Understanding Disease-Drug Interactions in Cancer Patients: Implications for Dosing Within the Therapeutic Window

The human inflammatory response can result in the alteration of drug clearance through effects on metabolizing enzymes or transporters. In this article we briefly review the theory of how cancer can lead to indirect changes in drug metabolism, review acute phase proteins and cytokines as markers of changes in cytochrome P450 (CYP) activity in cancer patients, and provide clinical case examples of how the inflammation in advanced cancer patients can lead to altered CYP-mediated drug clearance.

Abstract CT237: Interim results of a first-in-human phase 1 study of the oral MET kinase inhibitor, LY2801653, in patients with advanced cancer

Background: Aberrant MET signaling, whether due to genetic lesions, transcriptional upregulation, or ligand-dependent autocrine or paracrine mechanisms, plays a role in tumorigenesis and angiogenesis. Amplification of MET has also been demonstrated in tumor cells that have acquired resistance to treatments such as cisplatin, erlotinib, and gefitinib. The purpose of this phase 1 study is to evaluate the safety and tolerability of LY2801653, a type II MET kinase inhibitor, and to determine a recommended Phase 2 dose and schedule that may be safely administered to patients with advanced cancer.

Methods: Patients with a diagnosis of advanced or metastatic solid tumors and whose disease had demonstrated standard treatment failure were enrolled in the study (NCT01285037). Dose escalation was performed using a modified CRM design (Part A). Dose confirmation testing continued in Part B enrolling 4 tumor types -colorectal (CRC), squamous cell carcinoma of the head and neck (HNSCC), cholangiocarcinoma (CCA), and uveal melanoma.

Results: In Part A, 50 patients received daily oral doses of LY2801653 at one of 10 dose levels (3, 6, 5, 10, 20, 40, 80, 120, 160, and 240 mg). Reversible grade 3 elevations of AST/ALT were identified as the dose limiting toxicity and occurred at 240 mg (n=2), 160 mg (n=2) and 120 mg

(n=1). A dose of 120 mg QD was selected for further study (geometric mean AUC0-24hr = 3070 ng*hr/mL, CV=79%, n=9; geometric mean Cmax= 298 ng/mL, CV=67%, n=10). As of 08/20/2013, 30 patients (19 CRC; 5 HNSCC; 6 CCA) have received LY2801653 at 120 mg QD in Part B. Among all treated patients (N=80), the most frequent therapy-related adverse events, all ≤ Grade 3 in severity, were fatigue (23.8%), increased AST (21.3%) or ALT (20%), nausea (15%), limb edema (12.5%), and increased ALP (11.3%). The primary reason for discontinuation was progressive disease (n=48, 60%), and 4 patients discontinued due to treatment related adverse events of fatigue, AST increase, bilirubin increase, or left ventricular systolic dysfunction. In Part A, 9 patients have been treated for ≥4 months, including 1CRC patient (707 days) and 1 squamous cervical cancer patient (566 days). Although the data is still immature in Part B, 4 patients (2 CRC; 1 HNSCC; 1 CCA) have been treated for ≥4 months, all with stable disease and 3 with a reduction in tumor size from baseline.

Conclusions: In dose escalation testing, once daily dosing with LY2801653 demonstrated an acceptable toxicity profile. Single agent testing is ongoing at 120 mg in 4 tumor specific cohorts as well as two additional arms investigating LY2801653 in combination with cetuximab in HNSCC and with cisplatin in CCA.

Citation Format: Jimmy Hwang, Roger Cohen, Kimberly Perez, Howard Safran, Aiwu Ruth He, Jennifer Giles, Tianle Hu, Brian Moser, Patricia Kellie Turner, Richard A. Walgren, Elizabeth Plimack. Interim results of a first-in-human phase 1 study of the oral MET kinase inhibitor, LY2801653, in patients with advanced cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr CT237. doi:10.1158/1538-7445.AM2014-CT237

First-in-human dose escalation study of LY2875358 (LY), a bivalent MET antibody, as monotherapy and in combination with erlotinib (E) in patients with advanced cancer

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Background: Activation of the hepatocyte growth factor (HGF)/MET receptor pathway promotes tumor growth, invasion and dissemination. LY is a humanized IgG4 monoclonal bivalent antibody against MET which inhibits ligand dependent- and ligand independent activation of MET. Based on preclinical results, we examined LY alone in patients with advanced solid tumors and LY+E in advanced NSCLC patients. Methods: LY monotherapy was administered 20-2,000 mg Q2W IV to 23 patients with advanced solid tumors. Combination therapy with 700-2,000 mg Q2W IV of LY and E (150 mg QD) was completed in 14 patients with advanced NSCLC. The primary objective was to determine a recommended phase II dose (RPTD) for LY and LY+E. Secondary objectives included assessment of toxicity, PK, PD (including MET extracelluar domain and HGF), and antitumor activity. Results: LY and LY+E were well tolerated. No dose-limiting toxicities, serious adverse events, or ≥ Grade 3 adverse events (AEs) possibly related to LY have been observed. The most frequent (≥5% of patients) AEs possibly related to LY2875358 monotherapy were nausea (8.7 %), vomiting (8.7%), and diarrhea (8.7%). The most frequent (≥10% of patient) grade 1 or 2 adverse event possibly related to LY2875358 in patients treated with LY+E were fatigue (21.4%) and anorexia (14.3%). Durable PR according to RECIST were observed for LY (n=1) and LY+E (n=2 out of 13 evaluable patients; both PR patients positive for MET protein expression). Conclusions: LY appears to be safe when administered as single agent and in combination with E up to 2,000 mg Q2W IV. The RPTD of LY is 750 mg Q2W IV for monotherapy and in combination with E based on PK/PD data. Clinical trial information: NTC 01287546.

Assessment of toxicity reduction in wastewater effluent flowing through a treatment wetland using Pimephales promelas, Ceriodaphnia dubia, and Vibrio fischeri

Effluent toxicity is regularly assessed with Ceriodaphnia dubia short-term chronic and Vibrio fischeri toxicity tests. Condition factor and hemotocrit of fish have recently been used to assess fish health following exposure to xenoestrogens in complex municipal effluents. To assess the ability of a treatment wetland to reduce or remove toxicity of a municipal effluent, we compared C. dubia and V. fischeri bioassays to Pimephales promelas responses in situ. Final whole effluent was diverted to a constructed wetland and effluent samples were taken daily from four sites, at incremental distances from the inflow, for a 3-week study. Overlapping 7-day C. dubia tests and V. fischeri assays were conducted with samples from each wetland site concurrent with a 3-week fish exposure. C. dubia survival and fecundity were significantly (< 0.0001) reduced at the inflow, but steadily improved with distance from the inflow. Fish condition and hematocrit were lower (alpha < 0.05) at wetland sites closer to the inflow than other wetland sites and laboratory controls. However, effluent toxicity was not detected by V. fischeri bioassays. Our findings indicate that 7-day C. dubia bioassays were most sensitive to effluent toxicity and suggest that other bioassays should be used concurrent with V. fischeri assays for municipal effluent toxicity testing.