Oliver Rosen

Phase I Study of the Humanized Antiepidermal Growth Factor Receptor Monoclonal Antibody EMD72000 in Patients With Advanced Solid Tumors That Express the Epidermal Growth Factor Receptor

PURPOSE To investigate the safety and tolerability and to explore the pharmacokinetic and pharmacodynamic profile of the humanized antiepidermal growth factor receptor monoclonal antibody EMD72000 in patients with solid tumors that express epidermal growth factor receptor (EGFR). PATIENTS AND METHODS This was a phase I dose-escalation trial of EMD72000 in patients with advanced, EGFR-positive, solid malignancies that were not amenable to any established chemotherapy or radiotherapy treatment. EMD72000 was administered weekly without routine premedication until disease progression or unacceptable toxicity. RESULTS Twenty-two patients were treated with EMD72000 at five different dose levels (400 to 2,000 mg/wk). National Cancer Institute common toxicity criteria grade 3 headache and fever occurring after the first infusion were dose limiting at 2,000 mg/wk; thus, the maximum-tolerated dose was 1,600 mg/wk. No other severe side effects, especially no allergic reactions or diarrhea, were observed. Acneiform skin reaction was the most common toxicity, but it was mild, with grade 1 in 11 patients (50%) and grade 2 in three patients (14%). Pharmacokinetic analyses demonstrated a predictable pharmacokinetic profile for EMD72000. Pharmacodynamic studies on serial skin biopsies revealed that EMD72000 effectively abrogated EGFR-mediated cell signaling (eg, reduced phosphorylation of EGFR and mitogen-activated protein kinase), with no alteration in total EGFR protein. Objective responses (23%; 95% CI, 8% to 45%) and disease stabilization (27%; 95% CI, 11% to 50%) were achieved at all dose levels, and responding patients received treatment for up to 18 months without cumulative toxicity. CONCLUSION Treatment with EMD72000 was well tolerated and showed evidence of activity in heavily pretreated patients with EGFR-expressing tumors. EMD72000 at the investigated doses significantly inhibited downstream EGFR-dependent processes.

The clinical benefit of bevacizumab in metastatic colorectal cancer is independent of K-ras mutation status: analysis of a phase III study of bevacizumab with chemotherapy in previously untreated metastatic colorectal cancer.

PURPOSE Mutations of the K-ras gene were identified as a prognostic marker in metastatic colorectal cancer (mCRC). In addition, emerging data suggest that K-ras mutations are a negative predictor of clinical benefit from anti-epidermal growth factor receptor treatment in mCRC. Previously reported data suggest that the longer overall survival (OS) observed with bevacizumab treatment in mCRC is independent of alterations in the Ras/Raf/Mek/Erk pathway. We conducted additional analyses to better describe the clinical benefit of bevacizumab treatment in mCRC relative to K-ras mutation status. PATIENTS AND METHODS Additional statistical analyses were done with data from K-ras mutation analyses in 230 patients who were treated with irinotecan, fluorouracil, and leucovorin (IFL) in combination with either bevacizumab or placebo in a randomized phase III study. Following microdissection, tissue was subject to DNA sequencing to identify K-ras mutations in codons 12 and 13. Hazard ratios for the bevacizumab group relative to the control group were estimated from an unstratified Cox regression model. The median progression-free survival (PFS), OS times, and objective response rates were compared. RESULTS K-ras status was assessed in 230 patients (28.3%). The median PFS was significantly longer in bevacizumab-treated patients with wild-type (wt)- (13.5 versus 7.4 months; hazard ratio 0.44, p < .0001) and mutant (m)-K-ras (9.3 versus 5.5 months; hazard ratio 0.41, p = .0008). A significantly higher response rate for IFL plus bevacizumab was observed only in wt-K-ras patients (60.0% versus 37.3%, p = .006) compared with 43.2% versus 41.2% in the m-K-ras group. CONCLUSION Bevacizumab provides significant clinical benefit in patients with mCRC expressing either mutant or wild-type K-ras.

Addition of Bevacizumab to Fluorouracil-Based First-Line Treatment of Metastatic Colorectal Cancer: Pooled Analysis of Cohorts of Older Patients From Two Randomized Clinical Trials

PURPOSE Colorectal cancer (CRC) occurs predominantly in older persons. To provide more statistical power to assess risk/benefit in older patients, we examined the clinical benefit of bevacizumab (BV) plus fluorouracil-based chemotherapy in first-line metastatic CRC (mCRC) treatment in patients aged > or = 65 years, using data pooled from two placebo-controlled studies. PATIENTS AND METHODS Pooled efficacy data for 439 patients > or = 65 years old randomized to BV plus chemotherapy (n = 218) or placebo plus chemotherapy (n = 221) in study 1 and study 2 were retrospectively analyzed on an intent-to-treat basis for overall survival (OS), progression-free survival (PFS), and objective response. Safety analysis was based on reports of targeted adverse events in treated patients. RESULTS Median OS with BV plus chemotherapy was 19.3 v 14.3 months with placebo plus chemotherapy (hazard ratio [HR] = 0.70; 95% CI, 0.55 to 0.90; P = .006). Patients treated with BV plus chemotherapy had a median PFS of 9.2 v 6.2 months for placebo plus chemotherapy patients (HR = 0.52; 95% CI, 0.40 to 0.67; P < .0001). The objective response rate was 34.4% with BV plus chemotherapy versus 29.0% with placebo plus chemotherapy (difference not statistically significant). Rates of BV-associated adverse events in the pooled BV plus chemotherapy group were consistent with those reported in the overall populations for the two studies. CONCLUSION Analysis of pooled patient cohorts age >/= 65 years from two similar trials in mCRC indicates that adding bevacizumab to fluorouracil-based chemotherapy improved OS and PFS, similar to the benefits in younger patients. Also, the risks of treatment do not seem to exceed those in younger patients with mCRC.

Analysis of Early Hypertension and Clinical Outcome With Bevacizumab: Results From Seven Phase III Studies

BACKGROUND Hypertension is associated with antivascular endothelial growth factor treatment, but the clinical implications of hypertension are uncertain. To assess the prognostic and predictive value of bevacizumab-related hypertension, a comprehensive analysis of whether hypertension and efficacy outcomes are associated was conducted on seven company-sponsored placebo-controlled phase III studies of bevacizumab. METHODS Patient-specific data were available from 6,486 patients with metastatic colorectal, breast, non-small cell lung, pancreatic, and renal cell cancers. Primary hypertension endpoint was a blood pressure (BP) increase of >20 mmHg systolic or >10 mmHg diastolic within the first 60 days of treatment. Additional endpoints included other predefined thresholds of change in BP and severity of hypertension graded using the National Cancer Institutes Common Terminology Criteria for Adverse Events. To analyze the general prognostic importance of an early BP increase, multivariate Cox regression models were used to assess the correlation between BP changes and progression-free (PFS) and overall survival (OS) outcomes in the control groups. To analyze whether early BP increases could predict for benefit from bevacizumab, similar analyses were conducted in the bevacizumab-treated and control groups. RESULTS In six of seven studies, early BP increase was neither predictive of clinical benefit from bevacizumab nor prognostic for the course of the disease. For study AVF2107g, early increased BP was associated with longer PFS and OS times in the bevacizumab group but shorter OS time in the control group. CONCLUSIONS Early treatment-related BP increases do not predict clinical benefit from bevacizumab based on PFS or OS outcomes. BP increases do not appear to have general prognostic importance for patients with advanced cancer.

Modernizing Clinical Trial Eligibility Criteria: Recommendations of the American Society of Clinical Oncology–Friends of Cancer Research Brain Metastases Working Group

Purpose Broadening trial eligibility to improve accrual and access and to better reflect intended-to-treat populations has been recognized as a priority. Historically, patients with brain metastases have been understudied, because of restrictive eligibility across all phases of clinical trials. Methods In 2016, after a literature search and series of teleconferences, a multistakeholder workshop was convened. Our working group focused on developing consensus recommendations regarding the inclusion of patients with brain metastases in clinical trials, as part of a broader effort that encompassed minimum age, HIV status, and organ dysfunction. The working group attempted to balance the needs of protecting patient safety, facilitating access to investigational therapies, and ensuring trial integrity. On the basis of input at the workshop, guidelines were further refined and finalized. Results The working group identified three key populations: those with treated/stable brain metastases, defined as patients who have received prior therapy for their brain metastases and whose CNS disease is radiographically stable at study entry; those with active brain metastases, defined as new and/or progressive brain metastases at the time of study entry; and those with leptomeningeal disease. In most circumstances, the working group encourages the inclusion of patients with treated/stable brain metastases in clinical trials. A framework of key considerations for patients with active brain metastases was developed. For patients with leptomeningeal disease, inclusion of a separate cohort in both early-phase and later-phase trials is recommended, if CNS activity is anticipated and when relevant to the specific disease type. Conclusion Expanding eligibility to be more inclusive of patients with brain metastasis is justified in many cases and may speed the development of effective therapies in this area of high clinical need.

Abstract LB-039: Translational research in a phase I proof-of-concept study supports that DCC-2618 is a pan-KIT inhibitor

Background: DCC-2618 is a potent switch control inhibitor of KIT and PDGFRα kinases maintains potent inhibition of mutant forms across all exon regions in preclinical models. Gastrointestinal stromal tumor (GIST) is an important disease to achieve a proof-of-concept due to the heterogeneity of resistance mutations in KIT which emerge on treatment with approved KIT inhibitors. In later lines of therapy resistance mechanisms independent of the KIT gene have also been described. Methods: The ongoing phase 1, PK-guided dose escalation study of DCC-2618 given orally BID [28-day cycle] tested doses from 20 mg to 200 mg in patients (pts) with advanced solid tumors including GIST (NCT02571036). We report preliminary longitudinal results of plasma cell free (cf) DNA sequencing by Guardant 360 collected throughout the study and levels of circulating tumor cells (CTCs) based on a viral telomerase promoter-driven GFP expression assay. Results: To date, 24 out of 31 enrolled pts had metastatic KITm GIST refractory to standard therapy. A high, total mean exposure of DCC-2618 and its active metabolite was achieved at 100 and 150 mg BID, affording steady state Cmax >5 µM in Cycle 1. Starting with 50 mg BID dose level, concentrations of total drug exceeding IC90 of the most resistant mutations to DCC-2618 were achieved. Next-generation sequencing of plasma cfDNA revealed a total of 40 KIT mutations in 16 of 18 GIST pts at baseline. DCC-2618 led to rapid decrease and/or clearance of the heterogeneous array of KIT mutations from plasma cfDNA including exons 9, 11, 13, 14, 17, and 18. Independent of suppressed KIT mutation burden, longitudinal monitoring of cfDNA revealed changes in non-KIT oncogenic mutations which may contribute to heterogenous mechanisms of resistance. KIT mutation burden will be correlated with metabolic response assessment by PET scans and exposure to DCC-2618. CTCs have been detected in blood from all GIST patients at baseline using a non-biased assay capable of identifying sarcoma cells. Preliminary result show that CTCs with immunofluorescent detection of KIT or PDGFRα, corresponding to their respective mutational status, show 1 of 3 patterns when compared to radiologic response: most pts show relatively stable low levels at stable disease (SD), a minority of pts with prolonged SD a decline in CTCs and 2 pts with progressive disease had significant increase in KIT positive CTCs. Conclusions: DCC-2618 and its active metabolite achieved high plasma concentrations sufficient to inhibit the most resistant KIT mutations at well-tolerated exposures. Monitoring of cfDNA KIT mutation frequency demonstrates rapid clearance of a broad spectrum of KIT mutations in this heavily pretreated GIST patient population and suggests candidate resistance genes that are independent of KIT. Our data provide a first signal that CTC monitoring might represent a potential marker for tumor control in KIT mutant GIST. Citation Format: Filip Janku, Albi Razak, Michael Gordon, David Brooks, Daniel Flynn, Anu Gupta, Michael Kaufman, Cynthia Leary, Bryan Smith, Deb Westwood, Neeta Somaiah, Elena Helman, Eric Gerstenberger, Oliver Rosen, Suzanne George. Translational research in a phase I proof-of-concept study supports that DCC-2618 is a pan-KIT inhibitor [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr LB-039. doi:10.1158/1538-7445.AM2017-LB-039