Phase I study of dasatinib in combination with capecitabine, oxaliplatin, and bevacizumab followed by an expanded cohort in previously untreated metastatic colorectal cancer

513

Background: SRC is a non-receptor tyrosine kinase involved in normal and tumor cell signaling functions including cell proliferation, angiogenesis and survival. Dasatinib (D) is a potent inhibitor of SRC kinase activity. Preclinical data suggests the addition of D to standard chemotherapy agents for colon cancer may increase anti-tumor activity. We evaluated D in combination with capecitabine (C), oxaliplatin (O) and bevacizumab (B) in a phase I dose escalation study followed by an expanded cohort in 1st line colorectal.

Methods: For dose escalation, eligible patients had advanced solid tumors with adequate organ and bone marrow function and no increased risk for class-related toxicities. B and O were given intravenously, and C and D were orally administered; cycle length was 21 days. C was dosed at 850 mg/m2 on days 1-14; O was dosed at 130 mg/m2 and B was dosed at 7.5 mg/kg on day one of each cycle. D was dosed at 50 mg twice daily in cohort one and 70 mg once daily in cohort -1. Dose limiting toxicity (DLT) was assessed in cycle 1.

Results: Dose escalation is complete with 10 subjects evaluable for toxicity and 11 subjects evaluable for efficacy. Two DLTs were observed out of 5 evaluable subjects in cohort one. Six evaluable subjects were enrolled in the -1 cohort with 1 DLT. Possible grade ≥ 3 treatment-related adverse events (AEs) included neutropenia, febrile neutropenia, anorexia, diarrhea, fatigue, anemia, hypophosphatemia, hyponatremia and grade 5 GI-perforation. One non-treatment related death was due to disease progression. D-related nausea and fatigue were responsive to low dose oral steroids; fluid retention was responsive to diuretics. Of 10 subjects evaluable for efficacy, 1 subject had a partial response (PR), 2 had a minor response (MR), and 4 had stable disease (SD). Four subjects had disease control (PR, MR, or SD) ≥ 6 months.

Conclusions: D in combination with C, O and B is well-tolerated with a toxicity profile similar to standard C, O and B.The recommended phase II dose is C at 850 mg/m2 on days 1-14, O at 130 mg/m2 and B at 7.5 mg/kg on day one of each cycle, and D at 70 mg once daily. Enrollment in the expanded cohort of 1st line colorectal is ongoing.

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A phase I study of erlotinib, bevacizumab, and external beam radiation therapy (RT) for patients with localized pancreatic carcinoma (PC)

281

Background: Localized PC is commonly managed with chemoradiotherapy, with or without surgical resection. The optimal combination of agents and doses is the subject of continued investigation. This phase I study examines the combination of two targeted radiosensitizing agents in combination with radiation therapy.

Methods: Eligible patients had resectable, borderline resectable or locally advanced adenocarcinoma. Patients received RT (1.8 Gy qd to 50.4 Gy) concurrent with bevacizumab and erlotinib. Dose-level 1 was bevacizumab 10 mg/kg weeks 1, 3 and 5 and erlotinib 100 mg daily, RT days only. Drug doses were escalated depending on encountered toxicity. The primary endpoint was determination of the maximally tolerated dose of this combination. Secondary endpoints included toxicity and activity assessment.

Results: Nine patients were enrolled in the phase I study. Maximal EUS/CT stage was T2N0 (n=1), T3N0 (n=1), T3N1 (n=2) or T4N0 (n=5). Of 3 patients in dose-level 1, two had radiographic stable disease (SD) and one partial response (PR). One pt underwent exploratory laparotomy and found to be unresectable, experiencing prolonged postoperative incisional healing. Three patients were then enrolled at dose-level 2 (bevacizumab 10 mg/kg, erlotinib 125 mg). Two had SD and one progressive disease (PD). One pt underwent exploratory laparotomy, aborted due to previously undetected hepatic metastases. Three patients were then enrolled at dose-level 3 (bevacizumab 10 mg/kg, erlotinib 150 mg). One pt had SD and two PR. One pt underwent distal pancreatectomy, experiencing postoperative pancreatic leak and abscess formation. All patients with elevated CA 19-9 at baseline had a decrease, with amedian decrease of 69% (R:13-93%). Dose-limiting toxicity (DLT) was not encountered at any dose-level. Primary non-dose limiting toxicities in all cohorts included NCI CTCAE v3.0 grade 1-2 nausea/vomiting, rash, diarrhea, fatigue, and anorexia.

Conclusions: Concurrent chemoradiotherapy utilizing erlotinib and bevacizumab is reasonably well-tolerated. The recommended phase II dose is bevacizumab 10 mg/kg weeks 1, 3, and 5 and erlotinib 150 mg RT days only. Phase II accrual is underway.

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Similarities in treatment (Tx) patterns and clinical outcomes (CO) in patients (pts) with metastatic colorectal cancer (mCRC) initially treated with FOLFOX/BV or FOLFIRI/BV: Results from ARIES, a bevacizumab (BV) observational study

480

Background: COs associated with varying Tx patterns in mCRC pts are poorly understood because patterns diverge from the randomized trials (RCT). The RCTs of BV (Avastin) plus chemotherapy (CT) in mCRC pts continued BV until progressive disease (PD), even if CT was stopped/changed. Some RCTs of BV+CT in mCRC show ∼50% of pts stopping Tx early for reasons other than PD with possible lessening of benefit. It is unclear if this is due to use of a particular CT regimen or other practice pattern. While the beneficial effect of post-PD BV Tx has been shown in ARIES (HR 0.52 BBP vs No BBP) [A Cohn, ASCO 2010], the effect of stopping BV or CT before PD is unclear. ARIES, a community based observational study with a large cohort of 1st line BV-treated mCRC pts, will assess the COs associated with different 1st line Tx patterns (BV and CT) based on real world practice.

Methods: ARIES enrolled mCRC pts receiving first- or second-line CT+BV. No Tx regimens or assessments are protocol specified. Data are collected prospectively at baseline (BL) and quarterly. Analyses included first-line pts with PD. Tx patterns of pts initially treated with FOLFOX/BV or FOLFIRI/BV are described and preliminary COs (PFS and OS) are estimated from K-M curves. Tx duration is calculated from enrollment date.

Results: As of 2/5/10, 1,548 first-line mCRC pts enrolled (median follow up = 21 m); 1,133 pts had PD. Of 1,133 pts with PD, most had FOLFOX/BV (63%) or FOLFIRI/BV (16%) as first CT. BL characteristics were similar, but the FOLFOX/BV group had more stage 4 pts (74%). Main reasons for stopping BV include AE, max benefit achieved and CT holiday. Tx patterns and COs are in the table.

Conclusions: ARIES first-line mCRC pts treated with FOLFOX/BV or FOLFIRI/BV had similar Tx patterns and COs despite the common opinion that they may differ in tolerability and possibly effectiveness. Additional analyses will assess the impact of stopping BV and/or CT before PD.

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Bleeding events in bevacizumab-treated cancer patients who received full-dose anticoagulation and remained on study

Background:

Bevacizumab provides clinical benefit in multiple solid tumours, but is associated with some increase in bleeding risk. Thrombotic events necessitating therapeutic anticoagulation (TA) are common in cancer. This report describes the safety of concurrent bevacizumab and TA in three large placebo-controlled clinical studies.

Methods:

Study 1 (metastatic colorectal cancer (mCRC)), study 2 (mCRC), and study 3 (advanced non-small cell lung cancer) were blinded phase III studies. Eligibility criteria excluded patients on TA. Patients on protocol treatment who developed thrombotic events requiring TA were permitted to continue bevacizumab or placebo under specified conditions. Adverse events in patients who received bevacizumab and TA concurrently were assessed using the NCI–CTCAE scale.

Results:

While experience is limited, venous thrombotic events were the most common reason for TA initiation in the three studies. Severe bleeding event rates for patients receiving TA in the bevacizumab-treated groups were similar in frequency to the placebo groups, ranging from 0 to 8% or 0 to 67 events per 100 patient-years. No severe pulmonary bleeding was reported in any of the TA-treated populations.

Conclusions:

These data suggest that bevacizumab did not increase the risk of severe bleeding in cancer patients who received TA.

Phase Ib study of recombinant human Apo2L/TRAIL plus irinotecan and cetuximab or FOLFIRI in metastatic colorectal cancer (mCRC) patients (pts): Preliminary results

4129

Background: Preclinical data suggest that recombinant human Apo2 ligand/TNF-related apoptosis-inducing ligand (rhApo2L/TRAIL) induces tumor cell death through pro-apoptotic receptors DR4 and DR5. In specific mouse xenograft colon cancer models, tumors regressed in the majority of mice given rhApo2L/TRAIL and irinotecan. In this ongoing study of rhApo2L/TRAIL in previously treated mCRC pts, the primary objectives are to assess the safety and pharmacokinetics of rhApo2L/TRAIL combined with irinotecan and cetuximab or FOLFIRI. Methods: As of 12/12/08, 30 pts have received rhApo2L/TRAIL (on Days 1–5) with irinotecan (on Day 1) and cetuximab (on Days 1, 8, and 15) in 21-day cycles; rhApo2L/TRAIL dose cohorts range from 1.5–8 mg/kg/day. 5 pts have received rhApo2L/TRAIL 9 mg/kg (on Days 1–3) with FOLFIRI (leucovorin, 5-FU, and irinotecan on Day 1) in 14-day cycles. Results: In the first cohort, rhApo2L/TRAIL was given at 4 mg/kg/d with irinotecan (350 mg/m2) and cetuximab; the first 3 pts developed Grade 3–4 neutropenia. The study was amended to allow irinotecan dose reductions to 300 mg/m2 for pts at risk for irinotecan-related toxicities and patients were started on a lower dose of Apo2L/TRAIL at 1.5 mg/kg/d. An additional 32 pts received rhApo2L/TRAIL at 1.5–9 mg/kg/d. The most common adverse events thus far are diarrhea, fatigue, and nausea. A pt with anemia at screening developed Grade 4 anemia DLT. 2 pts (1 with progressive liver disease) discontinued therapy due to elevated ALT. Conclusions: Preliminary data indicate that rhApo2L/TRAIL can be safely combined with irinotecan-based regimens. Full data will be available by June 2008. A phase II study of rhApo2L/TRAIL with FOLFIRI should provide more information on safety, efficacy, and a potential diagnostic for rhApo2L/TRAIL.

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A phase I trial of sns-314, a novel and selective pan-aurora kinase inhibitor, in advanced solid tumor patients

2536

Background: Aurora Kinases are a family of serine/threonine kinases (Aurora Kinases (AK) A, B, and C) critical for mitosis. Elevated AKs expression occurs in a high percentage of melanoma, colon, breast, ovarian, gastric, and pancreatic tumors; in a subset of these tumors the AURKA locus (20q13) is amplified. SNS-314 is a selective pan-AK inhibitor with low nanomolar IC50s. Methods: Study design is 3+3 phase 1 dose escalation by modified Fibonacci. Patients (pts) with advanced solid tumors received SNS-314 by 3 hour infusion qweek X 3 (28 day cycle). Primary endpoints: safety, tolerability, and DLT assessment. Secondary endpoints: MTD, pharmacokinetics (PK), pharmacodynamics, and antitumor activity. Pharmacodynamic endpoint was inhibition of Histone H3 phosphorylation (pHH3) evaluated by immunohistochemistry of skin punch biopsies taken pre- and 2 hours post-infusion. Results: Thirty-two pts (16M/16F; median age = 58.5 years) were enrolled into 8 cohorts: dose range 30–1800 mg/m2. Median cycles received =2. SNS-314 was generally well tolerated with Grade 1–2 toxicities ≥ 15% incidence: nausea (31%), fatigue (28%), vomiting, constipation, and pain (16% each), and no Grade 3+ toxicities of ≥ 15% incidence. A DLT of Grade 3 neutropenia preventing administration of all 3 doses was observed at 1440 mg/m2. Plasma PK were dose proportional for exposure with no accumulation of SNS-314 following weekly administration. Clearance was moderate (5.65 L/hr/m2, CV 39.4%); Vss approximated total body water (21.5 L/m2, CV 78.1%); terminal half-life was 10.4 hours (CV 66.8%). Six patients had stable disease as their best response. Inhibition of pHH3 by SNS-314 was observed in skin biopsies of patients treated at doses of 240 mg/m2 and greater. Conclusions: SNS-314 is a novel inhibitor of AKs A, B, and C. The compound has been generally well tolerated; MTD was not established. No objective responses were observed. Pharmacodynamic activity was demonstrated by inhibition of pHH3.

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A phase I study of gemcitabine plus dasatinib (GD) or gemcitabine plus dasatinib plus cetuximab (GDC) in refractory solid tumors

e15506

Background: Dasatinib (D) is a small molecule tyrosine kinase inhibitor with activity against both bcr-abl and src. Cetuximab (C) is a monoclonal antibody that blocks EGFR. Preclinical models suggest D reverses resistance to G. In addition, src and EGFR pathways interact; synergism of dual blockade by D + C is possible. We evaluated two combination regimens, GD and GDC, in a Phase I dose escalation study. Methods: Patients (pts) with advanced solid tumors were enrolled in cohorts of 3–6 to either GD or GDC. G was dosed in mg/m2 weekly for 3 of 4 weeks, D was dosed in mg PO BID, and C was dosed at 250 mg/m2 weekly after loading dose of C=400; cycle length was 28 days. Dose levels were as follows: 1) G 1000 + D 50 ± C; 2) G 1,000 + D 70 ± C; 3) G 1,000 + D 100 ± C. Standard cycle 1 DLT definitions were used. Eligible pts had advanced solid tumors, adequate organ and marrow function, and no co-morbidities that would increase risk of toxicity. Serum, plasma, and skin biopsy biomarkers were obtained pre- and on treatment. Results: 25 pts have been enrolled, including 21 with pancreatic adenocarcinoma, 3 of whom had received prior G. 21 pts were evaluable for toxicity and 18 for efficacy. Four DLT were observed: Gr 3 ANC with infection (GDC1, n=1), Gr 3 ALT (GD2, n=2), and Gr 5 pneumonitis (GDC2, n=1). Possible treatment-related adverse events in later cycles included: Gr3–4 ANC (n=4), Gr4 colitis (n=1), Gr3 bilirubin (n=2), Gr3 Hgb (n=2), Gr3 Plt (n=2), Gr3 edema/fluid retention syndrome (n=1), and Gr3 vomiting (n=2). One previously untreated pt had a partial response. Eight of 18 pts, 3 of whom had received prior G, had stable disease as best response, median duration = 5 months (range 1–7). Biomarker results are pending. Conclusions: The MTD of the GD arm is G1000/D50BID. Stable disease in previous G-refractory pts was noted. Hematologic toxicities were dose-limiting; later toxicities including hematologic, LFT changes, pneumonitis, and fluid retention were seen. To address these toxicities, once daily dosing of D will be explored, followed by an expanded cohort of G + daily D vs G + bid D in pts with treatment-naïve pancreatic cancer.

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Phase III study of standard triweekly versus dose-dense biweekly capecitabine (C) + oxaliplatin (O) + bevacizumab (B) as first-line treatment for metastatic colorectal cancer (mCRC): XELOX-A-DVS (dense versus standard): Interim analysis

4078

Background: Every 3 week (Q3W) COB has been shown to be highly active and non-inferior to FOLFOX+B in first-line mCRC. Phase II data suggest that dose-dense every 2 week (Q2W) COB may be significantly more active and better tolerated than Q3W COB. Methods: XELOXA-DVS was a phase III, open-label study of 435 patients with chemonaive mCRC who met standard eligibility criteria. Patients were randomized to Q3W: C 850 mg/m2 BID d1–14 + O 130 mg/m2 d1 + B 7.5 mg/kg d1 or Q2W: C 1500 mg/m2 BID d1–7 + O 85 mg/m2 d1 + B 5 mg/kg d1 for up to 72 weeks. Complete surgical resection was allowed using pre-defined criteria. The primary endpoint, progression-free survival (PFS), was estimated using the Kaplan- Meier method, while the hazard ratio and 95% CI were estimated using Cox regression analysis, based on the intent-to-treat population. No formal statistical testing was conducted. Results: The median PFS was 8.4 months (Q2W) and 9.7 months (Q3W) (hazard ratio [HR]=0.84; 95% CI=0.62–1.13). The median PFS (on-treatment) was 9.1 months and 10.2 months, respectively (HR=0.81). Of the 72 and 73 patients with disease progression (DP), the median time to DP was 9.4 and 10.8 months, respectively (HR=0.86). The objective response rates were 21.7% vs 29.4%, respectively (HR=1.05). Patients in the Q2W vs Q3W group experienced higher rates of grade 3/4 diarrhea (29% vs 24%), hand-foot syndrome (12% vs 8%), and treatment discontinuation rates (40% vs 20%), respectively. Other grade 3/4 toxicities (>5%, Q2W vs Q3W) included fatigue (13% vs 13%), dehydration (12% vs 10%), nausea (8% vs 9%), peripheral neuropathy (5% vs 9%), anorexia (5% vs 7%), and abdominal pain (5% vs 7%). Conclusions: At the dose and schedule used, dose-dense Q2W COB was not superior to standard Q3W COB. These data further confirm the activity and tolerability of Q3W COB. The activity and tolerability of a lower C dose Q2W, with more aggressive dose reduction, combined with B and O or irinotecan is currently being evaluated (X-BIO).

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Phase I study of daily administration of MGCD265 to patients with advanced malignancies (Study 265–101)

e14525

Background: MGCD265 is a novel multitargeted receptor tyrosine kinase (RTK) inhibitor that targets the mesenchymal epithelial transition (c-Met) and the vascular endothelial growth factor (VEGF) receptors (VEGFR1, VEGFR2, and VEGFR3). Additional RTK targets include Tie-2, and Ron. Those kinases are known to be involved in tumor development and angiogenesis. The objective of this Phase I study is to evaluate the safety, pharmacokinetics (PK) and pharmacodynamics (PD) of daily administration of MGCD265 in patients with solid tumors. Methods: This is a multicenter, open-label, dose escalation study of oral MGCD265 administered as a continuous 21-day cycle. Cohorts of 3–4 patients were enrolled per dose level, initially with dose doubling between cohorts, followed by smaller increments once grade 2 drug-related toxicity is observed. Dose limiting toxicity (DLT) was defined as: grade 4 neutropenia; grade 4 thrombocytopenia; any > grade 3 nonhematologic toxicity; severe/sustained hypertension; or any toxic effect leading to a patient missing > 4 doses of MGCD265. Treatment would continue until disease progression or toxicity. Results: Ten patients with advanced solid tumors have been treated. Characteristics: age range 25–75; gender: 8 M/2F; ECOG: 0 (1 patient); 1 (9 patients). At dose levels of 24, 48 and 96 mg/m2, no DLTs nor grade 2 or greater drug-related AEs during cycle 1 have been reported. Eight patients received treatment for 2 cycles or more. Preliminary PK profile after the first dose of administration shows a dose dependent increase in AUC and Cmax with an approximate mean half-life of 23 hours (see Table below). At the 96 mg/m2 dose, exposure was in the range of the lower end of the efficacious exposure in certain xenograft models. PD markers including plasma HGF and VEGF and shed/soluble receptors s-Met and s-VEGFR2 have been evaluated. Conclusions: Daily oral administration of MGCD265 was found to be well tolerated at doses of 24, 48, and 96 mg/m2. Further dose escalation is underway.

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