Rilotumumab exposure-response relationship in patients with advanced or metastatic gastric cancer.

PURPOSE: Rilotumumab is an investigational, fully human monoclonal antibody to hepatocyte growth factor. In a randomized phase II study, trends toward improved survival were observed with rilotumumab (7.5 or 15 mg/kg) plus epirubicin, cisplatin, and capecitabine (ECX) versus placebo plus ECX in gastric/gastroesophageal junction (GEJ) cancer patients, especially in MET-positive patients. Here, we quantitatively characterized the longitudinal exposure-response [tumor growth (TG) and overall survival (OS)] relationship for rilotumumab. EXPERIMENTAL DESIGN: Rilotumumab concentrations, tumor sizes, and survival time from the phase II study were pooled to develop a longitudinal exposure versus TG model and parametric OS model that explored predictive/prognostic/treatment effects (MET expression, rilotumumab exposure, relative tumor size). Model evaluation included visual predictive checks, nonparametric bootstrap, and normalized prediction distribution errors. Simulations were undertaken to predict the relationship between rilotumumab dose and OS. RESULTS: Rilotumumab exhibited linear time-independent pharmacokinetics not affected by MET expression. The TG model adequately described tumor size across arms. A Weibull distribution best described OS. Rilotumumab exposure and change in tumor size from baseline at week 24 were predictive of OS. MET-positive patients showed shorter survival and responded better to rilotumumab than MET-negative patients. Simulations predicted a median (95% confidence interval) HR of 0.38 (0.18-0.60) in MET-positive patients treated with 15 mg/kg rilotumumab Q3W. CONCLUSIONS: Rilotumumab plus ECX demonstrated concentration-dependent effects on OS, influenced by MET expression, and tumor size in gastric/GEJ cancer patients. These findings support the phase II testing of rilotumumab 15 mg/kg every 3 weeks in MET-positive gastric/GEJ cancer (RILOMET-1; NCT01697072).

Rilotumumab in combination with epirubicin, cisplatin, and capecitabine as first-line treatment for gastric or oesophagogastric junction adenocarcinoma: an open-label, dose de-escalation phase 1b study and a double-blind, randomised phase 2 study.

BACKGROUND: Dysregulation of the hepatocyte growth factor (HGF)/MET pathway promotes tumour growth and metastasis. Rilotumumab is a fully human, monoclonal antibody that neutralises HGF. We aimed to assess the safety, efficacy, biomarkers, and pharmacokinetics of rilotumumab combined with epirubicin, cisplatin, and capecitabine (ECX) in patients with advanced gastric or oesophagogastric junction cancer. METHODS: We recruited patients (≥18 years old) with unresectable locally advanced or metastatic gastric or oesophagogastric junction adenocarcinoma, an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1, who had not received previous systemic therapy, from 43 sites worldwide. Phase 1b was an open-label, dose de-escalation study to identify a safe dose of rilotumumab (initial dose 15 mg/kg intravenously on day 1) plus ECX (epirubicin 50 mg/m(2) intravenously on day 1, cisplatin 60 mg/m(2) intravenously on day 1, capecitabine 625 mg/m(2) twice a day orally on days 1-21, respectively), administered every 3 weeks. The phase 1b primary endpoint was the incidence of dose-limiting toxicities in all phase 1b patients who received at least one dose of rilotumumab and completed the dose-limiting toxicity assessment window (first cycle of therapy). Phase 2 was a double-blind study that randomly assigned patients (1:1:1) using an interactive voice response system to receive rilotumumab 15 mg/kg, rilotumumab 7·5 mg/kg, or placebo, plus ECX (doses as above), stratified by ECOG performance status and disease extent. The phase 2 primary endpoint was progression-free survival (PFS), analysed by intention to treat. The study is registered with ClinicalTrials.gov, number NCT00719550. FINDINGS: Seven of the nine patients enrolled in the phase 1b study received at least one dose of rilotumumab 15 mg/kg, only two of whom had three dose-limiting toxicities: palmar-plantar erythrodysesthesia, cerebral ischaemia, and deep-vein thrombosis. In phase 2, 121 patients were randomly assigned (40 to rilotumumab 15 mg/kg; 42 to rilotumumab 7·5 mg/kg; 39 to placebo). Median PFS was 5·1 months (95% CI 2·9-7·0) in the rilotumumab 15 mg/kg group, 6·8 months (4·5-7·5) in the rilotumumab 7·5 mg/kg group, 5·7 months (4·5-7·0) in both rilotumumab groups combined, and 4·2 months (2·9-4·9) in the placebo group. The hazard ratio for PFS events compared with placebo was 0·69 (80% CI 0·49-0·97; p=0·164) for rilotumumab 15 mg/kg, 0·53 (80% CI 0·38-0·73; p=0·009) for rilotumumab 7·5 mg/kg, and 0·60 (80% CI 0·45-0·79; p=0·016) for combined rilotumumab. Any grade adverse events more common in the combined rilotumumab group than in the placebo group included haematological adverse events (neutropenia in 44 [54%] of 81 patients vs 13 [33%] of 39 patients; anaemia in 32 [40%] vs 11 [28%]; and thrombocytopenia in nine [11%] vs none), peripheral oedema (22 [27%] vs three [8%]), and venous thromboembolism (16 [20%] vs five [13%]). Grade 3-4 adverse events more common with rilotumumab included neutropenia (36 [44%] vs 11 [28%]) and venous thromboembolism (16 [20%] vs four [10%]). Serious adverse events were balanced between groups except for anaemia, which occurred more frequently in the combined rilotumumab group (ten [12%] vs none). INTERPRETATION: Rilotumumab plus ECX had no unexpected safety signals and showed greater activity than placebo plus ECX. A phase 3 study of the combination in MET-positive gastric and oesophagogastric junction cancer is in progress. FUNDING: Amgen Inc.

Randomized phase Ib/II trial of rilotumumab or ganitumab with panitumumab versus panitumumab alone in patients with wild-type KRAS metastatic colorectal cancer.

PURPOSE: Panitumumab, a fully human anti-epidermal growth factor receptor monoclonal antibody (mAb), has demonstrated efficacy in patients with wild-type KRAS metastatic colorectal cancer (mCRC). Rilotumumab and ganitumab are investigational, fully human mAbs against hepatocyte growth factor (HGF)/scatter factor and IGF1R, respectively. Here we evaluate combining rilotumumab or ganitumab with panitumumab in previously treated patients with wild-type KRAS mCRC. EXPERIMENTAL DESIGN: Part 1 was a phase Ib dose-finding study of panitumumab plus rilotumumab. The primary endpoint was the incidence of dose-limiting toxicities (DLT). Part 2 was a randomized phase II trial of panitumumab in combination with rilotumumab, ganitumab, or placebo. The primary endpoint was objective response rate (ORR); safety, progression-free survival (PFS), and overall survival (OS) were secondary endpoints. Archival tissue specimens were collected for exploratory correlative work. RESULTS: In part 1, no DLTs were reported. A recommended phase II dose of 10 mg/kg rilotumumab was selected. In part 2, for the panitumumab plus rilotumumab (n = 48), panitumumab plus ganitumab (n = 46), and panitumumab plus placebo arms (n = 48), the ORRs were 31%, 22%, and 21%, respectively. The median PFS was 5.2, 5.3, and 3.7 months and median OS 13.8, 10.6, and 11.6 months, respectively. Adverse events were tolerable. Exploratory biomarker analyses, including MET and IGF-related protein expression, failed to indicate conclusive predictive evidence on efficacy endpoints. CONCLUSIONS: Panitumumab plus rilotumumab met the prespecified criterion for improvement in ORR whereas ganitumab did not. This is the first study to suggest a benefit for combining an HGF inhibitor (rilotumumab) with panitumumab in previously treated patients with wild-type KRAS mCRC.

Population pharmacokinetics of rilotumumab, a fully human monoclonal antibody against hepatocyte growth factor, in cancer patients.

Rilotumumab is an investigational, fully human, monoclonal antibody immunoglobulin G2 against hepatocyte growth factor (HGF) that blocks the binding of HGF to its receptor MET and has shown trends toward improved survival in a phase 2 clinical trial in gastric cancer. To characterize rilotumumab pharmacokinetics in patients with cancer and to identify factors affecting the pharmacokinetics, rilotumumab concentration data from seven clinical trials were analyzed with a nonlinear mixed-effect model. We found that rilotumumab exhibited linear and time-invariant kinetics over a dose range of 0.5-20 mg/kg. Typical systemic clearance and central volume of distribution were 0.184 L/day and 3.56 L, respectively. Body weight is the most significant covariate, and sex, cancer type, coadministration of chemotherapeutics, baseline plasma HGF and tumor MET levels, and renal and hepatic functions did not have an effect on rilotumumab pharmacokinetics. The concentration-time profiles for the rilotumumab clinical regimens were projected well with the model.

Putative predictive biomarkers of survival in patients with metastatic pancreatic adenocarcinoma treated with gemcitabine and ganitumab, an IGF1R inhibitor.

PURPOSE: This planned exploratory analysis assessed the predictive nature of baseline circulating factors of the insulin-like growth factor (IGF) axis on the treatment effect of ganitumab (monoclonal antibody inhibitor of IGF-1 receptor) plus gemcitabine in a randomized phase II study in metastatic pancreatic adenocarcinoma. EXPERIMENTAL DESIGN: Baseline levels of IGFs/IGF binding proteins (IGFBP) were analyzed in serum or plasma. Mutations and gene expression were analyzed in archival samples. Treatment effects between biomarker subgroups were compared for overall survival (OS). Associations of tumor markers with OS were evaluated. RESULTS: For patients with evaluable samples, ganitumab was associated with improved OS versus placebo (HR, 0.49; 95% CI: 0.28-0.87). The treatment effect on improved OS was strong in the patient subset with higher levels of IGF-1, IGF-2, or IGFBP-3, or lower levels of IGFBP-2, but not so on the other corresponding subset. Median OS of ganitumab versus placebo in patients with higher levels of IGF-1, IGF-2, and IGFBP-3 was 16 versus 6.8 months (HR, 0.25; 95% CI: 0.09-0.67), 16 versus 5.9 months (HR, 0.24; 95% CI: 0.09-0.68), and 16 versus 6.8 months (HR, 0.28; 95% CI: 0.11-0.73), and in patients with lower IGFBP-2 levels was 12.7 versus 6.6 months (HR, 0.19; 95% CI: 0.07-0.55). Interaction between treatment and IGFs/IGFBPs in multivariate analyses suggested predictive potential for IGF-2 (P = 0.002) and IGFBP-2 (P = 0.02). KRAS mutation status and PTEN expression were not associated with OS. CONCLUSIONS: Baseline circulating factors of the IGF axis may predict OS benefit from ganitumab plus gemcitabine in metastatic pancreatic adenocarcinoma.

Ganitumab with either exemestane or fulvestrant for postmenopausal women with advanced, hormone-receptor-positive breast cancer: a randomised, controlled, double-blind, phase 2 trial.

BACKGROUND: Insulin-like growth factors (IGF-1 and IGF-2) bind to the IGF-1 receptor (IGF-1R), increasing cell proliferation and survival. Ganitumab is a monoclonal IgG1 antibody that blocks IGF-1R. We tested the efficacy and safety of adding ganitumab to endocrine treatment for patients with hormone-receptor-positive breast cancer. METHODS: We did this phase 2 trial in outpatient clinics and hospitals. We enrolled postmenopausal women with hormone-receptor-positive, locally advanced or metastatic breast cancer previously treated with endocrine treatment. They were randomly assigned (2:1) with a central randomisation schedule to receive intravenous ganitumab 12 mg per kg bodyweight or placebo in combination with open-label intramuscular fulvestrant (500 mg on day 1, then 250 mg on days 15, 29, and every 28 days) or oral exemestane (25 mg once daily) on a 28-day cycle. Patients, investigators, study monitors, and the sponsor staff were masked to treatment allocation. Response was assessed every 8 weeks. The primary endpoint was median progression-free survival in the intention-to-treat population. We analysed overall survival as one of our secondary endpoints. The study is registered at ClinicalTrials.gov, number NCT00626106. FINDINGS: We screened 189 patients and enrolled 156 (106 in the ganitumab group and 50 in the placebo group). Median progression-free survival did not differ significantly between the ganitumab and placebo groups (3·9 months, 80% CI 3·6-5·3 vs 5·7 months, 4·4-7·4; hazard ratio [HR] 1·17, 80% CI 0·91-1·50; p=0·44). However, overall survival was worse in the the ganitumab group than in the placebo group (HR 1·78, 80% CI 1·27-2·50; p=0·025). With the exception of hyperglycaemia, adverse events were generally similar between groups. The most common grade 3 or higher adverse event was neutropenia-reported by six of 106 (6%) patients in the ganitumab group and one of 49 (2%) in the placebo group. Hyperglycaemia was reported by 12 of 106 (11%) patients in the ganitumab group (with six patients having grade 3 or 4 hyperglycaemia) and none of 49 in the placebo group. Serious adverse events were reported by 27 of 106 (25%) patients in the ganitumab group and nine of 49 (18%) patients in the placebo group. INTERPRETATION: Addition of ganitumab to endocrine treatment in women with previously treated hormone-receptor-positive locally advanced or metastatic breast cancer did not improve outcomes. Our results do not support further study of ganitumab in this subgroup of patients. FUNDING: Amgen.

Targeted MET inhibition in castration-resistant prostate cancer: a randomized phase II study and biomarker analysis with rilotumumab plus mitoxantrone and prednisone.

PURPOSE: To evaluate the efficacy, safety, biomarkers, and pharmacokinetics of rilotumumab, a fully human, monoclonal antibody against hepatocyte growth factor (HGF)/scatter factor, combined with mitoxantrone and prednisone (MP) in patients with castration-resistant prostate cancer (CRPC). EXPERIMENTAL DESIGN: This double-blinded phase II study randomized (1:1:1) patients with progressive, taxane-refractory CRPC to receive MP (12 mg/m(2) i.v. day 1, 5 mg twice a day orally days 1-21, respectively) plus 15 mg/kg rilotumumab, 7.5 mg/kg rilotumumab, or placebo (i.v. day 1) every 3 weeks. The primary endpoint was overall survival (OS). RESULTS: One hundred and forty-four patients were randomized. Median OS was 12.2 versus 11.1 months [HR, 1.10; 80% confidence interval (CI), 0.82-1.48] in the combined rilotumumab versus control arms. Median progression-free survival was 3.0 versus 2.9 months (HR, 1.02; 80% CI, 0.79-1.31). Treatment appeared well tolerated with peripheral edema (24% vs. 8%) being more common with rilotumumab. A trend toward unfavorable OS was observed in patients with high tumor MET expression regardless of treatment. Soluble MET levels increased in all treatment arms. Total HGF levels increased in the rilotumumab arms. Rilotumumab showed linear pharmacokinetics when co-administered with MP. CONCLUSIONS: Rilotumumab plus MP had manageable toxicities and showed no efficacy improvements in this estimation study. High tumor MET expression may identify patients with CRPC with poorer prognosis.

Differential Pharmacokinetics of Ganitumab in Patients With Metastatic Pancreatic Cancer Versus Other Advanced Solid Cancers.

Ganitumab is an investigational, fully human monoclonal antibody antagonist of the insulin-like growth factor-1 receptor (IGF1R) that has shown trends towards improved progression-free survival and overall survival in a phase 2 pancreatic cancer clinical trial. To characterize ganitumab pharmacokinetics (PK) and identify factors affecting PK, ganitumab serum concentration data from three clinical trials were analyzed. The PK of ganitumab as monotherapy and in combination with gemcitabine in patients with pancreatic or non-pancreatic cancer were assessed with a non-linear mixed-effect model. We found that ganitumab exhibited linear and time-invariant kinetics. A two-compartment model adequately described data over a dose range of 1-20 mg/kg with good predictive capability. Typical clearance and central volume of distribution values were 1.7- and 1.3-fold higher, respectively, in patients with pancreatic cancer than in patients with other advanced solid cancers, resulting in lower ganitumab exposure. Covariate analysis was used to evaluate effects of cancer type, gemcitabine coadministration, clinical study, demographics, and laboratory values on ganitumab PK. Pancreatic cancer type was the most significant covariate on clearance along with weight, albumin, and serum creatinine. Gemcitabine coadministration did not affect ganitumab clearance. Thus, disease state can significantly affect PK and should be considered when selecting the clinically effective dose.

Phase 1 study of ganitumab (AMG 479), a fully human monoclonal antibody against the insulin-like growth factor receptor type I (IGF1R), in Japanese patients with advanced solid tumors.

PURPOSE: This study was to investigate the safety and tolerability of ganitumab in Japanese patients with advanced solid tumors. METHODS: Patients were enrolled into 1 of 3 dose cohorts (6, 12, or 20 mg/kg) of single-agent ganitumab administered intravenously every 2 weeks. Dose-limiting toxicity (DLT) was assessed for the first 28 days. The primary objectives were to assess the safety, tolerability, and pharmacokinetics (PK) of ganitumab in Japanese patients with advanced solid tumors. An exploratory pharmacodynamic analysis was done to investigate the relationship between exposure and changes in the level of circulating factors in IGF1R pathway (IGFBP-3 and total IGF-1). RESULTS: Nineteen patients with ECOG performance status 0-1 (6 in cohort 1 and 3, 7 in cohort 2) received at least 1 dose of ganitumab. Median age was 58.0 years. Tumor types included: breast (4), gastric (3), rectal (2), NSCLC (2), thymic (2), and other cancers (6). No DLTs were observed. The most common grade ≥3 adverse events were neutropenia (21 %), leukopenia (16 %) and lymphopenia (11 %). There was a trend of dose-dependency on severity of thrombocytopenia, but not on that of neutropenia. No neutralizing anti-ganitumab antibodies were detected during this study. Dose-linearity on PK of ganitumab was indicated in the dose range. Tumor response was assessed for 19 patients. Stable disease as best response was reported in 7 patients. CONCLUSIONS: Ganitumab up to 20 mg/kg was tolerable in Japanese patients with advanced solid tumors. The safety and PK profiles were similar to those previously observed in non-Japanese patients.

A phase II study evaluating the efficacy and safety of AMG 102 (rilotumumab) in patients with recurrent glioblastoma.

This phase II study evaluated the efficacy and safety of AMG 102 (rilotumumab), a fully human monoclonal antibody against hepatocyte growth factor/scatter factor (HGF/SF), in patients with recurrent glioblastoma (GBM). Patients with histologically confirmed, measurable recurrent GBM or gliosarcoma (World Health Organization grade 4) and ≤3 relapses or prior systemic therapies received AMG 102 (10 or 20 mg/kg) by infusion every 2 weeks. The primary endpoint was best confirmed objective response rate (central assessment) per Macdonald criteria. Of the 61 patients who enrolled, 60 received AMG 102. Twenty-nine patients (48%) had previously received bevacizumab. There were no objective responses per central assessment, but 1 patient had an objective response per investigator assessment. Median overall survival (95% CI) in the 10- and 20-mg/kg cohorts was 6.5 months (4.1-9.8) and 5.4 months (3.4-11.4), respectively, and progression-free survival (PFS) per central assessment was 4.1 weeks (4.0-4.1) and 4.3 weeks (4.1-8.1), respectively. PFS was similar among patients who had previously received bevacizumab compared with bevacizumab-naive patients. The most common adverse events were fatigue (38%), headache (33%), and peripheral edema (23%). AMG 102 serum concentrations increased approximately dose-proportionally with 2-fold accumulation at steady state. Plasma total HGF/SF and soluble c-Met concentrations increased 12.05- and 1.12-fold, respectively, from baseline during AMG 102 treatment. AMG 102 monotherapy at doses up to 20 mg/kg was not associated with significant antitumor activity in heavily pretreated patients with recurrent GBM.

Drug-induced QTc interval prolongation: a proposal towards an efficient and safe anticancer drug development.

The goal of drug development is to define potential risks and benefits of new therapies. Assessment of new drugs for their potential to alter cardiac repolarisation, prolong QTc interval and induce potentially fatal proarrhythmias such as 'torsade de pointes' is now one of the major goals during phase I-II studies. The results from these early phase clinical studies can profoundly influence 'go, no-go' decisions as well as decisions on the selection of optimal dose regimen for subsequent development, its delivery and conduct of pivotal clinical studies, including eligibility of patients. Increasingly, anticancer drugs are now also attracting attention with regard to their proarrhythmic safety. Unfortunately, regulatory guidelines focus essentially on non-cytotoxic drugs and there is no clear guidance available for evaluation of the potential of cytotoxic drugs to alter cardiac repolarisation during their development. We propose a strategy to assess the QT-liability of a cytotoxic agent in early phase I-II studies without compromising the objectives of these studies or patient access to potentially beneficial novel agents. A pragmatic and thoughtful strategy for the assessment of this proarrhythmic risk and its management, involving close collaboration between drug developers, regulatory agencies, oncologists and cardiologists, is essential for the development of these oncology agents.

Phase I trial of tirapazamine, cisplatin, and concurrent accelerated boost reirradiation in patients with recurrent head and neck cancer.

PURPOSE: Reirradiation (re-RT) with concurrent chemotherapy offers a therapeutic option in patients who have locoregional recurrence of head and neck cancer (HNC). The hypoxic cell sensitizer, tirapazamine (TPZ), has demonstrated promising results in first-line therapy for HNC. This phase I trial was designed to test the feasibility of giving TPZ in the re-RT setting. METHODS AND MATERIALS: Patients with recurrent HNC who received prior radiotherapy (RT) were enrolled and received TPZ (260 mg/m2) and cisplatin (50 mg/m2) Weeks 1, 3, and 5 concurrently with RT (72 Gy, 42 fractions over 6 weeks). TPZ (160 mg/m2) alone was added on Days 1, 3, and 5 of Week 2 (cohort 1) or Weeks 2 and 4 (cohort 2). RESULTS: Twenty-five subjects were enrolled, 7 and 18 on cohorts 1 and 2, respectively. Significant toxicities included Grade 3 dermatitis (20%) and Grade 3 mucositis (40%). Dose-limiting toxicity was observed on cohort 2 (1 patient with aspiration pneumonia). Four deaths occurred during treatment. Two fatalities occurred after completing therapy as a result of carotid artery rupture. With a minimum and median follow-up of 14 and 24 months, respectively, median overall survival was 14 months with actuarial 1-year and 2-year survival of 56% and 27%, respectively. CONCLUSION: Reirradiation with concomitant chemotherapy including TPZ in patients with unresectable recurrent HNC is feasible and results in long-term survival in a significant proportion of patients.