Surgical resection is associated with improved long-term survival of patients with resectable pancreatic head cancer compared to multiagent chemotherapy

BACKGROUND

Standard of care for resectable pancreatic cancer is a combination of surgical resection (SR) and multiagent chemotherapy (MCT). We aim to determine whether SR or MCT is associated with superior survival for patients receiving only single-modality therapy.

METHODS

Patients with stage I-IIb pancreatic head adenocarcinoma who received either MCT or SR were identified in the NCDB (2013-2015). Following a piecewise approach to estimating hazards over the course of follow-up, conditional overall survival (OS) at 30, 60, and 90 days after treatment initiation was estimated using landmark analyses.

RESULTS

3103 patients received MCT alone (60.3%) and 2043 underwent SR alone (39.7%). SR had an OS disadvantage at 30 (HR 3.99, 95% CI 3.12-5.11) and 60 days (HR 1.85, 95% CI 1.4-2.45), but an OS advantage after 90 days (HR 0.59, 95% CI 0.55-0.64). In a landmark analysis conditioned on 90 days survival post treatment initiation, median OS was improved for SR (17.0 vs. 12.2 months, p < 0.0001); SR improved 3-year OS by 21.3% (p < 0.05), despite patients being older (median 72 vs. 67 years, p < 0.0001) with higher Charlson-Deyo comorbidity scores (≥2: 11.2 vs. 8.6%, p = 0.006).

CONCLUSION

For patients with resectable pancreatic cancer, SR is associated with superior long-term survival compared to MCT.

Abstract 6536: Safety and efficacy of autologous tumor lysate particle loaded dendritic cell (TLPLDC) vaccination in combination with systemic therapies in patients with metastatic melanoma

Background: The treatment of melanoma has changed drastically with the advent of immunotherapy, particularly checkpoint inhibition (CPI). Unfortunately, only 50-60% of tumors respond to current immunotherapy. The autologous tumor lysate, particle loaded, dendritic cell (TLPLDC) vaccine utilizes the whole antigenic panel of the patient's tumor to stimulate T-cells and may work synergistically with other immunotherapies. We have previously demonstrated both safety and efficacy of TLPLDC vaccine as adjuvant therapy for patients (pts) with resected stage III or IV melanoma who complete the primary vaccine series. Here, we describe results in pts with metastatic melanoma treated with the TLPLDC vaccine together with other approved therapies.

Methods: The TLPLDC vaccine is created by loading autologous tumor lysate into yeast cell wall particles which are then phagocytosed by autologous dendritic cells ex-vivo. Pts who recurred while enrolled in a randomized phase IIb trial of adjuvant TLPLDC vaccine (crossover arm) and pts with metastatic melanoma with measurable disease (MM arm) were offered TLPLDC vaccine in an open-label fashion in addition to other approved therapies as determined by their treating physician. The vaccine is given via intradermal injection monthly x4 followed by boosters at six and nine months. Tumor response is measured by RECIST 1.1 criteria.

Results: To date, 53 pts have been enrolled (28 in the crossover arm and 25 in the MM arm). Within the crossover arm, 18 pts had received TLPLDC as part of the phase IIb trial, 8 were from the placebo group, and 2 patients withdrew prior to vaccination. Within the MM arm, 2 were excluded for no evidence of disease at time of vaccination and 1 withdrew. The vaccine was well tolerated, with 24% of patients experiencing a treatment-related adverse event (AE), with no grade ≥3 AE. Concurrent therapies were varied in the crossover arm, but 36% received CPI, compared with 68% in the MM arm. Of those receiving CPI, 59% had &gt;1 immune-related AE, none of which were grade ≥3. In the crossover arm, 12-month overall survival (OS) was 83.3% in the vaccine-naïve cohort at median follow-up of 6.0 months vs. 94.7% in the re-vaccinated cohort at median follow-up of 9.0 months (p=0.961). In the MM arm, 12-month OS was 61.2% at a median follow-up of 7.7 months. In a pooled analysis of 33 evaluable pts, vaccine-naïve pts (n=21) had a 42.9% non-progression rate compared to a 66.7% non-progression rate in re-vaccinated pts (n=12).

Conclusion: Vaccination with the TLPLDC vaccine in combination with approved systemic therapies in MM pts is well tolerated, with acceptable rates of immune-related AE when combined with CPI. Additionally, vaccination, and specifically re-vaccination, may provide clinical benefit particularly if used in combination with other approved therapies.

Citation Format: Robert Connor Chick, Annelies T. Hickerson, Guy Travis Clifton, Phillip M. Kemp Bohan, Tommy A. Brown, Jessica L. Cindass, John W. Myers, Timothy J. Vreeland, Doreen O. Jackson, Diane F. Hale, Kaitlin M. Peace, Garth S. Herbert, Xianzhong Yu, Thomas Wagner, George E. Peoples. Safety and efficacy of autologous tumor lysate particle loaded dendritic cell (TLPLDC) vaccination in combination with systemic therapies in patients with metastatic melanoma [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 6536.

Final analysis of a phase I/IIa trial of the folate-binding protein-derived E39 peptide vaccine to prevent recurrence in ovarian and endometrial cancer patients

BACKGROUND

E39, an HLA-A2-restricted, immunogenic peptide derived from the folate-binding protein (FBP), is overexpressed in multiple malignancies. We conducted a phase I/IIa trial of the E39 + GM-CSF vaccine with booster inoculations of either E39 or E39' (an attenuated version of E39) to prevent recurrences in disease-free endometrial and ovarian cancer patients(pts). Here, we present the final 24-month landmark analysis.

PATIENTS AND METHODS

HLA-A2 + patients receiving E39 + GM-CSF were included in the vaccine group (VG), and HLA-A2- pts (or HLA-A2 + patients refusing vaccine) were followed as the control group (CG). VG group received 6 monthly inoculations as the primary vaccine series (PVS) and were randomized to receive either E39 or E39' booster inoculations. Demographic, safety, immunologic, and disease-free survival (DFS) data were collected and evaluated.

RESULTS

Fifty-one patients were enrolled; 29 in the VG and 22 in the CG. Fourteen patients received <1000 μg and 15 received 1000 μg of E39. There were no clinicopathologic differences between VG and CG or between dose groups. E39 was well tolerated. At the 24 months landmark, DFS was 55.5% (VG) vs 40.0% (CG), P = 0.339. Patients receiving 1000 μg and boosted patients also showed improved DFS (P < 0.03). DFS was improved in the 1000 μg group after treatment of primary disease (90.0% vs CG:42.9%, P = 0.007), but not in recurrent patients. In low-FBP expressing patients, DFS was 100.0% (1000 μg), 50.0% (<1000 μg), and 25.0% (CG), P = 0.029.

CONCLUSIONS

This phase I/IIa trial reveals that E39 + GM-CSF is safe and may be effective in preventing recurrence in high-risk ovarian and endometrial cancer when optimally dosed (1000 μg) to FBP low patients being treated for primary disease.

Initial phase I/IIa trial results of an autologous tumor lysate, particle-loaded, dendritic cell (TLPLDC) vaccine in patients with solid tumors

INTRODUCTION

Tumor vaccines use various strategies to generate immune responses, commonly targeting generic tumor-associated antigens. The tumor lysate, particle-loaded, dendritic cell (TLPLDC) vaccine is produced from DC loaded with autologous tumor antigens, creating a patient-specific vaccine. Here, we describe initial phase I/IIa trial results.

METHODS

This trial includes patients with any stage solid tumors, ECOG ≤1, and >4 months life-expectancy. A personalized vaccine is created using 1 mg of tumor and 120 ml blood (to isolate DC). Primary vaccination series (PVS) is four monthly inoculations. Patients are followed per standard of care (SOC). Endpoints include safety and tumor response (RECIST v1.1).

RESULTS

44 patients were enrolled and vaccinated consisting of 31 late stage patients with residual/measurable disease, and 13 disease-free patients after SOC therapies. While 4 patients progressed before completing the PVS, 12/31 (39%) demonstrated clinical benefit (2 complete responses, 4 partial responses, 6 stable disease). In the adjuvant setting, 46% of late stage patients remain disease free at a median of 22.5 months.

CONCLUSIONS

The TLPLDC vaccine is scalable, generates a personalized DC vaccine, and requires little autologous tumor tissue and few DC. The vaccine is safe, with primarily grade 0-2 toxicities, and nearly 40% clinical benefit rate in varied tumors, warranting further study.

TRIAL REGISTRATION

ISRCTN81339386, Registered 2/17/2016.

Tumor lysate particle loaded dendritic cell vaccine: preclinical testing of a novel personalized cancer vaccine

Aim: We developed a novel approach to efficiently deliver autologous tumor antigens to the cytoplasm of dendritic cells (DC) using yeast cell wall particles (YCWP). Materials and Methods: Loading of YCWP, leakage of protein from loaded YCWP and cytoplasmic delivery of YCWP content was assessed using fluorescent-tagged experiments. Spectrophotometric analysis compared the epitope-specific T-cell responses following antigen presentation via YCWP versus exogenous loading. The in vivo effectiveness of tumor lysate (TL) particle loaded DC (TLPLDC) vaccine was assessed using murine melanoma models. Results: In fluorescence-tagged experiments, YCWP efficiently delivered antigen to the cytoplasm of DC. TLPLDC loading was more effective than conventional exogenous loading of DC. Finally, in murine melanoma models, TLPLDC outperformed an analogous dendritoma vaccine. Conclusion: The TLPLDC vaccine is commercially scalable and holds the potential of producing personalized vaccines.

A prospective, randomized, blinded, placebo-controlled, phase IIb trial of an autologous tumor lysate + yeast cell wall particles (YCWP) + dendritic cells (DC) vaccine vs unloaded YCWP + DC and embedded phase I/IIa trial with tumor lysate particle only (TLPO) vaccine in stage III and stage IV (resected) melanoma to prevent recurrence

TPS201

Background: Melanoma is a potentially lethal skin malignancy; patients with stage III/IV resected disease have a recurrence rate of 50-90%. Adjuvant checkpoint inhibitor immunotherapy decreases the risk of recurrence but also causes significant immune-related toxicity. Vaccines are a promising strategy for patients with high risk melanoma. The optimal time to intervene may be in the adjuvant setting after attaining a disease-free state through standard of care therapies. Our strategy uses autologous tumor lysate (TL) in a yeast cell wall particle (YCWP) to load dendritic cells (DC) ex vivo. The tumor lysate particle loaded dendritic cell (TLPLDC) vaccine is then given to prevent melanoma recurrences. An alternate vaccine delivery method that we are evaluating utilizes the tumor lysate particle-only (TLPO) technique, in which tumor lysate is loaded into capped YCWP and injected intradermally, allowing an in vivo uptake by the patient’s dendritic cells. Methods: We are performing a prospective, randomized, blinded, placebo-controlled phase IIb trial in patients with resected stage III/IV melanoma who have been rendered disease-free but remain at high risk of recurrence. The study will utilize the TLPLDC strategy vs placebo (2:1) in 120 patients, followed by a bridging study of TLPO vs TLPLDC (2:1) in 60 patients. Both TLPLDC and TLPO inoculations will be monthly x3, followed by boosters at 6, 12, and 18 months. Primary endpoints will be disease free survival (DFS) at 24 months in the TLPLDC arm, and overall safety in the TLPO arm. We have completed enrollment in the phase IIb portion of the study. Clinical trial information: NCT02301611.

Immunologic efficacy of E39 & E39' vaccination in a phase I/IIa trial in ovarian and endometrial cancer patients

75

Background: The treatment options for cancer are ever-evolving & now include vaccines targeting tumor-specific immunogenic peptides to induce tumor cytolysis. Folate binding protein (FBP) is a tumor-associated antigen (TAA) highly expressed in most endometrial & ovarian cancers (Ca), shielded from the normal immune system. The most promising FBP peptides are E39 & an attenuated form, E39' (aka J65). In our most recent phase I/IIa trial we evaluated an E39+GM-CSF inoculation series at 3 doses (VG) vs controls (CG) as well as booster vaccination with E39 or E39' after the initial inoculation series. Here we present the immunologic data from this phase I/IIa trial. Methods: Patients (pts) with ovarian or endometrial Ca who were disease-free after standard of care therapy but at risk for recurrence were enrolled. HLA-A2+ pts were vaccinated in a 3+3 dose escalation of 100mcg, 500mcg, & 1000mcg. The remaining pts received 1000mcg inoculations. Vaccine was given every 3-4 weeks for a total of 6 inoculums. Pts were then offered to participate in booster vaccination with 9 pts randomized to receive E39 & 9 pts E39'. FBP expression level was measured on the resected disease. Overall immunologic response & by subgroups was measured by delayed type hypersensitivity (DTH) & ELISPOT in the VG. Results: A total of 29 pts were vaccinated. Mean DTH prior to the initial dose of E39 was 5.74mm & after final dose was 10.33mm (p = 0.018). Mean overall ELISPOT change over time through 18 months was +69.1 when compared to baseline (p = 0.675). At 18 months, mean ELISPOT increased by 97.1 in 1000mcg vs -57.0 in < 1000mcg dosed pts (p = 0.047) & by +255.33 in pts with > average initial DTH vs -0.75 in < average initial DTH (p = 0.004) when compared to baseline. Immunological analyses were not significantly different between FBP hi/lo expression or E39 vs E39’ booster (p > 0.05). Conclusions: E39 demonstrated significant overall immunogenicity on in vivo testing as measured by DTH. Ex vivo analysis (ELISPOT) suggests that E39 is more immunogenically efficacious in pts with > average initial DTH & those who are optimally dosed (1000mcg). FBP expression level & E39 vs E39’ use in booster inoculations did not significantly impact in vivo or ex vivo immunogenicity. Clinical trial information: NCT01580696.

Interim analysis of a phase I/IIa trial assessing E39+GM-CSF, a folate binding protein vaccine, to prevent recurrence in ovarian and endometrial cancer patients

BACKGROUND

Folate binding protein(FBP) is an immunogenic protein over-expressed in endometrial(EC) and ovarian cancer(OC). We are conducting a phase I/IIa trial of E39 (GALE 301)+GM-CSF, an HLA-A2-restricted, FBP-derived peptide vaccine to prevent recurrences in disease-free EC and OC patients. This interim analysis summarizes toxicity, immunologic responses, and clinical outcomes to date.

METHODS

HLA-A2+ patients were vaccinated(VG), and HLA-A2- or -A2+ patients were followed as controls(CG). Six monthly intradermal inoculations of E39+250mcg GM-CSF were administered to VG. Demographic, safety, immunologic, and recurrence rate(RR) data were collected and evaluated.

RESULTS

This trial enrolled 51 patients; 29 in the VG and 22 in the CG. Fifteen patients received 1000mcg E39, and 14 received <1000mcg. There were no clinicopathologic differences between groups(all p ≥ 0.1). E39 was well-tolerated regardless of dose. DTH increased pre- to post-vaccination (5.7±1.5 mm vs 10.3±3.0 mm, p = 0.06) in the VG, and increased more in the 1000mcg group (3.8±2.0 mm vs 9.5±3.5 mm, p = 0.03). With 12 months median follow-up, the RR was 41% (VG) vs 55% (CG), p = 0.41. Among the 1000mcg patients, the RR was 13.3% vs 55% CG, p = 0.01. Estimated 2-year DFS was 85.7% in the 1000mcg group vs 33.6% in the CG (p = 0.021).

CONCLUSIONS

This phase I/IIa trial reveals that E39+GM-CSF is well-tolerated and elicits a strong, dose-dependent in vivo immune response. Early efficacy results are promising in the 1000 mcg dose cohort. This study proves the safety and establishes the dose of E39 for a larger prospective, randomized, controlled trial in HLA-A2+ EC and OC patients to prevent recurrence.

Routine Pre-Treatment MRI for Breast Cancer in a Single-Payer Medical Center: Effects on Surgical Choices, Timing and Outcomes

Introduction: Pre-operative MRI is being used with increasing frequency to evaluate breast cancer patients, but the debate surrounding risks and benefits of this use continues. At our institution, we instituted a standardized protocol for pre-operative MRI. Here, we compare patients seen prior to routine use of MRI to those seen after and examine effects on surgical choices, timing and outcomes.

Methods: This is a retrospective review of a prospectively collected database of all new invasive breast cancers seen from January 2007 to December 2012. The control group (CG) did not receive MRI, while the MRI group (MRG) underwent MRI according to our pretreatment protocol. Groups were compared with regards to basic demographics, initial surgical choices, need for re-excision, and surgical timing. The electronic medical records of patients in the MRG who underwent mastectomy as their initial surgery were examined closely to determine the main factors leading to their choice of surgery. Finally, correlation between findings on MRI and final surgical pathology was analyzed.

Results: Of 282 patients included, 38 were in the CG and 244 in the MRG; the groups were well matched. The MRG had a significantly higher percentage of patients choosing initial mastectomy (MRG: 47.1% vs CG 21.1%, p=0.003). Patients seen in the first 2 years of the study were less likely to choose mastectomy than those enrolled in the latter years (29.2%vs 48.6%, p=0.004). The MRG had a lower chance of return to the operating room for re-excision (15.2% vs 28.9%, p=0.035). The average time from initial imaging to initial surgery was approximately the same between groups (MRG: 39.7 days vs CG 42.1 days, p=0.45) and the MRG actually had shorter time to definitive (margin-negative) surgical management (MRG: 43.5 days vs CG: 50.3 days, p=0.079). One hundred-fifteen patients in the MRG underwent mastectomy as initial surgery. Of these, 64 (55.7%) had no additional findings on MRI and chose mastectomy based on patient preference; 30 patients (26.1%) (29 unilateral, 1 bilateral) had mastectomy because of MRI findings. Of the 31 breasts removed (29 unilateral and 1 bilateral mastectomies) because of MRI findings, 26 (83.9%) had histologic findings that correlated with the MRI findings, while 5 (16.1%) did not.

Conclusion: Patients receiving routine pre-treatment MRI had an increased mastectomy rate, but had a lower re-excision rate. We found no delay to initial surgical therapy and, perhaps more importantly, a slight decrease in time to margin-negative surgical therapy in the MRI group. Women choosing mastectomy after MRI did so because of personal preference over half of the time, while MRI findings influenced this choice in 26% of these women. When MRI findings did lead to mastectomy, these findings were confirmed by pathology results in the vast majority of cases.

Abstract CT162: Pre-specified interim analysis in a prospective, randomized phase II trial of trastuzumab vs trastuzumab + NeuVax to prevent breast cancer recurrence in HER2+ breast cancer patients

Introduction: The HER2-targeted monoclonal antibody, trastuzumab (Tz), is standard of care (SOC) for HER2-positive (HER2+) breast cancer (BCa) and has been shown to reduce recurrence. We have previously shown that NeuVax (E75 peptide + GM-CSF), a HER2-targeted peptide vaccine, is safe, immunogenic, and may have synergistic clinical efficacy when combined with Tz. Given the known cardiac toxicity of Tz, there is concern that adding a HER2-directed vaccine to Tz therapy may exacerbate this effect. We are currently enrolling patients (pts) in a multi-center, prospective, randomized, single-blinded, placebo-controlled phase II trial combining Tz and Neuvax in the adjuvant setting to prevent recurrence in HER2+ BCa pts. Here, we present the initial safety data.

Methods: HLA-A2/A3+ BCa pts with stage I-III HER2+ disease at high risk for recurrence (pts not achieving complete response after Tz-containing neoadjuvant therapy or those undergoing up-front surgery with any node-positive disease if ER/PR- or ≥4 positive nodes if ER/PR+) were enrolled after SOC surgery, radiation and neo-adjuvant/adjuvant chemotherapy with approved Tz-containing regimen. Pts were randomized to receive Tz and NeuVax in the vaccine group (VG) or Tz and GM-CSF only in the control group (CG). Pts received vaccinations of NeuVax or GM-CSF intradermally every 3 weeks for 6 total vaccinations (primary vaccine series, PVS) starting with the third dose of Tz maintenance therapy. Starting 6 months after the completion of the PVS, pts received four booster inoculations, one every 6 months. Cardiac ejection fraction (EF) was assessed by either echo or MUGA at baseline and serially during treatment. Demographic and safety data were collected and analyzed. Safety analysis was initiated after enrollment of the 50th patient.

Results: To date, we have enrolled 50 pts (VG n=22, CG n=28). There were no significant clinicopathologic differences between groups. There were no related grade 4 or 5 toxicities and no differences in related toxicities between the VG and CG (Grade 1: 96% vs 98.5%; Grade 2: 3.2% vs 1.5%; Grade 3: 0.8% vs 0%, p=0.14). There was no significant reduction in EF pre- to post-treatment in either group (VG: 61.1±5.4% vs 60.1±4.8%, p=0.55; CG: 62.3±5.7% vs 61.9±4.0%, p=0.74) and there was no difference in change between groups (p=0.54).

Conclusion: The combination of Tz and Neuvax in HER2+ BCa pts is well tolerated and the cardiac effects from Tz are not worsened by the addition of NeuVax. We will continue to enroll up to our goal of 100 pts in this ongoing trial, and will report immunologic and clinical outcomes in the planned primary analysis after 24-months follow-up.

Citation Format: Kaitlin M. Peace, Jennifer K. Litton, Rashmi Murthy, Timothy J. Vreeland, Diane F. Hale, Doreen O. Jackson, John S. Berry, Alfred F. Trappey, Garth S. Herbert, Guy T. Clifton, Mark O. Hardin, George E. Peoples, Elizabeth A. Mittendorf. Pre-specified interim analysis in a prospective, randomized phase II trial of trastuzumab vs trastuzumab + NeuVax to prevent breast cancer recurrence in HER2+ breast cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT162. doi:10.1158/1538-7445.AM2017-CT162

Abstract CT036: Early trial results of an autologous tumor lysate, particle-loaded, dendritic cell (TLPLDC) vaccine in ovarian cancer patients

Introduction: Late-stage ovarian cancer remains difficult to treat with 1-year disease free survival rates of roughly 55% and 40% in patients (pts) with stage III and IV disease, respectively1. To date, the majority of ovarian cancer vaccines have targeted specific tumor-associated antigens with little benefit. Our vaccine approach harnesses the most potent antigen presenting cell in the body, the dendritic cell (DC), and exposes these cells to the full repertoire of tumor antigens from an individual’s cancer. Autologous tumor lysate (TL) is loaded into yeast cell wall particles (YCWP) that are naturally and efficiently taken up into the pt’s DC ex vivo. This process uses a small amount of blood and tumor and can be completed in 48 hours. The autologous TL, particle-loaded, DC (TLPLDC) vaccine is then injected intradermally (ID). This vaccine is being tested in multiple tumor types, and here we present the results in ovarian cancer.

Methods: Pts with stage III or IV ovarian cancer were identified prior to surgical intervention for enrollment and tumor acquisition. Pts were treated with standard of care therapy, then enrolled in the per protocol (PP) phase I/IIa trial if disease-free or in an open label treatment registry (OTR) if they had measureable residual disease. A tumor sample (&gt;1mg) was collected at the time of surgery, and 120mL of blood (or 50mL after a single dose of Neupogen) was drawn to isolate the pt’s DC. TL was produced through freeze/thaw cycling and loaded into YCWP, which were introduced to DC for phagocytosis; thus creating an individualized TLPLDC vaccine for each pt. Each vaccine dose contained 1x106 TLPLDC, which was injected ID in the thigh. In the PP group, the primary vaccine series (PVS) consisted of monthly vaccination x3 followed by boosters at 6 and 12 months. In the OTR, the PVS consisted of monthly vaccination x4 followed by boosters every 3 months. Pts were monitored for toxicity and recurrence or progression of disease, respectively.

Results: A total of 15 pts have been treated to date, (PP: 8, OTR: 7 with 1 pt vaccinated on compassionate use). 100% of pts had successful creation of vaccine. Minimal toxicities (all ≤ grade 2) were reported. To date, in the OTR, 1 pt has shown a complete response, 1 has stable disease, and 4 have had progressive disease (PD; only 1 pt with PD completed the PVS). In the PP group, after a median follow up of 10.8 months, 3 pts (37%) have recurred (only 1 of these pts completed PVS), while 5 pts (63%) remain disease free.

Conclusions: We have shown that the TLPLDC vaccine can be made efficiently (requiring only a small amount of blood, tumor and time) and is safe and well-tolerated. Our results suggest that the vaccine is better suited for the adjuvant setting rather than pts with residual disease. This data provides justification for a larger clinical trial in stage III/IV ovarian cancer pts in the adjuvant setting.

1 Kurta M, et al. Prognosis and conditional disease-free survival among pts with ovarian cancer. J Clin Oncol. 2014;32(36):4102-12.

Citation Format: Kaitlin M. Peace, Timothy J. Vreeland, Guy T. Clifton, Diane F. Hale, Doreen O. Jackson, John S. Berry, Alfred F. Trappey, Garth S. Herbert, Mark O. Hardin, Pauline T. Nichol, Sook L. Yin, Xianzhong Yu, Thomas E. Wagner, George E. Peoples. Early trial results of an autologous tumor lysate, particle-loaded, dendritic cell (TLPLDC) vaccine in ovarian cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT036. doi:10.1158/1538-7445.AM2017-CT036

Evaluation of Attenuated Tumor Antigens and the Implications for Peptide-Based Cancer Vaccine Development

INTRODUCTION: Peptide vaccines offer anti-tumor efficacy with very low toxicity. However, repeat stimulation with an immunogenic peptide leads to activation induced cell death (AICD), decreasing efficacy. We engineered variants of an immunogenic peptide (E39) and tested their ability to induce a robust, sustainable immune response.

METHODS: Multiple variants of E39 were created by exchanging 1 or 2 amino acids. We tested the PBMC proliferation, cytokine production and cytolytic activity induced by each variant peptide. RESULTS: Repeated stimulation with E39 likely led to in vitro AICD, while stimulation with E39' led to T-cell proliferation with less evidence of AICD, modest cytokine production and high CTL activity. CONCLUSIONS: E39' appears to be the optimal variant of E39 for inducing effective long-term immunity.

A novel cancer vaccine platform utilizing autologous tumor lysate loaded into capped yeast cell wall particles

169

Background: Our current tumor lysate, particle-loaded, dendritic cell (TLPLDC) vaccine employs yeast cell wall particles (YCWP) to deliver antigen to DC ex vivo and is being tested in a randomized phase IIb trial. This strategy may be improved by injecting TL-loaded YCWP as an intradermal vaccine, with in vivo DC uptake. Silicate capping should allow YCWP to retain TL longer and stimulate DC uptake. Here, we present preclinical data on the tumor lysate, particle only (TLPO) vaccine concept vs. TLPLDC. Methods: To test the TLPO concept, YCWP were loaded with fluorescence (flr) labeled albumin and capped (cp) vs. uncapped (ucp) particles were compared for flr leak. Next, YCWP were added to cultured macrophages to evaluate DC uptake. Cells were then lysed, centrifuged, and flr in the cytoplasm vs. organelles measured. 3 C57B mice were then injected with 100ml NaCl, 106empty cp YCWP, or 1mcg GM-CSF. 5 hours (hr) post-injection, 100ml NaCl was injected into the same site, withdrawn, and examined via microscope to count monocytes. TLPO was compared to TLPLDC in a B16 murine melanoma survival model. Finally, 4 grey horses with equine melanoma were treated with autologous TLPO, injected biweekly for 4 vaccinations. Target lesions were assessed over 6 months. Results: Compared to ucp YCWP, cp had decreased flr leak at 1 (15.8% vs. 24.7%) and 2 hr (6.7% vs. 16.6%), increased uptake by DC (2hr flr readings 11065 vs. 3928) and higher delivery to DC cytoplasm (68.9% vs. 48.8%). Empty cp YCWP showed increased recruitment of monocytes (276/hpf) vs. GM-CSF (55/hpf) or NaCl alone (18/hpf). In the B16 murine melanoma model, the median survival time in days was 21 for controls (n=5), 42 for TLPLDC (n=10), and 56 for TLPO (n=20). At 6 months, the equine model revealed 1 complete and 3 partial responses (50%, 68%, and 45% tumor reduction). Conclusions: Silicate capping of the YCWP effectively limits leakage of contents, improves uptake by DC and delivery to the cytoplasm without the need for GM-CSF. In early animal studies, TLPO appears to have equivalent efficacy to TLPLDC, but eliminates the need for in vitro DC loading. We plan to perform a bridging study comparing TLPO to TLPLDC after enrollment is complete in our phase IIb TLPLDC melanoma trial.

Abstract B007: Improved disease-free survival in endometrial and ovarian cancer patients with low folate binding protein expression after treatment with the E39 peptide vaccine in a Phase I/IIa trial

Introduction: One of the most encouraging examples of targeted therapy for cancer is trastuzumab, but its success is dependent on levels of expression of its target, HER2. We have found that HER2 expression levels also have a significant impact on the efficacy of HER2-directed peptide vaccines. Analogous to HER2 in breast cancer, Folate Binding Protein (FBP) is over-expressed on ovarian and endometrial cancer cells (up to 80 - 90-fold higher) and increased FBP expression is associated with aggressive disease. As a result, multiple FBP-directed therapies are being developed. We are investigating E39 + GM-CSF, which is an HLA-A2-restricted FBP-derived peptide vaccine used to prevent recurrence in disease-free endometrial and ovarian cancer patients (pts) after standard of care (SOC), multi-modality therapy. We have shown that E39 is safe, effectively generates E39-specific immune responses, and may improve DFS when optimally dosed in a phase I/IIa trial.1 Little is known about the effects of FBP expression levels on FBP-directed therapies, including our E39 vaccine.

Purpose: Here, we report clinical outcomes of patients based on FBP expression levels from a phase I/IIa trial of the E39+GM-CSF vaccine given for the prevention of recurrence in disease-free endometrial and ovarian cancer patients.

Methods: Disease-free, HLA-A2+ pts were vaccinated (VG), while HLA-A2- pts were followed as untreated controls (CG). The VG received 6 monthly inoculations of E39+GM-CSF, including either 100, 500, or 1000mcg of peptide and 250mcg of GM-CSF. FBP expression testing was performed by immunohistochemistry and the results were graded 0-4+ based on the percentage of positively staining cells. Patient's tumors were then categorized as low expression (FBPlo) if scored 0-1+ or high expression (FBPhi) if 2-4+. The pts were monitored for evidence of clinical recurrence through the SOC follow-up by their treating oncology team. Demographics, FBP expression and disease-free survival (DFS) were analyzed using appropriate statistical tests.

Results: Thirty-eight enrolled pts underwent FBP expression testing (CG n = 20; VG n = 18). There were no clinicopathologic differences between groups (p≥0.1). Nineteen pts were found to be FBPlo (CG, n = 11; VG, n = 8) and 19 were FBPhi (CG, n = 9; VG, n = 10). Median follow up was 16.3 months. There was no significant difference in overall DFS between the CG and the VG (34.6% vs. 34.6%, p = 0.208). In FBPlo pts, there was improved DFS in the VG vs. CG (85.7% vs. 17.5%, p = 0.01) while there was no such difference in FBPhi pts (VG:13.9% vs. CG:44.4%, p = 0.83). Though groups were small, there was a dose-dependent effect on DFS; pts receiving 1000mcg (n = 4) had improved DFS compared to the &lt;1000mcg pts (n = 4) and the CG (n = 11; 100% vs. 66.7% vs.17.5%, respectively, p = 0.03). Comparing FBPlo and FBPhi pts in the VG, the FBPlo pts had improved DFS (85.7% vs. 15.6%, p = 0.052). In the CG, FBPlo pts did worse (17.5% vs. 44.4% in FBPhi, p = 0.371).

Conclusion: This phase I/IIa trial has previously demonstrated that E39 is well-tolerated, elicits a strong, dose-dependent in vivo immune response and may improve DFS when properly dosed. This focused analysis based on FBP expression level revealed a DFS benefit in FBPlo, but not FBPhi, endometrial and ovarian cancer pts treated with E39. This may be due to immunotolerance from significantly higher endogenous exposure to the FBP antigen. This is concordant with findings in our trials of HER2-directed peptide vaccines in breast cancer pts. These findings warrant further study as they may have important implications regarding the target population for future E39 peptide vaccine trials.

1. Jackson DO, et al. Interim analysis of a phase I/IIa trial assessing E39+GM-CSF, a folate binding protein vaccine, to prevent recurrence in ovarian and endometrial cancer patients. In Press.

Citation Format: Kaitlin M. Peace, Diane F. Hale, Timothy J. Vreeland, Doreen O. Jackson, Julia M. Greene, John S. Berry, IV, Alfred F. Trappey, Garth S. Herbert, Guy T. Clifton, Mark O. Hardin, Kathleen M. Darcy, Chad A. Hamilton, G. Larry Maxwell, George E. Peoples. Improved disease-free survival in endometrial and ovarian cancer patients with low folate binding protein expression after treatment with the E39 peptide vaccine in a Phase I/IIa trial [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr B007.

Abstract CT073: Comparing an attenuated booster (E39’) vs E39 booster to potentiate the clinical benefit of the folate binding protein (FBP)-derived vaccine (E39 + GM-CSF) in a phase I/IIa trial to prevent recurrence in endometrial (EC) and ovarian cancer (OC) patients

Background: We have completed treatment in a phase I/IIa trial utilizing E39 (GALE-301, FBP 191-199, EIWTHSYKV), an HLA-A2 restricted, FBP-derived peptide + GM-CSF vaccine to prevent recurrence in EC and OC patients (pts). This vaccine has been shown to be safe and immunogenic, with promising early clinical results. Booster inoculations have improved disease-free survival (DFS) in our previous peptide vaccine trials, but repeated boosting can theoretically lead to overstimulation and loss of vaccine-induced T cells. To avoid this, we have developed an attenuated version of E39, E39’ (GALE-302, EIWTFSTKV), which has been shown to expand FBP-specific cytolytic T cells in vitro and in vivo. Therefore to assess this strategy, E39-vaccinated pts from the phase I/IIa trial were randomized to receive a booster series of either E39’ or E39 + GM-CSF and compared for safety, immunologic response, and DFS.

Methods: HLA-A2+ pts were vaccinated (VG), and HLA-A2- pts were followed as controls (CG). Six monthly intradermal inoculations of E39 + 250mcg GM-CSF were administered to the VG to complete the primary vaccine series (PVS). Patients were then randomized to receive 2 booster inoculations of 500mcg of E39’ or E39 + 250mcg GM-CSF at 6 (B1) and 12 (B2) months post-PVS. Local reactions (LR) were recorded 48-72 hours after each booster. Demographic, safety, immunologic, and DFS data were collected and evaluated with the appropriate statistical tests.

Results: A total of 51 pts were enrolled; 29 in VG and 22 in CG. 17 pts continued on to the booster series and were randomized. For B1, 9 received E39’ and 8 received E39; B2 included 7 pts in each group. There were no significant clinicopathologic differences between groups. No difference in toxicities were seen with no grade 3 or 4 toxicities in either group. The average LR for the E39’ vs E39 groups were 79.7+14.0 mm vs 82.1+8.3 mm, respectively for B1 (p = 0.45) and 74.1+11.5 mm vs 78+11.2 mm, respectively for B2 (p = 0.41). Clinically, the recurrence rate was 22.2% in the E39’ boost group vs 25% for E39. The estimated 2-year DFS for B1 pts for E39’, E39 and the CG were 66.7%, 58.3%, and 36.0%, respectively; and for B2 pts were 66.7%, 66.7%, and 36.0%. Comparing just the boosted groups, for B1 the hazard ratio (HR) for E39’ vs E39 = 0.71 (95% CI: 0.1 - 5.13), and for B2 the HR for E39’ vs E39 = 0.82 (95% CI: 0.05 - 13.24).

Conclusion: The use of an attenuated peptide (E39’) booster was safe and as immunogenic as the wildtype peptide (E39) in this randomized trial of optimal boosting strategies. More importantly, there appears to be a potential clinical advantage to the attenuated booster in this small trial. These results must be corroborated by further evaluation of this attenuated peptide vaccine and boosting strategy in a larger clinical trial.

Citation Format: Doreen O. Jackson, Timothy J. Vreeland, Diane F. Hale, Garth S. Herbert, Julia M. Greene, Erika J. Schneble, John S. Berry, Alfred F. Trappey, Guy T. Clifton, John C. Elkas, Chad Hamilton, Kathleen M. Darcy, George L. Maxwell, George E. Peoples. Comparing an attenuated booster (E39’) vs E39 booster to potentiate the clinical benefit of the folate binding protein (FBP)-derived vaccine (E39 + GM-CSF) in a phase I/IIa trial to prevent recurrence in endometrial (EC) and ovarian cancer (OC) patients. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr CT073.

Gaining ground on a cure through synergy: combining checkpoint inhibitors with cancer vaccines

INTRODUCTION

The approval of multiple checkpoint inhibitors (CPIs) for the treatment of advanced malignancies has sparked an explosion of research in the field of cancer immunotherapy. Despite the success of these medications, a large number of patients with advanced malignancy do not benefit from therapy. Early research indicates that a therapeutic combination of cancer vaccines with checkpoint inhibitors may lead to synergistic effects and higher response rates than monotherapy. Areas covered: This paper summarizes the previously completed and ongoing research on this exciting combination, including the use of the tumor lysate, particle-loaded dendritic cell (TLPLDC) vaccine combined with checkpoint inhibitors in advanced melanoma. Expert commentary: Increasing experience with CPIs has led to improved understanding of which patients may benefit and it is increasingly clear that the presence of a pre-existing immune response to the tumor, along with tumor-infiltrating lymphocytes, is key to the success of CPIs. One exciting possibility for the future is the addition of a cancer vaccine to CPI therapy, eliciting these crucial T cells, which can then be augmented and protected by the CPI. A number of current and future studies are addressing this very exciting combination therapy.

A phase I/IIa clinical trial in stage IV melanoma of an autologous tumor-dendritic cell fusion (dendritoma) vaccine with low dose interleukin-2

BACKGROUND

Stage IV melanoma has high mortality, largely unaffected by traditional therapies. Immunotherapy including cytokine therapies and checkpoint inhibitors improves outcomes, but has significant toxicities. In this phase I/IIa trial, we investigated safety and efficacy of a dendritoma vaccine, an active, specific immunotherapy, in stage IV melanoma patients.

METHODS

Autologous tumor lysate and dendritic cells were fused creating dendritoma vaccines for each patient. Phase I patients were vaccinated every 3 months with IL-2 given for 5 days after initial inoculation. Phase IIa patients were vaccinated every 6 weeks with IL-2 given on days 1, 3 and 5 after initial inoculation. Toxicity and clinical outcomes were assessed.

RESULTS

Twenty-five patients were enrolled and inoculated. All dendritoma and IL-2 toxicities were

CONCLUSIONS

The dendritoma vaccine has minimal toxicity profile with potential clinical benefit. There was OS advantage for NED stage IV patients, those receiving higher number of doses and increased frequency. Based on these results, we initiated a phase IIb trial utilizing improved dendritoma technology in the adjuvant setting for NED stage III/IV melanoma patients.

Collapse

Key Words

• Adjuvant
• Dendritic cell
• Dendritoma
• Melanoma
• Vaccine

Collapse

MESH Headings

• Aged
• Arthralgia/chemically induced
• Cancer Vaccines/adverse effects
• Cancer Vaccines/immunology
• Cancer Vaccines/therapeutic use
• Chills/chemically induced
• Combined Modality Therapy
• Dendritic Cells/immunology
• Dendritic Cells/metabolism
• Dose-Response Relationship, Drug
• Drug Administration Schedule
• Erythema/chemically induced
• Female
• Humans
• Interleukin-2/adverse effects
• Interleukin-2/immunology
• Interleukin-2/therapeutic use
• Kaplan-Meier Estimate
• Male
• Melanoma/immunology
• Melanoma/therapy
• Middle Aged
• Nausea/chemically induced
• Neoplasm Recurrence, Local
• Neoplasm Staging
• Treatment Outcome

Collapse

Grants

• Greenville Hospital System

Collapse

Affiliation(s)

Julia M Greene General Surgery Department, San Antonio Military Medical Center, 3851 Roger Brooke Drive, Joint Base San Antonio-Ft. Sam Houston, TX, USA
Erika J Schneble General Surgery Department, San Antonio Military Medical Center, 3851 Roger Brooke Drive, Joint Base San Antonio-Ft. Sam Houston, TX, USA
Doreen O Jackson General Surgery Department, San Antonio Military Medical Center, 3851 Roger Brooke Drive, Joint Base San Antonio-Ft. Sam Houston, TX, USA
Diane F Hale General Surgery Department, San Antonio Military Medical Center, 3851 Roger Brooke Drive, Joint Base San Antonio-Ft. Sam Houston, TX, USA.
Timothy J Vreeland General Surgery Department, San Antonio Military Medical Center, 3851 Roger Brooke Drive, Joint Base San Antonio-Ft. Sam Houston, TX, USA
Madeline Flores General Surgery Department, San Antonio Military Medical Center, 3851 Roger Brooke Drive, Joint Base San Antonio-Ft. Sam Houston, TX, USA
Jonathan Martin General Surgery Department, San Antonio Military Medical Center, 3851 Roger Brooke Drive, Joint Base San Antonio-Ft. Sam Houston, TX, USA
Garth S Herbert General Surgery Department, San Antonio Military Medical Center, 3851 Roger Brooke Drive, Joint Base San Antonio-Ft. Sam Houston, TX, USA
Mark O Hardin General Surgery Department, Madigan Army Medical Center, 9040 Jackson Ave., Tacoma, 98431, WA, USA
Xianzhong Yu Clemson University, Clemson, SC, USA
Thomas E Wagner Perseus PCI, Greenville, SC, USA
George E Peoples Cancer Vaccine Development Program, 600 Navarro Street, Suite 500, San Antonio, TX, 78205, USA. Department of Surgery, Uniformed Services University of the Health Sciences, Bethesda, MD, USA.

Collapse

Early trends in serum phosphate and creatinine levels are associated with mortality following major hepatectomy

BACKGROUND

Mortality after major hepatectomy remains high and is frequently related to post-hepatectomy liver failure (PHLF). Other than pre-existing liver disease and a small future liver remnant, few patient factors or early postoperative indicators identify patients at elevated risk for PHLF and mortality.

METHODS

Data on demographics, comorbidities, operative procedures and postoperative laboratory trends were reviewed for patients submitted to major hepatectomy (at least three Couinaud segments) for malignancy during 1998-2013. These factors were compared among patients who died within 90 days, survivors who met the 50-50 criteria and all remaining survivors.

RESULTS

A total of 1528 patients underwent major hepatectomy during the study period. Of these, 947 had metastatic colorectal cancer and underwent resection of a median of four segments. Overall, 49 patients (3.2%) died within 90 days of surgery and 48 patients (3.1%) met the 50-50 criteria for PHLF; 30 of these patients survived 90 days. Operative blood loss was higher in patients who died within 90 days compared with survivors (1.0 l versus 0.5 l; P < 0.001). Despite equivalent perioperative resuscitation and urine output, non-survivors had higher creatinine and phosphate levels than survivors on postoperative day (PoD) 1 (1.1 mg/dl versus 0.9 mg/dl and 4.6 mg/dl versus 3.7 mg/dl, respectively; P < 0.001).

CONCLUSIONS

Early trends in creatinine and phosphate (between the day of surgery and PoD 1) identify patients at risk for PHLF and mortality.

Prophylactic mesh to prevent incisional hernia: a note of caution

BACKGROUND

Ventral hernia is a common complication of open Roux-en-Y gastric bypass (RYGB). The aim of this study was to determine whether prophylactic mesh placement during RYGB would reduce the incidence of postoperative hernias.

METHODS

Obese patients undergoing RYGB by a single surgeon had prosthetic mesh placed in a subfascial location at the conclusion of the procedure. The incidences of recurrent hernia and morbidity associated with the placement of mesh were assessed.

RESULTS

Sixteen patients underwent RYGB with prophylactic mesh placement over 6 months. The average preoperative body mass index was 46.6 kg/m(2). Half of the patients were diabetics. None were smokers. During mean follow-up of 6 months, 4 patients (25%) required mesh excision, 3 for infection and 1 for a persistently symptomatic seroma. One patient was explanted incidentally in the course of reexploration for intractable nausea and vomiting. Another developed an incisional hernia despite prophylactic mesh.

CONCLUSIONS

In the investigators' experience, the use of prophylactic new-generation mesh at the time of open RYGB led to an unacceptable rate of local complications. They caution against this technique in patients undergoing open RYGB.

Acute and chronic mesenteric ischemia

This article briefly reviews the various etiologies, presentation, and diagnosis of different types of mesenteric ischemia. Operative management techniques and the applicability of percutaneous endovascular intervention are discussed. Finally, the authors explore emerging technologies that have the potential to further improve diagnosis and treatment of this frequently lethal disease process.

Prognostic significance of reactivation of telomerase in breast core biopsy specimens

BACKGROUND

Telomerase is not expressed in most somatic tissues, but activity has been shown in breast carcinoma and up to 90% of solid tumors. We sought to determine whether activation of telomerase, as shown by immunohistochemical staining for human telomerase reverse transcriptase (hTERT), held prognostic significance in core breast biopsy specimens.

METHODS

We identified women with atypical ductal hyperplasia (ADH) on core biopsy who either had underlying cancer or ADH. Immunohistochemistry with anti-hTERT antibody was performed on biopsy specimens, and staining was evaluated.

RESULTS

Core biopsy specimens stained strongly with the hTERT antibody in 7 (70%) specimens with ADH on open biopsy and 6 (86%) with underlying cancer. The difference was not statistically significant (P = .43).

CONCLUSIONS

Our study suggests telomerase may be activated early in the pathogenesis of breast cancer. The immunohistochemical evaluating expression of hTERT does not reliably identify those patients with ADH on core biopsy who are likely to have cancer.

The impact of nodal isolated tumor cells on survival of breast cancer patients

BACKGROUND

Isolated tumor cells (ITCs), often detectable only with immunohistochemical techniques, have an unknown significance in the prognosis of breast cancer. The American Joint Committee on Cancer guidelines classify such patients as N0 (immunohistochemistry +), staging them with node-negative patients. We sought to further elucidate the impact of ITCs on survival.

METHODS

We conducted a retrospective review of all women at our institution with breast cancer from 1996 to 2005. Of 514 patients, 16 had isolated tumor cells detected only with immunohistochemical staining. Survival then was compared with historical survival rates for women with node-free disease.

RESULTS

The 16 women with N0 (i+) disease had stage I or II disease. There was no documented recurrence among these women, with an average follow-up period of 2.5 years.

CONCLUSIONS

Our data suggest that ITCs detected in lymph nodes do not adversely impact survival or disease-free survival compared with women with node-negative disease. Larger studies will be required to confirm these findings.

Intestinal fatty acid binding protein (I-FABP) for the detection of strangulated mechanical small bowel obstruction

OBJECTIVE

Intestinal fatty acid binding protein (I-FABP), a protein released by necrotic enterocytes, is a useful marker for the detection of ischemia from mechanical small bowel obstruction.

DESIGN

Validation cohort.

SETTING

Academic medical center.

PARTICIPANTS

Cohort of 21 patients admitted with a clinical diagnosis of mechanical small bowel obstruction. Plasma and urine samples were collected from patients upon hospital admission and again immediately before laparotomy if surgical intervention was delayed.

RESULTS

Plasma and urine I-FABP levels (pg/ml by enzyme-linked immunosorbent assay) in patients found to have small bowel necrosis at the time of laparotomy were compared with those without significant ischemia upon laparotomy and those that did not require laparotomy and, by default, did not have small bowel ischemia. A positive test was defined as 1000-pg/ml I-FABP in urine and 100-pg/ml I-FABP in plasma. Small bowel necrosis was confirmed in 3 of 21 enrolled patients. Urine I-FABP levels were positive in 3 of 3 patients with necrosis and 3 of 18 patients without necrosis (sensitivity 100%, specificity 83%, PPV 50%, NPV 100%). Plasma I-FABP levels were positive in 3 of 3 patients with necrosis and 4 of 18 patients without necrosis (sensitivity 100%, specificity 78%, PPV 43%, NPV 100%).

CONCLUSIONS

I-FABP is a sensitive marker for ischemia in mechanical small bowel obstruction. Additional work should be done to validate I-FABP in a variety of clinical settings and to develop a rapid I-FABP laboratory assay.