Quantitative Analysis of Serial Positron Emission Tomography Imaging in Men with Metastatic Castration-resistant Prostate Cancer Treated with Enzalutamide.

BACKGROUND: The emergence of positron emission tomography (PET) in prostate cancer is impacting clinical practice, but little is known about PET imaging as a tool to determine treatment failure in metastatic castration-resistant prostate cancer (mCRPC). OBJECTIVE: To evaluate PET imaging dynamics in mCRPC patients on enzalutamide with stable computed tomography (CT) and technetium-99m (Tc99) bone scans. DESIGN, SETTING, AND PARTICIPANTS: All patients were on treatment with enzalutamide for first-line mCRPC in a clinical trial at the National Cancer Institute (Bethesda, MD, USA). A volunteer sample had serial 18F-sodium fluoride (NaF) PET in parallel with CT and Tc99. Regions of interest (ROIs) on NaF were analyzed quantitatively for response. INTERVENTION: Patients were randomized to enzalutamide with/without a cancer immunotherapy, Prostvac. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: A post hoc, descriptive analysis was performed comparing the changes seen on CT and Tc99 as per RECIST 1.1 with NaF PET scans including the use of a quantitative analysis. RESULTS AND LIMITATIONS: Eighteen mCRPC patients had 67 NaF scans. A total of 233 ROIs resolved after treatment, 52 (22%) of which eventually retuned while on therapy. In all, 394 new ROIs were seen, but 112(28%) resolved subsequently. Of 18 patients, 14 had new ROIs that ultimately resolved after appearing. Many patients experienced progression in a minority of lesions, and one patient with radiation intervention to oligoprogression had a remarkable response. This study is limited by its small number of patients and post hoc nature. CONCLUSIONS: These data highlight the dynamic nature of NaF PET in mCRPC patients treated with enzalutamide, where not all new findings were ultimately related to disease progression. This analysis also provides a potential strategy to identify and intervene in oligoprogression in prostate cancer. PATIENT SUMMARY: In this small analysis of patients with prostate cancer on enzalutamide, changes on 18F-sodium fluoride positron emission tomography (PET) imaging were not always associated with treatment failure. Caution may be indicated when using PET imaging to determine whether new therapy is needed.

Flutamide With or Without PROSTVAC in Non-metastatic Castration Resistant (M0) Prostate Cancer.

BACKGROUND: Before 2018, there was no standard of care for non-metastatic (M0) castration resistant prostate cancer nmCRPC. Androgen receptor antagonists (ARAs) were commonly used sequentially nmCRPC. METHODS: This was a multicenter, randomized clinical trial comparing the ARA flutamide+/-PROSTVAC, a pox viral vaccine targeting PSA that includes T-cell co-stimulatory molecules. Eligible men had negative CT and Tc99 bone scans, and rising PSA on ADT. Previous treatment with ARA was a stratification factor. Patients were also evaluated for antigen-specific immune responses using intracellular cytokine staining. RESULTS: Thirty-three patients randomized to flutamide and 31 to flutamide+vaccine. The median age was 71.8 and 69.8 years, respectively. The median time to treatment failure after a median potential follow-up of 46.7 months was, 4.5 months (range 2-70) for flutamide alone vs. 6.9 months (2.5-40; P = .38) with flutamide+vaccine. Seven patients in each arm had a >50% PSA response. Antigen-specific responses were similar in both arms (58% of patients in flutamide alone and 56% in flutamide+vaccine). The treatments were well tolerated. The most common side effect > grade 2 was injection site reaction seen in 29/31 vaccine patients which were self-limiting. CONCLUSION: The combination of flutamide+PROSTVAC did not improve outcomes in men with nmCRPC compared with flutamide alone. (ClinicalTrials.gov Identifier: NCT00450463).

First-in-human phase 1 clinical trial of anti-core 1 O-glycans targeting monoclonal antibody NEO-201 in treatment-refractory solid tumors.

BACKGROUND: NEO201 is a humanized IgG1 monoclonal antibody (mAb) generated against tumor-associated antigens from patients with colorectal cancer. NEO-201 binds to core 1 or extended core 1 O-glycans expressed by its target cells. Here, we present outcomes from a phase I trial of NEO-201 in patients with advanced solid tumors that have not responded to standard treatments. METHODS: This was a single site, open label 3 + 3 dose escalation clinical trial. NEO-201 was administered intravenously every two weeks in a 28-day cycle at dose level (DL) 1 (1 mg/kg), DL 1.5 (1.5 mg/kg) and DL 2 (2 mg/kg) until dose limiting toxicity (DLT), disease progression, or patient withdrawal. Disease evaluations were conducted after every 2 cycles. The primary objective was to assess the maximum tolerated dose (MTD) and recommended phase 2 dose (RP2D) of NEO-201. The secondary objective was to assess the antitumor activity by RECIST v1.1. The exploratory objectives assessed pharmacokinetics and the effect of NEO-201 administration on immunologic parameters and their impact on clinical response. RESULTS: Seventeen patients (11 colorectal, 4 pancreatic and 2 breast cancers) were enrolled; 2 patients withdrew after the first dose and were not evaluable for DLT. Twelve of the 15 patients evaluable for safety discontinued due to disease progression and 3 patients discontinued due to DLT (grade 4 febrile neutropenia [1 patient] and prolonged neutropenia [1 patient] at DL 2, and grade 3 prolonged (> 72 h) febrile neutropenia [1 patient] at DL 1.5). A total of 69 doses of NEO-201 were administered (range 1-15, median 4). Common (> 10%) grade 3/4 toxicities occurred as follows: neutropenia (26/69 doses, 17/17 patients), white blood cell decrease (16/69 doses, 12/17 patients), lymphocyte decrease (8/69 doses, 6/17 patients). Thirteen patients were evaluable for disease response; the best response was stable disease (SD) in 4 patients with colorectal cancer. Analysis of soluble factors in serum revealed that a high level of soluble MICA at baseline was correlated with a downregulation of NK cell activation markers and progressive disease. Unexpectedly, flow cytometry showed that NEO-201 also binds to circulating regulatory T cells and reduction of the quantities of these cells was observed especially in patients with SD. CONCLUSIONS: NEO-201 was safe and well tolerated at the MTD of 1.5 mg/kg, with neutropenia being the most common adverse event. Furthermore, a reduction in the percentage of regulatory T cells following NEO-201 treatment supports our ongoing phase II clinical trial evaluating the efficiency of the combination of NEO-201 with the immune checkpoint inhibitor pembrolizumab in adults with treatment-resistant solid tumors. TRIAL REGISTRATION: NCT03476681 . Registered 03/26/2018.

Identification of the O-Glycan Epitope Targeted by the Anti-Human Carcinoma Monoclonal Antibody (mAb) NEO-201.

Truncated O-glycans expressed in cancer cells support tumor progression, and they may serve as potential targets to improve the monitoring and treatment of cancers. Previously, we reported that NEO-201 binds to several tumors expressing tumor-associated CEACAM5 and CEACAM6 variants but does not bind to those expressed in healthy tissues. This specific binding may be associated with the presence of truncated O-glycans attached on the protein sequence of these variants. To evaluate the glycosylation pattern targeted by NEO-201 we performed an O-glycan array consisting of 94 O-glycans. O-glycan profiles were elucidated from the human pancreatic cancer cell line CFPAC-1, human hematological neoplastic cells (HL-60, U937, K562) and human neutrophils. The O-glycan array analysis showed that NEO-201 interacts with core 1-4 O-glycans and that the binding to a specific core 1 O-glycan was the strongest. The O-glycan profiling of the NEO-201-reactive cells CFPAC-1, HL-60, U937 and human neutrophils showed that cells recognized by NEO-201 express mostly core 1 and/or extended core 1 O-glycans. In addition, NEO-201 mediates antibody-dependent cell-mediated cytotoxicity (ADCC) against tumor cells expressing core 1 or extended core 1 O-glycan profiles. These results demonstrated that NEO-201 binds to core 1 and extended core 1 O-glycans expressed in its target cells. Since GalNAc residue can be added onto threonine and serine to form O-glycans, it is very likely that NEO-201 recognizes these O-glycans attached to any protein with amino acid regions containing serine and threonine.

Development and Characterization of an Anti-Cancer Monoclonal Antibody for Treatment of Human Carcinomas.

NEO-201 is an IgG1 humanized monoclonal antibody (mAb) that binds to tumor-associated variants of carcinoembryonic antigen-related cell adhesion molecule (CEACAM)-5 and CEACAM-6. NEO-201 reacts to colon, ovarian, pancreatic, non-small cell lung, head and neck, cervical, uterine and breast cancers, but is not reactive against most normal tissues. NEO-201 can kill tumor cells via antibody-dependent cell-mediated cytotoxicity (ADCC) and complement dependent cytotoxicity (CDC) to directly kill tumor cells expressing its target. We explored indirect mechanisms of its action that may enhance immune tumor killing. NEO-201 can block the interaction between CEACAM-5 expressed on tumor cells and CEACAM-1 expressed on natural killer (NK) cells to reverse CEACAM-1-dependent inhibition of NK cytotoxicity. Previous studies have demonstrated safety/tolerability in non-human primates, and in a first in human phase 1 clinical trial at the National Cancer Institute (NCI). In addition, preclinical studies have demonstrated that NEO-201 can bind to human regulatory T (Treg) cells. The specificity of NEO-201 in recognizing suppressive Treg cells provides the basis for combination cancer immunotherapy with checkpoint inhibitors targeting the PD-1/PD-L1 pathway.

Clinical and immunologic impact of short-course enzalutamide alone and with immunotherapy in non-metastatic castration sensitive prostate cancer.

BACKGROUND: The standard treatment for non-metastatic castration sensitive prostate cancer (nmCSPC) is androgen deprivation therapy (ADT) or surveillance. This study evaluated the potential synergy of immunotherapy and enzalutamide (without ADT) in nmCSPC. In addition, the immunologic impact of enzalutamide was also evaluated in men with normal testosterone. METHODS: Patients with rising prostate-specific antigen (PSA) after definitive therapy, normal testosterone and no radiographic metastasis were randomized to enzalutamide for 3 months with/without PROSTVAC for 6 months. Thereafter, patients could be retreated with another 3 month course of enzalutamide when PSA returned to baseline. Immune profiles were evaluated in these patients. RESULTS: Thirty-eight patients were randomized with a median PSA=4.38 ng/dL and PSA doubling time=4.1 months. No difference was observed between the two groups for PSA growth kinetics, but PSA responses to enzalutamide were noteworthy regardless of PROSTVAC. The median PSA decline after short-course enzalutamide without ADT/testosterone lowering therapy was 99% in both courses. The median time to PSA recovery to baseline after each 84-day course of enzalutamide was also noteworthy because of the duration of response after enzalutamide was discontinued. After the first and second 3 month cycle of enzalutamide, PSA recovery to baseline took a median 224 (range 84-1246) and 189 days (78-400), respectively. The most common adverse events related to the enzalutamide were grade 1 fatigue (71%) and grade 1 breast pain/nipple tenderness (81%). The only grade 3 toxicity was aspartate aminotransferase (AST)/alanine aminotransferase (ALT) elevation in two patients. Enzalutamide was independently associated with immune changes, increasing natural killer cells, naïve-T cells, and decreasing myeloid-derived suppressor cells. CONCLUSIONS: Three months of enzalutamide without ADT induced substantial PSA control beyond the treatment period and was repeatable, perhaps representing an alternative to intermittent ADT in nmCSPC. In addition, enzalutamide was associated with immune changes that could be relevant as future immune combinations are developed. TRAIL REGISTRATION NUMBER: clinicaltrials.gov (NCT01875250).

Cabozantinib plus docetaxel and prednisone in metastatic castration-resistant prostate cancer.

OBJECTIVE: To evaluate the safety and efficacy of cabozantinib combined with docetaxel. PATIENTS AND METHODS: This was a phase 1/2 multicentre study in patients with metastatic castration-resistant prostate cancer (mCRPC). Docetaxel (75 mg/m2 every 3 weeks with daily prednisone 10 mg) was combined with escalating doses of daily cabozantinib (20, 40 and 60 mg). Based on the results of the phase 1 study, the investigation was expanded into a randomized study of docetaxel with prednisone (hereafter 'docetaxel/prednisone') plus the maximum tolerated dose (MTD) of cabozantinib compared with docetaxel/prednisone alone. RESULTS: A total of 44 men with mCRPC were enrolled in this phase 1/2 trial. An MTD of 40 mg cabozantinib plus docetaxel/prednisone was determined. Dose-limiting toxicities were neutropenic fever and palmar-plantar erythrodysesthesia, and there was one death attributable to a thromboembolic event. In addition, grade 3 or 4 myelosuppression, hypophosphataemia and neuropathy were seen in three or more patients. In the phase 1 study, the median time to progression (TTP) and overall survival (OS) time were 13.6 and 16.3 months, respectively. In the phase 2 study, which was terminated early because of poor accrual, the median TTP and OS favoured the combination (n = 13) compared to docetaxel/prednisone alone (n = 12; 21.0 vs 6.6 months; P = 0.035 and 23.8 vs 15.6 months; P = 0.072, respectively). CONCLUSION: Despite the limited number of patients in this study, preliminary data suggest that cabozantinib can be safely added to docetaxel/prednisone with possible enhanced efficacy.

Evaluation of the Anti-Tumor Activity of the Humanized Monoclonal Antibody NEO-201 in Preclinical Models of Ovarian Cancer.

Purpose: Despite high initial response rates with cytoreductive surgery, conventional chemotherapy and the incorporation of biologic agents, ovarian cancer patients often relapse and die from their disease. New approaches are needed to improve patient outcomes. This study was designed to evaluate the antitumor activity of NEO-201 monoclonal antibody (mAb) in preclinical models of ovarian cancer where the NEO-201 target is highly expressed. Experimental Design: Functional analysis of NEO-201 against tumor cell lines was performed by antibody-dependent cellular cytotoxicity (ADCC) assays. Binding of NEO-201 to tumor tissues and cell lines were determined by immunohistochemistry (IHC) and flow cytometry, respectively. Further characterization of the antigen recognized by NEO-201 was performed by mass spectrometry. Ovarian cancer models were used to evaluate the anti-tumor activity of NEO-201 in vivo. NEO-201 at a concentration of 250 g/mouse was injected intraperitoneally (IP) on days 1, 4, and 8. Human PBMCs were injected IP simultaneously as effector cells. Results: Both IHC and flow cytometry revealed that NEO-201 binds prominently to the colon, pancreatic, and mucinous ovarian cancer tissues and cell lines. Immunoprecipitation of the antigen recognized by NEO-201 was performed in human ovarian, colon, and pancreatic cancer cell lines. From these screening, carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5) and CEACAM6 were identified as the most likely targets of NEO-201. Our results confirmed that NEO-201 binds different types of cancers; the binding is highly selective for the tumor cells without cross reactivity with the surrounding healthy tissue. Functional analysis revealed that NEO-201 mediates ADCC killing against human ovarian and colorectal carcinoma cell lines in vitro. In addition, NEO-201 inhibited tumor growth in the presence of activated human PBMCs in orthotopic mouse models of both primary and metastatic ovarian cancer. Importantly, NEO-201 prolonged survival of tumor-bearing mice. Conclusions: These data suggested that NEO-201 has an antitumor activity against tumor cells expressing its antigen. Targeting an antigen expressed in tumors, but not in normal tissues, allows patient selection for optimal treatment. These findings strongly indicate that NEO-201 warrants clinical testing as both a novel therapeutic and diagnostic agent for treatment of ovarian carcinomas. A first in human clinical trial evaluating NEO-201 in adults with chemo-resistant solid tumors is ongoing at the NIH clinical Center.

Phase II Study of Ensituximab, a Novel Chimeric Monoclonal Antibody, in Adults with Unresectable, Metastatic Colorectal Cancer.

PURPOSE: Patients with metastatic colorectal cancer refractory to chemotherapy have limited treatment options. Ensituximab (NEO-102) is a novel chimeric mAb targeting a variant of MUC5AC with specificity to colorectal cancer. PATIENTS AND METHODS: Single-arm, phase II trial assessed the efficacy and safety of ensituximab in patients with advanced, refractory cancer who expressed MUC5AC antigen in tumor tissue. Ensituximab was administered intravenously every 2 weeks with 3 mg/kg as recommended phase II dose (RP2D). A minimum sample size of 43 patients was required on the basis of the assumption that ensituximab would improve median overall survival (OS) by 7 months using a one-sided significance level of 10% and 80% power. Written informed consent was obtained from all patients. RESULTS: Sixty-three patients with advanced, refractory colorectal cancer were enrolled and 53 subjects were treated in phase II arm. Median age was 58 years and 46% of the patients were female. Among 57 evaluable patients, median OS was 6.8 months. No responses were observed, and stable disease was achieved in 21% of the patients. The most common treatment-related adverse events (AE) at RP2D included fatigue (38%), anemia (30%), nausea (15%), vomiting (11%), increased bilirubin (9%), constipation (8%), decreased appetite (6%), and diarrhea (6%). Serious AEs at least possibly related to ensituximab occurred in 4 patients and included anemia, nausea, increased bilirubin, and hypoxia. No patients discontinued treatment due to drug-related AEs. CONCLUSIONS: Ensituximab was well tolerated and demonstrated modest antitumor activity in patients with heavily pretreated refractory colorectal cancer.

An IL-15 Superagonist, ALT-803, Enhances Antibody-Dependent Cell-Mediated Cytotoxicity Elicited by the Monoclonal Antibody NEO-201 Against Human Carcinoma Cells.

BACKGROUND: A major mechanism of action for therapeutic antibodies is antibody-dependent cell-mediated cytotoxicity (ADCC). ALT-803 is an interleukin-15 superagonist complex that enhances ADCC against human carcinoma cells in vitro and exerts an antitumor activity in murine, rat, and human carcinomas in vivo. The authors investigated the ability of ALT-803 to modulate ADCC mediated by the humanized IgG1 monoclonal antibody (mAb) NEO-201 against human carcinoma cells. MATERIALS AND METHODS: ALT-803 modulating activity on ADCC mediated by NEO-201 was evaluated on several NEO-201 ligand-expressing human carcinoma cells. Purified human natural killer (NK) cells from multiple healthy donors were treated with ALT-803 before their use as effectors in ADCC assay. Modulation of NK cell phenotype and cytotoxic function by exposure to ALT-803 was evaluated by flow cytometry and gene expression analysis. RESULTS: ALT-803 significantly enhanced ADCC mediated by NEO-201. ALT-803 also upregulated NK activating receptors, antiapoptotic factors, and factors involved in the NK cytotoxicity, as well as downregulated gene expression of NK inhibiting receptors. CONCLUSIONS: These findings indicate that ALT-803 can enhance ADCC activity mediated by NEO-201, by modulating NK activation and cytotoxicity, suggesting a possible clinical use of ALT-803 in combination with NEO-201 for the treatment of human carcinomas.

Preclinical Characterization of a Novel Monoclonal Antibody NEO-201 for the Treatment of Human Carcinomas.

NEO-201 is a novel humanized IgG1 monoclonal antibody that was derived from an immunogenic preparation of tumor-associated antigens from pooled allogeneic colon tumor tissue extracts. It was found to react against a variety of cultured human carcinoma cell lines and was highly reactive against the majority of tumor tissues from many different carcinomas, including colon, pancreatic, stomach, lung, and breast cancers. NEO-201 also exhibited tumor specificity, as the majority of normal tissues were not recognized by this antibody. Functional assays revealed that treatment with NEO-201 is capable of mediating both antibody-dependent cellular cytotoxicity (ADCC) and complement-dependent cytotoxicity (CDC) against tumor cells. Furthermore, the growth of human pancreatic xenograft tumors in vivo was largely attenuated by treatment with NEO-201 both alone and in combination with human peripheral blood mononuclear cells as an effector cell source for ADCC. In vivo biodistribution studies in human tumor xenograft-bearing mice revealed that NEO-201 preferentially accumulates in the tumor but not organ tissue. Finally, a single-dose toxicity study in non-human primates demonstrated safety and tolerability of NEO-201, as a transient decrease in circulating neutrophils was the only related adverse effect observed. These findings indicate that NEO-201 warrants clinical testing as both a novel diagnostic and therapeutic agent for the treatment of a broad variety of carcinomas.

A Phase II Clinical Trial of TRC105 (Anti-Endoglin Antibody) in Adults With Advanced/Metastatic Urothelial Carcinoma.

BACKGROUND: In this trial we assessed the efficacy and tolerability of TRC105, a chimeric monoclonal antibody that targets CD105 (endoglin) in patients with advanced, previously treated urothelial carcinoma (UC). PATIENTS AND METHODS: Patients received TRC105 15 mg/kg every 2 weeks on days 1 and 15 of each 28-day cycle. The primary end point was progression-free survival (PFS) at 6 months. Secondary end points included safety, toxicity, and overall survival (OS). CD105 expression was evaluated using immunohistochemistry (IHC) in a separate cohort of 50 UC patients. Biomarker studies included immune subsets, circulating tumor cells (CTCs), circulating endothelial cells (CECs), circulating endothelial progenitor cells (CEPs), and osteopontin. RESULTS: Of 13 patients enrolled, 12 were evaluable for OS and PFS. The 3-month PFS probability was 18.2% (median PFS, 1.9 months [95% confidence interval (CI), 1.8-2.1 months). This met the criterion for ending accrual on the basis of the 2-stage design. Median OS was 8.3 months (95% CI, 3.3-17.0 months). IHC for CD105 scores was not associated with T stage (P = .26) or presence of lymph nodes (P = .64). Baseline levels of regulatory T and B cells, CEPs, and changes in CEC level after TRC105 exhibited trends toward an association with PFS or OS. CTCs pre- and post-TRC105 were detected in 4 of 4 patients. CONCLUSION: Although TRC105 was well tolerated, it did not improve 6-month PFS in heavily pretreated patients with advanced UC. CD105 staining was present in 50% of UC tumors at different intensities. Our observations on the pharmacodynamic significance of immune subsets, CECs, and CTCs warrant further study.

TARP vaccination is associated with slowing in PSA velocity and decreasing tumor growth rates in patients with Stage D0 prostate cancer.

T-cell receptor alternate reading frame protein (TARP) is a 58-residue protein over-expressed in prostate and breast cancer. We investigated TARP peptide vaccination's impact on the rise in PSA (expressed as Slope Log(PSA) or PSA Doubling Time (PSADT)), validated tumor growth measures, and tumor growth rate in men with Stage D0 prostate cancer. HLA-A*0201 positive men were randomized to receive epitope-enhanced (29-37-9V) and wild-type (27-35) TARP peptides administered as a Montanide/GM-CSF peptide emulsion or as an autologous peptide-pulsed dendritic cell vaccine every 3 weeks for a total of five vaccinations with an optional 6th dose of vaccine at 36 weeks based on immune response or PSADT criteria with a booster dose of vaccine for all patients at 48 and 96 weeks. 41 patients enrolled with median on-study duration of 75 weeks at the time of this analysis. Seventy-two percent of patients reaching 24 weeks and 74% reaching 48 weeks had a decreased Slope Log(PSA) compared to their pre-vaccination baseline (p = 0.0012 and p = 0.0004 for comparison of overall changes in Slope Log(PSA), respectively). TARP vaccination also resulted in a 50% decrease in median tumor growth rate (g): pre-vaccine g = 0.0042/day, post-vaccine g = 0.0021/day (p = 0.003). 80% of subjects exhibited new vaccine-induced TARP-specific IFNγ ELISPOT responses but they did not correlate with decreases in Slope Log(PSA). Thus, vaccination with TARP peptides resulted in significant slowing in PSA velocity and reduction in tumor growth rate in a majority of patients with PSA biochemical recurrence.

A phase 1 dose-escalation study of NEO-102 in patients with refractory colon and pancreatic cancer.

PURPOSE: NEO-102 is a novel chimeric IgG1 monoclonal antibody which recognizes a variant form of MUC5AC expressed specifically by human pancreatic and colorectal tumors. Preclinical models have demonstrated encouraging signs of anti-tumor activity through antibody-dependent cell-mediated cytotoxicity. METHODS: This is a phase 1, dose-escalation trial of NEO-102 (Ensituximab) for patients with refractory pancreatic and colorectal cancer. The primary objective was to determine safety and tolerability of escalating doses of NEO-102. Secondary objectives were to assess pharmacokinetics, anti-tumor activity and biologic correlates. Patients whose tumors express NPC-1 antigen were eligible. Dose-escalation was performed in a 3 + 3 design at doses of 1.5, 2, 3 and 4 mg/kg. RESULTS: A total of 19 patients (4 pancreatic and 15 colon cancer) were enrolled at participating institutions in the treatment phase. Most common treatment-related adverse events included anemia, fatigue, fevers, chills and flushing. There was no detectable hemolysis. Of twelve patients evaluable for disease response, the response rate at week 8 included 5 patients with stable disease and 8 patients with progressive disease (PD). Treatment-related grade 3/4 hyperbilirubinemia and anemia were observed at 4 mg/m2. Reversible hypoxia at 3 mg/kg was a dose-limiting toxicity. The maximum tolerated dose was established at 3 mg/kg. Of 74 patients who underwent tissue screening, positive NPC-1 expression was 47 % in colon and 59 % in pancreatic cancer. CONCLUSIONS: Treatment with the NEO-102, in this first-in-human study, is well tolerated with a manageable safety profile. A maximum tolerated dose of 3 mg/kg has been established. Toxicity profile is typical for this therapeutic class and allows for combination with conventional cytotoxic therapies.

Phase II trial of docetaxel, bevacizumab, lenalidomide and prednisone in patients with metastatic castration-resistant prostate cancer.

OBJECTIVE: To determine the safety and clinical efficacy of two anti-angiogenic agents, bevacizumab and lenalidomide, with docetaxel and prednisone. PATIENTS AND METHODS: Eligible patients with metastatic castration-resistant prostate cancer enrolled in this open-label, phase II study of lenalidomide with bevacizumab (15 mg/kg), docetaxel (75 mg/m(2) ) and prednisone (10 mg daily). Docetaxel and bevacizumab were administered on day 1 of a 3-week treatment cycle. To establish safety, lenalidomide dosing in this combination was escalated in a conventional 3 + 3 design (15, 20 and 25 mg daily for 2 weeks followed by 1 week off). Patients received supportive measures including prophylactic pegfilgrastim and enoxaparin. The primary endpoints were safety and clinical efficacy. RESULTS: A total of 63 patients enrolled in this trial. Toxicities were manageable with most common adverse events (AEs) being haematological, and were ascertained by weekly blood counts. Twenty-nine patients (46%) had grade 4 neutropenia, 20 (32%) had grade 3 anaemia and seven (11%) had grade 3 thrombocytopenia. Despite frequent neutropenia, serious infections were rare. Other common non-haematological grade 3 AEs included fatigue (10%) and diarrhoea (10%). Grade 2 AEs in >10% of patients included anorexia, weight loss, constipation, osteonecrosis of the jaw, rash and dyspnoea. Of 61 evaluable patients, 57 (93%), 55 (90%) and 33 (54%) had PSA declines of >30, >50 and >90%, respectively. Of the 29 evaluable patients, 24 (86%) had a confirmed radiographic partial response. The median times to progression and overall survival were 18.2 and 24.6 months, respectively. CONCLUSIONS: With appropriate supportive measures, combination angiogenesis inhibition can be safely administered and potentially provide clinical benefit. These hypothesis-generating data would require randomized trials to confirm the findings.

Docetaxel Alone or in Combination With a Therapeutic Cancer Vaccine (PANVAC) in Patients With Metastatic Breast Cancer: A Randomized Clinical Trial.

IMPORTANCE: Previous phase 1 and 2 trials of PANVAC, a poxviral-based cancer vaccine, have suggested clinical efficacy in some patients with breast, ovarian, and colorectal cancer and have shown evidence of immunologic activity. Preclinical data have shown that docetaxel can modify tumor phenotype, making tumor cells more amenable to T cell-mediated killing. OBJECTIVE: The goal of this study was to determine if the treatment combination of docetaxel and PANVAC improves clinical outcomes in patients with metastatic breast cancer compared with docetaxel treatment alone. DESIGN, SETTING, AND PARTICIPANTS: Between May 2006 and February 2012, this open-label, phase 2 randomized clinical trial enrolled 48 patients with metastatic breast cancer of all subtypes, without limitation on other lines of previous therapy, to receive treatment with either docetaxel with PANVAC (arm A) or docetaxel alone (arm B). Final clinical data were collected on September 16, 2013. All patients were treated at either the National Cancer Institute or the Department of Breast Medical Oncology, MD Anderson Cancer Center. MAIN OUTCOMES AND MEASURES: The primary end point was progression-free survival (PFS), using a phase 2.5 statistical design, with the intent of identifying a trend toward benefit (defined as 1-sided P≤.10) to guide a larger trial design. Secondary end points included safety and immunologic correlative studies. RESULTS: Forty-eight participants were enrolled: 25 were randomized to the combination treatment arm A, and 23 to arm B. No patient remained in the study at the time of the final analysis. Patient and tumor characteristics were well matched. Analysis of adverse events in both treatment arms demonstrated very little difference between the 2 groups. In the combination treatment arm (arm A), statistically significant increases were noted in the frequency of grades 1 and 2 edema (P=.02, likely related to greater median number of docetaxel cycles) and injection-site reactions (P<.001). In the final data analysis, median PFS was 7.9 months in arm A vs 3.9 months in arm B (hazard ratio, 0.65 [95% CI, 0.34-1.14]; P=.09). CONCLUSIONS AND RELEVANCE: The results suggest that the combination of PANVAC with docetaxel in metastatic breast cancer may provide a clinical benefit. This study was hypothesis generating and provides both rationale and statistical assumptions for a larger definitive randomized study. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00179309.

Phase I Trial of a Yeast-Based Therapeutic Cancer Vaccine (GI-6301) Targeting the Transcription Factor Brachyury.

The nuclear transcription factor brachyury has previously been shown to be a strong mediator of the epithelial-to-mesenchymal transition (EMT) in human carcinoma cells and a strong negative prognostic factor in several tumor types. Brachyury is overexpressed in a range of human carcinomas as well as in chordoma, a rare tumor for which there is no standard systemic therapy. Preclinical studies have shown that a recombinant Saccharomyces cerevisiae (yeast) vaccine encoding brachyury (GI-6301) can activate human T cells in vitro. A phase I dose-escalation (3+3 design) trial enrolled 34 patients at 4 dose levels [3, 3, 16, and 11 patients, respectively, at 4, 16, 40, and 80 yeast units (YU)]. Expansion cohorts were enrolled at 40- and 80-YU dose levels for analysis of immune response and clinical activity. We observed brachyury-specific T-cell immune responses in the majority of evaluable patients despite most having been heavily pretreated. No evidence of autoimmunity or other serious adverse events was observed. Two chordoma patients showed evidence of disease control (one mixed response and one partial response). A patient with colorectal carcinoma, who enrolled on study with a large progressing pelvic mass and rising carcinoembryonic antigen (CEA), remains on study for greater than 1 year with stable disease, evidence of decreased tumor density, and decreased serum CEA. This is the first-in-human study to demonstrate the safety and immunogenicity of this therapeutic cancer vaccine and provides the rationale for exploration in phase II studies. A randomized phase II chordoma study is now enrolling patients.