A randomized, placebo-controlled, phase 2 trial of INBRX-109 in unresectable or metastatic conventional chondrosarcoma

TPS11582

Background: Chondrosarcomas (CS) are the third most common type of primary bone cancer after myeloma and osteosarcoma. Conventional CS represent 85–90% of all cases and are typically treated with surgical resection. However, there are no approved systemic treatment options for patients with unresectable or metastatic conventional CS, and outcomes remain poor. INBRX-109 is a precision-engineered, tetravalent death receptor 5 (DR5) agonist antibody designed to overcome the limitations of earlier-generation agonists and exploit the tumor-specific cell death induced by DR5 activation. DR5 is one of two pro-apoptotic receptors for the trimeric tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). Early clinical activity of INBRX-109 was observed in an ongoing phase 1 trial and warrants further investigation. INBRX-109 has been granted an FDA fast-track designation for conventional CS. Methods: This is a multicenter, randomized, blinded, placebo-controlled phase 2 study in patients with unresectable or metastatic conventional CS, measurable disease by RECIST 1.1, and radiologic disease progression within 6 months prior to screening. Any number of prior lines of therapy are allowed, except for prior DR5 agonists. Patients must be ≥18 years of age and have an ECOG performance status of 0/1 and have archival or fresh tissue available. Approximately 201 patients will be randomized (2:1) to INBRX-109 (3 mg/kg intravenously, every 21 days) or placebo, stratified by histologic grade (Grade 1/2 vs 3), isocitrate dehydrogenase (IDH)1 R132/IDH2 R172 status (wildtype vs mutation), and line of systemic therapy (none vs prior). Treatment will continue until disease progression/unacceptable toxicity. Patients treated with a placebo will have the option to cross over to INBRX-109 upon disease progression. The primary endpoint is progression-free survival (PFS) by independent radiology review. Secondary endpoints are overall survival, PFS by investigator assessment, quality of life, overall response rate, duration of response, disease control rate, safety, pharmacokinetics, and immunogenicity. Adverse events will be recorded and graded by NCI CTCAE Version 5.0. Median PFS of 7.0 months is projected for INBRX-109 and 4.0 months for placebo (corresponding hazard ratio of 0.571); INBRX-109 will be declared superior if the 1-sided p-value from the stratified log-rank test is <0.025. More than 50 sites are planned across the US/Europe. The study is actively enrolling. Clinical trial information: NCT04950075.

MANTRA: A randomized, multicenter, phase 3 study of the MDM2 inhibitor milademetan versus trabectedin in patients with de-differentiated liposarcomas

TPS11589

Background: Murine double minute 2 (MDM2) is a negative regulator of tumor suppressor protein p53. MDM2 induces degradation of p53 and promotes tumorigenesis. MDM2 amplification occurs in many cancers but is documented in up to 100% of well-differentiated or dedifferentiated liposarcomas (WD/DDLPS) [Cancer Genome Atlas Research Network. Cell 2017]. Inhibition of the MDM2-p53 interaction is a promising therapeutic approach to restore p53 tumor suppressor activity in WD/DDLPS. Milademetan (RAIN-32) is a small-molecule MDM2 inhibitor that inhibits the MDM2-p53 interaction and restores p53 function at nanomolar concentrations. In a phase 1 study, milademetan showed promising efficacy in 53 patients with WD/DDLPS when administered on an intermittent schedule (260 mg QD on Days 1–3 and 15–17 on a 28-day cycle), with a median progression-free survival (PFS) of 7.4 months [Gounder et al. AACR-NCI-EORTC 2020]. WD/DDLS are relatively resistant to chemotherapy, and systemic treatment options for patients with advanced disease are limited. MANTRA (RAIN-3201) is a randomized, multicenter, open-label, phase 3 registration study designed to evaluate the efficacy and safety of milademetan versus trabectedin in patients with unresectable or metastatic DDLPS with disease progression on ≥ 1 prior systemic therapies. Methods: Eligible patients are ≥ 18 years of age with histologically confirmed unresectable and/or metastatic DDLPS, with or without a WD component, who have received ≥ 1 prior systemic therapies, including ≥ 1 anthracycline-based regimen, with radiographic evidence of progression by RECIST v1.1 within 6 months before study entry. Prior treatment with trabectedin or an MDM2 inhibitor is not permitted. Patients will be randomly assigned (1:1) to receive milademetan (260 mg once daily orally Days 1–3 and 15–17 on a 28-day cycle) or trabectedin (1.5 mg/m2 as a 24-hour intravenous infusion every 3 weeks). Randomization is stratified by Eastern Cooperative Oncology Group performance status (0 or 1) and number of prior treatments for WD/DDLPS (≤ 2 or > 2). Tumor response will be evaluated by RECIST v1.1 at Weeks 8, 16, 24, and 32, and then every 12 weeks. Primary endpoint: PFS by blinded independent central review. Secondary endpoints: overall survival; disease control rate; objective response rate; duration of response; PFS by investigator assessment; safety; health-related quality of life. Exploratory endpoints: molecular markers in peripheral blood and/or tumor tissue; milademetan pharmacokinetics. To demonstrate a 3-month increase in PFS (from 3 to 6 months) corresponding to a hazard ratio of 0.5, approximately 160 patients will be required to observe 105 events with 93.9% power and 2-sided significance level of 5%. Clinical trial information: NCT04979442.

COM701 with or without nivolumab: Results of an ongoing phase 1 study of safety, tolerability and preliminary antitumor activity in patients with advanced solid malignancies (NCT03667716)

2504

Background: COM701 is a novel first in class humanized IgG4 monoclonal antibody that binds with high affinity to poliovirus receptor related immunoglobulin domain containing (PVRIG), blocking its interaction with its ligand, PVRL2. Blocking of PVRIG leads to enhanced activation of T/NK cells and in mouse models inhibits tumor growth. We report new and updated results on safety/tolerability/pharmacokinetics and antitumor activity from this ongoing study including final results in dose escalation combination cohort, monotherapy expansion cohort (MEC). Methods: We enrolled a total of 51 DLT-evaluable pts: Arm A (COM701 mono dose escalation), 16 pts in 8 cohorts (0.01 – 20 mg/kg IV Q3/4 wks); Arm B (COM701 0.3 – 20 mg/kg + nivolumab (NIVO) 360 mg/480 mg IV Q3/Q4 wks), 15 pts in 5 cohorts; 20 pts in MEC (NSCLC, OVCA, breast, endometrial and CRC) at the recommended dose for expansion(RDFE), 20 mg/kg IV Q4 wks. Key inclusion criteria: Age ≥18 yrs, histologically confirmed metastatic solid malignancy, has exhausted available standard tx, ECOG 0-1, prior ICI permissible (except prior tx with a PVRIG inhibitor). Key exclusion criteria: active autoimmune disease requiring systemic tx, hx inflammatory lung disease. Primary objectives – safety/tolerability of COM701 ± NIVO (AEs, CTCAE v4.03), PK, RDFE. Key secondary/exploratory objectives - antitumor activity of COM701 ± NIVO (RECIST v1.1), evaluation of PVRL2 expression in tumor biopsy, blood cytokines and immunophenotyping. Results: No DLTs were reported in Arms A or B. COM701 PK profile similar in Arm A, 20 mg/kg IV Q4 wks (cohort 8) and Arm B cohort 5 (COM701 20 mg/kg + NIVO 480 mg; all IV Q4 wks). Frequency of TEAEs in safety population (N=54 pts): pts on COM701 mono (N=38)- No AE (4), Grade≤2 (21), G3 (11), G4 (1), G5 (1, PD), pts on combo (N=16) - Grade≤2 (8), G3 (7), G5 (1, PD). Serious TEAE: pts on COM701 mono 11/38, pts on combo 6/16. Most frequent AEs in Arm A: Grade ≤2 fatigue 12/38 pts (31%), nausea 9/38 (23%); Arm B: fatigue 7/16 pts (44%) and AST increased 4/16 pts (25%). Antitumor activity - in Arm A (cohort 8), a pt with platinum resistant primary peritoneal cancer had confirmed PR ongoing 14 months. In Arm B (COM701 10 mg/kg + NIVO 480 mg, all IV Q4 wks), a pt with anal SCCA; confirmed CR, ongoing 18 months, last tx with prior PD on NIVO. In addition, a pt with renal cell CA had confirmed SD [ongoing 13 months, COM701 0.3 mg/kg + NIVO 360mg; IV Q3 wks],] In MEC, 30% (6/20 pts) had best response of SD [1-endometrial, 3 NSCLC, 2 OVCA], 2 pts [NSCLC, OVCA] ongoing at 6/4 months. Overall 16pts had prior tx-refractory disease, 9(56%) had best response of ≥SD. Of 18 pts with prior tx with ICI, 13 (72%) had best response of ≥SD. Datacut 14Dec2020. Conclusions: COM701 ± NIVO well tolerated with no new safety signals. Encouraging signal of antitumor activity including in pts with prior tx with ICI or prior tx-refractory disease. Clinical trial information: NCT03667716..

P10015/SARC033: A phase 2 trial of trametinib in patients with advanced epithelioid hemangioendothelioma (EHE)

11503

Background: EHE is a rare vascular cancer arising in liver, lung, soft tissue and bone. The natural history of metastatic disease varies considerably from indolent growth over years to rapid growth with fatal outcome in months. Treatment of patients (pts) with metastatic EHE with antiangiogenic therapy induces tumor response in a minority of pts, and median PFS is 6-12 months. TAZ-CAMTA1 translocation results in activation of MAPK pathway and is an oncogenic driver in EHE. We sought to evaluate the effect of MEK inhibition using trametinib in pts with unresectable EHE. Methods: A phase 2 trial of trametinib 2 mg daily was conducted in pts with EHE though the Experimental Therapeutics Clinical Trials Network supported by NCI in collaboration with SARC. Additional support was provided by the EHE Rare Cancer Charity and the EHE Foundation. Pts had to have evidence of objective tumor progression or EHE-related pain requiring narcotics for relief prior to enrollment. Presence of TAZ-CAMTA1 translocation was analyzed by fusion-FISH after enrollment. Primary trial endpoint was objective response rate (ORR) per RECIST1.1 with at least 1 objective response required in the 1st 13 pts to expand enrollment to 27. The trial was amended after stage 1 to continue enrollment to 27 pts with TAZ-CAMTA1 detected by FISH with goal of >4 objective responses in this group. Secondary objectives were PFS and OS rates, safety and change in pt-reported global health and pain scores per PROMIS questionnaires. Results: 43 pts were enrolled between 6/2017 – 9/2020 across 10 sites and 41 started therapy. TAZ-CAMTA1 fusion was detected in 26, not detected in 7, test failed in 5 and was not performed due to insufficient tumor in 5. Median pt age was 54 (range 22-81 yrs) and 11 were >65 yrs; 25 were female; ECOG was 0 in 23, 1 in 16 and 2 in 3 pts. Most pts experienced reduction in tumor size. ORR per RECIST was 7% (3/41); in pts with TAZ-CAMTA1 detected, the ORR was 0% (0/26). Mean pain intensity and interference scores had a statistically significant improvement and global quality of life scores did not statistically change after 4 weeks of therapy. 17 pts remained on treatment > 6 months and 7 > 12 months. 25 pts stopped trametinib due to EHE progression, 6 died during treatment, 6 withdrew from treatment, 3 stopped drug due to adverse event and 1 is on treatment. The most common AEs related to trametinib were rash, fatigue, nausea/vomiting, diarrhea, alopecia and edema; Grade >3 AEs included anemia, dyspnea, hypoxia, hypotension, syncope and dermatitis. Conclusions: To our knowledge, this is the largest prospective clinical study focused on pts with EHE. Although the trial did not meet the ORR goal, stable disease > 6 months was seen in 40% of pts, and EHE-related pain improved on treatment. Trametinib was associated with expected cutaneous and GI adverse effects. Additional pt-reported outcomes and biomarkers of inflammation are undergoing analysis. Clinical trial information: NCT03148275.

Number of nonsynonymous genomic variants may correlate with prognosis in advanced pancreatic cancer

432

Background: Pancreatic cancer is associated with poor outcomes at any stage. A very small number of patients - approximately 3% of those with metastatic disease - experience long-term survival through 5 years but the biologic mechanisms underlying the benefit observed with these “exceptional responders” are incompletely understood. We explored potential genomic differences between exceptional responders and typical responders to treatment for advanced pancreatic cancer that could confer a more favorable biology. Methods: We included consecutive exceptional responders and matched controls (MCs) with advanced pancreatic cancer in a 1:3 ratio from the Cleveland Clinic from April, 2013 – August, 2017. ERs were defined as patients with overall survival (OS) > 18 months for metastatic disease and > 24 months for locally advanced disease. Controls were matched by age, gender, stage and type of chemotherapy given and experienced OS at or below median survival for their stages. Clinical variables including demographics, comorbidities, stage, histology and treatment history were collected. Next generation sequencing (NGS) was performed for DNA sequencing of 648 genes and tumor mutation burden (TMB) on available tissue. The study population initially comprised of 14 exceptional responders and 42 MCs. However, only 4 exceptional responders and 6 MCs were included for analysis due to insufficient tissue for NGS for the remaining patients. Descriptive statistics were used for statistical analysis. Differences in survival outcomes were assessed using the Kaplan-Meier method and log-rank test. Results: The median ages for the exceptional responders and MCs were 69 and 67.5 years, respectively. Both groups were at least 75% male and white. Of the exceptional responders, 50% had pancreatic tail primaries compared to 0% of the MCs. There were no differences between groups in first-line chemotherapy used. Exceptional responders had significantly fewer non-synonymous mutations compared to MCs (2.25 vs. 5.17, p = 0.014). Mutation count < 3 was associated with significantly better progression-free survival (PFS) and OS as shown in the Table. TMB did not differ between exceptional responders and MCs (4.88 vs. 5.70 Muts/Mb, p = 0.39). Of the exceptional responders, 50% had alterations in BAGE2 versus 0% of MCs. Conversely, 50% of MCs had alterations in LRP1B, CUL4B or APC vs. 0% of exceptional responders. Conclusions: Having a lower number of non-synonymous mutations may correlate with exceptional response to systemic therapy and therefore with improved survival in pancreatic cancer. Pancreatic tail primary may also be associated with improved outcomes. These findings, though limited by small sample size, should encourage future study into genomic signatures of exceptional response. [Table: see text]

A phase I study evaluating COM701 monotherapy and in combination with nivolumab in patients with advanced solid malignancies

TPS23

Background: COM701 is a novel 1st-in-class monoclonal antibody that binds with high affinity to poliovirus receptor related immunoglobulin domain containing (PVRIG) blocking its interaction with its ligand, PVRL2. In preclinical experiments inhibition of PVRIG alone and in combination with a PD-1 inhibitor leads to activation of T cells in the tumor microenvironment generating an anti-tumor immune response leading to tumor growth inhibition. Novel checkpoint therapies are needed for the treatment of patients with advanced malignancies. We hypothesized that COM701 monotherapy and in combination with nivolumab will be safe and tolerable and demonstrate preliminary antitumor activity in pts with advanced solid malignancies. Methods: This ongoing phase 1 study (NCT03667716) is evaluating the safety and tolerability of escalating doses of COM701 monotherapy IV Q3 or Q4 weekly and in combination with nivolumab 360 mg IV Q3 weekly or 480 mg IV Q4 weekly. Key Inclusion Criteria: Age ≥18 yrs, histologically or cytologically confirmed advanced solid malignancy and has exhausted all available standard therapy, ECOG performance status 0-1, prior ICI permissible. Key Exclusion Criteria: Symptomatic interstitial lung disease or inflammatory pneumonitis, untreated or symptomatic central nervous system metastases. Primary outcome measures are the incidence of adverse events and dose-limiting toxicities (21-day or 28-day DLT window), pharmacokinetics of COM701 and to identify the maximum tolerated dose and/or the recommended dose for expansion. Key secondary outcome measures are to characterize the immunogenicity and preliminary antitumor activity of COM701 as monotherapy and in combination with nivolumab. Study Design: Hybrid accelerated titration and 3+3 study design. Statistical Considerations: Adverse events graded as per CTCAE v4.03, responses as per RECIST v1.1. Analyses of all study objectives are descriptive and hypothesis generating. As of the date of this submission dose level 8 of COM701 monotherapy and dose level 3 of the combination arm are open to enrollment. Updated data will be presented at the conference. Clinical trial information: NCT03667716.

A pilot clinical trial of p53/p16-independent epigenetic therapy for pancreatic ductal adenocarcinoma (PDA)

699

Background: PDA treatment is limited to cytotoxic drugs. A key factor limiting their efficacy is TP53 mutations, omnipresent in PDA, which counter apoptosis-mediated cell kill. We evaluated a novel epigenetic approach using decitabine (Dec) to inhibit DNA methyltransferase 1 (DNMT1) and effect cancer cell cycle exits by epithelial-differentiation, combined with tetrahydrouridine (THU) to inhibit cytidine deaminase (CDA) and thereby permit oral bioavailability and solid-tissue distribution of Dec. Methods: Open-label single-arm, IRB-approved clinical trial at Cleveland Clinic and University Hospitals for patients with metastatic PDA that had progressed on prior chemotherapy, ECOG PS of 0-2. Treatment was oral, weight-based, with Dec 10-20 mg, and THU 500-1000 mg daily, 5 days/week. Primary endpoint was DNMT1 protein levels at 16-week vs baseline biopsies. Results: From Apr to Aug 2017, we enrolled 13 patients. Median age was 65 (range 44-74) years; 7 (54%) males; 11 (85%) Caucasians. Median time from diagnosis was 13 (3.9-53.5) months, with a median of 2 (1-3) prior lines of therapy. Baseline ECOG PS was 0/1 in 12 (92%) patients. All patients started study drugs; median time on treatment was 35 (4-63) days, and on study 72 (25-105) days. The most frequent adverse events attributable to the study drugs were anemia (n=5), and anorexia, dehydration, nausea, fatigue, febrile neutropenia and decreased lymphocyte count, in 3 patients each; no deaths. Eight (62%) patients underwent evaluation scans at 8 weeks, showing stable disease in 1 patient and progression in 7. Common reasons for coming off of study drugs were progression (n=6), physician discretion (n=3), and adverse events (n=2). Overall, 6 patients died; median survival was 3.1 months, and patients did not reach the 16-week biopsy. Shifts in blood counts, a sensitive indicator of Dec systemic activity, were unexpectedly mild, and plasma CDA enzyme activity was increased versus other cancer and normal controls. Conclusions: This first-of-its-kind study demonstrated feasibility and safety of the novel oral epigenetic therapy. Systemically elevated CDA in these patients requires higher doses of THU; a trial accordingly refined is planned. Clinical trial information: NCT02847000.

An open-label expanded-access study to evaluate the safety, tolerability, and pharmacokinetics of trifluridine/tipiracil in patients with advanced solid tumors and hepatic impairment

2559

Background: The Phase 3 RECOURSE study showed that trifluridine/tipiracil (FTD/TPI) was effective in the treatment of refractory metastatic colorectal cancer (Mayer et al. N Engl J Med 2015;372:1909-19). A Phase 1 open-label study evaluated the safety and pharmacokinetics of FTD/TPI in patients with advanced solid tumors and varying degrees of hepatic impairment to inform dosing recommendations for these patients. Methods: Patients aged ≥18 years with advanced solid tumors, an Eastern Cooperative Oncology Group performance status ≤2, normal hepatic function, and mild, moderate, or severe impaired hepatic function according to the National Cancer Institute criteria were enrolled. Patients received FTD/TPI 35 mg/m2 orally twice daily on days 1-5 and days 8-12 of each 28-day cycle, except for those with severe impaired hepatic function (dose was to be determined). Results: 24 patients were enrolled to normal (n=8), mild (n=10), and moderate (n=6) groups. Study enrollment was stopped as 5/6 patients in the moderate group experienced elevated bilirubin levels (grade ≥3). The other baseline characteristics were similar across groups. Overall, 12 patients (50%) had at least 1 adverse event leading to study discontinuation: 2 in normal, 5 in mild, and 5 in the moderate hepatic impairment groups. Pharmacokinetic results are summarized in the table. Conclusions: The exposure to FTD or TPI was not increased by hepatic impairment and the patients who experienced grade 3 and 4 increased total bilirubin were not overexposed to FTD or TPI. Clinical trial information: NCT02301104. [Table: see text]

Axitinib plus crizotinib in patients with advanced solid tumors and metastatic renal cell carcinoma (mRCC): Preliminary phase 1b results

2551

Background: Axitinib (AX) is a tyrosine kinase inhibitor (TKI) of vascular endothelial growth factor receptor (VEGFR) and a standard treatment for mRCC. Upregulation of mesenchymal-epithelial transition factor (c-MET) is implicated in resistance to VEGFR-directed therapy. An ongoing ph Ib study (NCT01999972) evaluated the safety and efficacy of AX + crizotinib (CZ), a TKI of c-MET, anaplastic lymphoma kinase (ALK), and ROS1. Methods: mRCC patients (pts) with advanced solid tumors were treated with AX + CZ in a dose escalation phase (DESC). After determining maximum tolerated dose (MTD) (modified toxicity probability interval), mRCC pts were enrolled into 2 cohorts in a dose expansion phase (DEXP). Cohort 1 (C1) was treatment-naïve and C2 had 1–2 prior therapies. The primary objectives were to assess the tolerability of AX + CZ, to obtain the MTD, and to select the recommended phase II dose. Results: As of Aug 5, 2016, 24 pts were screened and 22 pts treated in the DESC. Pts received AX 3 mg twice daily (BID) + CZ 200 mg BID (n = 5); AX 3 mg BID + CZ 250 mg BID (n = 3); AX 5 mg BID + CZ 200 mg BID (n = 4); or AX 5 mg BID + CZ 250 mg BID (n = 10) in a median 4 (range 1–23) cycles. There were no cycle 1 dose-limiting toxicities. One pt discontinued due to an AX-related alanine aminotransferase increase. Fifteen (68.2%) pts experienced Grade 3–4 adverse events (AEs), none in ≥2 pts; 1 pt had a Grade 5 AE (disease progression). AX 5 mg BID + CZ 250 mg BID was established as the MTD. Most frequent AEs in the MTD group were fatigue (70.0%), nausea (70.0%) and diarrhea (60.0%). In the ongoing DEXP, 15 pts have been treated at the MTD (n = 11 in C1, and 4 C2). Response evaluation (RECIST) is ongoing, with 1 complete response (CR), 3 partial responses (PR) and 4 stable disease (SD) in 10 pts in C1, and 1 PR and 2 SD in 4 pts in C2. Overall, 10 (66.7%) pts experienced Grade 3–4 AEs and 1 pt had a Grade 5 AE (disease progression). Most frequent AEs (≥60% pts) were nausea and diarrhea. Conclusions: We have identified AX 5 mg BID + CZ 250 mg BID as the MTD for combination therapy. This regimen has manageable toxicities and exhibits antitumor activity in treatment-naïve and pretreated mRCC. Further studies in VEGFR, c-MET, ALK and ROS1 tumor types are warranted. Clinical trial information: NCT01999972.

Phase II study evaluating the effect of concomitant ramucirumab (RAM) on the pharmacokinetics (PK) of irinotecan (IRI) and its metabolite SN-38 when coadministered with folinic acid (FA) and 5-fluorouracil (5-FU) (FOLFIRI) in patients (pts) with advanced malignant solid tumors

691

Background: The primary objective was to assess the effect of concomitant RAM on the PK of IRI and its metabolite SN-38 when coadministered with FA and 5-FU. Methods: Key eligibility criteria included pts aged ≥18 years with metastatic or locally advanced malignant solid tumors resistant to standard therapy or for which no standard therapy was available, and an Eastern Cooperative Oncology Group performance status of 0 to 2. Pts received intravenous infusions of FOLFIRI and RAM 8 mg/kg on day 1 of a 2-week cycle. FOLFIRI was administered alone in cycle 1; RAM was administered followed by FOLFIRI in all subsequent cycles. Blood for PK was collected at regular intervals after infusions in cycles 1 and 2 to determine IRI and SN-38 plasma concentrations. Pts who completed the first 2 cycles of study treatment were included in the drug-drug interaction (DDI) population. All pts who received at least 1 dose of RAM or FOLFIRI were included in the safety population. Results: The safety population comprised 29 pts, and the DDI population included 25 of these 29 pts. The dose-normalized area under the concentration versus time curve from zero to infinity [AUC(0-∞)] and the maximum observed drug concentration (Cmax) of IRI and SN-38 were comparable between cycle 1 (FOLFIRI alone) and cycle 2 (RAM+FOLFIRI). The ratios of geometric least-squares (LS) means for IRI were 0.93 (90% CI; 0.83, 1.05) for AUC(0-∞) and 1.04 (90% CI; 0.97, 1.12) for Cmax. The ratios of geometric LS means for SN-38 were 0.95 (90% CI; 0.88, 1.04) for AUC(0-∞) and 0.97 (90% CI; 0.85, 1.12) for Cmax. The most prevalent treatment-emergent adverse events (TEAEs) were fatigue/asthenia (n=19, 65.5%), diarrhea (n=16, 55.2%), neutropenia (n=15, 51.7%), nausea (n=14, 48.3%), and decreased appetite and anemia (n=13 each, 44.8%). Grade ≥3 TEAEs were rare, except for neutropenia in 7 (24.1%) pts. Conclusions: The PKs of IRI and its metabolite, SN-38, were not affected when coadministered with RAM. RAM with FOLFIRI was well-tolerated in this study without new safety concerns. Clinical trial information: NCT01634555.

Challenges with genomic testing in pancreaticobiliary cancers: Results of a prospective cohort study

314

Background: Therapeutic options for advanced pancreaticobiliary (PB) malignancies may be improved by genomics-driven therapies. We conducted a prospective cohort study of outpatient genomic testing to identify prevalence of actionable alterations and therapeutic impact of such testing in PB cancers. Methods: Eligibility requirements included confirmed pathologic diagnosis of select solid tumor malignancies without a known curative option, age ≥ 18 years, and an ECOG performance status of 0-2. Data for the PB cancer subgroup are presented here. Tumor samples were sequenced for up to 315 candidate genes in collaboration with Foundation Medicine, Inc. (Cambridge, MA). Results were discussed at the Cleveland Clinic Genomics Tumor Board that made therapeutic recommendations to treating physicians. Results: From Aug 2013 to Aug 2014, samples from 228 patients were analyzed; 24 (11%) had PB cancers. For the latter subgroup, median age was 60 years; 14 (58%) were male; 20 (83%) were white. Twelve (50%) tumors were pancreatic, 11 (46%) from biliary tract/gallbladder, and 1 (4%) periampullary. Median time from consent to result was 24 (range, 3-84) days. Eight (33%) samples had inadequate tissue compared with 6/174 (3%) non-PB samples (p<0.001). Among patients with adequate tissue (n=16), a median of 3 (1-7) mutations were detected per sample; TP53 (50%), CDKN2A/p16 (44%) and KRAS (38%) were most common. A targeted therapy was recommended in 7 (44%) patients. Of these, 78% of recommendations were for specific clinical trials. To date, no patient with PB cancer has received a targeted therapy, compared with 6/45 (13%) patients with colorectal cancer (p=0.18). The most common reason for non-receipt of recommended targeted therapy was non-availability of clinical trials. Conclusions: Compared with other common solid tumors, genomic profiling in pancreaticobiliary cancers is challenged by paucity of diagnostic tissue collected during routine clinical care. Targeted therapy options (on-study or off-label) are few at this time. Precision oncology in pancreaticobiliary cancers will remain under-utilized until access to clinical trials is enhanced.

Genomic testing to enhance treatment choices and clinical trial accrual in metastatic colorectal cancer: Results of a prospective cohort study

593

Background: Tumor genome sequencing is being used widely in clinical settings but its value to individual patients has not been well-studied. A prospective cohort study of outpatient genomic testing to identify prevalence of actionable alterations and their impact on management decisions was conducted. Methods: Eligibility requirements included pathologic diagnosis of select solid tumor malignancies without a known curative option, age ≥18 years, and an ECOG PS of 0-2. Data for the colorectal cancer (CRC) subgroup are presented here. Tumor samples were sequenced for up to 315 candidate genes using FoundationOne (Cambridge, MA). Results were discussed at the Cleveland Clinic Genomics Tumor Board that made therapeutic recommendations to treating physicians. Results: From Aug 2013 to Aug 2014, samples from 45 patients with CRC were analyzed. Median age was 60 years; 23 (51%) were female; 38 (84%) were white. Median time from consent to result was 25 (range, 7-75) days. One (2%) sample had inadequate tissue. A median of 5 (range, 2-19) mutations were detected per sample; APC (89%), TP53 (73%) and KRAS (66%) were most common. A therapy targeting an actionable alteration was recommended in 22 (51%) patients; 88% of these recommendations were for clinical trials. To date, 6 (33%) of 18 patients who switched management after test results received genomics-driven therapies (Table). Previously unknown RAS (KRAS Q61H, NRAS) mutations were detected in an additional 3 patients, influencing EGFR antibody use decisions. The commonest reason for non-receipt of therapy based on the test result was non-availability of clinical trials. Conclusions: Routine tumor genome profiling in CRC patients is feasible and influenced treatment decisions in a third of patients. A genomics tumor board for the interpretation of rapidly evolving information, and improved access to clinical trials of targeted agents are critical to the success of precision oncology. [Table: see text]

Immune cell repertoire in patients with indolent metastatic renal cell carcinoma

429

Background: Immune dysfunction is well documented in renal cell carcinoma (RCC) patients and likely influences tumor progression. An ongoing prospective trial of observation in metastatic RCC patients prior to systemic therapy is investigating circulating immune cell populations. Methods: Asymptomatic patients with low volume metastatic disease are enrolled and followed until starting initial systemic treatment. Peripheral blood specimens are collected at the time of enrollment and again at the time of initiating therapy. The immune parameters measured include CD3+ and CD4+ INF-γ producing T cells (INF-γ+ T), CD4+CD25+FoxP3+ regulatory T-cells (Treg), and CD33+HLADr-CD15+CD14- neutrophilicmyeloid-derived suppressor cells (N-MDSC). Similar immune parameters were recorded for treatment-naïve patients prior to immediate systemic therapy and healthy volunteers on separate IRB-approved protocols. Results: 25 patients are enrolled in the study, of whom 14 started systemic therapy and had immune function analyzed for this report. Patient characteristics included 100% male, median age 74. 13 patients were favorable or intermediate risk by both MSKCC and Heng prognostic criteria; one patient was poor-risk. The median observation period was 13.9 months. The median tumor burden at the time of enrollment was 3.6 cm, which increased 38% during the observation period. As shown in the table below, the observation group had lower levels of Tregand N-MDSC, and higher levels of INF-γ+ T compared to the treatment group. In contrast, the observation group’s INF-γ+ T was similar to that of controls although N-MDSC was elevated. Conclusions: Metastatic RCC patients with indolent disease have low levels of Tregand N-MDSC, and a relatively preserved immune cell repertoire compared to patients requiring immediate therapy. [Table: see text]

Gallium nitrate suppresses the production of nitric oxide and liver damage in a murine model of LPS-induced septic shock

The efficacy of gallium (Ga) nitrate was examined in a murine model of sepsis. Male Balb/c mice (6-8 weeks) were randomized into 3 groups: 1) vehicle-treated controls 2) mice with sepsis induced by treatment with 0.3 mg i.v. of Propionibacterium acnes followed one week later by 0.01 microg lipopolysaccharide (LPS) and 10 mg of D-galactosamine (GalN) 3) mice with sepsis injected with 45 mg/kg s.c. of gallium nitrate (calculated as elemental Ga) 24 hours prior to LPS/GalN. Two hours after LPS/GalN or vehicle, plasma concentrations of tumor necrosis factor (TNF-alpha) in groups 1, 2 and 3 were 54+/-31 (n=6), 21,390+/-5139 (n=4), and 21,909+/-943 (n=5) pg/ml, respectively. After 6 hours, plasma concentrations of gamma interferon (IFN-gamma) were <10 (n=8), 4771+/-1078 (n=6), and 1622+/-531 (n=15) pg/ml, respectively, and of nitrate/nitrite (products of nitric oxide) were 64+/-8 (n=7), 146+/-18 (n=8), and 57+/-8 (n=15) microM. At 18 hours, serum chemistries were; SGOT 171+/-46 (n=13), 10,986+/-3062 (n=7), and 1078+/-549 (n=8) IU/L; SGPT 165+/-59, 17,214+/-4340, and 2088+/-1097 IU/L; and total bilirubin 0.2+/-0.0, 0.9+/-0.4, and 0.2+/-0.0 mg/dl for groups 1, 2, and 3 respectively. Blinded histologic evaluation of livers at 18 hours revealed inflammatory infiltrate scores (x [range], 0=none, 1=minimal, 2=mild, 3=moderate, and 4=severe) of 0.1 [0-1] (n=8), 3.0 [2-4] (n=15), and 2.0 [0-3] (n=10), and necrosis scores of 0.0, 2.8 [0-4], and 0.9 [0-4]. Although Ga did not affect production of TNF-alpha, it ameliorated hepatocellular injury and protected against necrosis. Based on this model of sepsis, Ga may have a role in treating the human disease.

The effects of gallium nitrate on osteopenia induced by ovariectomy and a low-calcium diet in rats

The effects of gallium nitrate (GN) were evaluated on osteopenia induced by ovariectomy (OVX) and a low-calcium diet (LCD) in Sprague-Dawley rats. Twenty-five rats (300-400 g) were randomized into four groups of 5-7 animals: (I) OVX LCD treated with GN for 22 weeks; (II) OVX LCD treated with GN for 10 weeks; (III) OVX LCD treated with saline; and (IV) sham-operated (SO), normal diet, treated with saline. GN-treated rats received a 30-mg/kg subcutaneous single dose of elemental gallium, followed by 10 mg/kg per week, whereas control animals received an equal volume of saline. All animals were euthanized at 22 weeks. Measurements of bone density and histomorphometry, performed on the proximal portion of the tibia, indicated significant bone loss in all OVX LCD animals. GN-treated rats in group I gained significantly less weight than those in the other groups, and their blood urea nitrogen increased, suggesting a nephrotoxic effect. After discontinuation of GN, rats in group II gained weight at the same rate as those which had received only saline. Bone formation rates in the GN-treated rats were double those of the saline-treated OVX animals and more than 10 times those of SO controls. Although the bone formation rate in GN-treated rats increased, GN had no effect in preventing the loss of bone surface, density and volume induced by OVX LCD. These findings suggest that although GN may enhance osteoblastic activity, this agent alone does not appear effective in the prevention of bone loss induced by OVX LCD.

Aminohydroxybutane bisphosphonate and clenbuterol prevent bone changes and retard muscle atrophy respectively in tail-suspended rats

Hind-limb unloading by tail suspension of rats, an established model of simulated microgravity, was used to examine the efficacy of aminohydroxybutane bisphosphonate (AHBuBP) and clenbuterol in preventing bone loss and muscle atrophy, respectively. Male Sprague-Dawley rats (299-372 g) were randomized into six groups of six: 1) unsuspended, saline, 2) unsuspended, saline, pair fed with group 3, 3) suspended, saline, 4) suspended, 0.03 mg/kg/day x 2 of AHBuBP, 5) suspended, 0.3 mg/kg/day x 2 of AHBuBP and 6) suspended, 0.3 mg/kg/day x 2 of AHBuBP + clenbuterol (0.5 mg/kg/day i.p. x 6, then 1 mg/kg/day i.p. x 6). Animals in groups 3 to 6 were tail suspended for 14 days from a system of double pulleys and allowed free mobility with their hind limbs unloaded. On days -2 and -1, before suspension on day 0, all rats received a single s.c. injection of either 2 ml/kg of normal saline (vehicle) or AHBuBP. All rats were tested for exercise tolerance before day -2 and on day 10, and grip strength before day -2 and on day 13. On day 14, the rats were euthanized and their humeri, tibias and femurs analyzed in vitro for bone density (by single-photon absorptiometry), strength and stiffness (by 3-point bending). Muscles were analyzed for weight, protein concentration and enzyme activity. Pair feeding had no effect other than on food consumption and body weight. AHBuBP caused a dose-dependent increase in bone density in humeri, tibias and femurs, even in tail-suspended rats, relative to control unsuspended animals, with no significant difference in bone strength or stiffness between AHBuBP groups and unsuspended animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Lack of effect of gallium nitrate on bone density in a rat model of simulated microgravity

The effect of gallium (Ga) nitrate upon bone density was studied in 24 male Sprague-Dawley rats (275-335 g) in an established model of simulated microgravity. Rats, tail-suspended for 14 d from a system of double pulleys, were allowed free mobility with their hind limbs unloaded. Animals were randomized into four groups of six: 1) unsuspended, saline; 2) suspended, saline; 3) unsuspended, Ga; and 4) suspended, Ga. On day 0, 1 d prior to suspension, rats received equal volumes of a single subcutaneous injection of either saline or 30 mg/kg of elemental Ga in the form of Ga nitrate. On day 15, all animals were euthanized under anesthesia, and their hind limbs analyzed in vitro using single-photon absorptiometry. Although we previously demonstrated that Ga inhibits bone resorption in patients with Paget's disease of bone, and although Ga exhibits many apparent similarities in efficacy to diphosphonates, which prevent bone loss in ovariectomized, paralyzed, and single-limb immobilized rats, Ga failed to prevent bone loss in the tail-suspended rats.

Inhibition and induction of theophylline metabolism by 8-methoxypsoralen. In vivo study in rats and humans

The effects of 8-methoxypsoralen (8-MOP) on the metabolism of theophylline were studied in rats and humans. Rats were randomized into three groups and prepared with iv jugular catheters. Group I (N = 4) received a single ip injection of 27 mg/kg of 8-MOP, group II (N = 5) vehicle (corn oil), and group III (N = 4) 50 mg/kg/day of 8-MOP for 3 days. Rats were subsequently administered 15 mg/kg of theophylline iv, and timed blood samples (0.2 ml) were assayed for theophylline by HPLC. Theophylline clearance (ml/min/kg; mean +/- SD) was 1.7 +/- 0.3, 2.4 +/- 0.5, and 9.5 +/- 1.6 in groups I, II, and III, respectively. The half-life (harmonic mean) from 0.5 to 12 hr was 7.2, 3.6, and 0.8 hr. Urinary excretion of unchanged theophylline (mean +/- SD) from 0 to 24 hr was 60 +/- 10, 41 +/- 6, and 13 +/- 3% of the administered dose. In a crossover study, three healthy, male, nonsmokers received 600 mg of oral theophylline. Urine and plasma were collected for 48 hr. One week later, subjects received 1.2 mg/kg of oral 8-MOP followed in 1 hr by 600 mg of oral theophylline. Mean residence time of theophylline increased from 10.7, 17.2, and 12.2 hr in the control period, to 20.3, 19.0, and 18.4 hr after 8-MOP. The AUC (microgram.hr/ml) of theophylline increased from 204, 213, and 204, to 555, 364, and 432, while clearance (ml/min/kg) decreased from 0.74, 0.57 and 0.63, to 0.27, 0.33, and 0.30, respectively. Urinary excretion of unchanged theophylline from 0 to 48 hr increased from 14, 14, and 15, to 24, 21, and 20%. We conclude that 8-MOP administered acutely is a potent inhibitor of theophylline metabolism and chronically in the rat is a powerful inducer.

Use of gallium to treat Paget's disease of bone: a pilot study

The effects of gallium nitrate on bone turnover were evaluated in four patients with active Paget's disease. Treatment with gallium nitrate (100 mg/m2 daily for 5 days, intravenously in 5% glucose) significantly reduced serum calcium, serum phosphate, urinary calcium, and the ratio of maximum tubular reabsorption of phosphate to glomerular filtration rate in each patient. Serum parathyroid hormone levels rose. The findings suggest that the fall in serum calcium caused secondary hyperparathyroidism, resulting in a fall in serum phosphate. Serum alkaline phosphatase and urinary hydroxyproline levels fell substantially, showing that gallium effectively suppressed bone turnover. The fall in hydroxyproline excretion preceded that in serum alkaline phosphatase, suggesting that suppression of bone resorption by osteoclasts preceded that of bone formation by osteoblasts. Alkaline phosphatase levels remained low throughout follow-up (85-141 days), so the effect of gallium seems to be long-lasting.