Gavin Choy

The Novel, Small-Molecule DNA Methylation Inhibitor SGI-110 as an Ovarian Cancer Chemosensitizer

Purpose: To investigate SGI-110 as a “chemosensitizer” in ovarian cancer and to assess its effects on tumor suppressor genes (TSG) and chemoresponsiveness-associated genes silenced by DNA methylation in ovarian cancer. Experimental Design: Several ovarian cancer cell lines were used for in vitro and in vivo platinum resensitization studies. Changes in DNA methylation and expression levels of TSG and other cancer-related genes in response to SGI-110 were measured by pyrosequencing and RT-PCR. Results: We demonstrate in vitro that SGI-110 resensitized a range of platinum-resistant ovarian cancer cells to cisplatin (CDDP) and induced significant demethylation and reexpression of TSG, differentiation-associated genes, and putative drivers of ovarian cancer cisplatin resistance. In vivo, SGI-110 alone or in combination with CDDP was well tolerated and induced antitumor effects in ovarian cancer xenografts. Pyrosequencing analyses confirmed that SGI-110 caused both global (LINE1) and gene-specific hypomethylation in vivo, including TSGs (RASSF1A), proposed drivers of ovarian cancer cisplatin resistance (MLH1 and ZIC1), differentiation-associated genes (HOXA10 and HOXA11), and transcription factors (STAT5B). Furthermore, DNA damage induced by CDDP in ovarian cancer cells was increased by SGI-110, as measured by inductively coupled plasma-mass spectrometry analysis of DNA adduct formation and repair of cisplatin-induced DNA damage. Conclusions: These results strongly support further investigation of hypomethylating strategies in platinum-resistant ovarian cancer. Specifically, SGI-110 in combination with conventional and/or targeted therapeutics warrants further development in this setting. Clin Cancer Res; 20(24); 6504–16. ©2014 AACR.

Targeting PIM kinase activity significantly augments the efficacy of cytarabine

Drug resistance is a major cause of treatment failure for patients with acute myeloid leukaemia (AML) and novel strategies that circumvent resistance mechanisms are urgently needed (Swords et al, 2010). The PIM kinases (PIM1, PIM2, PIM3) are a small family of proto-oncogenes within the CAMK superfamily that are frequently overexpressed in many forms of cancer including AML. PIM kinases have essential roles in the regulation of signal transduction cascades that promote cell survival, proliferation, and drug resistance (Amaravadi & Thompson, 2005; Giles, 2005; Nawijn et al, 2011). However, the specific roles of PIM kinases as regulators of AML pathogenesis and of the sensitivity to standard agents utilized in AML therapy remain to be fully elucidated. SGI-1776 is novel small molecule inhibitor of PIM kinase activity that has demonstrated preclinical activity in cancer models and has entered Phase I clinical trials (Chen et al, 2009; Mumenthaler et al, 2009). Considering the roles of the PIM kinases in the regulation of cell survival and proliferation and their high basal expression in AML cells, we hypothesized that SGI-1776 would possess significant anti-leukaemic activity in AML models. We first investigated the in vitro efficacy of SGI-1776 in a panel of nine human AML cell lines (Fig 1A). Treatment of AML cells with SGI-1776 led to a dose-dependent reduction in viability, impaired clonogenic survival (Fig 1B), and apoptotic cell death (Fig 1C, D). These effects were associated with a significant reduction in the phosphorylation of the PIM kinase substrate and apoptotic regulator Bad (Ser112), an event that increases its pro-apoptotic function. The drug-related reduction in Bad phosphorylation did not appear to be due to alterations in AKT activity as SGI-1776 treatment did not significantly affect the phosphorylation of AKT (Thr308) in MV4-11 cells, which have constitutive AKT activity (Fig 1E). Approximately 30% of patients with AML have constitutive fms-like tyrosine kinase-3 (FLT3) activity due to internal tandem duplication (ITD) or activating mutations. Considering that in vitro kinase activity screens with SGI-1776 and other PIM kinase inhibitors have demonstrated some offtarget inhibition of FLT3, we utilized MV4-11 cells with stable FLT3 knockdown to investigate whether these potential off-target effects were a critical factor underlying the antileukaemic activity of SGI-1776 (Swords et al, 2010). FLT3 knockdown caused a modest reduction in sensitivity to SGI1776 (Fig 1F), indicating that FLT3 inhibition contributes to the efficacy of SGI-1776, but is not its primary mechanism of action in AML. Several recent studies have suggested a mechanistic link between aberrant expression of PIM kinases and reduced sensitivity to certain anticancer agents (Xie et al, 2006, 2010). To address this issue in a manner relevant to AML therapy, we evaluated the expression levels of PIM1, PIM2, and PIM3 in paired HL-60 cells that are sensitive and resistant to cytarabine (ara-C). Our results showed that the levels of PIM1 and PIM3, but not PIM2, were significantly higher in ara-C-resistant HL60 cells (Fig 2A, B). Consistent with this observation, ara-C treatment led to increased PIM1 and PIM3 expression as assessed by immunoblotting (MOLM-13 cells, Fig 2C) and quantitative reverse transcription polymerase chain reaction (RT-PCR) (MOLM-13 cells and primary AML blasts, Fig 2D). We next investigated whether inhibiting PIM kinase signalling with SGI-1776 could augment the efficacy of ara-C. Treatment of AML cells with the combination of ara-C and SGI-1776 led to significantly greater diminished viability and inhibition of clonogenic survival over what was achieved by either single agent (Fig 2E, F). Propidium iodide/fluorescence-activated cell sorting (PI/FACS) analysis of the effects of SGI-1776, ara-C, and the combination of these agents on cell cycle distribution showed that SGI-1776 promoted the accumulation of cells with G1 DNA content (Fig 2G). HL-60 ara-C sensitive and resistant cells were utilized to investigate whether targeting PIM kinase activity with SGI1776 could be used as a strategy to overcome intrinsic ara-C resistance. Our results showed that SGI-1776 partially restored the sensitivity of ara-C resistant cells to ara-C (Fig 2H), indicating that ara-C resistance is a multifaceted problem with multiple underlying mechanisms including PIM overexpression (Fig 2A, B). Additionally, our findings show that abrogating PIM kinase activity could possibly be utilized as a novel approach to improve the therapeutic efficacy of ara-C including in circumstances of de novo ara-C resistance. In order to further investigate the therapeutic utility of this combination, we established AML xenografts in nude mice using the MOLM-13 AML cell line. Mice were randomized into groups of 10 and were administered vehicle, ara-C, SGI1776, or ara-C and SGI-1776 for 21 d. Treatment with the combination of these two agents was well tolerated and significantly increased the efficacy of single agent ara-C therapy (Fig 2I, J). Immunohistochemical analyzes of tumours from mice revealed that SGI-1776 significantly diminished Bad phosphorylation and cooperated with ara-C in vivo to promote correspondence

Targeting PIM kinase enhances the activity of sunitinib in renal cell carcinoma

Background:Upregulation of PIM kinase expression has been reported in many malignancies, suggesting that inhibition of PIM kinase activity may be an attractive therapeutic strategy. We hypothesised that inhibition of PIM kinase activity with SGI-1776, a novel small molecule inhibitor of PIM kinase activity, would reduce the viability of renal cell carcinoma (RCC) cells and enhance the activity of sunitinib.Methods:Immunoblotting, qRT–PCR, and gene expression arrays were carried out to identify genes modulated by SGI-1776 treatment. The anticancer activity of SGI-1776 and sunitinib was determined by viability and apoptosis assays and in tumour xenografts in vivo.Results:Treatment with SGI-1776 led to a decrease in phosphorylated and total c-Myc levels, which resulted in the modulation of c-Myc target genes. SGI-1776 in combination with sunitinib induced a further reduction in c-Myc levels, which was associated with enhanced anticancer activity. siRNA-mediated knockdown of c-Myc demonstrated that its expression has a key role in regulating the sensitivity to the combination of SGI-1776 and sunitinib. Importantly, the combination significantly reduced tumour burden in two RCC xenograft models compared with single-agent therapy and was very well tolerated.Conclusion:These data indicate that targeting PIM kinase signalling is a promising treatment strategy for RCC.

Abstract 2320: Clinical epigenetic resensitization of platinum-resistant, recurrent ovarian cancer patients with SGI-110, a novel, second-generation, subcutaneously administered hypomethylating agent (HMA)

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA Background: Epigenetic changes have been implicated in acquired resistance to platinum. SGI-110 is a second generation SQ HMA with improved pharmaceutical properties compared to decitabine. Here we report the clinical results and pharmacodynamic analyses of the phase 1 study of SGI-110 in combination with carboplatin in patients with recurrent platinum resistant high-grade serous, epithelial ovarian cancer (EOC), primary peritoneal carcinoma (PPC) or fallopian tube (FT) cancer. Methods: SGI-110 was administered SQ QD x 5 followed by carboplatin IV on Day 8 of a 28-day cycle. Patients were required to have either measurable disease according to RECIST v1.1 or detectable disease (modified Rustin) with clinical response assessed using the applicable criteria. Safety assessments were graded using CTCAE v4. Results: Twenty patients (18 EOC, 1 PPC, 1 FT) were enrolled and treated in the phase 1 portion of the trial. Median age was 55.8 years (38-72); ECOG PS of 0/1/2 was 10/10/0, respectively. Median number of prior regimens was 7 (1-9). The starting doses were SGI-110 45 mg/m2 SQ QD x 5 and carboplatin AUC5 in the first cohort of 6 patients. Four DLTs of myelosuppression (neutropenia and thrombocytopenia) in the first cohort led to dose reduction to SGI-110 30 mg/m2 and carboplatin AUC4 with granulocyte-CSF permitted at the discretion of the physician. No DLTS were observed in 14 patients and this dose was recommended for the subsequent phase 2 study. Grade 3/4 AEs regardless of relationship to the combination ≥ 10% included anemia, leukopenia, neutropenia, thrombocytopenia, nausea, vomiting, constipation, small intestinal obstruction, infusion related reaction and pulmonary embolism. Three PRs and 9 SDs as best response were observed in 20 patients for an overall response rate and clinical benefit rate of 15% and 60%, respectively. All PRs and 3 SDs were accompanied by CA-125 decrease. LINE-1 hypomethylation, a marker of global DNA methylation, was recorded in PBMCs with SGI-110 30 mg/m2 (avg: -19.5%, n=14) and 45 mg/m2 (avg: -17.4%, n=6). Gene specific methylation of RASSF1A and BRCA-1 measured by pyrosequencing was significantly decreased at C2D8 compared to baseline in paired tumor biopsies/ascites (n=9). Gene re-expression measured by quantitative RT-PCR was observed in tumor biopsies. Conclusions: Priming treatment with SGI-110 prior to carboplatin induced clinical responses in a heavily-pretreated platinum resistant ovarian cancer population with expected and manageable safety profile. Potent LINE-1 demethylation and demethylation and re-expression of silenced tumor genes were recorded. The phase 2 portion of the trial is currently ongoing with patients randomized to either the RP2D dose combination or a physician choice of 1 of 4 treatment options (topotecan; liposomal doxorubicin; weekly paclitaxel; or weekly gemcitabine). Citation Format: Gini Fleming, Sharad Ghamande, Yvonne Lin, Angeles Alvarez Secord, John Nemunaitis, Merry-Jennifer Markham, Kenneth Nephew, Fang Fang, Shweta Gupta, Sue Naim, Gavin Choy, Simone Jueliger, Pietro Taverna, Yong Hao, Harold Keer, Mohammad Azab, Daniela Matei. Clinical epigenetic resensitization of platinum-resistant, recurrent ovarian cancer patients with SGI-110, a novel, second-generation, subcutaneously administered hypomethylating agent (HMA). [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2320. doi:10.1158/1538-7445.AM2014-2320

Abstract LB-214: Interim results from a randomized Phase 1-2 first-in-human (FIH) study of PK/PD guided escalating doses of SGI-110, a novel subcutaneous (SQ) second generation hypomethylating agent (HMA) in relapsed/refractory MDS and AML

SGI-110 is a novel second generation HMA, formulated as a low volume SQ injection. It is designed as a dinucleotide incorporating decitabine and guanosine, to prolong in vivo exposure and potentially improve efficacy of its active component, decitabine by protecting decitabine from rapid deamination by cytidine deaminase. Preclinically, SGI-110 demonstrated potent activity in-vivo using different routes of administration. A randomized Phase 1-2 FIH PK/PD-guided, dose-escalation study is being conducted in subjects with relapsed/refractory intermediate or high-risk MDS or AML. The objective of the first stage of the study is to determine the safety and tolerability of SGI-110 and to establish the MTD and the biologically effective dose (BED). Subjects are randomized to one of two SQ regimens (daily x5 or once weekly x3, both given in 28-day courses). PD is evaluated by LINE-1 global DNA hypomethylation. The second stage of the study will be a randomized Phase 2 dose expansion, once the BED and MTD have been determined. Currently, 5 dose-cohorts have been fully enrolled, (n= 55) at doses ranging from 3mg/m2 to 60 mg/m2 daily x5, and 6mg/m2 to 90 mg/m2 weekly x3 but are not yet fully evaluable. PK guidance has allowed rapid dose escalation, and PD assessment of global hypomethylation has been correlated with increased dose and exposure levels. Apart from manageable local injection site pain, SGI-110 has been well tolerated. Other AE9s were neutropenia, thrombocytopenia, or anemia. There have been 3 remissions in relapsed AML subjects: 1 CR with weekly (60mg/m2) and 1 PR and 1 CR with daily (36 and 60 mg/m2 respectively). The PK profile showed efficient conversion of SGI-110 to decitabine achieving exposures in the therapeutic range as predicted from the SGI-110 rational design, characterized by decitabine AUC in therapeutic range (cohorts 4-5), lower Cmax, and longer effective half life, as compared to historical data based on molar equivalent doses of IV decitabine. Dose-dependent hypomethylation induction in the first 5 cohorts was observed. The subject who achieved a CR had the highest degree of hypomethylation induction of all subjects tested to date, and also the highest decitabine AUC in the cohort. Updated efficacy, safety, PK, and PD data of both regimens will be presented. SGI-110 is safe and well tolerated to date; biologically effective and therapeutic dose levels have been achieved with little toxicity so far with both regimens. Preliminary efficacy (PR+CR) has been observed in relapsed AML subjects. The PK profile showed efficient conversion of SGI-110 to decitabine with achievable therapeutic exposures, longer apparent half life, and lower Cmax than predicted equivalent decitabine doses given IV. Global Hypomethylating effects were observed at all dose levels, evaluated to date with both regimens. The results justify the progress of the study to the second dose-expansion Phase 2 stage after establishing the BED and MTD. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-214. doi:1538-7445.AM2012-LB-214

Abstract B209: A self‐emulsifying lipid suspension formulation enhances oral bioavailability of MP‐470 in a randomized two‐way crossover study in healthy male subjects

Background: MP‐470 is an orally bioavailable multi‐targeted tyrosine kinase inhibitor specifically designed to be a potent inhibitor of mutant c‐Kit and PDGFR. MP‐470 is also active as an inhibitor of DNA repair following chemotherapy. MP‐470 has shown significant synergistic activity with DNA damaging chemotherapy in several xenograft models and in a phase I combination study. Oral bioavailability of this agent is limited by its solubility but not permeability. An in vitro/in vivo iterative approach was utilized preclinically for formulation selection. In the Beagle dog model, the oral bioavailability of MP‐470 is enhanced to a maximum of 4–5‐fold by formulating it in tocopherols and lipidic surfactants with self‐emulsification ability (5%, dry powder vs. 20%, lipid suspension). Results presented herein are from a randomized two‐way crossover pharmacokinetic (PK) study evaluating two formulations in healthy human subjects. Methods: Twelve healthy male subjects 18–45 years with a body mass index of 18–35 kg/m2 were randomized in a 1:1 ratio to receive either a 100 mg dry powder capsule or 90 mg (3 × 30 mg) lipid suspension capsules in a fasted condition with 240 mL of water. Subjects receiving MP‐470 90 mg lipid suspension capsules ingested all three capsules within one minute. The alternate formulation was administered after a 14 day washout. Plasma for PK assessments was collected and evaluated at pre‐dose through hour 48 post MP‐470 administration. Results: Comparative PK results from twelve subjects are summarized below. Additional information will be summarized in the final presentation. Conclusions: Solubility of the drug in the formulation vehicle alone plays a limited role in bioavailability enhancement; rather the ability of the formulation to keep the drug in solution after dilution in the GI tract seems critical. It is also possible that physiological mechanisms such as active transport or metabolism contribute to the enhanced absorption of MP‐470 in the tocopherol‐based vehicles. Consistent with preclinical Beagle dog data, the lipid suspension formulation offers an enhanced oral bioavailability over the dry powder formulation in healthy human subjects. The lipid suspension formulation will be utilized in future MP‐470 clinical studies. Citation Information: Mol Cancer Ther 2009;8(12 Suppl):B209.

Abstract 2095: A phase 2 study of Amuvatinib (MP-470), the first RAD51 inhibitor in combination with platinum-etoposide (PE) in refractory or relapsed small cell lung cancer (ESCAPE).

Proceedings: AACR 104th Annual Meeting 2013; Apr 6-10, 2013; Washington, DC Background: Amuvatinib is an oral multi-targeted TKI of c-Kit and PDGFRα and modulates DNA repair by down regulation of Rad51. Rad51 is a key protein in the homologous recombination repair pathway for DNA double strand breaks which can mediate resistance to DNA-damaging agents. Amuvatinib has demonstrated synergistic activity preclinically with DNA damaging chemotherapy agents including etoposide and doxorubicin. Amuvatinib in combination with DNA damaging agents resulted in clinical responses in SCLC patients, induced Rad51 suppression, and increased DNA damage (53BP1 foci) in skin punch biopsies. These results provided the justification for a Phase 2, OL study of amuvatinib in combination with platinum and etoposide (PE) chemotherapy in SCLC patients who have not responded to or relapsed after standard treatment (ESCAPE; TrEatment of Small Cell lung cancer with Amuvatinib in combination with Platinum Etoposide). Methods: Patients ≥ 18 years, ECOG PS 0-2, with confirmed SCLC who met one of the following major eligibility criteria were enrolled based on prior PE response: 1) disease progression during PE, 2) relapse ≤ 90 days, 3) SD as best response after at least 2 cycles. Patients who received second-line therapy were eligible if they met any one of these 3 conditions and all other study eligibility criteria. An optimal Simon 2-stage design was employed (α=10%, β=10%, p=10%, p1=25%). In Stage 1, 21 patients were to be enrolled and ≥ 3 confirmed responses (CR or PR) were required in order to proceed to Stage 2, where an additional 29 patients were to be enrolled. Amuvatinib was administered PO 300 mg TID. Results: Twenty-three patients, median age of 62 years (range, 44-80); 11 M/12 F; ECOG PS 0 (n=3), 1 (n=12), 2 (n=6), were enrolled in Stage 1 and received a median of two 21-day cycles (range, 1-10). At study entry, 9 (39%), 11 (48%), and 3 (13%) patients presented with disease progression, relapse ≤ 90 days, and SD after at least 2 cycles of PE, respectively. Per PIs assessment, 4 PRs and 7 SDs were observed as best response. Per RECIST 1.1, 2 PRs and 3 SDs were confirmed by follow-up scan ≥ 4 weeks apart for an overall clinical benefit rate (CBR) of 5/23 (22%). No CRs were observed. Grade 3/4 suspected amuvatinib related AEs were neutropenia, thrombocytopenia, atrial fibrillation, diarrhea, esophagitis, and hypercalcemia (1 patient each; 4%); hypokalemia and leukopenia, (2 patients each; 9%). By IHC, baseline expression of RAD51, ERCC1, Chk2, ATM, cKit, and RB will be evaluated and correlated with response. Conclusions: Amuvatinib demonstrated an overall CBR of 22% in refractory SCLC. While clinical activity was observed, the response rate in Stage 1 did not meet pre-specified study primary endpoint. The safety profile of amuvatinib is consistent with previous published reports of manageable toxicity with non-overlapping toxicities with PE chemotherapy. Citation Format: Lauren Byers, Leora Horn, Jitendra Gandhi, Goetz Kloecker, Taofeek K. Owonikoko, Saiama Waqar, Maciej J. Krzakowski, Gavin Choy, Nancy Cecchettini, Pietro Taverna, Amarpal Sahai, Mojtaba Noursalehi, Mohammad Azab, D. Ross Camidge. A phase 2 study of Amuvatinib (MP-470), the first RAD51 inhibitor in combination with platinum-etoposide (PE) in refractory or relapsed small cell lung cancer (ESCAPE). [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 2095. doi:10.1158/1538-7445.AM2013-2095

Abstract 2096: Bozitinib, a highly selective inhibitor of cMet, demonstrates robust activity in gastric, lung, hepatic and pancreatic in vivo models

Background: cMET is a receptor tyrosine kinase that is located on the cell surface and is activated by the binding of its ligand, hepatocyte growth factor (HGF). In cancer cells, MET can be aberrantly active and cause abnormal signaling, which leads to tumor growth, angiogenesis, and metastasis. In vitro studies have demonstrated that bozitinib (CBT-101, PLB-1001) is a highly selective and specific inhibitor (8 nM) of tumor cell proliferation. Methods: In-vivo PD studies of gastric (MKN45), lung (LUM858, LU1901, LU2503), hepatic (LIM0612, LIM0801), and pancreatic (KP4) were evaluated. These models covered both the HGF-dependent and HGF-independent mechanisms. Among these models, LUM858, LU1901, LU2503, LIM0612 and LIM0801 are PDX models. In particular, in the LU1901 model, bozitinib (BT) was compared to capmatinib (INC280). Groups included: BT at 1, 3 and 10 mg/kg QD×21 and INC280 at 1, 3, and 10 mg/kg QD×21 and 10 mg/kg BID×21 via IG, CDDP 5 mg/kg, Q7D×3 as a positive control via IP and the vehicle control (QD×21 via IG). Each group (n=8 mice) and the tumor volume was evaluated on D21. Results: In MKN45, LU2503, LIM0612 and LIM0801, the effect of BT seemed superior than that of crizotinib; in LUM858, its effect was higher than that of erlotinib; in LU1901, its effect was higher than that of crizotinib and INC280. In the LU1901 model, the strongest activity was observed at BT 10 mg/kg with a T/C ratio of 2%, compared to an equi-dose of INC280 (T/C of 22%). All doses of BT and INC280 were well tolerated; no mouse experienced weight loss. In MKN45 model, BT showed a PK/PD correlation and dose-dependence. BT inhibited the phosphorylation of c-Met protein; the rate of target inhibition exceeded 90% at >7 mg/kg. The plasma concentration for BT decreased over time with a significant decrease 16h after its administration, conferring at least 16h of phosphorylation inhibition of the c-Met protein. Conclusions: In conclusion, BT was well-tolerated, with no animal death nor major weight loss. The in vivo experiments demonstrated that BT is a viable candidate with effective anti-tumor activities. BT is currently under evaluation in cMet dysregulated NSCLC (NCT02896231) with additional trials planned. Citation Format: Joe Shih, Boyu Zhong, Hepeng Shi, David Xue, Gavin S. Choy, Sanjeev Redkar. Bozitinib, a highly selective inhibitor of cMet, demonstrates robust activity in gastric, lung, hepatic and pancreatic in vivo models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2096. doi:10.1158/1538-7445.AM2017-2096

Effect of novel peptide vaccines on secondary recurrences and survivorship.

e274 Background: According to the NCI Office of Cancer Survivorship, in 2014, it is estimated there are 14.5 million cancer survivors in the US. By 2024, it is projected there will be 19 million cancer survivors. Peptide-based vaccines are being developed to prevent recurrence in cancer patients following standard of care and increase survivorship by inducing immune responses using antigenic epitopes derived from tumor associated antigens. Two peptide vaccines, nelipepimut-S, a HLA-A2/A3-restricted immunogenic peptide derived from the HER2 protein and E39, a HLA-A2-restricted, folate binding protein (FBP) derived peptide, are being developed to prevent breast cancer and gynecological cancers recurrence, respectively. METHODS Early phase dose finding clinical trials results for both agents have been previously reported by Mittendorf et al. (2014) and Greene et al. (2015). Both agents are concomitantly administered with GM-CSF in the adjuvant setting. Toxicity was monitored and recurrences were documented. Disease free survival (DFS) was analyzed by Kaplan-Myers curves and groups were compared by log-rank test. RESULTS In the nelipepimut-S Phase 1/2 trial, 97 patients were enrolled in the node positive group. The reported 3-year DFS was 100% in the optimally dosed (1000 mcg vaccine + 250 mcg GM-CSF) vaccinated group vs. 77.8% in the control (p = 0.035, n = 45). In the E39 Phase 1/2 trial, with 9.8 months median follow-up, among optimally dosed (1000 mcg), there is only one recurrence (6.7% vs. 5I% CG, p = 0.01). The 2-year DFS estimate is 19.2% (CG) vs. 85.7% (1000 mcg) (p = 0.09). Nelipepimut-S and E39 were well tolerated. CONCLUSIONS Preliminary results from both Phase 1/2 trials indicate these peptide vaccines derived from the HER2 protein and FBP may be administered chronically, thereby preventing recurrence and increase survivorship in patients with breast, ovarian, and endometrial cancers. Nelipepimut-S is currently being investigated in three ongoing adjuvant clinical trials - 1) single agent in a registrational Phase 3, PRESENT, under a FDA-approved SPA; 2) combination with trastuzumab in IHC 1+/2+ and IHC 3+. Early results of E39 are encouraging and a Phase 2b is being planned in gynecological malignancies. CLINICAL TRIAL INFORMATION NCT00841399, NCT00584789.

An observational study evaluating the expression of HER2 (1+, 2+, and 3+) with HLA A2/A3+ in gastric adenocarcinoma patients.

18 Background: Gastric cancer remains a major health issue and results in 800,000 annual deaths worldwide. Despite approximately 50% of the gastric and gastroesophageal (GE) junction adenocarcinomas are diagnosed with resectable disease, 40% of disease recurrence is observed in 24 months. While trastuzumab has shown to increase overall survival in HER2 IHC3+ metastatic disease, no current therapies are available for low expressing, or IHC 1+ or 2+ patients. NeuVax (nelipepimut-S) is an immunogenic peptide epitope derived from the extracellular domain of HER2/nu protein administered in combination with rhGM-CSF. NeuVax binds to HLA-A2 and A3 on tumor and antigen presenting cells (APC) and elicits a proliferation of CD8+ (cytotoxic) T-cell immune response against HER2 expressing cancer cells. A proof of concept clinical study will be conducted to assess the effectiveness of nelipepimut-S to prevent recurrence and increase disease free survival in gastric cancer patients with all levels of HER2 expression wi...