Brian Schwartz

Discovery and development of sorafenib: a multikinase inhibitor for treating cancer

Since the molecular revolution of the 1980s, knowledge of the aetiology of cancer has increased considerably, which has led to the discovery and development of targeted therapies tailored to inhibit cancer-specific pathways. The introduction and refinement of rapid, high-throughput screening technologies over the past decade has greatly facilitated this targeted discovery and development process. Here, we describe the discovery and continuing development of sorafenib (previously known as BAY 43-9006), the first oral multikinase inhibitor that targets Raf and affects tumour signalling and the tumour vasculature. The discovery cycle of sorafenib (Nexavar; Bayer Pharmaceuticals) — from initial screening for a lead compound to FDA approval for the treatment of advanced renal cell carcinoma in December 2005 — was completed in just 11 years, with approval being received ∼5 years after the initiation of the first Phase I trial.

Phase I Clinical and Pharmacokinetic Study of the Novel Raf Kinase and Vascular Endothelial Growth Factor Receptor Inhibitor BAY 43-9006 in Patients With Advanced Refractory Solid Tumors

PURPOSE BAY 43-9006 is a novel dual-action Raf kinase and vascular endothelial growth factor receptor inhibitor that inhibits tumor cell proliferation and angiogenesis. This study established the safety and pharmacokinetics of BAY 43-9006 in 69 patients with advanced refractory solid tumors. PATIENTS AND METHODS BAY 43-9006 (50 to 800 mg) was administered once or twice daily on a varying weekly schedule. Pharmacokinetic sampling was performed in all patients; preliminary tumor response was also assessed. The effect of BAY 43-9006 on phorbol myristate acetate-stimulated ERK phosphorylation in peripheral blood lymphocytes was studied using flow cytometry. RESULTS Mild to moderate diarrhea was the most common (55%) treatment-related adverse event. The maximum-tolerated dose was 400 mg bid continuous. Dose-limiting toxicities were grade 3 diarrhea and fatigue at 800 mg bid, and grade 3 skin toxicity at 600 mg bid. BAY 43-9006 pharmacokinetics were highly variable for single and multiple dosing, and toxicity did not appear to be dose dependent. Significant decreases of phorbol myristate acetate-stimulated ERK phosphorylation (P < .01) were identified at doses >/= 200 mg bid continuous. Forty-five patients were assessable for efficacy; one patient had a partial response (hepatocellular carcinoma at 400 mg bid continuous), 25 patients had stable disease, with eight lasting > 6 months and five for >12 months. Eighteen patients had progressive disease, and tumor response could not be evaluated in one patient. CONCLUSION Oral BAY 43-9006 was well tolerated and appeared to provide some clinical benefits. Based on the results of this study, BAY 43-9006 at 400 mg bid continuous is recommended for ongoing and future studies.

Tivantinib for second-line treatment of advanced hepatocellular carcinoma: a randomised, placebo-controlled phase 2 study

BACKGROUND Tivantinib (ARQ 197), a selective oral inhibitor of MET, has shown promising antitumour activity in hepatocellular carcinoma as monotherapy and in combination with sorafenib. We aimed to assess efficacy and safety of tivantinib for second-line treatment of advanced hepatocellular carcinoma. METHODS In this completed, multicentre, randomised, placebo-controlled, double-blind, phase 2 study, we enrolled patients with advanced hepatocellular carcinoma and Child-Pugh A cirrhosis who had progressed on or were unable to tolerate first-line systemic therapy. We randomly allocated patients 2:1 to receive tivantinib (360 mg twice-daily) or placebo until disease progression. The tivantinib dose was amended to 240 mg twice-daily because of high incidence of treatment-emergent grade 3 or worse neutropenia. Randomisation was done centrally by an interactive voice-response system, stratified by Eastern Cooperative Oncology Group performance status and vascular invasion. The primary endpoint was time to progression, according to independent radiological review in the intention-to-treat population. We assessed tumour samples for MET expression with immunohistochemistry (high expression was regarded as ≥2+ in ≥50% of tumour cells). This study is registered with ClinicalTrials.gov, number NCT00988741. FINDINGS 71 patients were randomly assigned to receive tivantinib (38 at 360 mg twice-daily and 33 at 240 mg twice-daily); 36 patients were randomly assigned to receive placebo. At the time of analysis, 46 (65%) patients in the tivantinib group and 26 (72%) of those in the placebo group had progressive disease. Time to progression was longer for patients treated with tivantinib (1·6 months [95% CI 1·4-2·8]) than placebo (1·4 months [1·4-1·5]; hazard ratio [HR] 0·64, 90% CI 0·43-0·94; p=0·04). For patients with MET-high tumours, median time to progression was longer with tivantinib than for those on placebo (2·7 months [95% CI 1·4-8·5] for 22 MET-high patients on tivantinib vs 1·4 months [1·4-1·6] for 15 MET-high patients on placebo; HR 0·43, 95% CI 0·19-0·97; p=0·03). The most common grade 3 or worse adverse events in the tivantinib group were neutropenia (ten patients [14%] vs none in the placebo group) and anaemia (eight [11%] vs none in the placebo group). Eight patients (21%) in the tivantinib 360 mg group had grade 3 or worse neutropenia compared with two (6%) patients in the 240 mg group. Four deaths related to tivantinib occurred from severe neutropenia. 24 (34%) patients in the tivantinib group and 14 (39%) patients in the placebo group had serious adverse events. INTERPRETATION Tivantinib could provide an option for second-line treatment of patients with advanced hepatocellular carcinoma and well-compensated liver cirrhosis, particularly for patients with MET-high tumours. Confirmation in a phase 3 trial is needed, with a starting dose of tivantinib 240 mg twice-daily. FUNDING ArQule, Daiichi Sankyo (Daiichi Sankyo Group).

Randomized Phase II Study of Erlotinib Plus Tivantinib Versus Erlotinib Plus Placebo in Previously Treated Non–Small-Cell Lung Cancer

PURPOSE c-MET (MET) receptor activation is associated with poor prognosis and epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) resistance in non-small-cell lung cancer (NSCLC). This global, randomized phase II trial examined erlotinib plus tivantinib (ARQ 197; ArQule, Woburn, MA), a novel MET inhibitor. METHODS Previously treated patients with EGFR TKI-naive advanced NSCLC were randomly assigned to receive oral erlotinib (150 mg daily) plus oral tivantinib (360 mg twice daily) or erlotinib plus placebo (EP). The primary end point was progression-free survival (PFS). At the time of progression, cross-over from EP to erlotinib plus tivantinib (ET) was permitted. Archival tumor tissue specimens were required. RESULTS One hundred sixty-seven patients were randomly assigned to ET (n = 84) and to EP (n = 83). Median PFS was 3.8 months for ET and 2.3 months for EP (hazard ratio [HR], 0.81; 95% CI, 0.57 to 1.16; P = .24). Exploratory analysis revealed that the small cohort with KRAS mutations achieved a PFS HR of 0.18 (95% CI, 0.05 to 0.70; interaction P = .006). Objective responses were seen in 10% of patients on ET, 7% of patients on EP, and in two patients who crossed over from EP to ET, including one with EGFR mutation and MET gene copy number greater than 5. There were no significant differences in adverse events between study arms. CONCLUSION The combination of the MET inhibitor tivantinib and erlotinib is well-tolerated. Although the study did not meet its primary end point, evidence of activity was demonstrated, especially among patients with KRAS mutations. Additional study of tivantinib and erlotinib in patients with NSCLC is planned.

Phase I safety and pharmacokinetics of BAY 43-9006 administered for 21 days on/7 days off in patients with advanced, refractory solid tumours

BAY 43-9006 is a novel dual-action Raf kinase and vascular endothelial growth factor receptor (VEGFR) inhibitor that targets tumour cell proliferation and tumour angiogenesis. This Phase I study was undertaken to determine the safety profile, maximum tolerated dose (MTD), dose-limiting toxicities (DLTs), pharmacokinetics, and tumour response profile of oral BAY 43-9006 in patients with advanced, refractory solid tumours. BAY 43-9006 was administered daily for repeated cycles of 21 days on/7 days off. A total of 44 patients were enrolled at doses from 50 to 800 mg b.i.d. Pharmacokinetic profiles of BAY 43-9006 in plasma were determined during the first treatment cycle. The most frequently reported adverse events over multiple cycles were gastrointestinal (75%), dermatologic (71%), constitutional (68%), pain (64%), or hepatic (61%) related. A MTD of 400 mg b.i.d. BAY 43-9006 was defined. BAY 43-9006 was absorbed rapidly; steady-state conditions were reached within 7 days. BAY 43-9006 exposure increased nonproportionally with increasing dose. In all, 32 patients were evaluated for tumour response: 15 patients showed tumour progression, 16 patients experienced stable disease (>6 months in eight patients), and one patient with renal cell carcinoma achieved a partial response. BAY 43-9006 given for 21 days with 7 days off treatment was safe, well tolerated, and showed antitumour activity.

Phase I trial of sorafenib and gemcitabine in advanced solid tumors with an expanded cohort in advanced pancreatic cancer.

Background: With its potent inhibitory effects against Raf-1 kinase and vascular endothelial growth factor receptor-2, sorafenib is a novel oral anticancer agent targeting signal transduction and angiogenic pathways. This study is designed to combine sorafenib and gemcitabine due to their compatibility in preclinical models and nonoverlapping clinical toxicities. Experimental Design: An initial dose-escalation part of the study enrolled patients with advanced solid tumors, followed by an expanded cohort at the recommended dose for patients with advanced unresectable or metastatic pancreatic cancer. Sorafenib is administered continuously, whereas gemcitabine is given at 1,000 mg/m2 weekly × 7 followed by 1 rest week, then weekly × 3 every 4 weeks. Results: Forty-two patients have been enrolled overall, including 19 in the dose-escalation part and 23 in the extended pancreatic cancer cohort. Demographics were as follows: male-to-female ratio = 26:16; median age = 61 years (range 39-83 years); Eastern Cooperative Oncology Group performance status 0:1:2 ratio = 16:21:5. The recommended dose of this combination is sorafenib 400 mg twice daily and gemcitabine 1,000 mg/m2. The most frequent grade 3 or 4 adverse events of all causalities were thrombocytopenia (28.6%), lymphopenia (21.4%), lipase elevation (19%), neutropenia (16.7%), and fatigue (14.3%). Antitumor activity was observed in both groups, with 2 (10.5%) confirmed partial responses in ovarian cancer and 12 patients (63.2%) with disease stabilization in the dose-escalation part; 13 patients (56.5%) achieved disease stabilization in the pancreatic cohort. There was no consistent pharmacokinetic drug-to-drug interaction between sorafenib and gemcitabine. Conclusions: Sorafenib and gemcitabine are well tolerated in combination; further evaluations in pancreatic and ovarian cancers are warranted.

Phase I trial of a selective c-MET inhibitor ARQ 197 incorporating proof of mechanism pharmacodynamic studies

PURPOSE The hepatocyte growth factor/c-MET axis is implicated in tumor cell proliferation, survival, and angiogenesis. ARQ 197 is an oral, selective, non-adenosine triphosphate competitive c-MET inhibitor. A phase I trial of ARQ 197 was conducted to assess safety, tolerability, and target inhibition, including intratumoral c-MET signaling, apoptosis, and angiogenesis. PATIENTS AND METHODS Patients with solid tumors amenable to pharmacokinetic and pharmacodynamic studies using serial biopsies, dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), and circulating endothelial cell (CEC) and circulating tumor cell (CTC) enumeration were enrolled. RESULTS Fifty-one patients received ARQ 197 at 100 to 400 mg twice per day. ARQ 197 was well tolerated, with the most common toxicities being grade 1 to 2 fatigue, nausea, and vomiting. Dose-limiting toxicities included grade 3 fatigue (200 mg twice per day; n = 1); grade 3 mucositis, palmar-plantar erythrodysesthesia, and hypokalemia (400 mg twice per day; n = 1); and grade 3 to 4 febrile neutropenia (400 mg twice per day, n = 2; 360 mg twice per day, n = 1). The recommended phase II dose was 360 mg twice per day. ARQ 197 systemic exposure was dose dependent and supported twice per day oral dosing. ARQ 197 decreased phosphorylated c-MET, total c-MET, and phosphorylated focal adhesion kinase and increased terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick-end labeling (TUNEL) staining in tumor biopsies (n = 15). CECs decreased in 25 (58.1%) of 43 patients, but no significant changes in DCE-MRI parameters were observed after ARQ 197 treatment. Of 15 patients with detectable CTCs, eight (53.3%) had ≥ 30% decline in CTCs after treatment. Stable disease, as defined by Response Evaluation Criteria in Solid Tumors (RECIST), ≥ 4 months was observed in 14 patients, with minor regressions in gastric and Merkel cell cancers. CONCLUSION ARQ 197 safely inhibited intratumoral c-MET signaling. Further clinical evaluation focusing on combination approaches, including an erlotinib combination in non-small-cell lung cancer, is ongoing.

Phase III Multinational, Randomized, Double-Blind, Placebo-Controlled Study of Tivantinib (ARQ 197) Plus Erlotinib Versus Erlotinib Alone in Previously Treated Patients With Locally Advanced or Metastatic Nonsquamous Non–Small-Cell Lung Cancer

PURPOSE Tivantinib, a MET receptor tyrosine kinase inhibitor, demonstrated increased anticancer activity in preclinical and early clinical studies when combined with erlotinib. Our study aimed to confirm efficacy and safety of the combination in previously treated patients with non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS Patients with advanced nonsquamous NSCLC previously treated with one to two systemic regimens, including a platinum doublet, were randomly assigned at a 1:1 ratio to receive erlotinib 150 mg daily plus oral tivantinib 360 mg twice daily (E + T) or erlotinib plus placebo (E + P) until disease progression. Tumor specimens were evaluated for EGFR and KRAS mutations, MET expression, and MET gene amplification. The primary end point was overall survival (OS). Secondary and exploratory objectives included progression-free survival (PFS), OS in molecular subgroups, and safety. RESULTS The study enrolled 1,048 patients and was discontinued for futility at the interim analysis. OS did not improve with E + T versus E + P (median OS, 8.5 v 7.8 months, respectively; hazard ratio [HR], 0.98; 95% CI, 0.84 to 1.15; P = .81), even though PFS increased (median PFS, 3.6 v 1.9 months; HR, 0.74; 95% CI, 0.62 to 0.89; P < .001). Exploratory subgroup analyses suggested OS improvement in patients with high MET expression (HR, 0.70; 95% CI, 0.49 to 1.01). Most common adverse events occurring with E + T versus E + P were rash (33.1% v 37.3%, respectively), diarrhea (34.6% v 41.0%), asthenia or fatigue (43.5% v 38.1%), and neutropenia (grade 3 to 4; 8.5% v 0.8%). CONCLUSION E + T was well tolerated and increased PFS but did not improve OS in the overall nonsquamous NSCLC population.

Tivantinib (ARQ 197), a selective inhibitor of MET, in patients with microphthalmia transcription factor-associated tumors: results of a multicenter phase 2 trial.

Microphthalmia transcription factor (MITF)‐associated (MiT) tumors are a family of rare malignancies, including alveolar soft part sarcoma (ASPS), clear cell sarcoma (CCS), and translocation‐associated renal cell carcinoma (tRCC) that have dysregulated expression of oncogenic MITF family proteins. The MET receptor tyrosine kinase gene is transcriptionally activated by MITF family proteins, making MET a potential therapeutic target for MiT tumors. This study assessed the activity of tivantinib (ARQ 197), a selective MET inhibitor, in patients with MiT‐associated tumors.

Early Clinical Development of ARQ 197, a Selective, Non–ATP-Competitive Inhibitor Targeting MET Tyrosine Kinase for the Treatment of Advanced Cancers

Expression of the receptor tyrosine kinase c-MET (MET, mesenchymal-epithelial transition factor) in many cancers, and its participation in multiple signal transduction pathways involved in malignant tumor growth, suggest a wide therapeutic potential for MET inhibition in human cancer. Here we describe the discovery and early clinical development of ARQ 197, a novel, selective, non-ATP-competitive inhibitor of MET. Phase I studies demonstrate that ARQ 197 has a predictable pharmacokinetics and favorable safety profile, making it a potentially ideal partner for combination with cytotoxic chemotherapies and targeted anticancer agents. Results from phase I and phase II trials demonstrate preliminary evidence of anticancer activity. New data from a global phase II randomized trial comparing a combination of ARQ 197 plus erlotinib with erlotinib/placebo, in endothelial growth factor receptor inhibitor-naïve patients with locally advanced/metastatic non-small cell lung cancer, demonstrate improvement in progression-free and overall survival with combined therapy. Results were especially pronounced for patients with non-squamous lung cancer histologies, and in particular molecularly defined subgroups including KRAS mutations. These and other data from ARQ 197 clinical trials in hepatocellular, germ-cell, pancreatic (in combination with gemcitabine), and colorectal (in combination with cetuximab and irinotecan) cancers further highlight the potential role of ARQ 197 in existing and emerging anticancer therapeutic regimens.