|
|||||
|
|
||||||
Originally published as JCO Early Release 10.1200/JCO.2005.03.4801 on March 6 2006 © 2006 American Society of Clinical Oncology. Phase I Study of Antisense Oligonucleotide Against Vascular Endothelial Growth Factor: Decrease in Plasma Vascular Endothelial Growth Factor With Potential Clinical Efficacy
From the Departments of Medicine, Pathology, and Preventive Medicine, University of Southern California (USC), Keck School of Medicine, Los Angeles, CA Address reprint requests to Alexandra M. Levine, MD, USC/Norris Comprehensive Cancer Center and Hospital, 1441 Eastlake Ave, Suite 3468, Los Angeles, CA 90033; e-mail: alevine{at}usc.edu
PURPOSE: Vascular endothelial growth factor antisense (VEGF-AS) is an antisense oligonucleotide that targets VEGF, inhibiting angiogenesis and tumor cell proliferation. This study established the safety, biologic effects, and pharmacokinetics of VEGF-AS in 51 patients with advanced malignancies. METHODS: VEGF-AS was administered as a 2-hour infusion daily for 5 consecutive days for only one cycle on the first four dose levels, and then administered daily for 5 days every other week for up to 4 months on subsequent levels. Pharmacokinetics, tumor response, and the effect on plasma VEGF levels were determined. RESULTS: The maximum-tolerated dose was 200 mg/m2. Dose-limiting toxicities included grade 4 fever, and pulmonary embolism in one patient each at 250 mg/m2. Mild anemia, fever, fatigue, and gastrointestinal complaints were the most common adverse events. VEGF-AS t1/2ß (beta-phase terminal half-life of drug concentration) was 2.25 hours (range, 1.97 to 2.95 hours). Mean plasma VEGF-A (P = .002) and VEGF-C (P = .01) levels decreased 24 hours postinfusion, with a trend towards greater decreases at higher dose levels. At the maximum-tolerated dose, five of six patients demonstrated reductions in plasma VEGF. Clinical responses included complete remission in one patient with AIDS-Kaposi's sarcoma, a mixed but dramatic response in one patient with cutaneous T-cell lymphoma, and prolongation of progression-free survival compared with that obtained on the immediate prior regimen in six patients (12%) with renal cell, bronchoalveolar, small cell lung, thyroid, and ovarian carcinomas, and chondrosarcoma, respectively. CONCLUSION: VEGF-AS was well tolerated, with biologic effects and preliminary evidence of clinical efficacy.
Angiogenesis is the process whereby new blood vessels sprout in response to local stimuli. The switch to the angiogenic phenotype is crucial in both tumor progression and metastasis.1 The key factor involved in signaling for angiogenesis in nearly all human tumors is vascular endothelial growth factor (VEGF),2,3 which is also required for vascular development.4,5 Thus, loss of only one VEGF allele in knockout mice results in embryonic death.4,5 Similarly, VEGF receptors are essential for blood vessel formation.6,7 Increased expression of VEGF receptors in endothelial cells of tumor vasculature attests to the significance of VEGF in tumor angiogenesis.8,9 Interactions between VEGF, its three known receptor tyrosine kinases (VEGFR-1/Flt-1, VEGFR-2/Flk-1/KDR, and neuropilin-1), and tumor endothelium may result in augmentation of angiogenesis through recruitment of paracrine circuits.10 In addition, during neoplastic transformation, tumor cells may acquire aberrant expression of VEGFR-2 with the ability to carry mitogenic VEGF signals to the nucleus, a function otherwise limited to endothelial cells.11 This autocrine growth factor activity of VEGF, demonstrated in a wide variety of tumor types, may also contribute to metastatic potential and poor outcome.12,13 We developed a 21-mer phosphothioate-linked antisense oligodeoxynucleotide (VEGF-AS or Veglin [VasGene Therapeutics Inc, Los Angeles, CA]) against VEGF, which targets the coding region of VEGF common to all isoforms. The VEGF-AS binds to mRNA, inducing RNAse-H activity, resulting in mRNA degradation. In addition, the target mRNA cannot be translated when bound to VEGF-AS, due to size constraints in the ribosome complex. The overall effect of VEGF-AS is the reduction of VEGF protein levels.14 The VEGF-AS was capable of inhibiting cell viability in tumor lines that expressed both VEGF and VEGFR (VEGFR),13 and was also shown to be active in mice implanted with various human tumor cell lines including ovarian, prostate, bladder, and pancreas carcinomas, melanoma, mesothelioma, and Kaposi's sarcoma (KS).13-15 Subsequent preclinical development demonstrated safety in mouse and monkey models.16 We herein report results of a phase I dose-escalation study of VEGF-AS administered to 51 patients with advanced malignancy.
Study Design We sought to determine the dose-limiting toxicity (DLT) and maximum-tolerated dose (MTD) of VEGF-AS administered as an intravenous infusion over 2 hours daily for 5 days on one occasion only (in the first four dose levels), and then administered daily for 5 days every other week for as long as 4 months in the subsequent 10 dose levels. To be assessable for DLT, patients were required to complete the 28-day safety assessment. Unassessable patients were replaced. This phase I trial used the standard 3 + 3 design, in which three patients were enrolled at each new dose level.17 The MTD was the highest dose level in which no more than one experienced a DLT, with six patients treated. No dose escalations were permitted within patients; however, two patients were entered twice, on two dose levels (Patient 3 was entered on dose level 1, then subsequently as patient 19 on level 6. Patient 13 was entered on dose level 3 and subsequently as patient 17 on level 6). Demographic data are presented for the cohort of 49 patients, whereas toxicity data are presented for the full 51 patients.
Definition of DLT
VEGF-AS Characteristics
Treatment Dose Levels
Entry Criteria All patients signed an informed consent form approved by the institutional review board. Patients were accrued with any malignancy for which standard therapeutic measures were ineffective. All stages of disease were allowed. Age 18 years or older and Karnofsky performance score (KPS) of at least 50 were required, with estimated survival of at least 3 months. Bilirubin was required as less than or equal to 1.5x the upper limit of normal, AST/ALT less than or equal to 2.5x the upper limit of normal; creatinine less than or equal to 1.5 mg/dL. An absolute neutrophil count at least 1,500/mm3 was required, with platelets at least 75,000/mm3, unless marrow was involved. Patients were excluded for neoplastic involvement of brain or CSF; history of deep vein thrombosis, pulmonary embolism or stroke; history of congestive heart failure, unstable angina, significant cardiac arrhythmia or myocardial infarction; chemotherapy or radiotherapy within 4 weeks; and major surgery within 2 weeks. Pregnant or lactating females were excluded.
Pharmacokinetic Analyses
VEGF-A and VEGF-C Levels in Plasma
Definition of Response and Progression-Free Survival
Statistical Analyses
Patients Accrued A total of 49 patients were accrued, including two individuals who were treated twice, on two distinct dose levels, resulting in 51 dose registrations. Characteristics of these patients are presented in Table 2.
Doses of VEGF-AS Administered A total of 837 doses were administered. The average number of doses received per patient was 20 (range, 5 doses to 40 doses), administered over 10 to 112 days (Table 1).
Toxicity
No significant cardiac toxicity was observed. No patient experienced congestive heart failure or myocardial infarction. Multi-gated acquisition scans were obtained at baseline in all patients, and at the completion of the first course (10 doses) of therapy and at the off-study visit in 40 of 51 patients. The median change in cardiac ejection fraction from baseline to end of study was 0% (range, 25% increase to 21% decrease). Four patients experienced asymptomatic decreases in ejection fraction over 10%, yet only one of these experienced a fall to below the normal range (patient 2, 52% to 43%). These decreases occurred at 15 mg/m2, 96 mg/m2, 125 mg/m2, and 200 mg/m2, respectively. Serious adverse events that were not drug related included death due to progressive cancer in 11 patients, neutropenic fevers in two patients with pre-existing neutropenia due to marrow involvement; and hospitalizations due to grade 3 anemia in one patient; gastrointestinal bleed from tumor in one patient; leg fracture secondary to trauma in one patient; esophageal stricture in one patient; and seizures secondary to underlying malignancy in one patient.
Pharmacokinetics of VEGF-AS
Plasma VEGF-A Levels
Plasma VEGF-C Levels The mean pretreatment VEGF-C level was 2,863 pg/mL (95% CI, 2,565 to 3,194 pg/mL), and fell to a mean of 2,529 pg/mL (95% CI, 2,302 to 2,778 pg/mL) at 24 hours postinfusion, representing a 11.2% decline (95% CI, 19.5% to 3.1%; paired t-test P = .010) Ten (23%) of 43 tested patients experienced a decline in VEGF-C more than 25% at 24 hours, whereas 31 patients (72%) had no change, and two patients (7%) had an increase of more than 25%. In a posthoc analysis, VEGF-C levels were more likely to decrease at VEGF-AS doses in excess of 100 mg/m2 (mean change, 21.4%; 95% CI, 33.9% to 6.6%), than at doses less than 100 mg/m2 (mean change, 5.3%; 95% CI, 14.9% to 5.4%; P = .049).
Clinical Responses A second patient with tumor-stage cutaneous T-cell lymphoma experienced a dramatic, although mixed response to VEGF-AS, administered at level 7 (74 mg/m2). His baseline VEGF-A level was 122 pg/mL, falling to 60 pg/mL by day 42. He experienced a 64% decrease of measurable disease after cycle one (Fig 2A), with normalization of the skin on [18F]fluorodeoxyglucose positron emission tomography scan (Fig 2B). The patient received local radiation therapy to pre-existing tumors on the buttock and lower left leg during cycle one, and missed a total of 15 of the planned 40 doses of VEGF-AS therapy (38%). On day 99 of therapy, during cycle four, he developed a new tumor on the leg, whereas his skin continued to improve. This patient had received local radiotherapy to tumors on the leg in the past without experiencing an abscopal or distant effect of the radiation in terms of improvement of his skin disease.
Six additional patients (12%) experienced stable disease, with the duration of PFS longer than that documented on the immediate prior regimen, based on review of scans obtained at onset and completion of that prior regimen. In these individuals, the median time to documented tumor progression on the immediate prior regimen was 76 days (range, 58 to 127 days), whereas the median time to tumor progression after VEGF-AS was 126.5+ days (range, 92+ to 185 days). A broad range of tumor types was represented in this group, including renal cell cancer, bronchoalveolar cancer, papillary and serous carcinoma of the fallopian tube, chrondrosarcoma, small-cell lung, and thyroid cancer. Median decline in VEGF level at 5 days postVEGF-AS infusion in this group was 48% (range, 98% to +1,031%). Four of these six patients had received higher doses of VEGF-AS, from 200 to 250 mg/m2. Another patient with mesothelioma (patient 40), who refused prior standard therapy despite symptomatic pleural effusions requiring thoracentesis, was treated at a dose of 175 mg/m2, and has continued to have stable disease parameters at 255+ days from institution of VEGF-AS, without requiring additional thoracentesis.
We have demonstrated that use of an antisense oligonucleotide against VEGF (VEGF-AS, Veglin) is associated with minimal toxicity at the MTD of 200 mg/m2, and is capable of inducing decreases in plasma levels of VEGF-A and VEGF-C within 24 hours of administration. At the MTD, five of six patients demonstrated significant reductions in plasma VEGF levels by 24 hours postinfusion, and all five patients experienced additional reductions through day 5. Furthermore, the drug was associated with an objective tumor response in one individual, a mixed response in a second patient, and prolongation in PFS in six additional patients, when compared with the documented PFS obtained from the immediate prior therapy. A total of 63% (five of eight) of these individuals with evidence of some clinical effect experienced a more than 25% fall in VEGF-A by day 5 postVEGF-AS versus 40% of the nonresponders, with a median fall in VEGF level at day 5 of 49% in responders, whereas nonresponders had a median fall of 26%. Evidence of an antineoplastic effect was seen in a variety of tumor types, including KS, lymphoma, renal cell, bronchoalveolar, thyroid, fallopian tube papillary serous, chondrosarcoma, and small-cell lung cancer.
One of the most potent stimulants of angiogenesis is tissue hypoxia, which commonly occurs as tumors outgrow their capillary blood supply. The resulting hypoxia stimulates expression of hypoxia-induced factor 1- In addition to their effects on tumor vasculature, VEGFRs have also been demonstrated on malignant cells of various tumor types, thus providing another potential mechanism for enhanced tumor cell growth, with VEGF signaling through autocrine pathways. VEGFR-2 expression, which gives a mitogenic signal to vasculature and is the major mediator of VEGF in target cells,31 has been documented in melanoma, ovarian carcinoma, KS, and other malignancies.13 Through inhibition of autocrine growth loops, VEGF-AS could decrease cell proliferation, as was demonstrated in several patients in this trial, who achieved objective tumor responses after use of the drug. Additional antitumor effects of VEGF blockade may also occur through inhibition of paracrine growth signals, as shown by the ability of VEGF to stimulate stromal cells to produce interleukin-6, which may itself stimulate tumor cell growth.10 VEGF-A and VEGF-C levels were statistically decreased within 24 hours after infusion of VEGF-AS, providing proof of the principle that the antisense did, in fact, specifically decrease these angiogenic proteins. In vitro, VEGF-AS has been shown to inhibit VEGF-A and to a lesser extent, VEGF-C and VEGF-D, presumably due to partial homology between them.13,32,33 It is possible that the early indication of efficacy of this approach is related to the ability of VEGF-AS to downregulate several members of the VEGF family. The DLTs of VEGF-AS were shown to be fever and pulmonary embolism, the latter of which occurred in one patient (2%). No other patient developed evidence of venous thrombotic events (VTEs). The risk of VTE appears to be lower than that described for other angiogenesis inhibitors,34-36 and metastatic carcinoma is a known risk factor for development of VTE, even in the absence of angiogenesis inhibitors.37 No patient developed evidence of symptomatic cardiac compromise. Serial assessments of cardiac ejection fraction revealed asymptomatic decreases over 10% in four individuals, only one of which fell to below the normal range. VEGF-AS was also associated with grade 4 fever in one patient, serving as a DLT for the drug. Other grade 1 and 2 toxicities included fever, hypotension, and various gastrointestinal symptoms. Grade 1 flushing of the hands or face was also noted in 10% of patients, while sensations of a hot flash occurred in 14% of patients. Anemia (grade 2 or 3) occurred in 18% of patients, all of whom had been heavily pretreated for malignant disease. The current study was limited by its phase I design, such that full information regarding the efficacy of this compound, or the optimal schedule or method of drug delivery have not yet been ascertained. Nonetheless, the use of VEGF-AS has been shown to be feasible, and associated with minimal toxicity at the MTD. Evidence of both biologic effects (fall in plasma VEGF levels) and clinical efficacy were most notable at the higher dose levels, suggesting a dose response relationship. Additional phase II studies are underway, in patients with renal cell carcinoma and KS, as well as a phase I study using VEGF-AS as a daily subcutaneous injection for up to 6 months.
Although all authors completed the disclosure declaration, the following authors or their immediate family members indicated a financial interest. No conflict exists for drugs or devices used in a study if they are not being evaluated as part of the investigation. For a detailed description of the disclosure categories, or for more information about ASCO's conflict of interest policy, please refer to the Author Disclosure Declaration and the Disclosures of Potential Conflicts of Interest section in Information for Contributors.
Dollar Amount Codes (A) < $10,000 (B) $10,000-99,999 (C)
Abscopal: A reaction produced following irradiation but occurring outside the zone of actual radiation absorption. Capillary gel electrophoresis: A method for separating biopolymers (eg, DNA and polypeptides) in a capillary filled with a network of cross-linked or entangled linear polymers (sieving matrix) with an applied electric field. Chondrosarcoma: A malignant tumor arising from cartilage tissue. KPS (Karnofsky performance score): A KPS (100 to 0) is used to evaluate a patient's therapeutic progress. A lower score predicts a lower chance of survival. MUGA scan (multi-gated acquisition/angiogram): A noninvasive heart function test that uses a radioactive tracer to delineate the chambers of the heart and major vessels.
Neutropenic fever: An oral temperature of at least 100.4°F for at least 1 hour when the absolute neutrophil count is Phosphothioate-linked antisense oligonucleotide: Phosphothioate is the substitution of one oxygen atom with sulfur in the internucleotide linkage. The phosphothioate modification renders the oligonucleotide more resistant to nuclease degradation without adversely affecting hybridization to complementary sequences. Thrombocytopenia: Reduced platelet count.
We thank Paul Ketteridge of VasGene Therapeutics Inc for supplying VEGF-AS for this trial, and Marita Salvosa for monitoring of the clinical trial.
Supported by in part by VasGene Therapeutics Inc, an L.K. Whittier Foundation grant to the USC/Norris Comprehensive Cancer Center and Hospital, Concern Foundation for Cancer Research, The Ezralow Family Foundation, and research Grant No. 1R01 CA 79218 from National Institutes of Health and the National Cancer Institute (Bethesda, MD). Presented in part at the 45th Annual Meeting of the American Society of Hematology, San Diego, CA, December 5-9, 2003; the 40th Annual Meeting of the American Society of Clinical Oncology, New Orleans, LA, June 5-8, 2004; and the 29th Congress of the European Society of Medical Oncology, Vienna, Austria, October 29-November 2, 2004. Terms in blue are defined in the glossary, found at the end of this article and online at www.jco.org. Authors' disclosures of potential conflicts of interest and author contributions are found at the end of this article.
1. Fidler IJ, Ellis LM: The implications of angiogenesis for the biology and therapy of cancer metastasis. Cell 79:185-188, 1994[CrossRef][Medline] 2. Dvorak HF, Brown LF, Detmar M, et al: Vascular permeability factor/vascular endothelial growth factor, microvascular hyper-permeability, and angiogenesis. Am J Pathol 146:1029-1039, 1995[Abstract] 3. Senger DR, Van de Water L, Brown LF, et al: Vascular permeability factor (VPF, VEGF) in tumor biology. Cancer Metastasis Rev 12:303-324, 1993[CrossRef][Medline] 4. Ferrara N, Carver-Moore K, Chen H, et al: Heterozygous embryonic lethality induced by targeted inactivation of the VEGF gene. Nature 380:439-442, 1996[CrossRef][Medline] 5. Carmeliet P, Ferreira V, Breier B, et al: Abnormal blood vessel development and lethality in embryos lacking a single VEGF allele. Nature 380:435-439, 1996[CrossRef][Medline] 6. Fong GH, Rossant J, Gertsenstin M, et al: Role of the Flt-1 receptor tyrosine kinase in regulating the assembly of vascular endothelium. Nature 376:66-70, 1995[CrossRef][Medline] 7. Shalaby F, Rossant J, Yamaguchi TP, et al: Failure of blood island formation and vasculogenesis in Flk-1 deficient mice. Nature 376:62-66, 1995[CrossRef][Medline] 8. Chan AS, Leung SY, Wong MP, et al: Expression of vascular endothelial growth factor and its receptors in the anaplastic progression of astrocytoma, oligtodendroglioma, and ependymoma. Am J Surg Pathol 22:816-826, 1998[CrossRef][Medline] 9. Leung SY, Chan AS, Wong MP, et al: Expression of vascular endothelial growth factor and its receptors in pilocytic astrocytoma. Am J Surg Pathol 21:941-950, 1997[CrossRef][Medline] 10. Dankbar B, Padro T, Leo R, et al: Vascular endothelial growth factor and interleukin-6 in paracrine tumor-stromal cell interactions in multiple myeloma. Blood 95:2630-2636, 2000 11. Takahashi T, Shibuya M: The 230 kDa mature form of KDR/Flk-1 (VEGF receptor-2) activates the PCL gamma pathway and partially induces mitotic signals in HIV3T3 fibroblasts. Oncogene 14:2079-2089, 1997[CrossRef][Medline] 12. Masood R, Cai J, Zheng T, et al: Vascular endothelial growth factor/vascular permeability factor is an autocrine growth factor for AIDS-Kaposi's sarcoma. Proc Natl Acad Sci U S A 94:979-984, 1997 13. Masood R, Cai J, Zheng T, et al: Vascular endothelial growth factor (VEGF) is an autocrine growth factor for VEGF receptor positive human tumors. Blood 98:1904-1913, 2001 14. Masood R, Kundra A, Zhu S, et al: Malignant mesothelioma growth inhibition by agents that target the VEGF and VEGF-C autocrine loops. Int J Cancer 104:603-610, 2003[CrossRef][Medline] 15. Hotz HG, Hines OJ, Masood R, et al: VEGF antisense therapy inhibits tumor growth and improves survival in experimental pancreatic cancer. Surgery 137:192-199, 2005[CrossRef][Medline] 16. VEGF-Antisense Oligonucleotide (VEGF-AS) (investigator's brochure). Los Angeles, CA: VasGene Therapeutics Inc, 2004 17. Simon RM: Design of clinical trials, in DeVita JM Jr, Hellman S, Rosenberg SA (eds): Cancer: Principles and Practice (ed 5). Philadelphia, PA, Lippincott-Raven Publishers, 1997, pp 514 18. Raynaud FI, Orr RM, Goddard PM, et al: Pharmacokinetics of G3139, a phosphorothioate oligodeoxynucleotide antisense to bcl-2, after intravenous administration or continuous subcutaneous infusion to mice. J Pharmacol Exp Ther 281:420-428, 1997 19. Therasse P, Arbuck SG, Eisenhauer EA, et al: New guidelines to evaluate the response to treatment in solid tumors. J Natl Cancer Inst 92:205-216, 2000 20. Cheson BD, Horning SJ, Coiffier B, et al: Report of an international workshop to standardize response criteria for non-Hodgkin's lymphomas: NCI Sponsored International Working Group. J Clin Oncol 17:1244-1253, 1999 21. Krown SE, Metroka C, Wernz JC: Kaposi's sarcoma in the acquired immune deficiency syndrome: A proposal for uniform evaluation, response, and staging criteriaAIDS Clinical Trials Group Oncology Committee. J Clin Oncol 7:1201-1207, 1989[Abstract] 22. Cheson BD, Cassileth PA, Head DR, et al: Report of the National Cancer Institute sponsored workshop on definitions of diagnosis and response in acute myeloid leukemia. J Clin Oncol 8:813-819, 1990[Abstract] 23. Zar JH: Paired sample hypothesis, in Biostatistical Analysis. Englewood Cliffs, NJ, Prentice-Hall Inc, 1974, pp 121-129 24. Zar JH: Simple linear correlation, in Biostatistical Analysis. Englewood Cliffs, NJ, Prentice-Hall Inc, 1974, pp 236-251 25. Gill PS, Lunardi-Iskandar Y, Louie S, et al: The effects of preparations of human chorionic gonadotropin on AIDS-related Kaposi's sarcoma. N Engl J Med 335:261-269, 1996 26. Gill PS, McLaughlin T, Espina BM, et al: Phase I study of a preparation of human chorionic gonadotropin given subcutaneously to patients with AIDS related Kaposi's sarcoma. J Natl Cancer Inst 89:1797-1892, 1997 27. Noy A, Scadden DT, Lee J, et al: Angiogenesis inhibitor IM 862 is ineffective against AIDS-Kaposi's sarcoma in a phase III trial, but demonstrates sustained, potent effect of highly active antiretroviral therapy: From the AIDS Malignancy Consortium and IM 862 Study Team. J Clin Oncol 23:990-998, 2005 28. Gleadle JM, Ratcliffe PJ: Hypoxia and the regulation of gene expression. Mol Med Today 4:122-129, 1998[CrossRef][Medline] 29. Ferrara N, Henzel WJ: Pituitary follicular cells secrete a novel heparin-binding growth factor specific for vascular endothelial cells. Biochem Biophys Res Commun 161:851-858, 1989[CrossRef][Medline] 30. Neufeld G, Tessler S, Gitay-Goren H, et al: Vascular endothelial growth factor and its receptors. Prog Growth Factor Res 5:89-97, 1994[CrossRef][Medline] 31. Millauer B, Wizigmann-Voos S, Schnurch H, et al: High affinity VEGF binding and developmental expression suggest Flk-1 as a major regulator of vasculogenesis and angiogenesis. Cell 72:835-846, 1993[CrossRef][Medline] 32. Kukk E, Lymboussaki A, Taira S, et al: VEGF-C receptor binding and pattern of expression with VEGFR-3 suggests a role in lymphatic vascular development. Development 122:3829-3837, 1996[Abstract] 33. Achen MG, Jeltsch M, Kukk E, et al: Vascular endothelial growth factor D (VEGF-D) is a ligand for tyrosine kinases VEGF receptor 2 (Flk-1) and VEGF receptor 3 (Flt 4). Proc Natl Acad Sci U S A 95:548-553, 1998 34. Zanagari M, Anaissie E, Barlogie B, et al: Increased risk of deep-vein thrombosis in patients with multiple myeloma receiving thalidomide and chemotherapy. Blood 98:1614-1615, 2001 35. Marx GM, Steer CB, Harper P, et al: Unexpected serious toxicity with chemotherapy and antiangiogenic combinations: Time to take stock! J Clin Oncol 20:1446-1448, 2002 36. Kuenen BC, Rosen L, Smit EF, et al: Dose-finding and pharmacokinetic study of cisplatin, gemcitabine, and SU5416 in patients with solid tumors. J Clin Oncol 20:1657-1667, 2002 37. Lee AYY, Levine MN: Venous thromboembolism and cancer: Risks and outcomes. Circulation 107:I17-I21, 2003 Submitted July 26, 2005; accepted December 22, 2005.
This article has been cited by other articles:
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
|||||||||||
|
Copyright © 2006 by the American Society of Clinical Oncology, Online ISSN: 1527-7755. Print ISSN: 0732-183X
|