxorubicin without evidence of clinical interaction. The recommended dose of doxorubicin to be combined with BAY 12-9566 800 mg po b.i.d is 60 mg/m(2), however, further development of BAY 12-9566 has been abandoned.

Hospital-acquired invasive group a streptococcal infections in Ontario, Canada, 1992-2000

BACKGROUND

A significant proportion of invasive group A streptococcal infections are hospital acquired. No large, prospective studies have characterized this subgroup of cases and evaluated the risk of transmission in hospitals.

METHODS

We conducted prospective, population-based surveillance of invasive group A streptococcal infections in Ontario, Canada, from 1992 to 2000. Epidemiologic and microbiologic investigations were conducted to identify cross-transmission.

RESULTS

We identified 291 hospital-acquired cases (12.4%) among 2351 cases of invasive group A streptococcal disease. Hospital-acquired invasive group A streptococcal infections are heterogeneous, including surgical site (96 cases), postpartum (86 cases), and nonsurgical, nonobstetrical infections (109 cases). Surgical site infections affected 1 of 100,000 surgical procedures and involved all organ systems. Postpartum infections occurred at a rate of 0.7 cases per 10,000 live births and exhibited an excellent prognosis. Nonsurgical, nonobstetrical infections encompassed a broad range of infectious syndromes (case-fatality rate, 37%). Nine percent of cases were associated with in-hospital transmission. Transmission occurred from 3 of 142 patients with community-acquired cases of necrotizing fasciitis requiring intensive care unit (ICU) admission, compared with 1 of 367 patients with community-acquired cases without necrotizing fasciitis admitted to the ICU and 1 of 1551 patients with other cases (P<.001). Fifteen outbreaks were identified; 9 (60%) involved only 2 cases. Hospital staff were infected in 1 of 15 outbreaks, but colonized staff were identified in 6 (60%) of 10 investigations in which staff were screened.

CONCLUSIONS

Presentation of hospital-associated invasive group A streptococcal infections is diverse. Cross-transmission is common; illness occurs in patients but rarely in staff. Isolation of new cases of necrotizing fasciitis and intervention after a single nosocomial case may also prevent transmission.

Phase I safety and pharmacokinetics of BAY 43-9006 administered for 21 days on/7 days off in patients with advanced, refractory solid tumours

BAY 43-9006 is a novel dual-action Raf kinase and vascular endothelial growth factor receptor (VEGFR) inhibitor that targets tumour cell proliferation and tumour angiogenesis. This Phase I study was undertaken to determine the safety profile, maximum tolerated dose (MTD), dose-limiting toxicities (DLTs), pharmacokinetics, and tumour response profile of oral BAY 43-9006 in patients with advanced, refractory solid tumours. BAY 43-9006 was administered daily for repeated cycles of 21 days on/7 days off. A total of 44 patients were enrolled at doses from 50 to 800 mg b.i.d. Pharmacokinetic profiles of BAY 43-9006 in plasma were determined during the first treatment cycle. The most frequently reported adverse events over multiple cycles were gastrointestinal (75%), dermatologic (71%), constitutional (68%), pain (64%), or hepatic (61%) related. A MTD of 400 mg b.i.d. BAY 43-9006 was defined. BAY 43-9006 was absorbed rapidly; steady-state conditions were reached within 7 days. BAY 43-9006 exposure increased nonproportionally with increasing dose. In all, 32 patients were evaluated for tumour response: 15 patients showed tumour progression, 16 patients experienced stable disease (>6 months in eight patients), and one patient with renal cell carcinoma achieved a partial response. BAY 43-9006 given for 21 days with 7 days off treatment was safe, well tolerated, and showed antitumour activity.

HTS magnetometers for fetal magnetocardiography

High temperature superconducting (HTS) SQUID sensors have adequate magnetic field sensitivity for adult magnetocardiography (MCG) measurements, but it remains to be seen how well they perform for fetal MCG (fMCG), where the heart signals are typically ten times smaller than the adult signals. In this study, we assess the performance of a prototype HTS SQUID system; namely, a three-SQUID gradiometer formed from three vertically-aligned HTS dc-SQUID magnetometers integrated into a fiberglass liquid nitrogen dewar of diameter 12.5 cm and height 30 cm. Axial gradiometers with short or long baseline, as well as a second order gradiometer, can be formed out of these magnetometers via electronic subtraction. The calibrated magnetometer sensitivities at 1 kHz are 109 fT/square root of Hz, 155 fT/square root of Hz and 51 fT/square root of Hz. Direct comparison is made between the HTS SQUID system and a LTS SQUID system by making recordings with both systems during the same session on adult and fetal subjects. Although the fMCG could be resolved with the HTS SQUID system in most near-term subjects, the signal-to-noise ratio was relatively low and the system could not be operated outside of a shielded room.