First-in-human phase I dose escalation trial of the first-in-class tumor microenvironment modulator VT1021 in advanced solid tumors

BACKGROUND

VT1021 is a cyclic peptide that induces the expression of thrombospondin-1 (TSP-1) in myeloid-derived suppressor cells (MDSCs) recruited to the tumor microenvironment (TME). TSP-1 reprograms the TME via binding to CD36 and CD47 to induce tumor and endothelial cell apoptosis as well as immune modulation in the TME.

METHODS

Study VT1021-01 (ClinicalTrials.gov ID NCT03364400) used a modified 3 + 3 design. The primary objective was to determine the recommended Phase 2 dose (RP2D) in patients with advanced solid tumors. Safety, tolerability, and pharmacokinetics (PK) were assessed. Patients were dosed twice weekly intravenously in 9 cohorts (0.5-15.6 mg/kg). Safety was evaluated using CTCAE version 5.0 and the anti-tumor activity was evaluated by RECIST version 1.1.

RESULTS

The RP2D of VT1021 is established at 11.8 mg/kg. VT1021 is well tolerated with no dose-limiting toxicities reported (0/38). The most frequent drug-related adverse events are fatigue (15.8%), nausea (10.5%), and infusion-related reactions (10.5%). Exposure increases proportionally from 0.5 to 8.8 mg/kg. The disease control rate (DCR) is 42.9% with 12 of 28 patients deriving clinical benefit including a partial response (PR) in one thymoma patient (504 days).

CONCLUSIONS

VT1021 is safe and well-tolerated across all doses tested. RP2D has been selected for future clinical studies. PR and SD with tumor shrinkage are observed in multiple patients underscoring the single-agent potential of VT1021. Expansion studies in GBM, pancreatic cancer and other solid tumors at the RP2D have been completed and results will be communicated in a separate report.

Avelumab or talazoparib in combination with binimetinib in metastatic pancreatic ductal adenocarcinoma: dose-finding results from phase Ib of the JAVELIN PARP MEKi trial

BACKGROUND

Combinations of avelumab [anti-programmed death-ligand 1 (anti-PD-L1)] or talazoparib [poly(adenosine diphosphate ribose) polymerase (PARP) inhibitor] with binimetinib (MEK inhibitor) were expected to result in additive or synergistic antitumor activity relative to each drug administered alone. Here, we report phase Ib results from JAVELIN PARP MEKi, which investigated avelumab or talazoparib combined with binimetinib in metastatic pancreatic ductal adenocarcinoma (mPDAC).

PATIENTS AND METHODS

Patients with mPDAC that had progressed with prior treatment received avelumab 800 mg every 2 weeks plus binimetinib 45 mg or 30 mg two times daily (continuous), or talazoparib 0.75 mg daily plus binimetinib 45 mg or 30 mg two times daily (7 days on/7 days off). The primary endpoint was dose-limiting toxicity (DLT).

RESULTS

A total of 22 patients received avelumab plus binimetinib 45 mg (n = 12) or 30 mg (n = 10). Among DLT-evaluable patients, DLT occurred in five of 11 patients (45.5%) at the 45-mg dose, necessitating de-escalation to 30 mg; DLT occurred in three of 10 patients (30.0%) at the 30-mg dose. Among patients treated at the 45-mg dose, one (8.3%) had a best overall response of partial response. Thirteen patients received talazoparib plus binimetinib 45 mg (n = 6) or 30 mg (n = 7). Among DLT-evaluable patients, DLT occurred in two of five patients (40.0%) at the 45-mg dose, necessitating de-escalation to 30 mg; DLT occurred in two of six patients (33.3%) at the 30-mg dose. No objective responses were observed.

CONCLUSIONS

Combinations of avelumab or talazoparib plus binimetinib resulted in higher-than-expected DLT rates. However, most DLTs were single occurrences, and the overall safety profiles were generally consistent with those reported for the single agents.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.govNCT03637491; https://clinicaltrials.gov/ct2/show/NCT03637491.

Safety and efficacy of the tumor-selective adenovirus enadenotucirev, in combination with nivolumab, in patients with advanced/metastatic epithelial cancer: a phase I clinical trial (SPICE)

BACKGROUND

Novel combination therapies to overcome anti-PD-1 resistance are required. Enadenotucirev, a tumor-selective blood stable adenoviral vector, has demonstrated a manageable safety profile and ability to increase tumor immune-cell infiltration in phase I studies in solid tumors.

METHODS

We conducted a phase I multicenter study of intravenous enadenotucirev plus nivolumab in patients with advanced/metastatic epithelial cancer not responding to standard therapy. Co-primary objectives were safety/tolerability and maximum tolerated dose and/or maximum feasible dose (MTD/MFD) of enadenotucirev plus nivolumab. Additional endpoints included response rate, cytokine responses, and anti-tumor immune responses.

RESULTS

Overall, 51 heavily pre-treated patients were treated, 45/51 (88%) of whom had colorectal cancer (35/35 patients with information available were microsatellite instability-low/microsatellite stable) and 6/51 (12%) had squamous cell carcinoma of the head and neck. The MTD/MFD of enadenotucirev plus nivolumab was not reached, with the highest dose level tested (1×10¹² vp day 1; 6×10¹² vp days 3 and 5) shown to be tolerable. Overall, 31/51 (61%) patients experienced a grade 3-4 treatment-emergent adverse event (TEAE), most frequently anemia (12%), infusion-related reaction (8%), hyponatremia (6%), and large intestinal obstruction (6%). Seven (14%) patients experienced serious TEAEs related to enadenotucirev; the only serious TEAE related to enadenotucirev occurring in >1 patient was infusion-related reaction (n=2). Among the 47 patients included in efficacy analyses, median progression-free survival was 1.6 months, objective response rate was 2% (one partial response for 10 months), and 45% of patients achieved stable disease. Median overall survival was 16.0 months; 69% of patients were alive at 12 months. Persistent increases in Th1 and related cytokines (IFNγ, IL-12p70, IL-17A) were seen from ~day 15 in two patients, one of whom had a partial response. Among the 14 patients with matching pre-tumor and post-tumor biopsies, 12 had an increase in intra-tumoral CD8⁺ T-cell infiltration and 7 had increased markers of CD8 T-cell cytolytic activity.

CONCLUSIONS

Intravenously dosed enadenotucirev plus nivolumab demonstrated manageable tolerability, an encouraging overall survival and induced immune cell infiltration and activation in patients with advanced/metastatic epithelial cancer. Studies of next-generation variants of enadenotucirev (T-SIGn vectors) designed to further re-program the tumor microenvironment by expressing immune-enhancer transgenes are ongoing.

TRIAL REGISTRATION NUMBER

NCT02636036.

342 Combining enadenotucirev and nivolumab increased tumour immune cell infiltration/activation in patients with microsatellite-stable/instability-low metastatic colorectal cancer in a phase 1 study

Background

Microsatellite-stable (MSS) and instability-low (MSI-L) metastatic colorectal cancer (mCRC) are typically characterised as ”immune-excluded/desert” tumour microenvironments lacking T-cell infiltration. Anti-PD-1 monotherapy has little clinical benefit in MSS/MSI-L mCRC1 and knowledge of the effects of PD-1 inhibition on T-cell activation/infiltration in this population is limited. Novel combination therapies to overcome anti-PD-1 resistance are required. SPICE is a multicentre, open-label, phase 1 study of the tumour-selective chimeric Ad11/Ad3 group B oncolytic adenovirus enadenotucirev plus nivolumab in patients with metastatic/advanced epithelial tumours refractory to standard therapy. Preliminary data from patients with MSS/MSI-L mCRC demonstrated a median overall survival of 14 months, manageable tolerability and intratumoural T-cell infiltration.2 Here we characterise the immunological effects of tumour re-engineering with enadenotucirev in combination with nivolumab in patients with MSS/MSI-L mCRC.

Methods

Patients received increasing doses and/or cycles of intravenous enadenotucirev followed by up to 8 cycles of nivolumab as previously described.2 Wherever possible, pre- and post-treatment (~5 weeks post-first enadenotucirev) biopsies were collected; samples were analysed using immunohistochemistry and automated image analysis. Peripheral blood mononuclear cell immunophenotyping (multiparameter flow cytometry) and serum cytokines were assessed at multiple times.

Results

43 patients with mCRC were treated (86% MSS/MSI-L; 14% unknown). Among the 13 patients (12/13 MSS/MSI-L; 1/13 unknown) with matched biopsies, 11 had increased intratumoural and stromal CD8+ T-cell infiltration in post-treatment biopsies (median [Q1-Q3] fold changes 6.5× [1.5–25.4] and 1.9× [1.5–3.9], respectively; figure 1). CD4+ T-cell density increased in 10/13 patients and 8/13 patients had increased proportions of PD-L1+ immune cells. Increases in CD8 T-cell proliferation (Ki67; 7/9 patients) and cytolytic activity (Granzyme B; 7/13 patients) markers were seen. 4/13 patients converted from a ”desert” to an ”inflamed” immune phenotype (pathologist scored CD8/pan-cytokeratin staining). Immunophenotyping showed trends towards increased T-cell activation (CD38+ and HLA-DR+ CD8+ T cell populations) post-treatment (9/10 patients), including in one patient who had only received enadenotucirev prior to sampling. Persistent increases in inflammatory cytokines (IFNγ, IL-12p70, IL-17a) were seen in two patients from ~Day 15, including one who achieved a sustained objective response.

Abstract 342 Figure 1

Tumour immune cell infiltration following treatment with enadenotucirev plus nivolumab

Conclusions

These data show that intravenous enadenotucirev plus nivolumab can induce immune infiltration/activation within MSS/MSI-L mCRC. These encouraging findings suggest that immune activation can be achieved even in ”immune-excluded/desert” tumours. SPICE has been closed following completion of dose-escalation. Efforts are now focused on the development of next-generation variants of enadenotucirev designed to further re-programme the tumour microenvironment by expressing immune-enhancer transgenes (T-SIGn vectors); these studies are ongoing (NCT04830592, NCT04053283, NCT03852511).

Acknowledgements

This study was funded by PsiOxus Therapeutics Limited and Bristol Myers Squibb. Medical writing support: Lola Parfitt, MRes, of PsiOxus Therapeutics Limited.

Trial Registration

EudraCT number

2017-001231-39NCT number: NCT02636036

References

Kawazoe A, Kuboki Y, Shinozaki E, et al. Multicenter phase I/II trial of napabucasin and pembrolizumab in patients with metastatic colorectal cancer (EPOC1503/SCOOP trial). Clin Cancer Res 2020;26:5887–5894.

Fakih M, Wang D, Harb W, et al. SPICE: a phase I multicenter study of enadenotucirev in combination with nivolumab in tumors of epithelial origin: an analysis of the metastatic colorectal cancer patients in the dose escalation phase. Ann Oncol 2019:30(suppl_5):v252.

Ethics Approval

The study was approved by the WCG Institutional Review Board (study approval number 20152656), UCLA Institutional Review Board (study approval number IRB#15-002010), Vanderbilt Institutional Review Board (study approval number IRB #171453) and Henry Ford Institutional Review Board (study approval number IRB #10349).

344 Avelumab + binimetinib in metastatic pancreatic ductal adenocarcinoma (mPDAC): dose-escalation results from the phase 1b/2 JAVELIN PARP MEKi trial

Background

Preclinical studies of avelumab (anti–PD-L1) + binimetinib (MEK inhibitor [MEKi]) showed encouraging antitumor activity. We report results from the phase 1b JAVELIN PARP MEKi trial (NCT03637491) evaluating avelumab + binimetinib in patients with mPDAC.

Methods

Eligible patients had mPDAC and disease progression during or following 1–2 prior lines for advanced or metastatic disease. Patients received avelumab 800 mg intravenously every 2 weeks and binimetinib 30 or 45 mg orally twice daily. The primary endpoint for phase 1b was dose-limiting toxicity (DLT). Secondary endpoints included safety, confirmed objective response per investigator (RECIST 1.1), pharmacokinetics, immunogenicity, and biomarker analyses. PD-L1 expression (SP263 assay) and CD8+ tumor-infiltrating lymphocytes (TILs) in baseline tumor samples were assessed using immunohistochemistry. Molecular alterations were assessed via plasma ctDNA analyses. Blood samples were collected to assess trough concentrations for avelumab, binimetinib, and AR00426032 (binimetinib metabolite) and end-of-infusion concentration for avelumab.

Results

22 patients received avelumab + binimetinib 30 mg (n=10) or 45 mg (n=12); all discontinued treatment. Among 21 DLT-evaluable patients, DLTs occurred in 3/10 (30.0%) in the 30-mg group (mucosal inflammation, dermatitis acneiform, blood creatine phosphokinase increased [n=1 each]) and 5/11 (45.5%) in the 45-mg group (detachment of retinal pigment epithelium, abdominal pain, diarrhea, nausea, vomiting, rash pustular, hypertension, blood creatine phosphokinase increased [n=1 each]). Any-grade treatment-related adverse events (TRAEs) occurred in all 22 patients; grade =3 TRAEs occurred in 8 (80.0%) and 4 (33.3%) in the 30- and 45-mg groups, respectively, most commonly blood creatine phosphokinase increased (n=3 [30.0%], n=2 [16.7%], respectively). No treatment-related deaths occurred. Objective response rates (95% CI) in the 30- and 45-mg groups were 0% (0.0–30.8) and 8.3% (0.2–38.5; 1 partial response), respectively; 1 (10.0%) and 6 (50.0%) had a best overall response of stable disease. Tumor shrinkage was associated with higher baseline PD-L1 expression, higher number of CD8+ TILs, and MEK1/2, PIK3CA, and RNF43 alterations, whereas ERBB4 alterations correlated inversely with tumor size change. Available data indicate that avelumab, binimetinib, and AR00426032 exposures were within range of previous monotherapy studies.

Conclusions

This study was terminated before a recommended phase 2 dose was established. In patients with mPDAC who received avelumab + binimetinib, DLTs occurred in both dose groups, although TRAEs were generally consistent with single agent safety profiles. The 45-mg binimetinib dose had a higher number of patients with stable disease and one confirmed partial response. Biomarker findings provide insights into potential mechanisms of treatment resistance and response.

Trial Registration

NCT03637491

Ethics Approval

The trial was approved by each site’s independent ethics committee.

Safety and Efficacy of a DNA Oligonucleotide Therapy in Patients with Relapsed or Refractory Diffuse Large B-Cell Lymphoma

BACKGROUND

PNT2258 is a liposomal formulation that encapsulates multiple copies of PNT100, a native, chemically unmodified, 24-base DNA oligonucleotide designed to target the regulatory region upstream of the B-cell lymphoma 2 (BCL2) gene.

METHODS

This phase II, multicenter, single-arm, open-label, 2-stage design study investigated the single-agent activity of PNT2258 in patients with relapsed/refractory DLBCL. Initially, patients had to have a performance status (PS) of ≤2 and prior exposure to CD20-targeted therapy, an alkylating agent, and a steroid with no upper limit. Criteria were modified to PS of 0 or 1 and at least 1 to ≤3 prior therapies (identified as the target population) after observing an initially high frequency of rapid disease progression in patients with extensive prior therapies or poor PS.

RESULTS

The study was stopped early following an interim analysis, despite surpassing the protocol predetermined futility boundary, because the ORR was below the expectations of response in an evolving DLBCL treatment landscape. The final analysis included all 45 enrolled patients and demonstrated an ORR of 11%. In the response evaluable subset (n = 26), defined as patients in the target population with exposure to ≥8 doses of PNT2258 within the first 35 days and evaluable baseline/post-baseline scans, the ORR was 19%. The most common adverse events were fatigue (44%), nausea (42%), diarrhea (40%), pyrexia (36%), anemia (32%), and vomiting (27%).

CONCLUSIONS

PNT2258 was well-tolerated in a chemotherapy refractory DLBCL population. Despite demonstration of single-agent activity, ORR was lower than acceptable for further new therapy development.

A Phase 2 Study of PNT2258 for Treatment of Relapsed or Refractory B-Cell Malignancies

BACKGROUND

PNT2258 consists of a native, chemically unmodified, 24-base DNA oligonucleotide designed to target the regulatory region upstream of the BCL2 gene, delivered in a protective liposome. Derangement of BCL2-regulated control mechanisms is a defining characteristic of certain malignancies, and it was hypothesized that the oligonucleotide would promote anticancer activity via suppression of BCL2 transcription.

METHODS

PNT2258 was evaluated in this, multicenter, nonrandomized, open-label Phase 2 study in 13 participants with relapsed/refractory B-cell malignancies to investigate potential antitumor activity and safety. Participants with follicular lymphoma, diffuse large B-cell lymphoma, mantle cell lymphoma, or chronic lymphocytic leukemia received intravenous PNT2258 120 mg/m² on Days 1 to 5 of a 21-day cycle for up to 8 cycles, followed by 100 mg/m² on Days 1 to 2 of a 28-day cycle until study withdrawal.

RESULTS

All 13 participants were treated with PNT2258 monotherapy and evaluable for response and safety and tolerability. The overall response rate was 53.8% (7/13; 95% confidence interval [CI], 25.1%-80.8%). Median duration of response was 23.4 months (range, 3, 31.5). The disease control rate of participants with stable disease or better was 84.6% (95% CI, 54.6%-98.1%). The most frequently (≥50%) observed adverse events (AEs) were nausea, chills, diarrhea, fatigue, headache, vomiting, and back pain. Hypertension (30.8%) and diarrhea (23.1%) were the most frequent grade ≥3 AEs. No deaths were observed.

CONCLUSION

Clinically meaningful and durable activity with an acceptable safety profile was observed in participants with relapsed/refractory B-cell malignancies who received single-agent PNT2258.

TRIAL REGISTRATION

NCT01733238, first posted 26-Nov-2012. https://clinicaltrials.gov/ct2/show/NCT01733238.

First-in-Human Phase I Study of Envafolimab, a Novel Subcutaneous Single-Domain Anti-PD-L1 Antibody, in Patients with Advanced Solid Tumors

LESSONS LEARNED

Subcutaneous injection was an effective route of administration for envafolimab with a favorable pharmacokinetic profile in patients with previously treated advanced solid tumors. Subcutaneous envafolimab was well tolerated and had durable antitumor activity at a wide range of doses and schedules. Envafolimab has the potential to be a more convenient option than currently approved intravenous PD-1/PD-L1 inhibitors.

BACKGROUND

Envafolimab is a novel fusion of a humanized single-domain PD-L1 antibody and human IgG1 Fc fragment formulated for subcutaneous injection. This study explored the safety and feasibility of subcutaneous administration of envafolimab as an alternative to intravenous administration of PD-1/PD-L1 inhibitors in the treatment of advanced, refractory solid tumors.

METHODS

This was a first-in-human, open-label phase I trial. In a dose-escalation phase, patients received subcutaneous envafolimab 0.01-10 mg/kg once weekly following a modified 3+3 design. In a dose-exploration phase, patients received subcutaneous envafolimab 300 mg once every 4 weeks.

RESULTS

Twenty-eight patients were enrolled (dose escalation n = 18, dose exploration n = 10, median age 66 years; 71% male; ECOG performance score = 0 [21%] or 1 [79%]). No dose-limiting toxicities or injection-site reactions were reported. Envafolimab demonstrated dose-proportional increases in area under the time-concentration curve and maximum plasma concentration. Median time to maximum plasma concentration was 4-7 days. In the dose-exploration phase, terminal half-life was 14 days after dose 1 in cycle 1 and 23 days at steady state. Three patients experienced a confirmed partial response.

CONCLUSION

Subcutaneous envafolimab had a favorable safety and pharmacokinetic profile, with promising preliminary antitumor activity in patients with advanced solid tumors.

Phase I Study of Elacestrant (RAD1901), a Novel Selective Estrogen Receptor Degrader, in ER-Positive, HER2-Negative Advanced Breast Cancer

PURPOSE

This phase I study (RAD1901-005; NCT02338349) evaluated elacestrant, an investigational oral selective estrogen receptor degrader (SERD), in heavily pretreated women with estrogen receptor-positive, human epidermal growth factor receptor 2-negative metastatic breast cancer, including those with estrogen receptor gene alpha (ESR1) mutation. The primary objective was to determine the maximum tolerated dose and/or recommended phase II dose (RP2D).

METHODS

The study consisted of a 3 + 3 design (elacestrant capsules) followed by expansion at RP2D (400-mg capsules, then 400-mg tablets) for the evaluation of safety and antitumor activity. Elacestrant was taken once daily until progression or intolerability.

RESULTS

Of 57 postmenopausal women enrolled, 50 received RP2D (400 mg once daily): median age, 63 years; median three prior anticancer therapies, including cyclin-dependent kinase 4,6 inhibitors (CDK4/6i; 52%), SERD (52%), and ESR1 mutation (circulating tumor DNA; 50%). No dose-limiting toxicities occurred; the most common adverse events at RP2D (400-mg tablet; n = 24) were nausea (33.3%) and increased blood triglycerides and decreased blood phosphorus (25.0% each). Most adverse events were grade 1-2 in severity. The objective response rate was 19.4% (n = 31 evaluable patients receiving RP2D), 15.0% in patients with prior SERD, 16.7% in patients with prior CDK4/6i, and 33.3% in patients with ESR1 mutation (n = 5/15). The clinical benefit rate (24-week) was 42.6% overall (n = 47 patients receiving RP2D), 56.5% (n = 23, ESR1 mutation), and 30.4% (n = 23, prior CDK4/6i). Elacestrant clinical benefit was associated with decline in ESR1 mutant allele fraction.

CONCLUSION

Elacestrant 400 mg orally once daily has an acceptable safety profile and demonstrated single-agent activity with confirmed partial responses in heavily pretreated patients with estrogen receptor-positive metastatic breast cancer. Notably, responses were observed in patients with ESR1 mutation as well as those with prior CDK4/6i and prior SERD. A phase III trial investigating elacestrant versus standard endocrine therapy is ongoing.

Abstract B31: Viagenpumatucel-L (HS-110) plus nivolumab in previously treated patients with advanced non-small cell lung cancer (NSCLC)

Background: Viagenpumatucel-L (HS-110) is an allogeneic cellular vaccine derived from a human lung adenocarcinoma (Ad) cell line transfected with the gp96-Ig fusion protein that functions as an antigen chaperone for cross-presentation and dendritic cell activation. In this context, gp96 serves as a potent immune adjuvant via Toll-like receptor 4/2 signaling, which serves to activate APCs to specialized dendritic cells as wells as cross-presentation of the gp96-chaperoned cancer testis peptide antigens (up to 725 represented) directly to MHC class I molecules for direct activation and expansion of CD8+ T-cells. DURGA is a multicohort study evaluating the combination of HS-110 and anti-PD-1 monoclonal antibodies in patients with advanced NSCLC. We report on Cohort A, which enrolled previously treated patients who have not received a checkpoint inhibitor prior to study entry.

Methods: Patients (pts) with previously treated NSCLC received 1 X 107 HS-110 cells intradermally every week for 18 weeks, and standard-of-care nivolumab IV until intolerable toxicity or tumor progression. Tissue was tested at baseline for PD-L1 expression (≥ 1% or < 1%) and tumor-infiltrating lymphocytes (TILs). TIL high was defined by more than 10% CD8+ lymphocytes in the tumor stroma. The primary objectives were safety and objective response rate (ORR).

Results: As of the March 2019 enrollment cut-off, there were 46 pts enrolled into cohort A (43 Ad and 3 squamous cell carcinoma), 6 (13%) of whom were EGFR positive. 9 pts (20%) were TIL high, 13 (28%) TIL low, and 24 (52%) TIL unknown. 8 pts (17%) were PD-L1 ≥ 1%, 21 (46%) were PD-L1 < 1%, and 17 (37%) were PD-L1 unknown. ORR was 22% and clinical benefit rate (objective response plus stable disease) was 48%. Median progression-free and overall survival were 1.9 and 16.9 months, respectively, with a median follow-up of 17 months. One- and 2-year survival were 48% and 30%, respectively. There were no statistically significant differences in subgroup analyses of PFS or OS based on TIL or PD-L1. In a prospectively defined secondary analysis, the presence of at least one injection site reaction (ISR) during treatment was associated with improved progression-free and overall survival: mPFS 6.1 vs. 1.6 months (HR 0.51 [95% CI 0.26, 0.97] p = 0.04), and mOS 42.1 vs. 5.9 months (HR 0.14 [95% CI 0.05, 0.36] p < 0.0001). 46 (100%) pts experienced at least one adverse event (AE), of which 29 (63%) were grade 1 or 2. The most common AEs were fatigue (26%), cough and arthralgia (17% each), and decreased appetite, constipation, and diarrhea (15% each). There were 2 grade 5 AEs (pulmonary embolism and acute MI) and 1 grade 4 AE (hyponatremia), none of which were considered to be treatment related.

Conclusions: The combination of HS-110 and nivolumab appears safe and well tolerated. Efficacy results are independent of TIL and PD-L1 levels, whereas the occurrence of ISR is associated with improved progression-free and overall survival.

Citation Format: Daniel Morgensztern, Lyudmila Bazhenova, Saiama N. Waqar, Lori McDermott, Jeff Hutchins, Wael Harb, Nathan Pennell, Roger B. Cohen. Viagenpumatucel-L (HS-110) plus nivolumab in previously treated patients with advanced non-small cell lung cancer (NSCLC) [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2019 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2020;8(3 Suppl):Abstract nr B31.

Development of 2 Bromodomain and Extraterminal Inhibitors With Distinct Pharmacokinetic and Pharmacodynamic Profiles for the Treatment of Advanced Malignancies

PURPOSE

Bromodomain and extraterminal (BET) proteins are key epigenetic transcriptional regulators, inhibition of which may suppress oncogene expression. We report results from 2 independent first-in-human phase 1/2 dose-escalation and expansion, safety and tolerability studies of BET inhibitors INCB054329 (study INCB 54329-101; NCT02431260) and INCB057643 (study INCB 57643-101; NCT02711137).

PATIENTS AND METHODS

Patients (≥18 years) with advanced malignancies, ≥1 prior therapy, and adequate organ functions received oral INCB054329 (monotherapy) or INCB057643 (monotherapy or in combination with standard-of-care) in 21-day cycles (or 28-day cycles depending on standard-of-care combination). Primary endpoints were safety and tolerability.

RESULTS

Sixty-nine and 134 patients received INCB054329 and INCB057643, respectively. Study INCB 54329-101 has been completed; INCB 57643-101 is currently active, but not recruiting (no patients were receiving treatment as of January 8, 2019). Terminal elimination half-life was shorter for INCB054329 versus INCB057643 (mean [SD], 2.24 [2.03] vs. 11.1 [8.27] hours). INCB054329 demonstrated higher interpatient variability in oral clearance versus INCB057643 (CV%, 142% vs. 45.5%). Most common (>20%) any-grade treatment-related adverse events were similar for both drugs (INCB054329; INCB057643): nausea (35%; 30%), thrombocytopenia (33%; 32%), fatigue (29%; 30%), decreased appetite (26%; 22%). Two confirmed complete responses and 4 confirmed partial responses with INCB057643 were reported as best responses.

CONCLUSIONS

INCB057643 exhibited a more favorable PK profile versus INCB054329; exposure-dependent thrombocytopenia was observed with both drugs which limited the target inhibition that could be safely maintained. Further efforts are required to identify patient populations that can benefit most, and an optimal dosing scheme to maximize therapeutic index.

An oral fixed-dose combination of decitabine and cedazuridine in myelodysplastic syndromes: a multicentre, open-label, dose-escalation, phase 1 study

BACKGROUND

Decitabine, a DNA methyltransferase 1 inhibitor or DNA hypomethylating compound, is not readily orally bioavailable because of rapid clearance by cytidine deaminase (CDA) in the gut and liver. This dose-escalation study, guided by pharmacokinetic and pharmacodynamic observations, evaluated whether simultaneous oral administration with the novel CDA inhibitor cedazuridine increases decitabine bioavailability for the treatment of myelodysplastic syndromes.

METHODS

In this phase 1 study, we enrolled patients aged 18 years or older with myelodysplastic syndromes or chronic myelomonocytic leukaemia. Eligible patients were assigned to cohorts to receive escalating oral doses of decitabine and cedazuridine. The starting dose was decitabine 20 mg and cedazuridine 40 mg. Treatment cycles lasted 28 days, with 5 days of drug administration. In cycle 1, each patient received a cohort-defined dose of oral decitabine on day -3, a 1-h intravenous infusion of decitabine 20 mg/m² on day 1, and cohort-defined doses of oral decitabine plus cedazuridine on days 2-5. In cycles 2 and beyond, the oral decitabine and cedazuridine were given on days 1-5. The dose of cedazuridine was escalated first and decitabine was escalated once CDA inhibition by cedazuridine approached the maximum effect. The drug dose was escalated if mean decitabine area under the curve (AUC) of the oral drug was less than 90% of that for intravenous decitabine in the cohort and if no dose-limiting toxicity was observed. Dose-limiting toxicity was defined as a grade 3 or greater non-haematologic toxicity or grade 4 haematologic toxicity lasting more than 14 days and unrelated to the underlying disease. Once the decitabine AUC target range set as the primary endpoint, and established with intravenous decitabine, was reached at a dose deemed to be safe, the cohort that most closely approximated intravenous decitabine exposure was expanded to 18 evaluable patients. The primary objectives were to assess the safety of decitabine plus cedazuridine, and to determine the dose of each drug needed to achieve a mean AUC for decitabine exposure similar to that for intravenous decitabine exposure. This study is registered with ClinicalTrials.gov, number NCT02103478.

FINDINGS

Between Oct 28, 2014, and Nov 13, 2015, we enrolled 44 eligible patients (of 75 screened) with previously treated or newly diagnosed myelodysplastic syndromes or chronic myelomonocytic leukaemia; 43 of the enrolled patients were evaluable. Participants were treated in five cohorts: cohorts 1-4 included six evaluable patients each; cohort 5 included 19 patients in a 13-patient expansion. Dose-dependent increases in decitabine AUC and peak plasma concentration occurred with each cohort dose escalation. There was no evident increase in toxicity compared with that reported for intravenous decitabine. Decitabine 30 mg and 40 mg plus cedazuridine 100 mg produced mean day-5 decitabine AUCs (146 ng × h/mL for decitabine 30 mg, and 221 ng × h/mL for decitabine 40 mg) closest to the mean intravenous-decitabine AUC (164 ng × h/mL). The most common grade 3 or more adverse events were thrombocytopenia (18 [41%] of 44 patients), neutropenia (13 [30%]), anaemia (11 [25%]), leukopenia (seven [16%]), febrile neutropenia (seven [16%]), and pneumonia (seven [16%]). Four (9%) patients died because of adverse events, none of which was considered drug related, and three (7%) patients died more than 30 days after discontinuing treatment because of progressive disease (two [5%]) and respiratory failure (one [2%]).

INTERPRETATION

Oral decitabine plus cedazuridine emulated the pharmacokinetics of intravenous decitabine, with a similar safety profile and dose-dependent demethylation. Clinical responses were similar to intravenous decitabine treatment for 5 days. Further study of decitabine plus cedazuridine as an alternative to parenteral therapy or in combination with other new oral agents for myeloid disorders is warranted.

FUNDING

Astex Pharmaceuticals, Inc.

Phase Ib Study of Binimetinib with Paclitaxel in Patients with Platinum-Resistant Ovarian Cancer: Final Results, Potential Biomarkers, and Extreme Responders

Purpose: Epithelial ovarian cancer (EOC) is a molecularly diverse disease. MEK inhibition targets tumors harboring MAPK pathway alterations and enhances paclitaxel-induced apoptosis in EOC. This phase Ib study evaluated the MEK inhibitor binimetinib combined with paclitaxel in patients with platinum-resistant EOC.Patients and Methods: Patients received intravenous weekly paclitaxel with oral binimetinib in three different administration schedules. Outcomes were assessed by RECIST and CGIC CA-125 response criteria. Tumor samples were analyzed using next-generation sequencing.Results: Thirty-four patients received ≥1 binimetinib dose. A 30-mg twice-a-day continuous or 45-mg twice-a-day intermittent binimetinib dose was deemed the recommended phase II dose (RP2D) in combination with 80 mg/m² i.v. weekly paclitaxel. Rate of grade 3/4 adverse events was 65%. The best overall response rate was 18%-one complete (CR) and four partial responses (PR)-among 28 patients with RECIST-measurable disease. Eleven patients achieved stable disease (SD), yielding a clinical benefit rate (CR+PR+SD) of 57%. Response rates, per both RECIST and CA-125 criteria, were highest in the 45-mg twice-a-day continuous cohort and lowest in the 45-mg twice-a-day intermittent cohort. All four evaluable patients with MAPK pathway-altered tumors experienced clinical benefit.Conclusions: The combination of binimetinib and intravenous weekly paclitaxel was tolerable in this patient population. The RP2D of binimetinib in combination with paclitaxel was 30 mg twice a day as a continuous or 45 mg twice a day as an intermittent dose. Although response rates were modest, a higher clinical benefit rate was seen in patients harboring alterations affecting the MAPK pathway. Clin Cancer Res; 24(22); 5525-33. ©2018 AACR.

A Phase Ib, open-label, dose-finding study of alpelisib in combination with paclitaxel in patients with advanced solid tumors

Phosphatidylinositol 3-kinase (PI3K) pathway activation is associated with resistance to paclitaxel in solid tumors. We assessed the safety and activity of alpelisib, an oral, selective PI3K p110α inhibitor, plus paclitaxel in patients with advanced solid tumors. This Phase Ib, multicenter, open-label, dose-finding study, with a planned dose-expansion phase of alpelisib once daily (QD) plus fixed-dose paclitaxel, recruited patients with advanced solid tumors. For the dose-finding phase, the primary objective was determination of maximum tolerated and/or recommended Phase II dose of alpelisib plus paclitaxel, and the secondary objectives included the assessment of safety for this combination. From March 2014 to August 2016, 19 patients with advanced solid tumors were treated with alpelisib QD (300 mg, n=6; 250 mg, n=4; 150 mg, n=9) plus paclitaxel (80 mg/m², per standard of care). During dose finding, five of 12 (41.7%) evaluable patients for MTD determination experienced dose-limiting toxicities: alpelisib 300 mg, Grade 2 hyperglycemia (n=1); alpelisib 250 mg, Grade 2 hyperglycemia (n=1), Grade 4 hyperglycemia and Grade 3 acute kidney injury (n=1); and alpelisib 150 mg, Grade 2 hyperglycemia (n=1) and Grade 4 leukopenia (n=1). The MTD of alpelisib when administered with paclitaxel was 150 mg QD. Most frequent all-grade AEs were diarrhea (73.7%; Grade 3/4 10.5%) and hyperglycemia (57.9%; Grade 3/4 31.6%). The planned dose-expansion phase was not initiated. Alpelisib plus paclitaxel has a challenging safety profile in patients with advanced solid tumors. This study was closed following the completion of the dose-finding phase. Clinical trial registration: ClinicalTrials.gov NCT02051751.

Phase Ib Study of Binimetinib with Paclitaxel in Patients with Platinum-Resistant Ovarian Cancer: Final Results, Potential Biomarkers, and Extreme Responders

Purpose: Epithelial ovarian cancer (EOC) is a molecularly diverse disease. MEK inhibition targets tumors harboring MAPK pathway alterations and enhances paclitaxel-induced apoptosis in EOC. This phase Ib study evaluated the MEK inhibitor binimetinib combined with paclitaxel in patients with platinum-resistant EOC.Patients and Methods: Patients received intravenous weekly paclitaxel with oral binimetinib in three different administration schedules. Outcomes were assessed by RECIST and CGIC CA-125 response criteria. Tumor samples were analyzed using next-generation sequencing.Results: Thirty-four patients received ≥1 binimetinib dose. A 30-mg twice-a-day continuous or 45-mg twice-a-day intermittent binimetinib dose was deemed the recommended phase II dose (RP2D) in combination with 80 mg/m² i.v. weekly paclitaxel. Rate of grade 3/4 adverse events was 65%. The best overall response rate was 18%-one complete (CR) and four partial responses (PR)-among 28 patients with RECIST-measurable disease. Eleven patients achieved stable disease (SD), yielding a clinical benefit rate (CR+PR+SD) of 57%. Response rates, per both RECIST and CA-125 criteria, were highest in the 45-mg twice-a-day continuous cohort and lowest in the 45-mg twice-a-day intermittent cohort. All four evaluable patients with MAPK pathway-altered tumors experienced clinical benefit.Conclusions: The combination of binimetinib and intravenous weekly paclitaxel was tolerable in this patient population. The RP2D of binimetinib in combination with paclitaxel was 30 mg twice a day as a continuous or 45 mg twice a day as an intermittent dose. Although response rates were modest, a higher clinical benefit rate was seen in patients harboring alterations affecting the MAPK pathway. Clin Cancer Res; 24(22); 5525-33. ©2018 AACR.

Abstract PD5-08: Not presented

This abstract was not presented at the symposium.

A phase 2 safety study of accelerated elotuzumab infusion, over less than 1 h, in combination with lenalidomide and dexamethasone, in patients with multiple myeloma

Elotuzumab, an immunostimulatory SLAMF7-targeting monoclonal antibody, induces myeloma cell death with minimal effects on normal tissue. In a previous phase 3 study in patients with relapsed/refractory multiple myeloma (RRMM), elotuzumab (10 mg/kg, ∼3-h infusion), combined with lenalidomide and dexamethasone, demonstrated durable efficacy and acceptable safety; 10% (33/321) of patients had infusion reactions (IRs; Grade 1/2: 29; Grade 3: 4). This phase 2 study (NCT02159365) investigated an accelerated infusion schedule in 70 patients with newly diagnosed multiple myeloma or RRMM. The primary endpoint was cumulative incidence of Grade 3/4 IRs by completion of treatment Cycle 2. Dosing comprised elotuzumab 10 mg/kg intravenously (weekly, Cycles 1-2; biweekly, Cycles 3+), lenalidomide 25 mg (daily, Days 1-21), and dexamethasone (28 mg orally and 8 mg intravenously, weekly, Cycles 1-2; 40 mg orally, weekly, Cycles 3+), in 28-day cycles. Premedication with diphenhydramine, acetaminophen, and ranitidine (or their equivalents) was given as in previous studies. If no IRs occurred, infusion rate was increased in Cycle 1 from 0.5 to 2 mL/min during dose 1 (∼2 h 50 min duration) to 5 mL/min for the entire infusion by dose 3 and also during all subsequent infusions (∼1-h duration). Median number of treatment cycles was six. No Grade 3/4 IRs occurred; only one Grade 1 and one Grade 2 IR occurred, both during the first infusion. These data support the safety of a faster infusion of elotuzumab administered over ∼1 h by the third dose, providing a more convenient alternative dosing option for patients.

Abstract P2-08-06: A phase 1 study of RAD1901, a novel, oral selective estrogen receptor degrader, for the treatment of ER-positive advanced breast cancer

Background: The majority of breast cancers are defined as estrogen receptor positive (ER+) breast cancer. Despite availability of standard therapies, such as aromatase inhibitors, many women eventually relapse with aggressive disease due to acquisition of endocrine resistance, including ESR1 mutations. To help address some of the challenges associated with current therapies including exposure limitations and intramuscular administration, we have developed RAD1901, a novel, non-steroidal, oral selective estrogen receptor degrader (SERD). Preclinical studies with RAD1901 have demonstrated a dose dependent degradation of ER consistent with a SERD mechanism of action. In multiple in vivo models of breast cancer, including patient-derived xenograft models that are sensitive or resistant to standard endocrine therapies, RAD1901 has anti-tumor efficacy both as a single agent and in combination with palbociclib and everolimus. Importantly, RAD1901 has shown superior efficacy compared to fulvestrant in a number these models including those harboring and ESR1 mutation.

Methods: RAD1901-005 is a Phase 1 study currently enrolling ER+ advanced metastatic breast cancer patients (ClinicalTrials.gov identifier: NCT02338349) with a dose escalation cohort based on a standard 3+3 design followed by a safety expansion cohort at a tolerated dose. Key inclusion criteria include postmenopausal women aged 18 years or older, with advanced ER+, HER2-negative breast cancer, who have received ≤ 2 prior chemotherapy regimens in the metastatic setting and > 6 months of prior endocrine therapy. In addition, circulating tumor DNA (ctDNA) was evaluated to determine ESR1 mutation status and to correlate it with clinical response.

Results: As of the cut-off date in March, 13 patients were enrolled in the dose escalation part of the study (3+3 design) at doses of 200 mg qd, 400 mg qd and 600 mg qd. RAD1901 exposure was dose dependent and the PK profile was comparable to PK data from a previous study in healthy volunteers. RAD1901 was well tolerated with the most common adverse events being low-grade nausea and dyspepsia. No DLTs were observed. A safety expansion cohort (Part B, n=20) was opened. At the cut-off date 4 of the 13 patients had been on study 4 or more months. Updated outcomes and biomarker data, including ctDNA, will be presented at the meeting.

Conclusion: RAD1901, a novel, non-steroidal, oral SERD, is well-tolerated with manageable adverse effects, and is associated with preliminary evidence of clinical activity in patients with advanced ER+ advanced postmenopausal breast cancer, including patients with ESR1 mutant tumors.

Citation Format: Kaklamani VG, Kabos P, Elledge R, Harb W, Purandare D, O'Neill A, Garner F, Bardia A. A phase 1 study of RAD1901, a novel, oral selective estrogen receptor degrader, for the treatment of ER-positive advanced breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-08-06.

Abstract OT2-01-10: A phase 1 study of RAD1901, a novel, orally available, selective estrogen receptor degrader, for the treatment of ER positive advanced breast cancer

The current NCCN treatment guidelines for ER+ breast cancer involves the use of approved agents such as fulvestrant, tamoxifen and aromatase inhibitors that either inhibit estrogen production or block estrogen receptor binding. While the initial treatment regimens with these selective estrogen receptor modulators (SERMs) and selective estrogen receptor degraders (SERDs) is often successful, many women eventually relapse with more aggressive forms of endocrine-resistant disease. To begin to overcome some of the challenges associated with current therapies including exposure limitations and intramuscular administration, we have developed RAD1901, a novel, non-steroidal, orally available SERD. Preclinical studies with RAD1901 have demonstrated potent dose dependent ER degradation consistent with a SERD mechanism of action, as well as potent inhibition of proliferation in vitro in breast cancer cell lines. RAD1901 also demonstrated significant anti-tumor efficacy in vivo, and notably single agent regressions in both MCF7 and a primary patient derived xenograft models harboring an ESR1 mutations.

A phase 1 monotherapy study conducted in healthy postmenopausal female volunteers evaluated forty four subjects treated once daily with RAD1901 with doses ranging from 200 mg/day up to 1000 mg/day for 7 days. All dose levels were generally well tolerated and pharmacokinetic analysis demonstrated plasma exposures consistent with preclinical efficacy in ER+ breast cancer models. Furthermore, 18F-estradiol positron emission tomography (FES-PET) was also performed at baseline and after 7 days of RAD1901 treatment, to evaluate estrogen receptor engagement. Standardized uptake values (SUV) pre- and post-treatment with RAD1901 demonstrated complete attenuation of FES-PET signal in ER+ tissues such as the uterus from the 200 mg/day dose level. Taken together, these results provide strong preclinical and clinical rationale for the development of RAD1901 as a potent and selective oral SERD for the treatment of hormone driven and hormone resistant ER + metastatic breast cancers.

RAD1901-005 is a Phase 1 study currently enrolling ER+ advanced metastatic breast cancer patients. The study consists of two parts: a monotherapy dose escalation followed by a safety expansion at the maximum tolerated dose (MTD). The dose escalation will follow a standard 3+3 design with once daily dosing to establish, safety, tolerability, and PK. Once the MTD for RAD1901 has been established, the safety expansion will further evaluate the safety, tolerability, biomarkers and preliminary efficacy at the recommended phase 2 dose (RP2D) following a continuous once daily schedule. Key inclusion criteria include post-menopausal women aged 18 years or older, with advanced ER positive, HER2 negative breast cancer, who have received ≤ 2 prior chemotherapy regimens in the metastatic setting and > 6 months of prior endocrine therapy. Patient enrollment started in early 2015, and is currently ongoing.

ClinicalTrials.gov identifier: NCT02338349.

Citation Format: Harb W, Garner F, McDermott J, Zimmerman T, Williams G, Hattersley G, Purandare D. A phase 1 study of RAD1901, a novel, orally available, selective estrogen receptor degrader, for the treatment of ER positive advanced breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr OT2-01-10.

A Phase I/II Multicenter, Open-Label Study of the Oral Histone Deacetylase Inhibitor Abexinostat in Relapsed/Refractory Lymphoma

PURPOSE

Additional targeted therapeutics are needed for the treatment of lymphoma. Abexinostat is an oral pan-histone deacetylase inhibitor (HDACi) displaying potent activity in preclinical models. We conducted a multicenter phase I/II study (N = 55) with single-agent abexinostat in relapsed/refractory lymphoma.

EXPERIMENTAL DESIGN

In phase I, 25 heavily pretreated patients with any lymphoma subtype received oral abexinostat ranging from 30 to 60 mg/m(2) twice daily 5 days/week for 3 weeks or 7 days/week given every other week. Phase II evaluated abexinostat at the maximum tolerated dose in 30 patients with relapsed/refractory follicular lymphoma or mantle cell lymphoma.

RESULTS

The recommended phase II dose was 45 mg/m(2) twice daily (90 mg/m(2) total), 7 days/week given every other week. Of the 30 follicular lymphoma and mantle cell lymphoma patients enrolled in phase II, 25 (14 follicular lymphoma, 11 mantle cell lymphoma) were response-evaluable. Tumor size was reduced in 86% of follicular lymphoma patients with an investigator-assessed ORR of 64.3% for evaluable patients [intent-to-treat (ITT) ORR 56.3%]. Median duration of response was not reached, and median progression-free survival (PFS) was 20.5 months (1.2-22.3+). Of responding follicular lymphoma patients, 89% were on study/drug >8 months. In mantle cell lymphoma, the ORR was 27.3% for evaluable patients (ITT ORR 21.4%), and median PFS was 3.9 months (range, 0.1-11.5). Grade 3-4 treatment-related adverse events (phase II) with ≥ 10% incidence were thrombocytopenia (20%), fatigue (16.7%), and neutropenia (13.3%) with rare QTc prolongation and no deaths.

CONCLUSIONS

The pan-HDACi, abexinostat, was overall well tolerated and had significant clinical activity in follicular lymphoma, including highly durable responses in this multiply relapsed patient population.

Safety and efficacy of neratinib in combination with capecitabine in patients with metastatic human epidermal growth factor receptor 2-positive breast cancer

PURPOSE

Neratinib is a potent irreversible pan-tyrosine kinase inhibitor with antitumor activity and acceptable tolerability in patients with human epidermal growth factor receptor 2 (HER2) -positive breast cancer. A multinational, open-label, phase I/II trial was conducted to determine the maximum-tolerated dose (MTD) of neratinib plus capecitabine in patients with solid tumors (part one) and to evaluate the safety and efficacy of neratinib plus capecitabine in patients with HER2-positive metastatic breast cancer (part two).

PATIENTS AND METHODS

Part one was a 3 + 3 dose-escalation study in which patients with advanced solid tumors received oral neratinib once per day continuously plus capecitabine twice per day on days 1 to 14 of a 21-day cycle at predefined dose levels. In part two, patients with trastuzumab-pretreated HER2-positive metastatic breast cancer received neratinib plus capecitabine at the MTD. The primary end point in part two was objective response rate (ORR).

RESULTS

In part one (n = 33), the combination of neratinib 240 mg per day plus capecitabine 1,500 mg/m(2) per day was defined as the MTD, which was further evaluated in part 2 (n = 72). The most common drug-related adverse events were diarrhea (88%) and palmar-plantar erythrodysesthesia syndrome (48%). In part two, the ORR was 64% (n = 39 of 61) in patients with no prior lapatinib exposure and 57% (n = 4 of 7) in patients previously treated with lapatinib. Median progression-free survival was 40.3 and 35.9 weeks, respectively.

CONCLUSION

Neratinib in combination with capecitabine had a manageable toxicity profile and showed promising antitumor activity in patients with HER2-positive metastatic breast cancer pretreated with trastuzumab and lapatinib.

Everolimus for postmenopausal women with advanced breast cancer: Updated results of the BOLERO-2 phase III trial

99

Background: Current treatment options for postmenopausal patients with estrogen-receptor–positive breast cancer (BC) who relapse or progress on a nonsteroidal aromatase inhibitor (NSAI) are limited. The BOLERO-2 trial supports the activity of everolimus (EVE; an oral mammalian target of rapamycin [mTOR] inhibitor) added to the steroidal aromatase inhibitor exemestane (EXE) to prolong progression-free survival (PFS) in this patient population. Long-term PFS and survival data are awaited. Methods: BOLERO-2 is a phase 3, double-blind, randomized, international trial comparing EVE (10 mg once daily) + EXE (25 mg once daily) vs. placebo (PBO) + EXE in postmenopausal women with advanced estrogen-receptor–positive BC progressing or recurring after NSAIs (letrozole or anastrozole). Patients were randomized (2:1) to EVE + EXE or PBO + EXE. The primary endpoint was PFS by local investigator assessment. Main secondary endpoints included centrally assessed PFS, overall survival (OS), safety, bone turnover, and overall response rate. Results: Baseline disease characteristics including tumor burden and prior cancer therapy were well balanced between treatment arms (N = 724). Median PFS was doubled and response rates were consistently improved with EVE + EXE (n = 485) vs PBO + EXE (n = 239) in interim analyses. Median PFS by local assessment was ~3 mo with PBO + EXE vs 6.9 mo (hazard ratio [HR], 0.43; P < .0001) and 7.4 mo (HR, 0.44; P < .0001) with EVE + EXE at 7.5 mo and 12.5 mo follow-up, respectively. Fewer deaths were reported with EVE + EXE (17.2%) vs PBO + EXE (22.7%) at 12.5 mo follow-up. Safety profiles were consistent with previous reports for mTOR inhibitors. PFS data including 528 events (protocol-specified final analysis), and updated OS and safety data will be presented. Conclusions: Adding EVE to EXE markedly prolonged PFS in patients with NSAI-refractory advanced estrogen-receptor–positive BC. There were fewer deaths among patients receiving EVE, and further follow-up will evaluate the effect of EVE on OS.

P1-12-09: Safety and Efficacy of Neratinib in Combination with Capecitabine in Patients with ErbB2-Positive Breast Cancer

Background: Neratinib (HKI-272) is an irreversible pan-ErbB receptor tyrosine kinase inhibitor that has shown antitumor activity in patients with ErbB2+ breast cancer. Capecitabine has demonstrated efficacy and tolerability in combination with lapatinib, a reversible dual ErbB1/ErbB2 kinase inhibitor, in patients with ErbB2+ advanced breast cancer. The current study evaluated the safety and clinical activity of neratinib in combination with capecitabine.

Methods: In part 1 of this open-label, phase 1/2 study, the maximum tolerated dose (MTD) of neratinib in combination with capecitabine was determined in adults with advanced solid tumors. Part 2 of the study further evaluated the safety and clinical activity of neratinib plus capecitabine at the MTD in adults with confirmed ErbB2+ metastatic or locally advanced breast cancer (ECOG Performance Status of 0–2). Eligible patients had received prior taxane treatment and ≥1 prior trastuzumab-containing regimen for ≥6 weeks for metastatic or locally advanced disease. The primary endpoint of part 2 was objective response rate (ORR); tumor responses were assessed by investigators using modified RECIST version 1.0 guidelines every 6 weeks.

Results: In part 1 (n = 33), the MTD was determined to be neratinib 240 mg/day plus capecitabine 750 mg/m2 twice daily on Days 1 to 14 of each 21-day cycle. In part 2, as of April 2011, 72 female patients (median age of 52 years [range, 33–79 years]) with ErbB2+ breast cancer were enrolled and treated at the MTD; 7 patients had prior lapatinib exposure and all had prior trastuzumab and taxane exposure. As of the snapshot date, 56% of patients at the MTD were still participating in the study. The most common drug-related adverse events (AEs) in part 2 were diarrhea (89%), palmar-plantar erythrodysesthesia (57%), nausea (33%), vomiting (26%), and decreased appetite (22%). Grade 3/4 drug-related AEs in ≥5% of patients were diarrhea (25%) and palmar-plantar erythrodysesthesia (13%). Eight patients withdrew from part 2 due to AEs, including 4 who withdrew due to diarrhea. Dose interruptions of neratinib and capecitabine, respectively, due to AEs were required by 19 and 29 patients; dose reductions due to AEs were required by 8 and 22 patients. As of June 2010 (interim analysis), 22 patients were evaluable for efficacy in part 2 of the study. Of these 22 patients, 11 achieved a partial response for an ORR of 50%. An additional 2 patients maintained stable disease for ≥24 weeks, resulting in a clinical benefit rate of 59%, and 8 patients had stable disease for &lt;24 weeks. One patient had progressive disease without achieving a response or stable disease. Updated efficacy data will be presented.

Conclusions: The results of this study indicate that neratinib combined with capecitabine is tolerable and has promising antitumor activity in patients with ErbB2+ metastatic or locally advanced breast cancer pretreated with trastuzumab. This study supports further evaluation of this combination in ErbB2+ breast cancer.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-12-09.

Randomized, double blind, multicenter, phase II study of pemetrexed (PEM), carboplatin (CARBO), bevacizumab (BEV) with enzastaurin (ENZ) or placebo (PBO) in chemotherapy-naive patients with stage IIIB/IV non-small cell lung cancer (NSCLC): Hoosier Oncology Group (HOG) LUN06–116

8035^

Background: Pre-clinical data suggests that ENZ and BEV may have complementary effects in inhibiting angiogenesis. This study compared ENZ vs PBO in combination with PEM+CARBO+ BEV. Methods: Pts ≥18 years of age, non-squamous NSCLC, no prior systemic therapy, disease measurable by RECIST, and ECOG PS 0–1 were randomized. Pts received either PBO or 500 mg ENZ daily after loading dose of 375 mg orally, TID, on day 1, cycle 1. Starting on day 8, cycle 1, patients received PEM 500mg/m2, CARBO AUC 6 and BEV 15mg/kg, intravenously, every 21 days. After 4 cycles, pts continued on BEV+ENZ or BEV+PBO. Pts were stratified by ECOG status, disease stage and site with a planned sample size of 90 pts. Primary end point was progression-free survival (PFS). Secondary end points included objective response rate (ORR) and toxicity. Results: Study was terminated after a planned interim analysis for safety and efficacy. From October 2007 to July 2008, 40 pts were enrolled: 20 in each arm. Median age was 60.5 years (range: 44 to 78); M 52.5%, F 47.5%; ECOG PS 0/1 52.5% and 47.5%; stage IIIB/IV 15% and 85%. Baseline characteristics were well matched. The PEM+CARBO+BEV+ENZ arm received a median of 3 cycles of therapy and the PEM+CARBO+BEV+PBO arm 4 cycles. Median PFS was 4.3 mo and 4.2 mo for ENZ and PBO, respectively (unadjusted HR: 0.94, 95% CI [0.39, 2.33]). ORR for ENZ and PBO was 20% and 25%, respectively. Overall, grade 3/4 toxicities were similar in both arms. One patient in ENZ arm experienced a grade 3/4 hemorrhage (vs. none in the PBO arm). Two patients experienced a GI perforation (1 on each arm): 1 resulted in death on the PBO arm. Both patients had a history of diverticulosis. Conclusions: Based upon the results of this interim efficacy analysis, addition of ENZ to PEM+CARBO+BEV will not significantly prolong PFS in patients with stage IIIB/IV NSCLC. This combination does not warrant further study in NSCLC.

[Table: see text]

ASCO Conflict of Interest Policy and Exceptions

In compliance with the guidelines established by the ASCO Conflict of Interest Policy (J Clin Oncol. 2006 Jan 20;24[3]:519–521) and the Accreditation Council for Continuing Medical Education (ACCME), ASCO strives to promote balance, independence, objectivity, and scientific rigor through disclosure of financial and other interests, and identification and management of potential conflicts. According to the ASCO Conflict of Interest Policy, the following financial and other relationships must be disclosed: employment or leadership position, consultant or advisory role, stock ownership, honoraria, research funding, expert testimony, and other remuneration (J Clin Oncol. 2006 Jan 20;24[3]:520). The ASCO Conflict of Interest Policy disclosure requirements apply to all authors who submit abstracts to the Annual Meeting.

For clinical trials that began accrual on or after April 29, 2004, ASCO's Policy places some restrictions on the financial relationships of principal investigators (J Clin Oncol. 2006 Jan 20;24[3]:521). If a principal investigator holds any restricted relationships, his or her abstract will be ineligible for placement in the 2009 Annual Meeting unless the ASCO Ethics Committee grants an exception. Among the circumstances that might justify an exception are that the principal investigator (1) is a widely acknowledged expert in a particular therapeutic area; (2) is the inventor of a unique technology or treatment being evaluated in the clinical trial; or (3) is involved in international clinical oncology research and has acted consistently with recognized international standards of ethics in the conduct of clinical research. NIH-sponsored trials are exempt from the Policy restrictions. Abstracts for which authors requested and have been granted an exception in accordance with ASCO's Policy are designated with a caret symbol (^) in the Annual Meeting Proceedings.

For more information about the ASCO Conflict of Interest Policy and the exceptions process, please visit www.asco.org/conflictofinterest .

Erlotinib and bevacizumab in chemotherapy-naive performance status 2 patients with advanced non-small cell lung cancer

e19082

Background: Poor performance status is a negative prognostic variable for survival and a risk for increased toxicities with standard chemotherapy. A phase 2 study combining erlotinib (E) and bevacizumab (B) demonstrated encouraging efficacy in the treatment of recurrent NSCLC with acceptable toxicity. We, therefore, tested this regimen in untreated PS 2 patients with advanced NSCLC. Methods: Single-arm phase 2 trial in treatment-naïve patients with advanced non-squamous NSCLC and either a PS of 2 or age >75. Only patients eligible for bevacizumab per label were allowed onto study. Patients received E 150 mg orally daily and B 15 mg/kg IV on day 1 every 21 days for up to 6 cycles. The primary end-point was the rate of non progressive disease at 4 months (alternative hypothesis P>60%). Other end-points included overall survival, progression free survival (PFS), toxicity evaluations and patient-reported PS (PRPS) measures. Results: 25 patients were enrolled. Patient characteristics: 56% female, median age 77 years (range: 52–90); 88% stage IV; 92% were PS 2; 20% were never or remote smokers (> 30 years) The PRPS was 1, 2, 3 in 32%, 52%, 8% respectively with data on 2 patients missing. The rate of non-progression at 4 months was 40%; overall best response: 5% PR, 40% SD, 50% PD and 5% unevaluable; median PFS 2.6 months, 95% CI (1.3–5.1); MST 5.8 months, 95% CI (3.8- 8.7). 2 patients had G3 rash. G3 diarrhea, G3 hemorrhage, G3 proteinuria, G3 duodenal ulcer and G3 pneumonitis each developed in one patient. Conclusions: E + B is an active regimen with an acceptable toxicity profile; however, this study did not meet its’ primary endpoint. Further study of this combination will not be pursued in the Hoosier Oncology Group for this patient population.

[Table: see text]

Effect of cucurbitacins on bilirubin-albumin binding in human plasma

The aim of this study is to investigate the effect of three cucurbitacins (Cuc) E, D and I on the bilirubin-albumin binding, both in human serum albumin (HSA) and in plasma. Bilirubin-HSA solution and plasma free of cucurbitacins were prepared as well as others containing serial concentrations of cucurbitacins. The concentration of unbound bilirubin was determined in bilirubin-HSA solution and the direct and total bilirubin concentrations were measured in plasma (with normal or elevated bilirubinemia) by Jendrassik and Grof method. In the conditions we adopted Cuc E and D (to a lesser extent), decreased the levels of unbound bilirubin in bilirubin-HSA solution and decreased direct bilirubin concentration and total bilirubin concentration in plasma in a dose-dependent manner while Cuc I had no effect. The effect of Cuc is related to the presence of native HSA. Thus, when albumin was absent or has been denatured by heating or by urea, Cuc E did not modify bilirubin levels, suggesting that the native structure of albumin is essential for such activity. The interaction of HSA with Cuc E was investigated by fluorescence spectroscopy. Cuc E increased the intrinsic fluorescence of the protein and the magnitude of fluorescence intensity of bilirubin-albumin complex. We concluded that Cuc E and D produced a rearrangement in the structure of albumin, particularly in the domain-II, resulting in an increase in the binding of bilirubin to albumin regardless to whether it's conjugated to glucuronic acid or unconjugated.

Radiation binary targeted therapy for HER-2 positive breast cancers: assumptions, theoretical assessment and future directions

A novel radiation targeted therapy is investigated for HER-2 positive breast cancers. The proposed concept combines two known approaches, but never used together for the treatment of advanced, relapsed or metastasized HER-2 positive breast cancers. The proposed radiation binary targeted concept is based on the anti HER-2 monoclonal antibodies (MABs) that would be used as vehicles to transport the nontoxic agent to cancer cells. The anti HER-2 MABs have been successful in targeting HER-2 positive breast cancers with high affinity. The proposed concept would utilize a neutral nontoxic boron-10 predicting that anti HER-2 MABs would assure its selective delivery to cancer cells. MABs against HER-2 have been a widely researched strategy in the clinical setting. The most promising antibody is Trastuzumab (Herceptin). Targeting HER-2 with the MAB Trastuzumab has been proven to be a successful strategy in inducing tumour regression and improving patient survival. Unfortunately, these tumours become resistant and afflicted women succumb to breast cancer. In the proposed concept, when the tumour region is loaded with boron-10 it is irradiated with neutrons (treatment used for head and neck cancers, melanoma and glioblastoma for over 40 years in Japan and Europe). The irradiation process takes less than an hour producing minimal side effects. This paper summarizes our recent theoretical assessments of radiation binary targeted therapy for HER-2 positive breast cancers on: the effective drug delivery mechanism, the numerical model to evaluate the targeted radiation delivery and the survey study to find the neutron facility in the world that might be capable of producing the radiation effect as needed. A novel method of drug delivery utilizing Trastuzumab is described, followed by the description of a computational Monte Carlo based breast model used to determine radiation dose distributions. The total flux and neutron energy spectra of five currently available neutron irradiation treatment facilities are examined for this application. The tumour boron concentrations and tumour to healthy tissue concentration ratios required to deliver 50 Gy-Eq to the tumour without exceeding 18 Gy-Eq in the skin are determined, as well as the associated therapeutic ratios. Discussion is provided to address the future research direction for assessing the feasibility of the proposed concept.

A Model for Double Asymmetric Induction in the Stereocontrolled Reduction of Glycosyl α-Ketoesters with Oxazaborolidines

Experimental diastereoselectivities for the stereocontrolled reduction of glycosyl alpha-ketoesters into the corresponding alpha-hydroxyesters have recently been reported with unexpected results. The process is catalyzed by a chiral oxazaborolidine derivative (the so-called CBS catalyst) and represents the key step in the synthesis of glycosyl alpha-amino acids synthons, a class of compounds that allow preparation of natural glycopeptides analogues exhibiting potential therapeutic relevance. Good to very good diastereomeric excesses have been obtained for a series of reactions with different glucidic derivatives, but surprisingly, the major product obtained does not correspond to that predicted by using Corey's model. In the present work, we carry out a theoretical investigation of these reactions at the density functional level. Separated effects from the catalyst and from the glucidic derivative have been computed to rationalize the observed diastereoselectivities and the double asymmetric induction.

Quantification of phthalocyanine concentration in rat tissue using laser-induced fluorescence spectroscopy

Quantification of photosensitizer concentration in tissue should improve planning and outcome of photodynamic therapy. Laser-induced fluorescence (LIF) can be used to measure in vivo fluorescence of photosensitizers in tissue. This study was designed to determine if in vivo fluorescence intensity of chloroaluminum phthalocyanine tetrasulfonate correlates with its concentration in different rat tissues. Following LIF measurements, the animals were humanely euthanized and the concentration of phthalocyanine in different tissues was determined using chemical extraction technique. The correlation of phthalocyanine fluorescence intensity and its concentration was determined for each tissue using Pearson product-moment correlation analysis. A strong correlation between in vivo phthalocyanine fluorescence intensity and its concentration was found for spleen, kidney, liver, and chemically induced mammary adenocarcinoma. Low correlation was found for thigh skin and planum of nose. No correlation was found for thigh muscle and tongue.