Angel H. Bair

Axitinib versus sorafenib as first-line therapy in patients with metastatic renal-cell carcinoma: a randomised open-label phase 3 trial

BACKGROUND In previous clinical trials of patients with metastatic renal-cell carcinoma, patients treated with axitinib as second-line therapy had longer median progression-free survival than those treated with sorafenib. We therefore undertook a phase 3 trial comparing axitinib with sorafenib in patients with treatment-naive metastatic renal-cell carcinoma. METHODS In this randomised, open-label, phase 3 trial, patients with treatment-naive, measurable, clear-cell metastatic renal-cell carcinoma from 13 countries were stratified by Eastern Cooperative Oncology Group performance status, and then randomly assigned (2:1) by a centralised registration system to receive axitinib 5 mg twice daily, or sorafenib 400 mg twice daily. The primary endpoint was progression-free survival, assessed by masked independent review committee in the intention-to-treat population. This ongoing trial is registered at ClinicalTrials.gov, NCT00920816. FINDINGS Between June 14, 2010, and April 21, 2011, we randomly assigned 192 patients to receive axitinib, and 96 patients to receive sorafenib. The cutoff date for this analysis was July 27, 2012, when 171 (59%) of 288 patients died or had disease progression, as assessed by the independent review committee. There was no significant difference in median progression-free survival between patients treated with axitinib or sorafenib (10·1 months [95% CI 7·2-12·1] vs 6·5 months [4·7-8·3], respectively; stratified hazard ratio 0·77, 95% CI 0·56-1·05). Any-grade adverse events that were more common (≥10% difference) with axitinib than with sorafenib were diarrhoea (94 [50%] of 189 patients vs 38 [40%] of 96 patients), hypertension (92 [49%] vs 28 [29%]), weight decrease (69 [37%] vs 23 [24%]), decreased appetite (54 [29%] vs 18 [19%]), dysphonia (44 [23%] vs ten [10%]), hypothyroidism (39 [21%] vs seven [7%]), and upper abdominal pain (31 [16%] vs six [6%]); those more common with sorafenib than with axitinib included palmar-plantar erythrodysaesthesia (PPE; 37 [39%] of 96 patients vs 50 [26%] of 189), rash (19 [20%] vs 18 [10%]), alopecia (18 [19%] vs eight [4%]), and erythema (18 [19%] vs five [3%]). The most common grade 3 or 4 adverse events in patients treated with axitinib included hypertension (26 [14%] of 189 patients), diarrhoea (17 [9%]), asthenia (16 [8%]), weight decrease (16 [8%]), and PPE (14 [7%]); common grade 3 or 4 adverse events in patients treated with sorafenib included PPE (15 [16%] of 96 patients), diarrhoea (five [5%]), and asthenia (five [5%]). Serious adverse events were reported in 64 (34%) of 189 patients receiving axitinib, and 24 (25%) of 96 patients receiving sorafenib. INTERPRETATION Axitinib did not significantly increase progression-free survival in patients with treatment-naive metastatic renal-cell carcinoma compared with those treated with sorafenib, but did demonstrate clinical activity and an acceptable safety profile. FUNDING Pfizer Inc.

Diastolic Blood Pressure as a Biomarker of Axitinib Efficacy in Solid Tumors

Purpose: To evaluate if diastolic blood pressure (dBP) ≥90 mm Hg during axitinib treatment is a marker of efficacy. Experimental Design: The relationship between dBP ≥90 mm Hg and efficacy was retrospectively explored across 5 phase II studies of single-agent axitinib for the treatment of 4 different tumor types. All patients had baseline BP ≤140/90 mm Hg and were stratified into 2 groups based on in-clinic BP measurements after initiating therapy: those with dBP <90 mm Hg throughout therapy and those with at least 1 dBP ≥90 mm Hg. Median overall survival (mOS), median progression-free survival (mPFS), objective response rate (ORR), and adverse events were evaluated by dBP group in individual and pooled analyses. Results: Two-hundred thirty patients were evaluated. Patients with dBP ≥90 mm Hg had a significantly lower relative risk of death than those with dBP <90 mm Hg [adjusted HR (95% CI) = 0.55 (0.39, 0.77); P < 0.001]. The relative risk of progression was also lower in patients with dBP ≥90 mm Hg [HR (95% CI) = 0.76 (0.54, 1.06), P = 0.107], and ORR was significantly higher (43.9% vs. 12.0%; P < 0.001). In an 8-week landmark analysis, mOS (25.8 vs. 14.9 months) and mPFS (10.2 vs. 7.1 months) were greater for patients in the ≥90 mm Hg group. Adverse events were similar between groups. Conclusions: Axitinib efficacy correlated with dBP ≥90 mm Hg. Further investigation of dBP as a predictive biomarker of efficacy in patients receiving axitinib is warranted. Clin Cancer Res; 17(11); 3841–9. ©2011 AACR.

Axitinib with or without dose titration for first-line metastatic renal-cell carcinoma: a randomised double-blind phase 2 trial

BACKGROUND Population pharmacokinetic data suggest axitinib plasma exposure correlates with efficacy in metastatic renal-cell carcinoma. Axitinib dose titration might optimise exposure and improve outcomes. We prospectively assessed the efficacy and safety of axitinib dose titration in previously untreated patients with metastatic renal-cell carcinoma. METHODS In this randomised, double-blind, multicentre, phase 2 study, patients were enrolled from 49 hospitals and outpatient clinics in the Czech Republic, Germany, Japan, Russia, Spain, and USA. Patients with treatment-naive metastatic renal-cell carcinoma received axitinib 5 mg twice daily during a 4 week lead-in period. Those patients with blood pressure 150/90 mm Hg or lower, no grade 3 or 4 treatment-related toxic effects, no dose reductions, and no more than two antihypertensive drugs for 2 consecutive weeks were stratified by Eastern Cooperative Oncology Group performance status (0 vs 1), and then randomly assigned (1:1) to either masked titration with axitinib to total twice daily doses of 7 mg, and then 10 mg, if tolerated, or placebo titration. Patients who did not meet these criteria continued without titration. The primary objective was comparison of the proportion of patients achieving an objective response between randomised groups. Safety analyses were based on all patients who received at least one dose of axitinib. FINDINGS Between Sept 2, 2009, and Feb 28, 2011, we enrolled 213 patients, of whom 112 were randomly assigned to either the axitinib titration group (56 patients) or the placebo titration group (56 patients). 91 were not eligible for titration, and ten withdrew during the lead-in period. 30 patients (54%, 95% CI 40-67) in the axitinib titration group had an objective response, as did 19 patients (34%, 22-48]) in the placebo titration group (one-sided p=0·019). 54 (59%, 95% CI 49-70) of non-randomised patients achieved an objective response. Common grade 3 or worse, all-causality adverse events in treated patients were hypertension (ten [18%] of 56 in the axitinib titration group vs five [9%] of 56 in the placebo titration group vs 45 [49%] of 91 in the non-randomised group), diarrhoea (seven [13%] vs two [4%] vs eight [9%]), and decreased weight (four [7%] vs three [5%] vs six [7%]). One or more all-causality serious adverse events were reported in 15 (27%) patients in the axitinib titration group, 13 (23%) patients in the placebo titration group, and 35 (38%) non-randomised patients. The most common serious adverse events in all 213 patients were disease progression and dehydration (eight each [4%]), and diarrhoea, vomiting, pneumonia, and decreased appetite (four each [2%]). INTERPRETATION The greater proportion of patients in the axitinib titration group achieving an objective response supports the concept of individual axitinib dose titration in selected patients with metastatic renal-cell carcinoma. Axitinib shows clinical activity with a manageable safety profile in treatment-naive patients with this disease.

Axitinib dose titration: analyses of exposure, blood pressure and clinical response from a randomized phase II study in metastatic renal cell carcinoma

BACKGROUND In a randomized, double-blind phase II trial in patients with metastatic renal cell carcinoma (mRCC), axitinib versus placebo titration yielded a significantly higher objective response rate. We evaluated pharmacokinetic and blood pressure (BP) data from this study to elucidate relationships among axitinib exposure, BP change, and efficacy. PATIENTS AND METHODS Patients received axitinib 5 mg twice daily during a lead-in period. Patients who met dose-titration criteria were randomized 1:1 to stepwise dose increases with axitinib or placebo. Patients ineligible for randomization continued without dose increases. Serial 6-h and sparse pharmacokinetic sampling were carried out; BP was measured at clinic visits and at home in all patients, and by 24-h ambulatory BP monitoring (ABPM) in a subset of patients. RESULTS Area under the plasma concentration-time curve from 0 to 24 h throughout the course of treatment (AUCstudy) was higher in patients with complete or partial responses than those with stable or progressive disease in the axitinib-titration arm, but comparable between these groups in the placebo-titration and nonrandomized arms. In the overall population, AUCstudy and efficacy outcomes were not strongly correlated. Mean BP across the population was similar when measured in clinic, at home, or by 24-h ABPM. Weak correlations were observed between axitinib steady-state exposure and diastolic BP. When grouped by change in diastolic BP from baseline, patients in the ≥10 and ≥15 mmHg groups had longer progression-free survival. CONCLUSIONS Optimal axitinib exposure may differ among patients with mRCC. Pharmacokinetic or BP measurements cannot be used exclusively to guide axitinib dosing. Individualization of treatment with vascular endothelial growth factor receptor tyrosine kinase inhibitors, including axitinib, is thus more complex than anticipated and cannot be limited to a single clinical factor.

Axitinib versus sorafenib as first‑line therapy in patients with metastatic renal cell carcinoma (mRCC).

LBA348 Background: In the phase III AXIS trial, second-line therapy with axitinib resulted in significantly longer progression-free survival (PFS) versus sorafenib for mRCC. We conducted a multicenter, randomized, open-label, phase III trial to compare PFS of axitinib vs sorafenib as first-line therapy. METHODS Patients with untreated, measurable (RECIST v1.0), clear‑cell mRCC and Eastern Cooperative Oncology Group performance status (PS) 0 or 1 were randomized 2:1 to axitinib 5 mg twice daily (BID) or sorafenib 400 mg BID. Randomization was stratified by PS. Primary endpoint was PFS per independent radiology committee. The study had 90% power to detect a 78% PFS improvement from 5.5 mo with sorafenib to 9.8 mo with axitinib, corresponding to a hazard ratio (HR) of 0.561 (overall 1-sided α=0.025). RESULTS Patients (N=288) were mainly from Eastern Europe (51%), Asia (25%), North America (14%), or South America (10%).Patient baseline characteristics for axitinib (n=192) vs sorafenib (n=96) included: median age, 58y vs 58y; male, 70% vs 77%; white, 71% vs 69%; favorable risk, 49% vs 55%; PS 0, 57% vs 57%; nephrectomy, 85% vs 90%. Median (m) PFS was 10.1 vs 6.5 mo with axitinib vs sorafenib (HR adjusted for PS, 0.767; 95% confidence interval [CI], 0.559-1.053; 1‑sided P=0.0377). In patients with PS 0 and 1, respectively, mPFS with axitinib vs sorafenib was 13.7 vs 6.6 mo (HR, 0.644; 95% CI, 0.419-0.991; 1‑sided P=0.022) and 6.5 vs 6.4 mo (HR, 0.931; 95% CI, 0.585-1.482; 1‑sided P=0.38). Objective response rates (ORRs) with axitinib vs sorafenib were 32.3% vs 14.6% (1‑sided P=0.0006 adjusted for PS). Overall survival data were not mature. All-grade all‑causality adverse events (≥20%) with axitinib vs sorafenib were diarrhea (50% vs 40%), hypertension (49% vs 29%), weight decreased (37% vs 24%), fatigue (33% vs 26%), decreased appetite (29% vs 19%), palmar-plantar erythrodysesthesia (26% vs 39%), dysphonia (23% vs 10%), asthenia (21% vs 16%), and hypothyroidism (21% vs 7%). CONCLUSIONS The study did not achieve its primary endpoint statistically, but axitinib demonstrated numerically longer mPFS and significantly higher ORR vs sorafenib, with an acceptable safety profile, as first-line therapy for mRCC. CLINICAL TRIAL INFORMATION NCT00920816.

Axitinib Versus Sorafenib in First-Line Metastatic Renal Cell Carcinoma: Overall Survival From a Randomized Phase III Trial

&NA; In a randomized phase III trial, axitinib did not significantly improve progression‐free survival over sorafenib in treatment‐naive patients with metastatic renal cell carcinoma. This updated analysis confirmed clinical activity of axitinib with an acceptable safety profile after long‐term treatment. Although axitinib did not prolong survival over sorafenib, axitinib might provide an acceptable first‐line treatment option in patients with good performance status. Background: In a randomized phase III trial in treatment‐naive patients with metastatic renal cell carcinoma (RCC), axitinib versus sorafenib yielded numerically longer progression‐free survival (median, 10.1 vs. 6.5 months; hazard ratio [HR], 0.77; 1‐sided P = .038) and significantly higher objective response rate (32% vs. 15%; 1‐sided P = .0006). In this article, we report overall survival (OS) and updated safety results. Patients and Methods: Previously untreated patients with metastatic RCC (n = 288), stratified according to Eastern Cooperative Oncology Group performance status (ECOG PS; 0 vs. 1), were randomized 2:1 to receive axitinib 5 mg twice per day (b.i.d.; n = 192) or sorafenib 400 mg b.i.d. (n = 96). Results: Median OS (95% confidence interval [CI]) was 21.7 months (18.0‐31.7) with axitinib versus 23.3 months (18.1‐33.2) with sorafenib (stratified HR, 0.995; 95% CI, 0.731‐1.356; 1‐sided P = .4883). Among patients with ECOG PS of 0, median OS was numerically longer with axitinib than with sorafenib (41.2 vs. 31.9 months; HR, 0.811, 1‐sided P = .1748), whereas among patients with ECOG PS 1, median OS was shorter with axitinib than with sorafenib (14.2 vs. 19.8 months; HR, 1.203; 1‐sided; P = .7973). Incidence and severity of common adverse events were consistent with previous reports. Conclusion: OS was similar between axitinib and sorafenib in treatment‐naive patients with metastatic RCC, and no new safety signals emerged.

Axitinib with or without dose titration for first-line metastatic renal cell carcinoma (mRCC): Unblinded results from a randomized phase II study.

LBA349 Background: Patients receiving the 5-mg twice daily (BID) axitinib starting dose exhibit variable drug exposure; prior pharmacokinetic analyses indicate higher exposure is associated with better outcomes in mRCC. Dose titration based on individual tolerability may optimize exposure and improve efficacy. METHODS Patients (N=213) with treatment-naïve mRCC received axitinib 5 mg BID for a 4-week lead-in period. Then, patients with 2 consecutive weeks of blood pressure ≤150/90 mmHg, no axitinib-related toxicities >grade 2, no dose reductions, and ≤2 antihypertensive medications were randomized (double-blind) to axitinib 5 mg BID + dose titration to 10 mg BID maximum with axitinib or placebo. Those not eligible for randomization continued axitinib 5 mg BID or lower. Primary endpoint was objective response rate (ORR) in randomized arms. Progression-free survival (PFS), overall survival, and safety were secondary endpoints. Assuming response rate under the null hypothesis is 0.15, this study had ≥80% power (1-sided type I error 10%) to detect a ≥25% absolute improvement in ORR with active vs placebo titration. RESULTS In all, 56 patients each were randomized to active and placebo titration arms, 91 were not randomized, and 10 withdrew during the lead-in period. As of Oct 12, 2012, ORR (95% confidence interval [CI]) was 54% (40-67) in the active titration arm vs 34% (22-48) in the placebo titration arm (1-sided P=0.019), and 59% (49-70) in the non-randomized arm. Median PFS (95% CI) from first dose was 14.5 mo (9.2-24.5) in the active titration arm vs 15.7 mo (8.3-19.4) in the placebo titration arm (hazard ratio favored active titration, 0.85; 95% CI, 0.54-1.35; 1-sided P=0.244), and 16.6 mo (11.2-22.5) in the non-randomized arm. Most frequent all-grade, all-causality adverse events in active titration, placebo titration, and non-randomized arms, respectively, were diarrhea (61% vs 63% vs 63%), hypertension (61% vs 43% vs 82%), and fatigue (45% vs 46% vs 54%). CONCLUSIONS Axitinib is effective and well tolerated in first-line mRCC with prolonged median PFS in all treatment arms compared to historical controls. Axitinib dose titration significantly improved ORR vs placebo. CLINICAL TRIAL INFORMATION NCT00835978.

Key predictive factors for efficacy of axitinib in first-line metastatic renal cell carcinoma: Subgroup analysis in Japanese patients from a randomized, double-blind phase II study

Axitinib demonstrated clinical activity and safety in treatment-naïve Japanese patients with metastatic renal cell carcinoma. Multivariate analyses identified potential predictive factors for axitinib efficacy in first-line metastatic renal cell carcinoma.

Overall survival of first‐line axitinib in metastatic renal cell carcinoma: Japanese subgroup analysis from phase II study

Subgroup analyses of a randomized global phase II study of axitinib showed objective response rate of 66% and median progression‐free survival of 27.6 months in treatment‐naïve Japanese patients with metastatic renal cell carcinoma (RCC). This analysis evaluated overall survival (OS) and safety in 44 Japanese patients and compared the results with 169 non‐Japanese patients. In addition, baseline characteristics for predictive factors that may influence OS in first‐line metastatic RCC were explored in all patients using a Cox proportional hazard model. With median follow‐up of 33 months, fewer than half (16 of 44) of the Japanese patients had died and median OS was not reached (95% confidence interval [CI], 38.8 months–not estimable), whereas 107 of 169 (63%) non‐Japanese patients had died and median OS was 33.9 months (95% CI, 28.9–42.7). Estimated 1‐year, 2‐year and 3‐year survival probability (95% CI) was 86.4% (76.2–96.5), 75.0% (62.2–87.8) and 68.2% (54.4–81.9), respectively, in Japanese patients, and was higher than that in non‐Japanese patients (75.1% [68.4–81.8], 62.1% [54.5–69.7] and 47.2% [39.3–55.1], respectively). The updated safety analysis did not reveal any new adverse events of concern among Japanese or non‐Japanese patients. The multivariate analysis identified that lower baseline Eastern Cooperative Oncology Group performance status, lower baseline tumor burden, and longer time from histopathological diagnosis to treatment were significant positive predictors of OS. The current analysis confirmed the clinical activity of axitinib in treatment‐naïve Japanese patients with metastatic RCC, with an acceptable toxicity profile.

Bevacizumab biosimilars: scientific justification for extrapolation of indications

The first biosimilar of bevacizumab was approved by the US FDA; other potential biosimilars of bevacizumab are in late-stage clinical development. Their availability offers opportunity for increased patient access across a number of oncologic indications. The regulatory pathway for biosimilar approval relies on the totality of evidence that includes a comprehensive analytical assessment, and a clinical comparability study in a relevant disease patient population. Extrapolation of indications for a biosimilar to other eligible indications held by the originator, in the absence of direct clinical comparison, frequently forms part of the regulatory judgment. Herein, we consider the evidence required to demonstrate biosimilarity for bevacizumab biosimilars, with particular focus on the rationale for extrapolation across oncologic indications.