Ixabepilone Research Articles

Metabolism and Disposition of [14C]Brivanib Alaninate after Oral Administration to Rats, Monkeys, and Humans

Brivanib [(R)-1-(4-(4-fluoro-2-methyl-1H-indol-5-yloxy)-5-methylpyrrolo[1,2,4]triazin-6-yloxy)propan-2-ol, BMS-540215] is a potent and selective dual inhibitor of vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF) signaling pathways. Its alanine prodrug, brivanib alaninate [(1R,2S)-2-aminopropionic acid 2-[4-(4-fluoro-2-methyl-1H-indol-5-yloxy)-5-methylpyrrolo[2,1-f][1,2,4]triazin-6-yloxy]-1-methylethyl ester, BMS-582664], is currently under development as an oral agent for the treatment of cancer. This study describes the in vivo biotransformation of brivanib after a single oral dose of [(14)C]brivanib alaninate to intact rats, bile duct-cannulated (BDC) rats, intact monkeys, BDC monkeys, and humans. Fecal excretion was the primary route of elimination of drug-derived radioactivity in animals and humans. In BDC rats and monkeys, the majority of radioactivity was excreted in bile. Brivanib alaninate was rapidly and completely converted via hydrolysis to brivanib in vivo. The area under the curve from zero to infinity of brivanib accounted for 14.2 to 54.3% of circulating radioactivity in plasma in animals and humans, suggesting that metabolites contributed significantly to the total drug-related radioactivity. In plasma from animals and humans, brivanib was a prominent circulating component. All the metabolites that humans were exposed to were also present in toxicological species. On the basis of metabolite exposure and activity against VEGF and FGF receptors of the prominent human circulating metabolites, only brivanib is expected to contribute to the pharmacological effects in humans. Unchanged brivanib was not detected in urine or bile samples, suggesting that metabolic clearance was the primary route of elimination. The primary metabolic pathways were oxidative and conjugative metabolism of brivanib.

Metabolism, Excretion, and Pharmacokinetics of Oral Brivanib in Patients with Advanced or Metastatic Solid Tumors

The goal of this study was to evaluate the pharmacokinetics, mass balance, metabolism, routes and extent of elimination, and safety of a single oral dose of (14)C-labeled brivanib alaninate and the safety and tolerability of brivanib after multiple doses in patients with advanced or metastatic solid tumors. This was a two-part, single-center, open-label, single oral-dose (part A) followed by multiple-dose (part B) study in patients with advanced or metastatic solid tumors. In part A, patients received a single dose of [(14)C]brivanib alaninate and in part B patients received 800 mg of nonradiolabeled brivanib alaninate every day. Four patients (two white, two black: two with non-small-cell lung cancer, one with ovarian cancer, and one with renal cell carcinoma) were treated in both parts. The median time to reach the maximal plasma concentration of brivanib was 1 h, geometric mean maximal plasma concentration was 6146 ng/ml, mean terminal half-life was 13.8 h, and geometric mean apparent oral clearance was 14.7 l/h. After a single oral dose of [(14)C]brivanib alaninate, 12.2 and 81.5% of administered radioactivity was recovered in urine and feces, respectively. Brivanib alaninate was completely converted to the active moiety, brivanib, and the predominant route of elimination was fecal. Renal excretion of unchanged brivanib was minimal. Brivanib was well tolerated; fatigue was the most frequent adverse event occurring in all patients and the most frequent treatment-related adverse event in three (75%). The best clinical response in one patient was stable disease; the other three had progressive disease. Brivanib alaninate was rapidly absorbed and extensively metabolized after a single 800-mg oral dose; the majority of drug-related radioactivity was excreted in feces.

Phase II trial of ixabepilone (IXA) plus cetuximab (C) as first-line therapy for advanced pancreatic carcinoma (PC).

4086 Background: Progress in the management of PC is desperately needed. Non-gemcitabine based regimens are understudied. IXA has demonstrated activity in preclinical PC models including synergistic activity in combination with C. In a phase II cooperative group study in chemo-naïve PC patients (pts) IXA showed promising efficacy. Here we present the results of a phase II, open label trial of IXA plus C as first line therapy for metastatic PC. Methods: Previously untreated pts (KPS 70–100) witheither locallyadvanced (LA) or metastatic (M) PC, were treated with IXA (32 mg/m2) IV over 3h on day 1 every 3 weeks and C, 400 mg/m2 IV (day 1) followed by weekly 250 mg/m2 doses. Pts were treated to progression or unacceptable toxicity. The primary endpoint was six month survival rate. The study tested the null hypothesis that the true 6-month rate ≤ 50% versus the alternative that the true rate > 70%. Results: Fifty-four pts (male/female 35/19; median age 63, range 47–84; LA/M 4/50) were enrolled in the study. A median of 4 cycles (range 1–21) were administered. All enrolled pts were evaluable for toxicity and survival endpoints and 31 pts were evaluable for response. The primary endpoint of 6-month survival rate was 62% (95% CI 49–75). The 95% CI for this 6 month rate did not exclude a prespecified hurdle of 50%. Median overall survival was 7.6 months (95% CI 5.5–12.2) and the 12-month survival rate was 40% (95% CI 26.91–53.75). Objective response rate was 13% (4 PRs), 77% SD, and 6% PD. Median progression free survival was 3.9 months (95% CI 2.6–4.4). Severe neutropenia was observed in 34% of treated patients (grade 3 in 20%; grade 4 in 16%). grade 3/4 febrile neutropenia occurred in 2 (4%) patients. The most frequent nonhematologic grade 3/4 toxicities were fatigue (19%), hypomagnesemia (8%), diarrhea (6%), hypersensitivity reactions (6%), peripheral neuropathy (6%) and acneiform rash (2%). Conclusions: IXA plus C is a feasible and active regimen with an acceptable toxicity profile in chemotherapy naïve PC pts. Author Disclosure Employment or Leadership Position Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Bristol-Myers Squibb Bristol-Myers Squibb Bristol-Myers Squibb Bristol-Myers Squibb

Characterization of brivanib pharmacokinetics and exposure-response (E-R): Relationship of fatigue in patients with advanced and metastatic solid tumors.

3095 Background: Brivanib alaninate is the L-alanine ester prodrug of brivanib, an oral selective dual inhibitor of vascular endothelial growth and fibroblast growth pathway receptors. It is curren...

Experimental treatment of oestrogen receptor (ER) positive breast cancer with tamoxifen and brivanib alaninate, a VEGFR-2/FGFR-1 kinase inhibitor: A potential clinical application of angiogenesis inhibitors

Purpose Tamoxifen, a selective oestrogen receptor modulator (SERM), and brivanib alaninate, a vascular endothelial growth factor receptor 2 (VEGFR-2) inhibitor, are two target specific agents that result in a substantial decrease in tumour growth when given alone. Tamoxifen activates SERM stimulated breast and endometrial tumour growth. Tamoxifen and brivanib alaninate have side-effects that can affect therapeutic outcomes. The primary goal of the current study was to evaluate the therapeutic effects of lower doses of both agents when given in combination to mice with SERM sensitive, oestrogen stimulated tumour xenografts (MCF-7 E2 tumours). Experiments were conducted to evaluate the response of SERM stimulated breast (MCF-7 Tam, MCF-7 Ral) and endometrial tumours (EnCa 101) to demonstrate the activity of brivanib alaninate in SERM resistant models. Experimental design In the current study, tumour xenografts were minced and bi-transplanted into the mammary fat pads of athymic, ovariectomised mice. Preliminary experiments were conducted to determine an effective oral dose of tamoxifen and brivanib alaninate that had minimal effect on tumour growth. Doses of 125 μg of tamoxifen and 0.05 mg/g of brivanib alaninate were evaluated. An experiment was designed to evaluate the effect of the two agents together when started at the time of tumour implantation. An additional experiment was done in which tumours were already established and then treated, to obtain enough tumour tissue for molecular analysis. Results Brivanib alaninate was effective at inhibiting tumour growth in SERM sensitive (MCF-7 E2) and SERM stimulated (EnCa 101, MCF-7 Ral, MCF-7 Tam) models. The effect of the low dose drug combination as an anti-tumour strategy for SERM sensitive (MCF-7 E2) in early treatment was as effective as higher doses of either drug used alone. In established tumours, the combination is successful at decreasing tumour growth, while neither agent alone is effective. Molecular analysis revealed a decreased phosphorylation of VEGFR-2 in tumours that were treated with brivanib alaninate and an increase in VEGFA transcription to compensate for the blockade of VEGFR-2 by increasing the transcription of VEGFA. Tamoxifen increases the phosphorylation of VEGFR-2 and this effect is abrogated by brivanib alaninate. There was also increased necrosis in tumours treated with brivanib alaninate. Conclusion Historically, tamoxifen has a role in blocking angiogenesis as well as the blockade of the ER. Tamoxifen and a low dose of an angiogenesis inhibitor, brivanib alaninate, can potentially be combined not only to maximise therapeutic efficacy but also to retard SERM resistant tumour growth.

The Antiangiogenic Activity in Xenograft Models of Brivanib, a Dual Inhibitor of Vascular Endothelial Growth Factor Receptor-2 and Fibroblast Growth Factor Receptor-1 Kinases

Tumor angiogenesis is a complex and tightly regulated network mediated by various proangiogenic factors. The fibroblast growth factor (FGF) and vascular endothelial growth factor (VEGF) family of growth factors, and associated tyrosine kinase receptors have a major influence in tumor growth and dissemination and may work synergistically to promote angiogenesis. Brivanib alaninate is the orally active prodrug of brivanib, a selective dual inhibitor of FGF and VEGF signaling. Here, we show that brivanib demonstrates antitumor activity in a broad range of xenograft models over multiple dose levels and that brivanib alaninate shows dose-dependent efficacy equivalent to brivanib in L2987 human tumor xenografts. Brivanib alaninate (107 mg/kg) reduced tumor cell proliferation as determined by a 76% reduction in Ki-67 staining and reduced tumor vascular density as determined by a 76% reduction in anti-CD34 endothelial cell staining. Furthermore, Matrigel plug assays in athymic mice showed that brivanib alaninate inhibited angiogenesis driven by VEGF or basic FGF alone, or combined. Dynamic contrast-enhanced magnetic resonance imaging, used to assess the effects of brivanib alaninate on tumor microcirculation, showed a marked decrease in gadopentetate dimeglumine contrast agent uptake at 107 mg/kg dose, with a reduction in area under the plasma concentration-time curve from time 0 to 60 minutes at 24 and 48 hours of 54% and 64%, respectively. These results show that brivanib alaninate is an effective antitumor agent in preclinical models across a range of doses, and that efficacy is accompanied by changes in cellular and vascular activities.

Highlights of This Issue

Tumorigenesis is influenced by natural selection processes, thus molecular evolutionary methodologies could be useful for understanding cancer biology. Zhang and colleagues describe a phylogenetic analysis of 353 cancer cell lines based on the alignment of 3252 variant nucleotides from 494 genes from 353 cancer cell lines. Reconstructed phylogenetic trees clustered cell lines by shared DNA variant patterns rather than tissue, suggesting that certain diverse cancer types have similar oncogenic pathways. Positive selection analysis revealed specific DNA variants that might be potential driver mutations. Their study supports the broader application of evolutionary approaches in the analyses of the cancer genome.The clinical efficacy of lapatinib, a small molecule inhibitor of ErbB2 and EGFR tyrosine kinases, is limited by the development of therapeutic resistance. Xia and colleagues show that lapatinib unexpectedly activated RelA/NF-κB in ErbB2+ breast cancer cell lines and in ErbB2+ breast cancer patients. Inhibition of RelA phosphorylation led to increased apoptosis in lapatinib-treated ErbB2+ breast cancer cells. Furthermore, increased phospho-RelA expression in tumors treated with lapatinib monotherapy correlated with a poorer clinical outcome in ErbB2+ breast cancer patients. These findings identify RelA as a promising therapeutic target to enhance the clinical efficacy of lapatinib in ErbB2+ breast cancers.Approaches to improve standard chemotherapeutic regimens by defining combinations are still empiric. Jimeno and colleagues evaluated a rational way of identifying relevant targets involved in the vulnerability of pancreatic cancer to gemcitabine. Pancreatic xenograft samples with known gemcitabine sensitivity were dynamically interrogated by exposure to gemcitabine and analysis of a preselected set of druggable genes. This identified Plk1 as a target dictating the susceptibility of pancreatic cancer to gemcitabine. Mechanistic studies aimed at testing this hypothesis were conducted utilizing gene interference and pharmacologic Plk1 inhibition, followed by in vivo testing in a direct xenograft model of pancreatic cancer.Brivanib is an oral, dual selective inhibitor of VEGF and FGF signaling under clinical investigation. Bhide and colleagues evaluated the antitumor activity and antiangiogenic activities of brivanib and its prodrug brivanib alaninate in xenograft models and Matrigel plug assays in athymic mice. Brivanib and brivanib alaninate demonstrated potent antitumor and antiangiogenic activity over multiple dose levels in a broad range of tumor types. Further, brivanib alaninate inhibited angiogenesis driven by VEGF or bFGF alone, or when both growth factors were combined. This data supports the utility of targeting both VEGF- and FGF-induced angiogenesis in solid tumors.

Ixabepilone plus Capecitabine for Metastatic Breast Cancer

Treatment options are few for patients with metastatic breast cancer (MBC) who have already been treated unsuccessfully with an anthracycline and a taxane. FDA approval of the epothilone known as ixabepilone has expanded the options. In a previous phase III, randomized trial involving patients with anthracycline- and taxane-resistant MBC, ixabepilone plus capecitabine yielded significantly …

Amplification of fibroblast growth factor receptor-1 in breast cancer and the effects of brivanib alaninate

Fibroblast growth factor receptor-1 (FGFR-1) is amplified in 10% of human breast cancers. The goal of this study was to test the correlation between FGFR-1 amplification and expression and sensitivity to brivanib, an FGFR-1 small molecule inhibitor, in breast cancer cell lines in vitro. Using CGH array and gene expression profiling, FGFR-1 DNA copy number, mRNA, and protein expression were measured in 21 cell lines and correlated with growth inhibition by brivanib. We examined FGFR-1 autophosphorylation and kinase activity, as well as phosphorylation of downstream signaling molecules in response to bFGF and brivanib exposure. CAMA, MDA-MB-361, and HCC38 cells had FGFR-1 amplification and protein overexpression. Brivanib GI(50) values were significantly lower in the gene amplified (15.17 μM, n = 3) compared to normal copy number (69.09 μM, n = 11) or FGFR-1 deleted (76.14 μM, n = 7) cells (P = 0.0107). Among nonamplified cells, there was no correlation between FGFR-1 mRNA or protein expression levels and brivanib sensitivity. Two of three FGFR-1 amplified cells were sensitive to bFGF-induced growth stimulation, which was blocked by brivanib. In cells with amplified FGFR-1, brivanib decreased receptor autophosphorylation, inhibited bFGF-induced tyrosine kinase activity, and reduced phosphorylation of ERK and AKT. Breast cancer cell lines with FGFR-1 gene amplification and protein overexpression are more sensitive to growth inhibition by brivanib than nonamplified cells. These findings suggest that FGFR-1 amplification or protein overexpression in breast cancers may be an indicator for brivanib treatment, where it may have direct anti-proliferative effects in addition to its' anti-angiogenic effects.

Antiangiogenic (AG) Synergy with Ixabepilone (IXA): Translation of Preclinical Studies to the Clinical Setting.

Abstract Background: Optimal benefit from AG therapy generally requires combination with cytotoxic agents, including taxane (TAX) microtubule stabilizing agents (MTSA), e.g. paclitaxel (PTX). IXA, is a new MTSA approved for the treatment of metastatic breast cancer (MBC). We evaluated the antitumor activity of IXA combined with several AG agents, relative to TAX based MTSAs and showed that IXA+BEV demonstrates advantages over PTX. Studies were conducted to determine parameters that might limit TAX effectiveness, while retaining IXA activity. A Phase II clinical trial provides preliminary support for the benefits of IXA+BEV in MBC.Methods: Three IXA+AG agent combinations were explored: BEV, sunitinib (SUN) or brivanib (BRV), a dual VEGF/FGF inhibitor in phase III clinical trial. Therapeutic synergy (TS) was evaluated in several human tumor xenografts (Table 1).Synergy of IXA with three diverse AG agents Antitumor activity (log cell kill, LCK)TumorIXAAG agentsIXA+AG agentsPat-21 (basal breast)1.60.3 (BEV)2.3 (+BEV)151b (renal)0.60.5 (SUN)1.3 (+SUN)L2987 (NSCLC)1.31.4 (BRV)2.4 (+BRV) In vitro AG activity was determined in endothelial cells (ECs) of bovine (ABAE) or human (HUVEC) origin, which express known TAX resistance factors, (βIII tubulin (βIII) and/or MDR1 P-glycoprotein (Pgp)). In vivo AG activity was determined using the Matrigel™ plug and tumoral microvessel density assays. Pgp and βIII expression was determined by Western blot or IHC. Effects of BEV on IXA tumor access was evaluated by determining acetylated α-tubulin (AαT), a post-translational marker of stabilized MTs. Phase II trial: women with locally advanced or MBC, randomized to Arm A (IXA 16 mg/m2 IV on days 1, 8 & 15 q28 days/ BEV 10 mg/kg IV q 2 wks), Arm B (IXA 40 mg/m2 IV q3 wks/BEV 15 mg/kg IV q 3 wks) or Arm C (PAC 90 mg/m2 IV, schedule/BEV as in Arm A).Results: IXA showed marked TS when combined with BEV, SUN or BRV and a 5X >LCK in the GEO colon model when combined with BEV than PAC+BEV. BEV did not enhance IXA induced AαT levels, a marker of tumor drug access. IXA was 3-fold more cytotoxic to ECs than PTX. Tumor associated ECs expressed high βIII and Pgp levels. IXA was more active than PTX in inhibiting EC infiltration and proliferation in Matrigel™ plugs in vivo (P<0.0001). In GEO, BEV+IXA produced synergistic reduction of tumoral vascular density compared to BEV (P<0.0001) or IXA (P=0.035). In contrast, BEV+PTX was not better than PTX alone (P=0.373). In a phase II trial, IXA+BEV showed an efficacy and safety profile similar to PTX+BEV (%ORR Arms A, B, C: 50, 71, 56%).Discussion: IXA has potent AG activity as a single agent and robust TS in combination with AG agents. Mechanism studies suggest that resistance factors found in ECs, like βIII and Pgp, have little impact on IXA, while limiting the activity of TAX. Initial clinical studies demonstrate that IXA+BEV is safe and effective for the 1st line treatment of patients with MBC, with a profile similar to that of PAC+BEV. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 206.

Clinical and Pharmacokinetic Study of Ixabepilone (IXA) Plus Epirubicin (EPI) as Therapy for Women with Advanced Breast Cancer (BC).

Abstract Background: IXA and EPI have established single agent activity in early and late stage BC, however, safety and pharmacokinetics (PK) of the combination are unknown. This study aimed to determine the dose-limiting toxicities (DLT), define the maximum tolerated dose (MTD), investigate PK, and evaluate safety and activity of the combination of IXA and EPI in women with advanced BC.Patients and Methods: Women with locally advanced, recurrent or metastatic BC with ≤ 1 prior chemotherapy regimen as 1st line therapy, a maximum cumulative dose of ≤ 450 mg/m2 for EPI, or ≤300 mg/m2 for doxorubicin were eligible. A short IV infusion of EPI was followed by a 3-hour IV infusion of IXA given every 3 weeks. Three cohorts (3 to 6 patients (pts) per cohort) received IXA/EPI at 25/75, 30/75 and 35/75 mg/m2 respectively. An additional 24 pts were enrolled at the MTD. Blood samples for PK analysis of IXA, EPI and epirubicinol (EOL, major metabolite of EPI) were collected from all pts during cycle 1 and analyzed using LC/MS/MS. PK samples were collected out to 120 h for ixabepilone and 24 h for EPI/EOL. PK parameters were generated by non-compartmental methods.Results: Forty-two pts, median age of 57 (33-69) yrs were treated, 6 at 25/75 mg/m2, 6 at 35/75 mg/m2 and 30 at 30/75 mg/m2, receiving a total of 249 cycles (median 6, range 1-10). All pts were evaluable for safety and efficacy and 38 were evaluable for PK. Two DLTs, febrile neutropenia and grade 3 vomiting, occurred at the 35/75 mg/m2 dose level; therefore 30/75 mg/m2 (IXA/EPI) was defined as the MTD. No deaths or grade 4 non-hematological toxicities were reported. Neutropenia was the most frequent treatment related severe toxicity.Objective responses were seen at all dose levels in 18/32 pts (56%) with measurable disease. In addition, 2/10 pts (17%) with non-measurable disease had complete response. PFS was ≥6 mo in 27 (64%) pts and ≥ 9 mo in 18 (43%). IXA plasma concentrations declined rapidly in the first 24 hrs, followed by a slower elimination phase. Observed means of both elimination half-life (34-52 h) and clearance (25-27 L/h) within each cohort indicate a slow elimination of IXA from plasma. The IXA Cmax and AUC were linear across the 3 dose levels evaluated. With the EPI dose remaining at 75mg/m2, no alteration in EPI AUC was observed across dose levels. Exposure to EOL decreased with increasing IXA dose (Geo Mean AUC: 575.48, 314.46 and 204.46 in each dose group respectively). This may be due to altered metabolism of EPI in the presence of IXA or Cremophor in the IXA formulation. No relationship was observed between PK parameters of IXA, EPI or EOL and nausea, vomiting, and neutropenia.Conclusions: The combination of IXA/EPI is feasible, efficacious and has an acceptable safety profile at the studied dose levels. No clinically relevant PK interactions were observed. The observed effect on EOL exposure deserves further investigation. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2097.

Abstract C237: A phase I study of the alternating administration of ixabepilone and vinflunine every three weeks in patients with advanced cancer

Abstract Background: Vinflunine (VFL) is a new microtubule inhibitor of the vinca alkaloid class. VFL inhibits tubulin polymerization. Ixabepilone (IXA), a microtubule inhibitor, binds directly to -tubulin subunits, leading to suppression of microtubule dynamics. These agents have complementary mechanisms of action and relatively non-overlapping toxicities. This study was conducted to determine the maximum tolerated dose (MTD) and dose limiting toxicity (DLT) of an alternating regimen of VFL and IXA in patients (pts) with advanced cancer and to recommend a Phase 2 dose. Materials and Methods: This was an open-label Phase 1 doseescalation study of IXA and VFL in pts with advanced cancer. IXA was administered as a 3-hour infusion alternating every 3 weeks (wks) with VFL administered as a 20-minute infusion. A cycle was defined as 6 wks (42 days), with DLT assessment during Cycle 1. Doses started at 30 mg/m2 IXA and 250 mg/m2 VFL (IXA30+VFL250). VFL doses were first escalated to a maximum of 320 mg/m2. Once an intolerable dose or the maximum dose of VFL was reached, IXA was to be escalated with a maximum dose level of IXA 40 mg/m2. A standard 3+3 escalation design was used. The MTD was defined as the dose level below which ≥2/6 pts experienced a DLT. Results: This was the first clinical study to evaluate vinflunine and ixabepilone as an alternating regimen. Nine pts were enrolled and treated; 3 each at IXA30+VFL250, IXA30+VFL280, and IXA30+VFL320. Further enrollment and dose escalation was stopped when the study was closed due to termination of VFL development at BMS. The treated pts consisted of 8 males / 1 female, 3 with SCLC, 4 with NSCLC, and 2 with sarcomas. The majority of pts were white (8 of 9). Median Age was 63 years (range 38–85). ECOG performance status was 0 (n=1) or 1 (n=8). Adverse events were summarized by treatment. Of interest, 3 pts experienced grade 1 peripheral neuropathy (1 IXA, 2 VFL); 5 pts with grade 3/4 neutropenia (2 IXA, 2 VFL, 1 IXA/VFL); 2 pts with grade 2 constipation (2 VFL). Serious adverse events (SAEs) were reported in 3 of 9 treated pts. The SAEs of pyrexia grade 2, neutropenia grade 2, and leucopenia grade 3 were considered related to study drug in 1 patient. None of the SAEs or non-serious AEs led to discontinuation of study treatment. Two pts experienced progression of disease which resulted in death. Antitumor activity (as defined by RECIST and assessed by the investigator) was observed: confirmed partial response in 1 pt with NSCLC (IXA30+VFL320 dose level) and stable disease lasting from 2.5 to 9 months in 3 pts (2 with SCLC in IXA30+VFL250 and 1 with NSCLC in IXA30+VFL280). Conclusions: There were no DLTs observed in the dose levels examined and the MTD was not reached due to termination of study. The toxicity of the alternating regimen was manageable. Antitumor activity was observed in all dose cohorts. The alternating regimen of vinflunine and ixabepilone may warrant further investigation. Citation Information: Mol Cancer Ther 2009;8(12 Suppl):C237.

Abstract B12: The antitumor and antiangiogenic activity of brivanib, a dual inhibitor of VEGFR-2 and FGFR-1 kinases

Abstract Angiogenesis plays a central supporting role in tumorigenesis in a wide variety of different cancer types. This complex and highly regulated process has been shown to be driven by various proangiogenic factors. The vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF) family of growth factors in conjunction with their associated tyrosine kinase receptors exert a major influence on tumor growth and dissemination, and potentially work synergistically to promote angiogenesis. Brivanib alaninate (BMS-582664) which is currently in phase III clinical trails is the orally active prodrug of brivanib (BMS-540215), a selective dual inhibitor of VEGF and FGF signaling. We demonstrate here that in vivo brivanib provides antitumor activity in a broad range of xenograft models over multiple dose levels, and that brivanib alaninate demonstrates dose-dependent efficacy equivalent to brivanib. Brivanib alaninate also reduces tumor cell proliferation as determined by a significant reduction in Ki-67 staining as well as a decrease in tumor vascular density as reflected by a reduction in CD34 staining, a cellsurface marker of endothelial cells. Additionally, using Matrigel™ plug assays in athymic mice we demonstrated that brivanib alaninate inhibits angiogenesis driven by VEGF or bFGF alone as well as when both of these cytokines are combined to drive angiogenesis in this model. Moreover, brivanib was more effective in inhibiting angiogenesis in this model system under all these conditions when compared to either bevacizumab, an antibody directed at the human VEGF cytokine or DC101, an antibody directed at the murine form of VEGF receptor-2. Dynamic contrast-enhanced magnetic resonance imaging, used to assess the effects of brivanib alaninate on tumor microcirculation, demonstrated a marked decrease in contrast agent uptake at an efficacious dose level, with a reduction in area under the plasma concentration-time curve from time 0 to 60 min (AUC60) at 24 h and 48 h of 54% and 64%, respectively. These results demonstrate that brivanib alaninate is an effective antitumor agent in preclinical tumor and angiogenesis models across a range of doses, and that efficacy is accompanied by changes in cellular and vascular activities. Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B12.

Fibroblastic Growth Factor Pathway

Fibroblastic Growth Factor Pathway

Mass balance, pharmacokinetics, and metabolism of [14C] brivanib (BMS-582664), prodrug of BMS-540215, in subjects with advanced or metastatic solid tumors

3566 Background: Brivanib alaninate (BMS-582664, B) is an oral prodrug of BMS-540215, a dual tyrosine kinase inhibitor of VEGFR and FGFR signaling pathways which are important for angiogenesis and tumor growth. The recommended phase II/III dose of B is 800 mg daily. Methods: A two-part, open-label, single-dose study was conducted in subjects with advanced or metastatic solid tumors. Part A represented the period for assessment of the pharmacokinetics (PK), metabolism, and elimination of B, In part A, subjects received a single oral dose of 800 mg [14C]-labeled B containing 100 μCi of total radioactivity (0.125 μCi/mg). Blood was collected at selected time points for analyses of PK, biotransformation, and total radioactivity over a 10-day period. Complete urinary and fecal output was collected over the 10-day period or until discharge, and analyzed for total radioactivity and biotransformation. Part B began when subjects completed Part A. Part B subjects received B administered orally at a dose of 800 mg once daily starting on approximately Day 15 to 17 of study. Subjects continued in this study until disease progression or unacceptable toxicity. Results: 4 subjects (2 NSCLC, 1 ovarian, 1 renal cell carcinoma) were treated with B in both parts A & B. B was tolerable with few G3/4 AEs (increased fatigue, 1 event, cognitive disturbance, 1 event). The results revealed that B is completely converted to active moiety, BMS-540215, after oral administration. BMS-540215 is extensively metabolized in humans. Elimination is primarily via the feces. Following a single oral dose of [14C]-labeled B, approximately 12% and 82% of the administered radioactivity was recovered in the urine and feces, respectively, within 10 days. BMS-540215 accounted for 0.00% and 7.4% of the administered dose in urine and feces, respectively, with the remainder of the dose being minor metabolites. The mean terminal t1/2 of BMS-540215 was 14 hours. Conclusions: After oral administration of single 800 mg oral doses of [14C] B, BMS-540215 was found to be the major active circulating moiety in plasma (22.5%). BMS-540215 is primarily eliminated via metabolism. [14C]-labeled B formulation was well tolerated with no AEs leading to the discontinuation of any subject. [Table: see text]

Preclinical pharmacokinetics and in vitro metabolism of brivanib (BMS-540215), a potent VEGFR2 inhibitor and its alanine ester prodrug brivanib alaninate

Brivanib alaninate is a prodrug of brivanib (BMS-540215), a potent oral VEGFR-2 inhibitor and is currently in development for the treatment of hepatocellular and colon carcinomas. In vitro and in vivo studies were conducted to characterize the preclinical pharmacokinetics and disposition of brivanib and brivanib alaninate, and antitumor efficacy in mice bearing human xenografts. In vitro studies were conducted in liver and intestinal fractions, plasma and Caco-2 cells to assess the metabolic stability. Pharmacokinetics of brivanib were determined in preclinical species after administration of single intravenous or oral doses of both brivanib and brivanib alaninate. The antitumor efficacy was assessed at equimolar doses in nude mice bearing human tumor xenografts. Human efficacious dose was predicted based on projected human pharmacokinetic parameters and exposure at efficacious doses in the mouse efficacy models. In vitro and in vivo studies indicated that brivanib alaninate was efficiently converted to brivanib. Brivanib showed good brain penetration in rats consistent with its high intrinsic permeability and lack of active efflux in Caco-2 cells. The oral bioavailability of brivanib varied among species (22-88%) and showed dissolution rate-limited absorption even when combined with organic co-solvents. Administration of brivanib as brivanib alaninate allowed completely aqueous vehicles, and an improvement in the oral bioavailability (55-97%) was observed. The clearance of brivanib in humans is anticipated to be low to intermediate (hepatic extraction ratio < 0.7), while its volume of distribution is expected to be high. The minimum efficacious dose of brivanib alaninate was determined to be 60 mg/kg per day. Brivanib alaninate is rapidly and efficiently converted to the parent, brivanib, as demonstrated both in vitro and in vivo and offers an excellent mode to deliver brivanib orally.

Advances of clinical treatment of drug-resistant advanced breast cancer

In the current clinical trials,observed treatment on recrudescent and metastatic breast cancer which can be anthracycline-resistant and taxane-resistant with Ixabepilone、Larotaxel and their combination;and treating climacteric-positive and tamoxifen-resistant advanced breast cancer with steroid sulfatase inhibitor STX64 or combination of exemestane and celecoxib;Treating chemotherapy-refractory HER2-positive metastatic breast cancer with lapatinib and pemetrexed as well as their combination.Results have demonstrated superior efficacy and safety,and some of which are worthy of further observation. Key words: Breast neoplasms; Drug therapy

429 POSTER Phase 1 study of food effects on pharmacokinetics of brivanib alaninate in patients with advanced or metastatic solid tumors

429 POSTER Phase 1 study of food effects on pharmacokinetics of brivanib alaninate in patients with advanced or metastatic solid tumors

Brivanib Alaninate, a Dual Inhibitor of Vascular Endothelial Growth Factor Receptor and Fibroblast Growth Factor Receptor Tyrosine Kinases, Induces Growth Inhibition in Mouse Models of Human Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common primary neoplasm; surgery is the only curative option but 5-year survival rates are only 25% to 50%. Vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF) are known to be involved in growth and neovascularization of HCC. Therefore, agents that target these pathways may be effective in the treatment of HCC. The aim of this study was to determine the antineoplastic activity of brivanib alaninate, a dual inhibitor of VEGF receptor (VEGFR) and FGF receptor (FGFR) signaling pathways. Six different s.c. patient-derived HCC xenografts were implanted into mice. Tumor growth was evaluated in mice treated with brivanib compared with control. The effects of brivanib on apoptosis and cell proliferation were evaluated by immunohistochemistry. The SK-HEP1 and HepG2 cells were used to investigate the effects of brivanib on the VEGFR-2 and FGFR-1 signaling pathways in vitro. Western blotting was used to determine changes in proteins in these xenografts and cell lines. Brivanib significantly suppressed tumor growth in five of six xenograft lines. Furthermore, brivanib-induced growth inhibition was associated with a decrease in phosphorylated VEGFR-2 at Tyr(1054/1059), increased apoptosis, reduced microvessel density, inhibition of cell proliferation, and down-regulation of cell cycle regulators. The levels of FGFR-1 and FGFR-2 expression in these xenograft lines were positively correlated with its sensitivity to brivanib-induced growth inhibition. In VEGF-stimulated and basic FGF stimulated SK-HEP1 cells, brivanib significantly inhibited VEGFR-2, FGFR-1, extracellular signal-regulated kinase 1/2, and Akt phosphorylation. This study provides a strong rationale for clinical investigation of brivanib in patients with HCC.

Direct and indirect separations of five isomers of Brivanib Alaninate using chiral high-performance liquid chromatography

Brivanib Alaninate is a novel chiral prodrug possessing two stereogenic centers. Simultaneous HPLC separation of five isomers of Brivanib Alaninate was systematically investigated on a wide variety of polysaccharide-based chiral stationary phases (CSPs) using underivatization and pre-column derivatization methods. The influence of derivatizing groups and mobile phase composition on the enantioseparation and retention behavior of Brivanib Alaninate compounds was studied. To better understand the chiral recognition mechanism, the temperature effect was also evaluated. The results of these studies led to the first complete HPLC resolution of all five isomers of Brivanib Alaninate as carbobenzyloxy (CBZ) derivatives on a cellulose benzoate CSP (OJ-H).