Andrew Louis Strahs

Antitumor Activity and Safety of Tivozanib (AV-951) in a Phase II Randomized Discontinuation Trial in Patients With Renal Cell Carcinoma

PURPOSE The antitumor activity and safety of tivozanib, which is a potent and selective vascular endothelial growth factor receptor-1, -2, and -3 inhibitor, was assessed in patients with advanced/metastatic renal cell carcinoma (RCC). PATIENTS AND METHODS In this phase II, randomized discontinuation trial, 272 patients received open-label tivozanib 1.5 mg/d (one cycle equaled three treatment weeks followed by a 1-week break) orally for 16 weeks. Thereafter, 78 patients who demonstrated ≥ 25% tumor shrinkage continued to take tivozanib, and 118 patients with less than 25% tumor change were randomly assigned to receive tivozanib or a placebo in a double-blind manner; patients with ≥ 25% tumor growth were discontinued. Primary end points included safety, the objective response rate (ORR) at 16 weeks, and the percentage of randomly assigned patients who remained progression free after 12 weeks of double-blind treatment; secondary end points included progression-free survival (PFS). RESULTS Of 272 patients enrolled onto the study, 83% of patients had clear-cell histology, 73% of patients had undergone nephrectomy, and 54% of patients were treatment naive. The ORR after 16 weeks of tivozanib treatment was 18% (95% CI, 14% to 23%). Of the 118 randomized patients, significantly more patients who were randomly assigned to receive double-blind tivozanib remained progression free after 12 weeks versus patients who received the placebo (49% v 21%; P = .001). Throughout the study, the ORR was 24% (95% CI, 19% to 30%), and the median PFS was 11.7 months (95% CI, 8.3 to 14.3 months) in the overall study population. The most common grade 3 and 4 treatment-related adverse event was hypertension (12%). CONCLUSION Tivozanib was active and well tolerated in patients with advanced RCC. These data support additional development of tivozanib in advanced RCC.

Overall survival results from a phase III study of tivozanib hydrochloride versus sorafenib in patients with renal cell carcinoma.

350 Background: Tivozanib hydrochloride (tivozanib) is a potent, selective, tyrosine kinase inhibitor targeting all three vascular endothelial growth factor receptors, with a long half-life. Tivozanib has shown tolerability and superior progression-free survival and overall response rate versus sorafenib in a phase III trial (TIVO-1) in patients with advanced renal cell carcinoma. Final overall survival (OS) data (August 27, 2012) from TIVO-1 and its open-label, multicenter extension study are reported. METHODS A total of 517 patients were randomized 1:1 to tivozanib 1.5 mg/d (3 weeks on, 1 week off) or sorafenib 400 mg/d (twice a day, continuously) (J Clin Oncol2012;30[suppl]:Abstract 4501). In the extension study, patients who progressed (PD) on sorafenib based on investigator assessment were eligible to receive tivozanib, and patients with PD on tivozanib received subsequent treatment according to regional standards of care. Final OS analysis was planned to be conducted after all patients had died or were lost to follow-up, or when all patients in follow-up had been on study for at least 2 years, whichever occurred first. OS was compared using the stratified log-rank test. OS distribution was estimated using the Kaplan-Meier method. Hazard ratio (HR) was estimated using the Cox proportional hazard regression model. RESULTS At the time of final OS analysis (2 years after last patient was enrolled), 219 deaths had occurred (tivozanib, n=118 [45.4%]; sorafenib, n=101 [39.3%]) (stratified HR=1.245; 95% confidence interval [CI] 0.954-1.624; p=0.105), trending in favor of the sorafenib arm. Median OS (95% CI) was 28.8 months (22.5-NA) for tivozanib and 29.3 months (29.3-NA) for sorafenib. Of the 257 patients on sorafenib, 155 (60.3%) had started next-line tivozanib at the time of the analysis. CONCLUSIONS There was no significant difference in OS between the two treatment arms. The high rate of utilization of second-line tivozanib in patients following PD on sorafenib may have affected the OS outcome. CLINICAL TRIAL INFORMATION NCT01030783.

Subgroup analyses of a phase III trial comparing tivozanib hydrochloride versus sorafenib as initial targeted therapy for patients (pts) with metastatic renal cell carcinoma (mRCC).

354 Background: Tivozanib hydrochloride (T) is a potent, selective, tyrosine kinase inhibitor of all 3 VEGF receptors with a long half-life. T has shown tolerability and has extended progression-free survival (PFS) compared with sorafenib (S; median 11.9 months vs. 9.1 months; p =0.042) in a phase III trial (TIVO-1) as initial targeted therapy for pts with mRCC. We report results of PFS subgroup analyses from TIVO-1. METHODS Pts with clear-cell mRCC, prior nephrectomy, and ≤1 prior treatment for mRCC were randomized to T (n=260) or S (n=257). Cox proportional hazards model was used to evaluate PFS. RESULTS Significant improvement in PFS by T vs. S was observed for the following prespecified subgroups: white, Eastern Cooperative Oncology Group (ECOG) performance status 0, ≥1 year since diagnosis, no prior treatment, ≥2 metastatic sites, North America/Western Europe, baseline systolic blood pressure (SBP) ≤140 mm Hg, and baseline diastolic BP (DBP) ≤90 mm Hg. Exploratory subgroup analysis showed a similar significant improvement by T vs. S in Memorial Sloan-Kettering Cancer Center (MSKCC) favorable prognostic group, and pts who developed hypertension on study had significantly longer PFS than pts with normal BP. The improvement in PFS by T vs S was more marked for the subgroups that developed hypertension (selected subgroups shown in the table). CONCLUSIONS PFS subgroup analyses showed a consistent advantage with T vs. S for mRCC. CLINICAL TRIAL INFORMATION NCT01030783. [Table: see text].

Absorption, Metabolism, and Excretion of [14C]-Tivozanib, a Vascular Endothelial Growth Factor Receptor Tyrosine Kinase Inhibitor, in Healthy Male Participants: A Phase I, Open-Label, Mass-Balance Study

Objective: To evaluate the absorption, metabolism, and excretion of tivozanib, a new investigational drug for renal cell carcinoma and solid malignancies. Methods: Eight healthy male participants received a single 1.5‐mg (˜160 μCi) dose of oral [14C]‐tivozanib. Whole blood, serum, urine, and feces were evaluated up to 28 days postdose for pharmacokinetics, radioanalysis, and metabolites. Adverse events were recorded throughout the study. Results: [14C]‐tivozanib concentration peaked at 10.9 ± 5.84 hours. The mean serum half‐life for [14C]‐tivozanib was 89.3 ± 23.5 hours. The maximum concentration and area under the curve for [14C]‐tivozanib were 12.1 ± 5.67 ng/mL and 1084 ± 417.0 ng·h/mL, respectively. Mean recovery of total radioactivity was 91.0% ± 11.0%; 79.3% ± 8.82% of the radioactivity was recovered in feces both as unchanged tivozanib and metabolites. In the urine, 11.8% ± 4.59% was recovered only as metabolites. No unchanged tivozanib was found in the urine. Conclusion: Tivozanib had a long half‐life with no major circulating metabolite, was well tolerated as a single dose, and was primarily eliminated via feces with no unchanged tivozanib found in urine. These pharmacokinetic data of [14C]‐tivozanib are consistent with previous studies of unlabeled tivozanib.

Effects of ketoconazole or rifampin on the pharmacokinetics of tivozanib hydrochloride, a vascular endothelial growth factor receptor tyrosine kinase inhibitor

The vascular endothelial growth factor (VEGF) pathway is associated with the promotion of endothelial cell proliferation, migration, and survival necessary for angiogenesis. VEGF and its three receptor isoforms are often overexpressed in many human solid tumors. Tivozanib is a potent, selective inhibitor of VEGF receptors 1, 2, and 3, with a long half‐life. The purpose of these studies was to evaluate the effect of ketoconazole, a potent inhibitor of CYP3A4, and rifampin, a potent inducer of CYP3A4, on the pharmacokinetics of tivozanib. Two phase I, open‐label, 2‐period, single‐sequence studies evaluated the effect of steady‐state ketoconazole (NCT01363778) or rifampin (NCT01363804) on the pharmacokinetic profile, safety, and tolerability of a single oral 1.5‐mg dose of tivozanib. Tivozanib was well tolerated in both studies. Steady‐state ketoconazole did not cause a clinically significant change in the pharmacokinetics of a single dose of tivozanib; therefore, dosing of tivozanib with a CYP3A4 pathway inhibitor should not cause a clinically significant change in serum tivozanib levels. However, coadministration of tivozanib with rifampin caused a significant decrease in the area under the curve from 0 to infinity and half‐life and an increase in clearance of tivozanib, which suggest increased clearance via the enhanced CYP3A4‐mediated metabolism of tivozanib.

Efficacy and safety data from patients with advanced renal cell cancer treated with tivozanib hydrochloride after progression on sorafenib.

364 Background: Tivozanib hydrochloride (tivozanib) is a potent, selective, tyrosine kinase inhibitor of all three vascular endothelial growth factor receptors, with a long half-life and has shown superior efficacy, measured as progression-free survival (PFS), as first-line, targeted therapy vs. sorafenib in a phase III trial (TIVO-1) in patients with advanced renal cell carcinoma (J Clin Oncol2012;30[suppl]:Abstract 4501). Patients who progressed (PD) on sorafenib could receive tivozanib in an open-label, prospective multicenter extension study of TIVO-1. We report preliminary efficacy and safety data for patients who had PD on sorafenib and subsequently received tivozanib in this extension study. METHODS Patients with PD on sorafenib, per RECIST version 1.0, were eligible to receive tivozanib dosed at 1.5 mg/day PO for 3 weeks followed by a 1-week rest, in repeated 4-week cycles, until PD or unacceptable toxicity. Patients were to have been no more than 4 weeks from last dose of sorafenib until initiation of tivozanib, and have an ECOG performance status of ≤2. Dose adjustments were performed as previously reported. Objectives included assessing objective response rate (ORR), duration of response, PFS for tivozanib following PD on sorafenib, and overall survival. RESULTS As of January 20, 2012, 127 patients (72.4% male) were evaluable for response. Median age was 59.0 years (range: 23-85 years). ORR was 7.9% (95% CI 3.8-14.0%; partial response [PR]=7.9%; stable disease [SD]=65.4%; PD=18.9%), and 71.3% of patients showed tumor shrinkage. Median duration of PR was 11.1 months (95% CI ≥7.5 months). Median duration of SD was 12.7 months (95% CI ≥7.4 months). Median PFS was 5.6 months (95% CI 5.4-9.1 months). Median OS was not yet reached. Most commonly reported treatment-emergent adverse events (all grades/Grade ≥3) were hypertension (22.4%/10.2%), asthenia (11.0%/3.1%), fatigue (11.0%/3.9%), palmar-plantar erythrodysesthesia (11.0%/1.6%), and diarrhea (10.2%/1.6%). CONCLUSIONS Tivozanib has anti-tumor activity after PD on sorafenib. The adverse-event profile of tivozanib after sorafenib is similar to that observed in TIVO-1. CLINICAL TRIAL INFORMATION NCT01076010.

Treatment benefit of tivozanib hydrochloride versus sorafenib on health-related quality of life (HRQoL) among patients (pts) with advanced/metastatic renal cell carcinoma (mRCC): TIVO-1 study results.

355 Background: Tivozanib hydrochloride (T) was superior to sorafenib (S) in progression-free survival (medians of 11.9 vs. 9.1 months, respectively; 12.7 vs. 9.1 months, respectively, for metastatic treatment-naïve pts) in the phase III TIVO-1 study in pts with mRCC. T showed a differentiated safety profile with lower rates of dose interruptions/reductions v S (18/12 vs. 35/43, respectively; p<0.001). TIVO-1 also evaluated patient self-reported HRQoL. METHODS Pts with mRCC were randomized 1:1 to receive T (1.5 mg PO once daily for 3 weeks on, 1 week off) or S (400 mg bid, continuously). HRQoL was assessed on Cycle 1/Day1 (baseline [BL]) and at the beginning of each cycle, using the Functional Assessment of Cancer Therapy-General (FACT-G), FACT-Kidney Symptom Index Disease Related Symptoms (FKSI-DRS), and EuroQol 5-dimensional (EQ-5D) questionnaires; EQ-5D scores are not reported here. Pts with BL and ≥1 post-BL evaluable forms were analyzed. Changes from BL in FACT-G and FKSI-DRS scores over 18 treatment cycles were analyzed using repeated measures mixed-effects models. QoL improvement/deterioration was defined as an increase/decrease from BL of ≥3 points for FACT-G subscales and FKSI-DRS total score and 7 points for the FACT-G total score during the study. RESULTS In the mixed effects analyses, no significant differences in HRQoL (FACT-G and FKSI-DRS) were noted between T and S. More pts receiving T vs. S experienced a significant improvement during the study in physical well-being (PWB) (25.7% vs. 16.4%; p=0.011) and a favorable trend in all other FACT-G and FKSI scores (p values: 0.078-0.405). FKSI improvement was greater with T than S in treatment-naïve pts (34.1% vs. 23.6%; p=0.023), pts with ≥2 metastases (32.9% vs. 24.7%; p=0.054), or pts <65 years old (33.0% vs. 22.8%; p=0.022). Median time to QoL deterioration was usually longer with T (3.75-7.66 months) than S (2.04-8.80 months). CONCLUSIONS HRQoL was generally similar for T and S. Non-significant numeric differences usually favored T over S, and PWB improvement occurred significantly more often with T. These results support the previously-reported PFS advantage of T over S. CLINICAL TRIAL INFORMATION NCT01030783.

The effect of food on the pharmacokinetics of tivozanib hydrochloride

Tivozanib hydrochloride (tivozanib) is a potent, selective tyrosine kinase inhibitor of the vascular endothelial growth factor receptors 1, 2, and 3, with a long half‐life. This Phase I study evaluated the effect of food on tivozanib pharmacokinetics (PK). A single oral dose of tivozanib was administered to healthy subjects in a fasted/fed and a fed/fasted state. Thirty subjects enrolled; 29 completed the study. Maximum concentration (Cmax) in the fed state was lower than in the fasted state (geometric means, 14.1 and 18.1 ng/mL). The geometric mean ratio (90% confidence interval) (fed/fasted states) for Cmax was 77.5% (72.9–82.4%), indicating a food effect on Cmax. There was no difference in tivozanib area under the curve to infinity (AUC0–∞) between states (geometric means, 2,377 and 2,198 ng h/mL). Geometric mean ratios also indicated no food effect on tivozanib AUC0–∞. Other PK parameters were similar between states. The most commonly reported adverse events affected the gastrointestinal system and were mild in intensity. There were no clinically significant changes in other safety measures. In conclusion, food does not have an impact on the AUC0–∞ of tivozanib but does decrease Cmax approximately 23%, suggesting that this agent can be dosed with or without food.

Relationship of hypoxia signature with variant subgroup of clear cell renal cell carcinoma (ccRCC) and its association with clinical activity on tivozanib hydrochloride.

361 Background: TIVO-1, a randomized Phase III trial in first-line targeted therapy for patients (pts) with ccRCC, demonstrated significant improvement in progression-free survival (PFS) in pts receiving tivozanib hydrochloride (T) vs. sorafenib (S) (11.9 vs. 9.1 months [12.7 vs. 9.1 in treatment-naïve pts]). To further characterize molecular ccRCC subtypes and assess relationships between subtypes and vascular endothelial growth factor tyrosine kinase inhibitor activity, we characterized available molecularly annotated datasets from TIVO-1. METHODS Tumor subtypes were established using hierarchical clustering and evaluated in two microarray ccRCC datasets using gene set enrichment analysis with 51 signatures representing a set of molecular phenotypes. A 9-gene signature comprising genes associated with hypoxia-inducible factor (HIF) transcription was quantified by RT-PCR on all available (69/517) formalin-fixed, paraffin-embedded material from patients using a predefined classifier score and cutoff. RESULTS Hierachical clustering generated 3 distinct tumor classes. Molecular clusters defining HIF gene expression (low), endothelial cell content (low), extracellular matrix (low), proliferation (high) epithelial cell phenotype (high), and metabolism (high) were differentially expressed in cluster 3 tumors, which represented approximately 15% of the populations. Based on predefined analysis, the hypoxia signature was significantly associated with better PFS on T using a previously established classifier (Table). The hypoxia signature was not significantly associated with PFS on S. There was no significant correlation to single largest diameter for either agent. CONCLUSIONS A novel molecular subtype of ccRCC is characterized by a distinct molecular profile and can be classified by a low hypoxia signature. This hypoxia gene signature may help identify T responders. This signature is seen in subsets of other solid tumors supporting the broad exploration of this candidate T response biomarker. CLINICAL TRIAL INFORMATION NCT01030783. [Table: see text].

Abstract 752: The effect of food on the pharmacokinetics of tivozanib

Background: Tivozanib, a potent, selective, long-half-life tyrosine kinase inhibitor of vascular endothelial growth factor receptors 1, 2, and 3, has demonstrated antitumor activity in a Phase II study in patients with renal cell carcinoma (RCC), and is currently being studied in clinical trials in patients with RCC and other solid tumors. The goal of this study was to investigate the effect of food on the pharmacokinetics (PK) of a single 1.5 mg dose of tivozanib in healthy subjects. Methods: This was a single-center, open-label, randomized, two-period, crossover Phase I trial. Subjects were admitted to the clinical research unit (CRU) 1 day before dosing, fasted ∼10 hours, and were randomized to fed (standard high-fat breakfast)/fasted or fasted/fed sequence. In each phase of the sequence, subjects received a single oral dose of tivozanib 1.5 mg with a 6-week washout period between doses. Subjects remained at the CRU for at least 48 hours post dose for blood sample collection and safety monitoring, and were assessed on an outpatient basis for up to 504 hours post dose. PK data were analyzed by non-compartmental methods. The effect of food on PK was assessed using standard criteria for bioequivalence based on the exposure parameters AUC 0-α and C max . If the 90% confidence intervals for the fed/fasted AUC 0-α and C max fell within the range of 80% to 125%, it was concluded that food had no effect on exposure. Results: Thirty healthy volunteers were enrolled (19M/11F; mean age 39 years [range 22-53 years]). There was no significant difference in AUC 0-α of serum tivozanib between the fed and fasted states (107.4%; Table 1). Food caused a significant decrease in serum tivozanib levels vs fasted state (C max : 77.5%). Conclusions: These results indicate that dosing tivozanib with food decreases maximal concentrations by ∼ 23%, but does not affect overall exposure. As tivozanib is dosed chronically in oncology patients and accumulates ∼6 to 7 times single-dose levels when at steady-state, these results are not likely to affect dosing. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 752. doi:1538-7445.AM2012-752