A phase I/IB study of paclitaxel in combination with VS-6063, a focal adhesion kinase (FAK) inhibitor, in patients (pts) with advanced ovarian cancer

TPS2620

Background: Blockade of FAK reduces tumor growth and metastasis through inhibition of tumor cell survival, proliferation and invasion as well as tumor angiogenesis. Furthermore, treatment with FAK inhibitors reduces the proportion of cancer stem cells (CSCs) in a dose dependent manner while paclitaxel treatment enriches for CSCs. (Kolev VN San Antonio Breast Cancer Symposia 2012 abstr P6-11-09). The ability of CSCs to survive exposure to chemotherapy but remain susceptible to novel drugs suggests a unique therapeutic approach whereby standard of care chemotherapy may be sequentially combined with targeted drugs to kill surviving CSCs and thus prevent tumor recurrence and metastasis. VS-6063 (previously PF-04554878) is a potent oral inhibitor of FAK and proline-rich tyrosine-kinase -2. The phase I first-in-man trial explored doses ranging from 12.5 -750 mg twice daily (BID). (Jones SF J Clin Oncol 2011 29:1 suppl; abstr 3002) Dose-limiting toxicities consisted of headache, fatigue, and unconjugated hyperbilirubinemia at various dose levels. A maximum tolerated dose was not defined, but doses > 100 mg BID consistently yielded concentrations above the preclinically predicted minimal efficacious concentration. Seven pts demonstrated stable disease lasting approximately 6 months or greater, including 3 heavily-pretreated ovarian cancer pts (2 platinum resistant). Methods: Pts with advanced or refractory ovarian cancer (≤ 4 prior regimens) will be enrolled. In the phase I portion, VS-6063 is administered continuously at a starting dose of 200mg BID with paclitaxel 80 mg/m2 on days 1, 8, and 15 every 28 days, and will be escalated to 400mg BID if tolerated. Pharmacokinetics will be analyzed. An additional 15 pts with biopsiable disease will be enrolled at the recommended dose. A 10-day run-in with VS-6063 alone will be used to obtain paired tumor biopsies in order to examine the effects on pFAK expression, CSCs, and other biomarkers. Patients will continue treatment until disease progression. Clinical trial information: NCT01778803.

Phase I study of margetuximab (MGAH22), an FC-modified chimeric monoclonal antibody (MAb), in patients (pts) with advanced solid tumors expressing the HER2 oncoprotein

3004

Background: The anti-HER2 MAb, trastuzumab (H), has proven effective for HER2+ breast cancer (BC) and gastroesophageal cancer (GEC). H’s mechanism of action is incompletely understood, but evidence indicates ADCC is important. MGAH22 is an Fc-modified chimeric MAb which preserves the antigen binding properties of H, and exhibits enhanced binding to the activating low affinity Fcg receptor, CD16A, and diminished binding to the inhibitory low affinity Fcg receptor, CD32B. Preclinical data indicate MGAH22 is more potent than H. Methods: 34 pts with HER2 positive (2+ or 3+ by IHC) tumors have been treated: 19 in 5 dose-escalation cohorts (0.1 - 6.0 mg/kg qw x 4); 15 in 6.0 mg/kg expansion. Tumor types include: BC (10), GEC (13), colon (5), lung (2), salivary (1), ampulla of Vater (1), endometrium (1), bladder (1). Results: MGAH22 was well tolerated. Most common adverse events (AEs) were Grade 1-2 constitutional symptoms and infusion-related reactions. Related AEs ≥ Grade 3 were limited to a single infusion reaction, 2 episodes of brief lymphopenia confounded by steroids, and transient worsening anemia. No cardiac toxicities were observed. Dose escalation was halted at 6 mg/kg, well above the preclinically predicted minimally effective dose (0.1 mg/kg). Antitumor activity has been observed at all dose levels, including partial responses (PRs) and long times to progression (≥ 5 mo). Two PRs lasting 3.5 and 5.5 mo were observed among the 10 BC pts (both had failed prior H and lapatinib). 4/13 GEC pts experienced stable disease lasting a median of 3.6 mo (range 1.5–5.3), all but one previously failing anti-HER2 treatment. Conclusions: Margetuximab is well tolerated with promising activity in pts with BC and GEC who have failed prior HER-2 therapies and in pts with HER2+ tumors for which H is considered ineffective. A phase II trial in relapsed or refractory HER2 2+, nonamplified BC is underway. Clinical trial information: NCT01195935. [Table: see text]

Clinical activity, safety, and biomarkers of MPDL3280A, an engineered PD-L1 antibody in patients with locally advanced or metastatic non-small cell lung cancer (NSCLC)

8008

Background: Human lung cancer expresses high levels of PD-L1, which may inhibit anti-cancer immune responses. MPDL3280A, a human monoclonal Ab containing an engineered Fc-domain designed to optimize efficacy and safety, targets PD-L1, blocking PD-L1 from binding its receptors, including PD-1 and B7.1. Methods: Pts with squamous or nonsquamous NSCLC received MPDL3280A IV q3w at doses between 1-20 mg/kg in a Ph I expansion study. Pts were treated for up to 1 y. Objective response rate (ORR) was assessed by RECIST v1.1. Reported ORR includes u/cCR and u/cPR. Results: As of Jan 10, 2013, 53 NSCLC pts were evaluable for safety and treated at doses of ≤1 (n=2), 10 (n=10), 15 (n=19) and 20 mg/kg (n=22). Pts had a median age of 61 y (range 24-83 y), 98% were PS 0-1, 89% had prior surgery and 55% had prior radiotherapy. 98% of pts received prior systemic therapy. Pts received treatment for a median duration of 106 days (range 1-324) of MPDL3280A. The incidence of all G3/4 AEs, regardless of attribution, was 34%, including pericardial effusion (6%), dehydration (4%), dyspnea (4%) and fatigue (4%). No G3-5 pneumonitis or diarrhea was reported. 37 NSCLC pts enrolled prior to Jul 1, 2012, were evaluable for efficacy. RECIST responses were observed at dose levels between 1 and 20 mg/kg, with all responses ongoing or improving. An ORR of 24% (9/37) was observed in pts with squamous and nonsquamous histologies, including several with rapid tumor shrinkage. Additional pts had delayed responses after apparent radiographic progression (not included in the ORR). The 24-week PFS was 48%. Analysis of biomarker data from archival tumor samples demonstrated a correlation between PD-L1 status and efficacy. Pts who were PD-L1 tumor status–positive showed an ORR of 100% (4/4) and a PD rate of 0% (0/4), while pts who were PD-L1 tumor status–negative showed an ORR of 15% (4/26) and a PD rate of 58% (15/26). Updated data will be presented. Conclusions: Treatment with MPDL3280A was well tolerated, with no pneumonitis-related deaths. Rapid and durable responses were observed. PD-L1 tumor status correlated with response to MPDL3280A. Clinical trial information: NCT01375842.

Clinical management and resolution of stomatitis in BOLERO-2

558

Background: In BOLERO-2, adding everolimus (EVE) to exemestane (EXE) more than doubled progression-free survival without affecting quality of life vs EXE alone in postmenopausal women with hormone-receptor–positive advanced breast cancer who had recurrence or progression on/after nonsteroidal aromatase inhibitor therapy. Although mTOR inhibitors are generally well tolerated, stomatitis is one of their most clinically relevant and potentially dose-limiting toxicities (Sonis Cancer2010). The incidence, grade, and clinical course of stomatitis among patients (pts) participating in the BOLERO-2 study are described. Methods: Pts were randomized 2:1 to receive EVE+EXE or placebo (PBO)+EXE. Stomatitis incidence, severity, consequent dose interruptions/adjustments, study drug discontinuations, and time to resolution were recorded. Results: The median duration of EVE+EXE treatment exposure was 30 wk (range, 1-123 wk). Stomatitis (any grade) occurred more frequently with EVE+EXE than with PBO+EXE (59% vs 12%, respectively). Grade 3 stomatitis occurred in 8% vs 1% of pts receiving EVE+EXE vs PBO+EXE, respectively; no grade 4 was reported. Onset of grade ≥2 stomatitis after treatment initiation was earlier in the EVE+EXE arm vs the PBO+EXE arm: median time was 15d vs 24d, respectively. In the EVE+EXE arm, 97% of pts with grade 3 stomatitis (n=38) improved to ≤1 after a median of 13 d. Complete resolution was observed in 82% of these pts after a median of 38 d. In the PBO+EXE arm, all pts with grade 3 stomatitis (n=2) improved to ≤1 after a median of 18 d. Complete resolution was observed after a median of 29 d. Overall, 24% of pts in the EVE+EXE arm required dose interruptions/adjustments vs 1% of pts in the PBO+EXE arm, and 3% of pts (n=13) discontinued EVE+EXE vs <1% of pts (n=1) discontinuing PBO+EXE, all related to stomatitis. Conclusions: The BOLERO-2 data foster a new era of combining targeted and endocrine therapies. In the study, treatment-emergent stomatitis was of mild to moderate intensity, occurred shortly after treatment initiation, and was generally reversible. Most incidents were successfully managed with palliative interventions and temporary dose modifications. Oral hygiene and other preventive measures are recommended. Clinical trial information: NCT00863655.

A phase I dose-escalation and PK study of continuous oral rucaparib in patients with advanced solid tumors

2585

Background: Rucaparib, a potent, oral small molecule inhibitor of poly (ADP-ribose) polymerase (PARP) 1 and -2, is being developed for treatment of homologous recombination repair deficient (HRD) ovarian cancer. This study evaluated oral rucaparib as monotherapy. Primary objectives were to define maximum tolerated dose (MTD), recommended Phase 2 dose (RP2D), and PK of continuous oral rucaparib. Methods: A standard 3+3 dose escalation design was used. Intra-patient dose escalation was allowed. Patients (pts) aged ≥18 with advanced solid tumor that progressed on standard treatments were recruited. Rucaparib was taken orally qd or bid until disease progression. Plasma PK assessments included full profile, trough levels, and food effect. Results: 29 pts (median age 52 yrs [range 21-71]; 26 female; 15 ECOG PS=0; 17 breast cancer (BC), 7 ovarian/peritoneal cancer (OC), 5 other tumor) were enrolled in 6 dose cohorts to date (40, 80, 160, 300 and 500 mg qd, 240 mg bid). Evaluation of 360 mg bid rucaparib is nearly complete. No DLTs have occurred and no pts have discontinued treatment due to toxicity. Treatment-related adverse events (primarily CTCAE grade 1-2) reported in ≥2 of 29 pts include fatigue (n=5), anorexia (n=3), nausea (n=3), vomiting (n=3), and diarrhea (n=2). To date, two pts (1 OC, 1 BC; both BRCA1mut) treated with 300 mg qd rucaparib achieved PR at wk 6; both are ongoing in wk 17. An additional 10 pts (5 OC, 4 BC, 1 CRC; 7 BRCAmut, 2 BRCAunk, 1 BRCAwt) achieved best response of stable disease (SD) >12 wks thus far; 4 pts (3 OC, 1 BC) are ongoing at 17 (n=2) and 30 (n=2) wks. Overall disease control rate (CR+PR+SD>12 wks) in OC pts across all dose levels was 86% (6/7). Dose proportional PK was observed up to 500 mg qd with mean t1/2 of 15 h (range 4.3 - 29 h). Following qd dosing, steady state was achieved by Day 8. As expected, bid dosing increased trough levels above 2 µM target with low interpatient variability. Conclusions: Continuous oral rucaparib is very well tolerated, with encouraging clinical activity, including objective responses and durable SD, observed during dose-escalation. Once confirmed, the RP2D will be evaluated in platinum-sensitive OC pts with a gBRCA mutation. Clinical trial information: NCT01482715.

Phase I study of safety and pharmacokinetics (PK) of GDC-0917, an antagonist of inhibitor of apoptosis (IAP) proteins in patients (Pts) with refractory solid tumors or lymphoma

2503

Background: GDCE0917 is a small molecule that triggers tumor cell apoptosis by selectively antagonizing IAP proteins. Preclinical studies demonstrated antitumor efficacy of GDC-0917 alone or in combination with chemotherapeutic agents. Methods: Oral GDC-0917 was given on Day (d) 1 followed by 2d off and a 2-week (w) on/ 1w off treatment (tx) schedule (21d cycle) starting d4. A modified continual reassessment method was used for dose escalation. Dose-limiting toxicity (DLT, assessed d1-24), PK, adverse events (AEs), pharmacodynamics (PD), and clinical activity were evaluated. Results: 42 pts of age 36-86 (median 60.5) were enrolled in 11 cohorts (5-600 mg) and received 1-15 cycles (median 2) of GDC-0917. One DLT, Grade (G) 3 fatigue, was observed at 450 mg. The maximum tolerated dose was not determined although plasma concentrations of preclinically defined IC90 were reached. The most frequent AEs were diarrhea, fatigue and nausea (26.2% each), vomiting (23.8%), and constipation (19%). The most frequent AEs reported as tx-related were mostly G1-2 and included fatigue and nausea (21.4% each), vomiting (14.3%), rash (11.9%) and pruritus (9.5%). AEs reported as tx-related that were ≥ G3 in > 1 pt were elevated AST and ALT (2 pts, at 450 and 600 mg). AEs reported as tx-related that resulted in tx discontinuation were G3 fatigue, G2 QTc prolongation, G2 drug hypersensitivity, G2 pneumonitis (1 pt each), and G3 pruritus/G2 rash (same pt). GDC-0917 peak concentrations were observed 2-3h post dosing. Exposure was dose-proportional with a mean plasma elimination t1/2of 4-8h and no apparent accumulation at steady state. Rapid down-modulation of cIAP1 was observed in PBMCs at all dose levels. Evaluation of tumor biopsies demonstrated decreases in cIAP1 (2 pts total, at 40 and 200 mg) and increases in activated caspase-3 and cPARP (1 pt at 200 mg). Two pts (4.8%) had a complete response (both unconfirmed, ovarian Ca and MALT lymphoma [PET]); 4 pts (9.5%) had stable disease for ≥ 3 months. Conclusions: GDC-0917 had a favorable safety, PK and PD profile in pts with advanced malignancies. These encouraging results support further clinical evaluation of this agent. Clinical trial information: NCT01226277.

Double-blind randomized phase II trial of carboplatin and pemetrexed with or without OGX-427 in patients with previously untreated stage IV non-squamous non-small-cell lung cancer (NSCLC): The Spruce Clinical Trial

TPS8120

Background: OGXE427 is an antisense oligonucleotide (ASO) designed to bind to Hsp27 (heat shock protein 27) mRNA, resulting in the inhibition of production of Hsp27 protein. Hsp27 is over-expressed in many cancers including lung, prostate, breast, and bladder. Increased expression has been associated with inhibition of chemotherapy-induced apoptosis, increased tumor cytoprotection, and the development of treatment resistance. OGX-427 is an inhibitor of Hsp27 that effectively targets and down-regulates Hsp27 mRNA and has been shown to increase apoptosis, inhibit tumor growth, and sensitize cells to various chemotherapy regimens in a variety of malignancies. Based on this preclinical data, addition of an Hsp27 inhibitor to standard chemotherapy may improve the efficacy of treatment. In this randomized phase II study, OGX-427 will be added to a standard carboplatin/pemetrexed regimen, with the goal of improving progression-free survival when compared to carboplatin and pemetrexed alone in the first-line treatment of non-squamous NSCLC patients. Methods: A total of 155 patients will be randomized in a 1:1 ratio. Randomization will be stratified by histology (adenocarcinoma vs. large cell carcinoma) and smoking status (smoker vs. non-smoker). Treatment will include a loading dose period with OGX-427 600 mg or placebo. On day one of each 21 day cycle, patients will receive OGX-427 1000 mg or placebo, pemetrexed 500 mg/m2, and carboplatin AUC 6, all administered IV. On days 8 and 15, OGX-427 or placebo will also be administered. Key eligibility criteria include; untreated recurrent or stage IV predominantly non- squamous NSCLC, measureable disease by RECIST v 1.1, ECOG PS 0 or 1, adequate organ function, and no known CNS disease. Serum Hsp27 levels will be assessed at screening, baseline and during treatment. In addition, archival tissues will be collected and assessed for PTEN (protein expression by IHC) and a panel of gene mutations for correlative analyses.

Phase I/II study of dianhydrogalactitol in patients with recurrent malignant glioma or progressive secondary brain tumor

2093

Background: Recurrent glial tumors of the brain continue to be one of the most challenging malignancies to treat, and median survival for patients with recurrent disease is approximately 6 months for glioblastoma multiforme (GBM). The front-line therapy for GBM - temozolomide (TMZ) - is subject to resistance by DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT), leading to poor prognoses for patients with recurrent GBM. Dianhydrogalactitol (VAL-083)is a first-in-class bi-functional N7 DNA alkylating agent shown to cross the blood-brain barrier, accumulate in brain tissue, and have activity against GBM. Studies suggest that VAL-083 overcomes MGMT-driven drug resistance in vitro and targets cancer stem cells. The purpose of this study is to determine the maximal tolerated dose (MTD) of VAL-083 in patients with recurrent GBM or progressive secondary brain tumor, and explore the safety, pharmacokinetics and tumor responses to treatment. Methods: Open-label phase I/II dose-escalation study of VAL-083 in patients with histologically confirmed primary WHO grade 4 malignant GBM, now recurrent, previously treated for GBM with surgery and/or radiation, if appropriate, and have failed both bevacizumab and temozolomide; or progressive secondary brain tumor, has failed standard brain radiotherapy, and has brain tumor progression after at least one line of systemic therapy. The study uses a 3 + 3 dose escalation design, until reaching the MTD or maximum specified dose. Patients receive IV VAL-083 on days 1, 2, and 3 of each 21-day treatment cycle. In phase II, additional patients are treated at the MTD (or selected optimum dose) to measure tumor responses. Results: Cohort 1 (3 patients) and cohort 2 (4 patients) were completed without any DLT’s. Adverse events (AEs) have all been grade 1/2, with only 1 grade 3 AE, unrelated to treatment. Cohort 3 currently has 4 patient enrolled, without reaching the MTD. 1/7 (14.3%) patients in cohorts 1and 2 has prolonged stable disease (15+ cycles) on VAL-083 treatment. Conclusions: VAL-083 up to the 2nd dose level was well tolerated without any safety signals. Dose escalation is continuing. Clinical trial information: NCT01478178.

Phase I study of the combination of BKM120 and bevacizumab in patients with relapsed/refractory glioblastoma multiforme (GBM) or other refractory solid tumors

e13045

Background: BKM120 is an oral pan-class I PI3 kinase (PI3K) inhibitor, with demonstrated CNS penetration. Enhanced PI3K signaling is common in GBM (56-75% of cases), and is associated with poor survival (Chakravarti et al, 2004). This phase I study was designed to determine the maximum tolerated dose (MTD) of BKM120 in combination with a standard dose of bevacizumab as treatment for patients with relapsed/refractory GBM or other refractory solid tumors. Methods: Patients with relapsed/refractory GBM or other refractory solid tumors for which bevacizumab was an appropriate therapy received BKM120 with bevacizumab in a standard 3+3 dose escalation design. Bevacizumab 10 mg/kg IV was administered days 1 and 15 of 28-day cycles, with escalating doses of BKM 120 self-administered daily. Patients were evaluated for response after 8 weeks; treatment continued until disease progression or unacceptable toxicity. Results: Twelve patients were treated at 2 BKM120 dose levels, DL 1 = 60 mg/day and DL 2 = 80 mg/day. DL 1 (n = 6) tumor types included: 2 GBM, 2 colorectal and 2 NSCLC with treated brain metastases. Dose-limiting toxicity (DLT) of G4 delirium was observed in 1 GBM patient. Three additional patients were enrolled, and no further DLTs occurred. DL 2 (n = 6) tumor types included: 3 GBM and 3 colorectal. DLTs were observed in 2 of 6 patients: 1 colorectal (G3 rash, G3 stomatitis, G3 dehydration, and G2 worsening vomiting), and 1 GBM (G3 ataxia and G3 mental status changes). 6 patients had CNS symptoms possibly related to treatment, including mood alteration (3 GBM and 1 colorectal), delirium, hallucinations, and mental status change (1 GBM patient each). Common treatment-related toxicities (all grades) included: dyspepsia (42%), nausea (33%), ALT elevation (25%), dehydration (25%), proteinuria (25%), rash (25%), and thrombocytopenia (25%). No objective responses were documented; however, 1 colorectal patient remains on treatment with stable disease for 8 months. Conclusions: The addition of BKM120 to standard dose bevacizumab was tolerated at a dose of 60 mg/day. A phase II study with this combination is currently underway in patients with relapsed/refractory GBM. Clinical trial information: NCT01349660.

Paclitaxel/carboplatin with or without sorafenib in the first-line treatment of patients with stage III/IV epithelial ovarian cancer: A randomized phase II study of the Sarah Cannon Research Institute

5513

Background: The combination of paclitaxel and carboplatin is the most widely used chemotherapy regimen for patients (pts) with advanced ovarian cancer, producing a median survival of approximately 36 months. Recently, the addition of bevacizumab, an angiogenesis inhibitor, has improved progression-free survival (PFS) when compared to paclitaxel/carboplatin alone. Sorafenib is an oral multi-kinase inhibitor with effects on tumor angiogenesis through inhibition of the VEGF receptor. The purpose of this randomized phase II study was to compare efficacy of paclitaxel/carboplatin with and without sorafenib. Methods: Women with histologically confirmed, maximally debulked, previously untreated stage III/IV epithelial ovarian carcinoma were randomized to receive paclitaxel 175 mg/m2and carboplatin AUC 6 (PC) or PC + sorafenib 400 mg PO BID (S). All patients received 6 cycles, given every 3 weeks; pts receiving PC+S continued single agent sorafenib for 52 weeks total. The primary endpoint was 2-year PFS rate. Results: 85 pts were randomized between 1/07 and 10/11 (PC+S 43; PC 42). Pt characteristics were similar between groups, except that more patients with only CA125 elevation received PC+S (65% vs 43%). Overall, 67 pts (79%) completed 6 cycles of chemotherapy (PC+S 74%; PC 83%). More patients stopped PC+S due to toxicity (14% vs 7%). 22 pts (51%) receiving PC+S began single agent S after 6 cycles PC, and 12 pts (28%) completed 52 weeks of S. There was no difference in the 2-year PFS rates: PC+S 40%, PC 39%. Overall survival comparisons were also similar (p = 0.36). Pts receiving PC+S had more grade 3 rash (33% vs 0%) and hand-foot syndrome (9% vs 0%). Conclusions: The addition of sorafenib did not improve the efficacy of standard first-line PC in pts with stage III/IV ovarian carcinoma, and resulted in additional toxicity. Clinical trial information: NCT00390611.

KRAS subset analysis from randomized phase II trials of erlotinib versus erlotinib plus sorafenib or pazopanib in refractory non-small cell lung cancer (NSCLC)

8091

Background: KRAS mutations are among the most common genetic alterations in NSCLC; however no targeted therapies have been approved to benefit this lung cancer subset. Between 2/2008 and 2/2011 our center conducted two consecutive multicenter randomized phase II trials in patients (pts) with refractory NSCLC comparing erlotinib/placebo versus erlotinib + either sorafenib or pazopanib, both oral multikinase inhibitors (Spigel et al, JCO 2011; Chicago MSTO 2012). Progression-free survival (PFS) was improved with the multikinase regimens in the EGFR wild-type (WT) subsets, but not in the overall populations. An unplanned analysis of the combined KRAS subset data is the subject of this report. Methods: Eligibility criteria for both trials included: stage IIIB/IV NSCLC; 1 to 2 prior regimens; ECOG performance status 0–2; measurable disease. PFS was the primary endpoint of each trial. Treatment groups included: erlotinib/placebo (N=121), erlotinib/sorafenib (N=112), and erlotinib/pazopanib (N=127). 168 pts (47%) in these three groups had sufficient tumor specimens for KRAS analysis. Results: The PFS and OS results based on KRAS results are shown in the Table below. Conclusions: Patients in whom the KRAS mutation status was known achieved a significantly longer PFS with erlotinib and a multikinase inhibitor than with erlotinib alone. Although this unplanned combined analysis has several limitations, the greater PFS and OS benefits in pts with KRAS mutations warrant further study. Clinical trial information: NCT00600015; NCT01027598. [Table: see text]

Safety, pharmacokinetics, and preliminary activity of the α-specific PI3K inhibitor BYL719: Results from the first-in-human study

2531

Background: BYL719 is an oral small-molecule inhibitor of the p110α catalytic subunit of phosphatidylinositol 3-kinase (PI3K), which is encoded by the PIK3CA gene, one of the most commonly mutated genes in human cancers. BYL719 inhibits proliferation of PI3Kα-driven cancer cell lines in vitro and causes regression of PIK3CA-mutant tumor models in vivo. Methods: This Ph I study was performed in patients (pts) with advanced solid tumors carrying a somatic mutation of PIK3CA. Dose escalation used an adaptive Bayesian logistic regression model with overdose control. Following determination of the maximum tolerated dose (MTD), an expansion cohort was opened at the MTD to evaluate safety, pharmacokinetics (PK), and clinical activity in pts with PIK3CA-mutant advanced solid tumors, including estrogen receptor-positive (ER+) metastatic breast cancer (mBC). Results: During dose escalation 36 pts received doses up to 450 mg/d, where 4/9 pts had dose-limiting toxicities (DLTs). The MTD for once-daily dosing was declared as 400 mg/d. As of Nov 20 2012, DLTs were hyperglycemia, nausea, vomiting, and diarrhea. The most common BYL719-related adverse events (all grades, all cohorts, >25%) were hyperglycemia (49%), nausea (45%), diarrhea (40%), decreased appetite (38%), vomiting (30%), and fatigue (27%). 39 pts are enrolled in the MTD dose-expansion cohort. Investigation of a twice-daily regimen is also ongoing. BYL719 has a favorable, approximately dose-proportional PK profile with a Tmax of 2h and a T½ of 11h at the MTD. Partial responses were seen in 7 pts (in ER+ breast [2], cervical, trichilemmal, endometrial, ovarian, and head &neck cancer [1 each]); 17 pts stayed on study for >24 weeks. For 67 pts (76%) treated at doses of ≥270 mg/d, the median progression-free survival (mPFS) was 3.6 months (mo; 95% CI: 3.5–5.5 mo). mPFS in 15 ER+ HER2– mBC pts treated at ≥270 mg/d was 5.5 mo (95% CI: 3–7 mo). Conclusions: BYL719 displays dose-proportional and predictable PK. The safety profile is favorable, with mostly manageable on-target toxicities. At doses of ≥270 mg/d, tumor regression and prolonged disease control were observed in heavily pretreated pts with various tumor types carrying a PIK3CA mutation. Clinical trial information: NCT01219699.

Clinical and pharmacodynamic (PD) results of a phase I trial with AMP-224 (B7-DC Fc) that binds to the PD-1 receptor

3044

Background: PD-1/B7-H1 (PD-L1) axis blockade can reinvigorate T cells, and overcome tumor immune evasion of multiple tumor types. AMP-224 is the first recombinant B7-DC-Fc fusion protein tested in patients that binds to and modulates the PD-1 axis through a unique MOA. The MoA hypothesis for AMP-224 is depletion of PD-1high expressing T-cells representing exhausted effector cells. Subsequent replenishment of the T-cell pool with functional T-cells may restore immune function. Methods: Patients with advanced solid tumors received low dose CTX on Day 0, followed by AMP-224 (IV infusion) on Days 1 and 15 of each 28-day cycle in doses ranging from 0.3 to 30 mg/kg. Blood samples were assessed serially for changes in lymphocyte subsets, PD-1HIT cells and T cell effector function. IHC staining of paired biopsies for B7-H1, CD8, PD-1, CD4 and FoxP3 was performed to assess immunological status of the tumor at baseline and following treatment and then relative to peripheral readouts. Results: 42 patients (83% melanoma) were treated with varying doses of AMP-224 [0.3 mg/kg (n = 6); 1 mg/kg (n=4); 3 mg/kg (n = 4); 10 mg/kg (n = 22); 30 mg/kg (n = 6)]. Infusion reactions were common (69% across dose cohorts) and occurred mostly at higher doses (86% at the 10 mg/kg dose). No drug-related inflammatory adverse events were identified contrary to PD-1 blocking antibodies. Fresh pre-treatment biopsies were collected from 33/42 (78.5%) patients and paired biopsies have been collected thus far from 19/36 (52.7%) patients on study. 31% of baseline tumors were B7-H1+. Several PD readouts in the periphery showed reductions in PD-1HIcells and emergence of a functional T cell response (increases in IFNg+, TNFa+, IL-2+ CD4 and CD8 T cells) in individual patients where partial response, stable disease, and mixed responses were seen. Conclusions: Data from peripheral readouts is consistent with hypothesized AMP-224 MoA. B7-H1+ was not always predictive of functional response to AMP-224 immunotherapy. Comprehensive PD readouts and evaluation of PK/PD relationships will be presented and may ultimately predict restoration of immune competence even in the presence of initial disease progression. Clinical trial information: NCT01352884.

Combination of a MEK inhibitor, pimasertib (MSC1936369B), and a PI3K/mTOR inhibitor, SAR245409, in patients with advanced solid tumors: Results of a phase Ib dose-escalation trial

2530

Background: PI3K/mTOR and MAPK signaling pathways are often deregulated in tumors. Simultaneous inhibition of these pathways with the MEK1/2 inhibitor, pimasertib, plus the dual PI3K/mTOR inhibitor, SAR245409, (ClinicalTrials.gov NCT01390818) was investigated. Methods: This was a phase Ib, modified 3+3, dose-escalation trial in patients (pts) with advanced solid tumors. Pts received pimasertib and SAR245409 at the following dose levels (DLs): DL1, 15/30; DL2a, 30/30; DL2b, 15/50; DL3, 30/50; DL4a, 60/50; DL4b, 30/70; DL5, 60/70; DL6a, 90/70; DL6b 60/90 and DL7, 90/90 mg (once-daily, qd). After the qd maximum tolerated dose (MTD) was established, twice-daily (bid) dosing was tested: DL1a, 60/30; DL1b, 45/50 and DL2 60/50 mg bid. A recommended phase II dose (RP2D) was determined. Enrollment continued at the RP2D in four expansion cohorts (18 pts each): dual KRAS/PIK3CA mutated (mt) colorectal cancer (CRC), triple-negative breast cancer, KRAS mt non-small cell lung cancer (NSCLC) and BRAFmt melanoma. Results: 53 pts were treated qd and 7 pts bid. The most common tumors were CRC (n=16), NSCLC (n=8), ovarian and pancreatic (n=7, each). At DL6b 2/3 pts had dose-limiting toxicities (DLTs; both grade [Gr] 3 nausea/vomiting). DL6a was confirmed as the MTD for the qd schedule. At bid DL1a 2/4 pts (both Gr 3 skin rash) and at DL1b 2/3 pts (Gr 3 skin rash and Gr 3 asthenia) had DLTs. DL5 was the RP2D based on tolerability after prolonged exposure. The most common adverse events in qd schedule were: rash (62%, 13% Gr 3), diarrhea (56%, 4% Gr 3), fatigue (51%, 2% Gr 3), nausea (49%, 2% Gr 3), vomiting (45%, 2% Gr 3), peripheral edema and pyrexia (34%, each) and visual impairment with underlying serous retinal detachment (21%). Preliminary pharmacokinetic results suggest no drug-drug interaction. There were 4 partial responses: KRAS mt CRC (n=1) and low-grade ovarian cancer (n=3, 1 KRAS mt/PIK3CA mt and 2 wild-type). Enrollment in expansion cohorts at DL5 is ongoing. Conclusions: Continuousqd dosing of pimasertib and SAR245409 is tolerated and has shown signs of activity. Phase II trials are being planned. Clinical trial information: NCT01390818.

Correlation of molecular alterations with efficacy of everolimus in hormone-receptor–positive (HR+), HER2-negative advanced breast cancer: Preliminary results from BOLERO-2

LBA509

The full, final text of this abstract will be available at abstract.asco.org at 7:30 AM (EDT) on Monday, June, 3, 2013, and in the Annual Meeting Proceedings online supplement to the June 20, 2013, issue of Journal of Clinical Oncology. Onsite at the Meeting, this abstract will be printed in the Monday edition of ASCO Daily News.

A study of MPDL3280A, an engineered PD-L1 antibody in patients with locally advanced or metastatic tumors

3000

Background: Tumor PD-L1 mediates cancer immune evasion. Therefore, inhibition of PD-L1 binding represents an attractive strategy to restore tumor-specific T-cell immunity.MPDL3280A, a human monoclonal antibody containing an engineered Fc-domain designed to optimize efficacy and safety, targets PD-L1, blocking PD-L1 from binding its receptors, including PD-1 and B7.1. Methods: A study was conducted with MPDL3280A administered IV q3w in pts with locally advanced or metastatic solid tumors, including 3+3 dose-escalation and expansion cohorts. ORR was assessed by RECIST v1.1 and includes u/cCR and u/cPR. Results: As of Jan 10, 2013, 171 pts were evaluable for safety. Administered doses include ≤1 (n=9), 3 (n=3), 10 (n=35), 15 (n=57) and 20 mg/kg (n=67). Pts in the dose-escalation cohorts did not experience DLTs. No MTD was identified. Pts had received MPDL3280A for a median duration of 127 days (range 1-330). 39% of pts reported G3/4 AEs, regardless of attribution. AEs of special interest included hepatitis, rash and colitis. No G3-5 pneumonitis was observed. MPDL3280A PK was linear at doses ≥1 mg/kg. 122 pts enrolled prior to Jul 1, 2012 were evaluable for efficacy. RECIST responses were observed in multiple tumor types including NSCLC, RCC, melanoma, CRC and gastric cancer. An ORR of 21% (25/122) was observed in nonselected solid tumors, including several pts who demonstrated tumor shrinkage within days of initiating treatment. Additional pts had delayed responses after apparent radiographic progression (not included in the ORR). Some responders demonstrated prolonged SD prior to RECIST responses. The 24-week PFS was 44%. Pts with PD-L1–positive tumors (from archival samples) showed an ORR of 39% (13/33) and a PD rate of 12% (4/33). In contrast, patients with PD-L1–negative tumors showed an ORR of 13% (8/61) and a PD rate of 59% (36/61). As of the cutoff date, all responses are ongoing or improving. Updated data will be presented. Conclusions: MPDL3280A was well tolerated, with no pneumonitis-related deaths. Durable responses were observed in a variety of tumors. PD-L1 tumor status appears to correlate with responses to MPDL3280A. PK supports q3w dosing at 15 mg/kg or fixed-dose equivalent. Clinical trial information: NCT01375842.

A phase I study of the safety and pharmacokinetics of DNIB0600A, an anti-NaPi2b antibody-drug-conjugate (ADC), in patients (pts) with non− small cell lung cancer (NSCLC) and platinum-resistant ovarian cancer (OC)

2507

Background: NaPi2b (SLC34A2) is a multi-transmembrane, sodium-dependent phosphate transporter expressed in non-squamous NSCLC and non-mucinous OC. DNIB0600A is an ADC consisting of a humanized IgG1 anti-NaPi2b monoclonal antibody and anti-mitotic agent, MMAE, that shows anti-proliferative activity in xenograft models. Methods: This study evaluated safety, pharmacokinetics, and pharmacodynamics of DNIB0600A (0.2-2.8 mg/kg) given every 3 weeks (q3w) to pts with NSCLC or OC. A traditional 3+3 design was used for dose escalation followed by expansion by disease at the recommended Phase 2 dose (RP2D). Tumor NaPi2b expression was evaluated in archival tissue. Anti-tumor activity was evaluated per RECIST 1.1. Results: As of 10 Dec 2012, 30 dose escalation pts have enrolled (16 NSCLC; 14 OC), median age 61 (range 45-78), PS 0-1, median number of prior regimens 5 (1-12), received a median of 3 (1-17) doses of DNIB0600A. No DLTs occurred at the maximum assessed dose of 2.8 mg/kg; enrollment in the expansion cohort at 2.4 mg/kg is ongoing. The most common related AEs regardless of Grade were fatigue (43%), decreased appetite (37%), nausea (30%), constipation, dysgeusia, vomiting, and peripheral neuropathy (each 17%), and diarrhea (13%). One pt at 1.8 mg/kg experienced a DLT (Grade 3 dyspnea), however, no additional DLTs occurred through the maximally administered dose of 2.8 mg/kg. Expansion at 2.4 mg/kg was selected based on totality of safety data. No accumulation of total antibody, free MMAE, or conjugated MMAE was observed. Exposure of each analyte was dose proportional. Approximately 70% of NSCLCs and 85% of OC expressed high levels (IHC 2+/3+) of NaPi2b. Of the 18 pts treated at dose levels 1.8-2.8 mg/kg (10 NSCLC; 8 OC) 3 pts had a confirmed partial response (PR) with response durations of 8.8+ (OC), 4.4+ (NSCLC), and 1.4+ (OC) months, censored at data cutoff, and 1 additional pt had an unconfirmed PR (OC). Dose expansion data will be presented. Conclusions: DNIB0600A administered q3w has an encouraging safety profile and evidence of anti-tumor activity in both NSCLC and OC. Further studies are planned. Clinical trial information: NCT01375842.

First-line carboplatin, pemetrexed, and panitumumab in patients with advanced nonsquamous KRAS wild type (WT) non-small cell lung cancer (NSCLC)

8062

Background: KRAS WT colorectal cancer (CRC) is responsive to the EGFR inhibitors panitumumab (P) and cetuximab. Phase III data suggest a small, but statistically significant overall survival (OS) advantage with cetuximab + chemotherapy in KRAS unselected NSCLC (Pirker, Lancet 2009); and phase I data suggest P alone has activity in non-CRC tumors including NSCLC (Weiner, Clin Ca Res. 2008). This single-arm phase II trial examined the safety and efficacy of P in combination with carboplatin (C) and pemetrexed (Pem) in patients (pts) with advanced non-squamous KRAS WT NSCLC. The addition of P was hypothesized to improve the median time-to-progression (TTP) from 3.6 months (mos) (historical) to 5.4 mos (1-sided α .10, 80% power). Methods: Pts with previously untreated, unresectable stage IIIB/IV non squamous KRAS WT NSCLC received P 9 mg/kg, Pem 500 mg/m2, and C AUC=6 IV day 1 every 21 days for 6 cycles, followed by P and Pem maintenance every 21 days until progressive disease or unacceptable toxicity. Responses were evaluated every 2 cycles per RECIST 1.1. KRAS mutation testing was performed centrally (DxS kit). Tissue was also collected for EGFR FISH testing. Results: 60 pts were enrolled; median age, 65 years; 58% female, ECOG PS 0-1 (98%), and prior adjuvant chemotherapy (10%). Median number of cycles was 5 (range 1-22). At a median follow-up of 8.7 mos, the median TTP was 6.2 mos (95% CI: 3.7, 9.5), PFS 6.2 mos (95% CI 3.0, 9.0), 1 year OS 65.5% (95% CI 44.8%, 80%). 23 pts (38%) had partial responses (PR); the disease control rate (PR + proportion with stable disease) was 68%. Treatment-related toxicity (TRT) included (all grades) nausea (38%), fatigue (30%), rash (30%), and mucositis (23%). Severe (grade 3/4) TRT in > 2 pts included: thrombocytopenia (11%), neutropenia (7%), and dehydration (5%). There were no treatment-related deaths. EGFR mutation and FISH analyses will be presented. Conclusions: The addition of panitumumab to carboplatin and pemetrexed in the first-line treatment of advanced KRAS WT NSCLC was safe and well-tolerated; the median TTP of 6.2 mos met the primary endpoint. Definitive assessment of the value of panitumumab in this setting requires a randomized trial. Clinical trial information: NCT01042288.

A community-based program for personalized cancer care using next-generation sequencing (NGS)

11102

Background: Despite growing interest and need, molecular profiling of tumor samples is largely unavailable in community cancer centers, where nearly 80% of cancer patients (pts) are treated. In 10/12, Sarah Cannon Research Institute (SCRI) launched a community-based molecular profiling program to: 1) better understand the molecular constituency of cancer patients, 2) identify appropriate pts for phase I and II clinical trials of targeted agents, and 3) identify pts with molecular abnormalities responsive to FDA-approved agents. Methods: Eligible pts consented to testing of available biospecimens, which were interrogated for alterations in 35 cancer-related genes using NGS (1000X average coverage) in a CLIA/CAP laboratory. Results were reported to the treating physician within 14 days and stored in a database to enable correlation with clinical outcomes. Results: As of 1/13, 209 pts had been enrolled with 84% having sufficient material for assay. At least 1 mutation was detected in 46% of tumors. Results in the 3 most commonly assayed tumor types are summarized (Table). Mutations for which there are FDA-approved targeted agents were found in 14 off-label tumors (EGFR 4, KIT 3, SMO 3, BRAF 2, HER2 2). 40 pts (27%) were subsequently enrolled in clinical trials; in 19 of these, assay results influenced clinical trial selection. Conclusions: This program provides molecular profiling data to community oncologists for clinical decision making. Experience to date indicates this information can be provided in a timely manner for incorporation into clinical practice. Profiling results will enable: 1) selection of pts with appropriate tumor targets for investigational targeted agents, 2) enhanced study enrollment, 3) evaluation of FDA approved targeted agents in off-label tumor types, and 4) correlation of treatment outcomes with patterns of tumor molecular abnormalities. [Table: see text]

Results of two phase I dose escalation studies of the oral heat shock protein 90 (Hsp90) inhibitor SNX-5422

2617

Background: SNX-5422 is a prodrug of SNX-2112, a highly potent, non-geldanamycin analog, HSP90 inhibitor with preclinical anti-tumor activity in multiple tumor models. These phase 1 studies were designed to evaluate safety and tolerability, determine dose limiting toxicities, maximum tolerated doses (MTDs), and describe pharmacokinetics of SNX-2112 and SNX-5422. Methods: Two phase 1, open-label, 3 + 3 dose-escalation studies evaluated SNX-5422 when given daily (QD) or every-other-day (QOD) during the first 30 days of treatment in patients (pts) with advanced solid tumors or lymphoma. Plasma concentrations of SNX-2112 and SNX-5422 were measured after the first and 11th (steady state) doses. Tumor assessments were performed every 8 weeks. Results: In both studies, pts received SNX-5422 QOD, 3 wks on/1 wk off, with doses ranging from 4 to 133 mg/m2 QOD. In one study, pts also received QD doses from 50 to 89 mg/m2, 3 wks on/1 wk off, and 50 mg/m2 QD continuously. Fifty-six pts (34M/22F; mean age 62 years) were enrolled. Treatment-related adverse events were mainly low grade (G), including diarrhea (64%), nausea (39%), vomiting (29%), fatigue (27%), abdominal pain (14%), and anorexia (14%). Reversible G 1 blurry vision, and G 1-2 blurry vision/vision darkening were reported by 1 pt on 100 mg/m2 QOD, and 4 pts treated with 50 to 89 mg/m2 QD. G 3 diarrhea was dose limiting in 2 of 3 pts (89 mg/m2 QD; 133 mg/m2 QOD). MTDs for the QOD and QD schedules were declared at100 mg/m2 and 67 mg/m2, respectively. The QD schedule was associated with higher incidences of treatment related adverse events. 38 pts were evaluable for response including 1 confirmed durable complete response, 1 unconfirmed partial response, and 17 with stable disease. Activity was seen in adrenal, lung, liver, neuroendocrine, GIST, and prostate. All but 2 were seen with the QOD schedule. Conclusions: SNX-5422 mono-therapy was generally well tolerated and showed promising signs of efficacy in pts with advanced solid tumors. Given the superior benefit-risk profile of QOD dosing over QD dosing based on these preliminary clinical findings, 100 mg/m2 QOD has been selected for further clinical testing. Clinical trial information: NCT00506805 and NCT01611623.

BOLERO-6: Phase II study of everolimus plus exemestane versus everolimus or capecitabine monotherapy in HR+, HER2- advanced breast cancer

TPS660

Background: Everolimus (EVE), an orally bioavailable inhibitor of the mammalian target of rapamycin (mTOR), has shown clinical activity as monotherapy and in combination with endocrine therapy (ET) in hormone-receptor–positive (HR+; estrogen and/or progesterone receptors) advanced breast cancer (ABC). In a pivotal phase 3 trial in patients with HR+ ABC progressing on ET, EVE + exemestane (EXE) significantly prolonged median progression-free survival (PFS) vs EXE alone per local (7.8 vs 3.2 months; log-rank P<.0001) or central (11.0 months for EVE+EXE vs 4.1 months for EXE alone; log-rank P<.0001) assessment. Capecitabine, an orally administered fluoropyrimidine carbamate indicated as monotherapy in paclitaxel and/or anthracycline-refractory ABC, has shown clinical benefit in patients with HR+, human epidermal growth factor receptor 2-negative (HER2-) ABC. The BOLERO-6 study in patients with HR+, HER2- ABC progressing on prior anastrozole or letrozole will compare PFS following EVE+EXE combination therapy vs EVE or capecitabine monotherapy. Methods: In this multicenter, open-label, randomized, 3-arm, phase 2 study, 300 patients will be randomized to receive either EVE (10 mg/d) + EXE (25 mg/d) combination therapy, or EVE (10 mg/d) alone, or capecitabine (1,250 mg/m2twice daily for 14 d/3-wk cycle) alone, until disease progression. Patients will be stratified based on the presence of visceral disease. Key eligibility criteria include age ≥18 years, postmenopausal status; histologic or cytologic confirmation of estrogen-receptor–positive, HER2- ABC; radiologic or objective evidence of recurrence or progression on prior aromatase inhibitors; Eastern Cooperative Oncology Group (ECOG) performance status ≤2. The primary endpoint is PFS with EVE+EXE vs EVE, based on local radiologic assessment (Response Evaluation Criteria in Solid Tumors [RECIST] 1.1). The key secondary endpoint is PFS with EVE+EXE vs capecitabine. Other secondary endpoints include overall survival, objective response rate, clinical benefit rate, safety, quality of life, and patient satisfaction with treatment. Enrollment will start in Q1 2013. Estimated study completion in Q1 2015. Clinical trial information: NCT01783444.

Safety, pharmacokinetics, and pharmacodynamics of the DR5 antibody LBY135 alone and in combination with capecitabine in patients with advanced solid tumors

PURPOSE

We evaluated the safety, maximum tolerated dose (MTD), pharmacokinetics, pharmacodynamics, biologic activity, and antitumor efficacy of the DR5 antibody, LBY135 ± capecitabine.

EXPERIMENTAL DESIGN

Escalating LBY135 was administered every 21 days, alone (Arm1) or with capecitabine (Arm2), to patients with advanced solid tumors.

RESULTS

In Arm1 (n = 40), LBY135 (0.3-40 mg/kg) resulted in no dose-limiting toxicities (DLTs); adverse events (AEs) included fatigue, hypotension, abdominal pain, dyspnea, and nausea. Stable disease (SD) was observed in 21/38 (55.3 %) patients. In Arm2 (n = 33), LBY135 (1-40 mg/kg) plus capecitabine resulted in 3 DLTs (each grade 3): dehydration and mucosal inflammation (1 mg/kg), colitis (20 mg/kg), and diarrhea (40 mg/kg). AEs included fatigue, nausea, dyspnea, and vomiting. Partial response was observed in 2 patients (rectal and breast cancer) and SD in 12/27 (44.4 %) patients. Mean elimination half-life of LBY135 ± capecitabine at saturation of clearance (≥10 mg/kg) ranged between 146 h and 492 h. Immunogenicity was detected in 16/73 (22 %) patients, of which 6 patients experienced reduced LBY135 exposure with repeat dosing. M30/M65 levels were not predictive for LBY135 response. FDG-PET responses were not consistently associated with RECIST responses.

CONCLUSIONS

LBY135 was well tolerated up to 40 mg/kg, the maximal dose administered; no MTD for LBY135 ± capecitabine was defined. Clearance was saturated at doses ≥10 mg/kg.

Abstract LB-86: Preliminary results from an ongoing phase I trial of RRx-001, a tumor selective cytotoxic agent

Background and objectives: RRx-001, is the first member of a new class of anticancer compounds that binds to hemoglobin and drives heme and iron-catalyzed redox reactions under hypoxic conditions thereby enhancing oxidative and nitrosative stress in cancer cells through glutathione depletion and the generation of high local concentrations of nitric oxide. The objectives of this Phase 1 dose-escalation trial were to investigate safety, dose-limiting toxicities (DLTs), pharmacodynamics and pharmacokinetics (PK) of RRx-001.

Methodology: Eligible patients had advanced solid tumor malignancies; ECOG PS 0-2; adequate bone marrow function. In a 3+3 escalation design, RRx-001 was administered intravenously (IV) for up to 6 hours weekly for 8 weeks to patients with advanced cancer in successive dose-escalating cohorts. PK samples were collected. Tumor response (CT, PET-CT, biopsy) was determined every 4 or 8 weeks.

Preliminary Data: 19 pts have been dosed over 5 successive cohorts (10, 16.7, 24.6, 33 and 55 mg/m2). Tumor types included pancreas (3), colorectal (9), head and neck (2), melanoma (1), cholangiocarcinoma (1), uterine (1), lung (1) and HCC (1). RRx-001 has been extremely well tolerated with no DLTs or treatment-associated SAEs observed. The only drug-related adverse event (AEs) across all cohorts was acute and transient injection-site vasodilation and pain on infusion, moderate in severity and generally managed with lengthening of the infusion time, using peripheral venous access and prior administration of corticosteroids. No RRx-001-induced systemic toxicities have been observed to date.

14 patients were evaluable for response, 1 with partial response (parotid tumor). Eight patients had stable disease (3 pancreas, 3 with colorectal cancer, 1 uterine, 1 HCC). Two of these pts (salivary and CRC) have remained stable for 6 and 10 months, respectively, and another 2 pts (uterine and HCC) are continuing stably on trial for &gt;3 months. The pt. with CRC who progressed after 10 months on trial responded to previously failed chemotherapy as evidenced by marked decrease in CEA (511 to 311) and re-stabilization of disease for &gt;3 months. Two patients with pancreatic and CRC had an increase in tumor size with extensive central necrosis suggestive of pseudoprogression.

Conclusions: In the ongoing nearly completed Phase 1 trial, RRx-001, an anticancer agent with a novel structure and mechanism of action, is well tolerated with infusion-site pain the only observed AE. Toxicities normally associated with anticancer agents were absent. Single agent activity with a high response rate (64-79%) among patients with advanced, refractory cancer was observed including a renewed response to a previously failed chemotherapy regimen. Phase 2 planning in colorectal cancer and HCC is underway.

Citation Format: Tony Reid, Jeffrey R. Infante, Asit Paul, Howard A. Burris, Bryan Oronsky, Curtis Scribner, Susan Knox, Janet Stephens, John Santini, Jan Scicinski. Preliminary results from an ongoing phase I trial of RRx-001, a tumor selective cytotoxic agent. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-86. doi:10.1158/1538-7445.AM2013-LB-86

Abstract 4672: Phase I/II study of val-083 in patients with recurrent malignant glioma or secondary brain tumor

Background: Recurrent glial tumors of the brain remain one of the most challenging malignancies to treat. Median survival for patients with recurrent disease is approximately 6 months for glioblastoma multiforme (GBM), as front-line therapy temozolomide (TMZ) is subject to resistance by DNA repair protein O6-methylguanine-DNA methyltransferase (MGMT). VAL-083 represents a first-in-class bi-functional N7 DNA alkylating agent that readily crosses the blood-brain barrier and accumulates in brain tissue. Previously published pre-clinical and clinical studies suggest that VAL-083 has activity against a range of tumor types, including GBM. Furthermore, research shows that VAL-083 overcomes MGMT-driven drug resistance in vitro and has activity against cancer stem cells. Hence, the purpose of this Phase I/II study is to determine the safety and the maximal tolerated dose (MTD) of VAL-083 in patients with recurrent GBM or progressive secondary brain tumor, and to explore the pharmacokinetic properties and tumor responses to treatment.

Objectives Part 1:

1) Establish the dose-limiting toxicities (DLT) of VAL-083 and identify appropriate dose and dosing regimen of VAL-083

2) Assess the safety and characterize the toxicities associated with VAL-083

3) Collect information about anti-tumor activity of VAL-083

Objectives Part 2:

4) Confirm the safety and tolerability of the chosen dose/dosing regimen in a larger number of patients

5) Obtain preliminary evidence of anti-tumor activity in GBM, as measured by response rate and progression free survival

Methods: An open-label, single arm Phase I/II dose-escalation study designed to evaluate the safety, tolerability, pharmacokinetics and anti-tumor activity of VAL-083 in patients with i) histologically confirmed initial diagnosis of primary WHO Grade IV malignant GBM, now recurrent, or ii) progressive secondary brain tumor, having failed standard brain radiotherapy, and with brain tumor progression after at least one line of systemic therapy. The study utilizes a 3 + 3 dose escalation design, until the MTD or the maximum specified dose is reached. Patients receive VAL-083 intravenously at the assigned dose on days 1, 2, and 3 of each 21-day treatment cycle. In Phase II, additional patients will be treated at the MTD (or other selected optimum Phase II dose) to measure tumor responses. All patients enrolled have previously been treated with surgery and/or radiation, if appropriate, and must have failed both bevacizumab and TMZ, unless contraindicated. Results (study ongoing): Cohort 1 (3 patients) and cohort 2 (4 patients) were completed without reaching DLT and no drug-related adverse effects (AEs) were detected. 28.5% (2/7 patients) show stable disease or tumor regression in response to VAL-083 treatment as assessed by regular MRI scans and check-ups. Cohort 3 currently has 1 patient enrolled without reaching DLT. ClinicalTrials.gov Identifier: NCT01478178

Citation Format: Dennis M. Brown, Jeffrey A. Bacha, William J. Garner, Kent C. Shih, Howard A. Burris, Richard Schwartz. Phase I/II study of val-083 in patients with recurrent malignant glioma or secondary brain tumor. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4672. doi:10.1158/1538-7445.AM2013-4672

Abstract LB-193: Phase I study of safety, tolerability, pharmacokinetics, and pharmacodynamics of AMP-224 (B7-DC Fc fusion protein) in a regimen containing cyclophosphamide (CTX) in patients with advanced solid tumors

Background: AMP-224 is a recombinant Fc fusion protein that binds to the programmed death-1 (PD-1) receptor. This first-in-human study was designed to determine the safety, tolerability, maximum tolerated dose (MTD), pharmacokinetic (PK) profile, pharmacodynamics (PD), and preliminary anti-tumor activity of AMP-224. Additional translational studies were incorporated to characterize MOA in patients and identify possible prognostic indicators and markers of response.

Methods: Cohorts of 3-6 eligible patients with advanced solid tumors received CTX on Day 0, followed by AMP-224 by intravenous (IV) infusion on Days 1 and 15 of each 28-day cycle in doses ranging from 0.3 to 30mg/kg. Following dose escalation, an expansion cohort is ongoing at 10 mg/kg in predominantly melanoma patients. Fresh pre-treatment biopsies were obtained from patients and evaluated via IHC for B7-H1 (PD-L1), PD-1, CD8 and CD4. PD testing performed throughout the study included serial blood samples to assess lymphocyte subsets, expression of PD-1 on T cells and changes in T cell effector function.

Results: 42 patients (83% melanoma), were treated in cohorts of 0.3mg/kg (n = 6); 1mg/kg (n=4); 3mg/kg (n = 4); 10mg/kg (n = 21); 30mg/kg (n = 6), mean age 56 years. Two dose-limiting toxicities were observed, 1 each at 10 mg/kg (infusion reaction) and 30 mg/kg (flu-like symptoms). Infusion reactions were common (61%) across all doses but manageable with pre-medications. Common treatment-related adverse events (all grades) were chills (54%), fatigue (34%) flushing (34%), nausea (32%), vomiting (29%), fever (27%), and headache (22%). No drug-related inflammatory adverse events were identified. Preliminary PK analysis showed that exposures of AMP-224 were linear, dose-proportional with no evidence of target mediated clearance or accumulation. PD assays confirmed PD-1 receptor targeting with specific reduction of PD-1HI CD4 and PD-1HI CD8 T cells in a dose dependent manner. B7-H1+ tumors were found in fresh pre-treatment tumor biopsies in 31.4% of patients, yet B7-H1 expression within the tumor did not predict AMP-224 clinical activity. The trial is ongoing and the preliminary evaluation of clinical activity suggests individual patients with partial response, stable disease, and mixed response.

Conclusions: AMP-224 was well-tolerated up to its maximally administered dose of 30mg/kg, with manageable infusion reactions in the majority of patients. The trial is ongoing including monitoring for clinical activity.

Citation Format: Patricia M. LoRusso, John Powderly, Howard A. Burris, Muaiad Kittaneh, Jessica Grice, James F. Smothers, Sara Brett, Margaret Fleming, Rena J. May, Shannon Marshall, Martin Devenport, Stanley Pillemer, Drew M. Pardoll, Lieping Chen, Solomon Langermann, Jeffrey Infante. Phase I study of safety, tolerability, pharmacokinetics, and pharmacodynamics of AMP-224 (B7-DC Fc fusion protein) in a regimen containing cyclophosphamide (CTX) in patients with advanced solid tumors. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-193. doi:10.1158/1538-7445.AM2013-LB-193