Proffered Paper session II Proffered Paper session

69O - A small molecule human PD-1/PD-L1 inhibitor promotes T cell immune activation and reduces tumor growth in a preclinical model (ID 286)

Presentation Number
69O
Lecture Time
10:00 - 10:15
Speakers
  • M. Vilalta Colomer (Mountain View, United States of America)
Session Name
Proffered Paper session II
Location
Room A, Geneva Palexpo, Geneva, Switzerland
Date
14.12.2018
Time
09:00 - 10:30
Authors
  • M. Vilalta Colomer (Mountain View, United States of America)
  • S. Punna (Mountain View, United States of America)
  • S. Li (Mountain View, CA, United States of America)
  • V. Malathong (Mountain View, CA, United States of America)
  • C. Lange (Mountain View, CA, United States of America)
  • D. McMurtrie (Mountain View, CA, United States of America)
  • J. Yang (Mountain View, CA, United States of America)
  • H. Roth (Mountain View, CA, United States of America)
  • J. McMahon (Mountain View, CA, United States of America)
  • J. J. Campbell (Mountain View, CA, United States of America)
  • L. S. Ertl (Mountain View, CA, United States of America)
  • R. Ong (Mountain View, CA, United States of America)
  • Y. Wang (Mountain View, CA, United States of America)
  • N. Zhao (Mountain View, CA, United States of America)
  • S. Yau (Mountain View, CA, United States of America)
  • T. Dang (Mountain View, CA, United States of America)
  • P. Zhang (Mountain View, CA, United States of America)
  • T. J. Schall (Mountain View, CA, United States of America)
  • R. Singh (Mountain View, CA, United States of America)

Abstract

Background

In recent years, antibody-based therapies targeting the Programmed cell Death-1/Programmed Death-Ligand 1 (PD-1/PD-L1) immune checkpoint axis have gained tremendous success in cancer immunotherapy. We embarked on an effort to identify and develop small molecules capable of targeting this immune checkpoint, with an aim to provide new therapeutic options with improved anticancer immune responses, increased tumor penetration, shorter half-life to better managing immune related adverse events, and lower cost of goods.

Methods

We developed a number of small molecule inhibitors based on the crystal structure of human PD-1/PD-L1 complex. Active compounds were first identified by an ELISA assay measuring inhibition of the PD-1/PD-L1 interaction, followed by functional cell-based reporter and mixed lymphocyte reaction (MLR) assays. Since these inhibitors specifically block human PD-1/PD-L1 interaction, we co-implanted A375 human melanoma cells along with human peripheral blood mononuclear cells (PBMCs) into immunodeficient NOD/SCID mice to test their efficacy in vivo.

Results

We have obtained potent human PD-1/PD-L1 inhibitors with marked activities in both the cell-based reporter and MLR assays. Moreover, lead compound CCX4503 reduced tumor growth in vivo to a similar extent as the positive control anti-human PD-L1 antibody. Anti-tumor activity was completely dependent on the presence of human PBMCs. The tumor microenvironment analysis indicated that the anti-tumor activity of CCX4503 was accompanied by a significantly higher CD8+ T-Cell/CD4+ T-cell ratio. An X-ray structure of CCX4503 co-crystallized with PD-L1 provided information about the structural basis by which the compound disrupts the PD-1/PD-L1 immune checkpoint interaction.

Conclusions

We have identified and advanced unique small molecule inhibitors of human PD-1/PD-L1 by rational design. Molecules resulting from these efforts, such as CCX4503, exhibited marked inhibition of the PD-1/PD-L1 interaction and signaling in vitro, and also clear anti-tumor effects in an animal model system in vivo.

Legal entity responsible for the study

ChemoCentryx, Inc., Mountain View, CA.

Funding

ChemoCentryx, Inc., Mountain View, CA.

Disclosure

M. Vilalta Colomer, S. Li, V. Malathong, C. Lange, D. McMurtrie, J. Yang, H. Roth, J. McMahon, J.J. Campbell, L.S. Ertl, R. Ong, Y. Wang, N. Zhao, S. Yau, T. Dang, P. Zhang, T.J. Schall, R. Singh: Full-time employee of ChemoCentryx. S. Punna: Stock holder: ChemoCentryx.

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Management of side effects Educational session

General discussion / Q&A (ID 29)

Lecture Time
10:20 - 10:30
Location
Room C, Geneva Palexpo, Geneva, Switzerland
Date
14.12.2018
Time
09:00 - 10:30
Imaging and nuclear medicine Educational session

Preclinical and clinical imaging of macrophages (ID 50)

Lecture Time
16:15 - 16:35
Speakers
  • M. Keyaerts (Brussels, Belgium)
Location
Room C, Geneva Palexpo, Geneva, Switzerland
Date
14.12.2018
Time
16:15 - 17:45
Authors
  • M. Keyaerts (Brussels, Belgium)
What’s new in haematological malignancies Educational session

CAR T cells in myeloid malignancies (ID 73)

Lecture Time
14:55 - 15:15
Speakers
  • M. G. Manz (Zurich, Switzerland)
Location
Room C, Geneva Palexpo, Geneva, Switzerland
Date
15.12.2018
Time
14:15 - 15:45
Authors
  • M. G. Manz (Zurich, Switzerland)
Poster Display session Poster Display session

3P - Dissecting the spatial heterogeneity of single CTCs reveals immune evasion through MAX regulated CCL5 overexpression in hepatocellular carcinoma (ID 208)

Presentation Number
3P
Lecture Time
12:30 - 12:30
Speakers
  • Y. Sun (Shanghai, China)
Session Name
Poster Display session
Location
Room B, Geneva Palexpo, Geneva, Switzerland
Date
14.12.2018
Time
12:30 - 13:00
Authors
  • Y. Sun (Shanghai, China)
  • X. Yang (Shanghai, China)
  • J. Fan (Shanghai, China)

Abstract

Background

The prognosis of hepatocellular carcinoma (HCC) is closely associated with recurrence and metastasis which has been proposed to be initiated by circulating tumor cells (CTCs). Yet, the transcriptomic plasticity and immune evasion mechanism of CTCs during circulation are not well defined.

Methods

Blood was drawn from 4 different vascular sites, including hepatic vein (HV), peripheral artery (PA), peripheral vein (PV) and portal vein (PoV) of 10 localized HCC patients. Single CTCs were isolated by negative enrichment and robotic micromanipulator, followed by single-cell RNA sequencing (scRNA-seq). After filtering, 113 CTCs with qualified data were subjected to bioinformatics analysis. The scRNA-seq results were further validated in three independent HCC cohorts.

Results

Our scRNA-seq data revealed remarkable intra- and inter-vascular heterogeneity among CTCs from four vascular sites. We determined CTC transcriptional dynamics during transportation through consecutive vascular sites and revealed their adaptation mechanisms under biomechanical stress. We further classified CTCs from different vascular sites into two subsets, namely dormant and activated CTCs. Dormant CTCs were associated with a non-cycling state and upregulation of EMT/angiogenic signatures and showed stronger prognostic ability for early relapse than activated CTCs. Furthermore, we discovered an immune escape mechanism by which CTCs recruited regulatory T cells (Tregs) via expression of CCL5, consequently promoting the formation of an immunosuppressive microenvironment favorable for their survival in bloodstream and distant colonization.We proved that MAX, activated through the p38 pathway, was the key transcriptional factor regulating CCL5 overexpression, which was validated by ChIP, luciferase reporter gene and in vitro/vivo knockdown assays. And we further determined that Tregs-derived TGF-β1 can heighten MAX expression, thus amplifying the CCL5 expression.

Conclusions

Collectively, our results reveal a previously unappreciated spatial heterogeneity of CTCs and a CTC immune-escape mechanism, which may aid in designing new anti-metastasis therapeutic strategies in HCC.

Legal entity responsible for the study

Jia Fan.

Funding

The State Key Program of National Natural Science of China.

Disclosure

All authors have declared no conflicts of interest.

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Beyond PD-1/PD-L1 axis blockade Educational session

General discussion / Q&A (ID 94)

Lecture Time
12:15 - 12:30
Location
Room A, Geneva Palexpo, Geneva, Switzerland
Date
16.12.2018
Time
11:00 - 12:30
Poster Display session Poster Display session

42P - A phase I clinical trial on intratumoral administration of autologous CD1c (BDCA-1)+ myeloid dendritic cells (myDC) in combination with ipilimumab (IPI) and avelumab (AVE) plus intravenous low-dose nivolumab (NIVO) in patients with advanced solid tumors (ID 349)

Presentation Number
42P
Lecture Time
12:30 - 12:30
Speakers
  • J. K. Schwarze (Brussels, Belgium)
Session Name
Poster Display session
Location
Room B, Geneva Palexpo, Geneva, Switzerland
Date
14.12.2018
Time
12:30 - 13:00
Authors
  • J. K. Schwarze (Brussels, Belgium)
  • G. Awada (Jette, Belgium)
  • I. Van Riet (Jette, Belgium)
  • B. Neyns (Jette, Belgium)

Abstract

Background

Intratumoral (IT) myDC play a pivotal role in initiating anti-tumor immune responses and in "re-licensing” of anti-tumor cytotoxic T-lymphocytes within the tumor microenvironment. IT injection of anti-PD-L1 IgG1 mAb AVE and anti-CTLA-4 IgG1 mAb IPI may reduce the number of regulatory T cells and lyse PD-L1+ tumor cells increasing the release of tumor antigens that can be captured and processed by IT co-administered CD1c (BDCA-1)+ myDC, reinvigorating the cancer immunity cycle.

Methods

Patients (pts) with advanced solid tumors who failed standard-of-care treatment were eligible for this phase I trial with IT injections of ≥ 1 non-visceral metastasis with IPI (max total dose of 10 mg) and AVE (max total dose of 40 mg) plus IV NIVO (10 mg) on day 1 followed by IT injection of autologous, non-manipulated CD1c (BDCA-1)+ myDC on day 2. Administration of AVE, IPI, and NIVO was repeated every 14 days thereafter. Primary endpoints were safety and feasibility. Clinical responses were defined according to iRECIST criteria.

Results

In this ongoing trial, 4 pts (3 primary melanoma, 1 epithelial ovarian carcinoma) were treated with IT injection of a median of 30.5x10(range 10-43x106) CD1c (BDCA-1)+ myDC. A median of 5.5 (range 4-7) study drug administrations were performed. One confirmed partial response was documented in a melanoma patient who previously progressed on immune checkpoint inhibitors. In 2 additional melanoma pts regression of the injected subcutaneous metastases coincided with progression of non-injected metastases. Overall, study treatment was well tolerated and adverse events consisted of transient grade 2 local pain at the injection site in 2 pts, grade 1 pruritus in 2 pts, grade 2 pneumonitis in 1 patient, and pruritus and redness of the skin overlaying the injected lesion in 1 patient.

Conclusions

IT injection of autologous, non-manipulated CD1c (BDCA-1)+ myDC with IT co-injection of AVE and IPI plus IV low-dose NIVO is feasible and tolerable and resulted in encouraging early signs of anti-tumor activity in injected as well as non-injected lesions.

Clinical trial identification

EudraCT: 2017-003280-35.

Legal entity responsible for the study

Universitair Ziekenhuis Brussel.

Funding

Kom op Tegen Kanker.

Disclosure

All authors have declared no conflicts of interest.

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Mini Oral session Mini Oral session

LBA2 - Proton pump inhibitors negatively impact survival of PD-1 inhibitor based therapies in metastatic melanoma patients (ID 491)

Presentation Number
LBA2
Lecture Time
08:00 - 08:05
Speakers
  • K. Homicsko (Lausanne, Vaud, Switzerland)
Session Name
Mini Oral session
Location
Room A, Geneva Palexpo, Geneva, Switzerland
Date
15.12.2018
Time
08:00 - 09:00
Authors
  • K. Homicsko (Lausanne, Vaud, Switzerland)
  • G. Richtig (Vienna, Austria)
  • F. Tuchmann (Vienna, Austria)
  • Z. Tsourti (Athens, Greece)
  • D. Hanahan (Lausanne, Switzerland)
  • G. Coukos (Epalinges, Switzerland)
  • M. Wind-Rotolo (New York, NY, United States of America)
  • E. Richtig (Graz, Austria)
  • P. Zygoura (Athens, Greece)
  • C. Holler (Vienna, Austria)
  • U. Dafni (Athens, Attica, Greece)
  • O. A. Michielin (Lausanne, Switzerland)

Abstract

Background

PD1 inhibitors as well as PD1/CTLA4 combinations have shown remarkable efficacy in the first-line treatment of metastatic melanoma. The impact of many concomitant medications on the clinical outcomes from PD1 based therapies remains elusive.

Methods

We retrospectively analyzed 140 patients included in the Checkmate 069 phase II clinical trial as a discovery cohort, comparing ipilimumab monotherapy with ipilimumab combined with nivolumab. We compared response rates, progression-free survival and overall survival of patients treated or not with 11 different classes of co-medications at immune therapy initiation. Disease stage, LDH levels, BRAF status, sex, age, and body mass index were also compared. Furthermore, a protein array was performed for 440 analytes in a subset of 135 patients for whom pretreatment serum was available. We validated the impact of proton pump inhibitors in an independent cohort of 68 PD1 monotherapy (pembrolizumab or nivolumab) treated patients.

Results

In univariate analysis, baseline proton pump inhibitor treatment almost halved the objective response rates, reduced progression-free and overall survival of patients treated with ipilimumab and nivolumab but not with ipilimumab alone. This effect was maintained when accounted for multiple comparisons and in a multivariate analysis. Pretreatment serum protein analysis showed increased NCAM1 and CSF3R levels in PPI users. We found increased baseline blood leukocyte and neutrophil levels in correlation with PPI use. The results were confirmed in an independent cohort of 68, first-line melanoma patients.

Conclusions

Our analysis shows that proton pump inhibitors could negatively impact on the benefit from PD1 based therapies both for monotherapy and also for ipilimumab and nivolumab combination therapy. PPIs might establish a unique inflammatory immune status, prior to immune therapy initiation that interferes with treatment efficacy. These results suggest that if possible PPIs should be avoided in patients who are destined for PD1-based immunetherapies. Also, the results will have important implication for design of future clinical trials.

Legal entity responsible for the study

Department of Oncology, CHUV, Lausanne, Switzerland.

Funding

Has not received any funding.

Disclosure

M. Wind-Rotolo: Employee of BMS. All other authors have declared no conflicts of interest.

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Poster Display session Poster Display session

81P - Optimizing novel anti-4-1BB antibodies on a in vivo drug screening platform (ID 446)

Presentation Number
81P
Lecture Time
12:30 - 12:30
Speakers
  • Y. Yang (Beijing, China)
Session Name
Poster Display session
Location
Room B, Geneva Palexpo, Geneva, Switzerland
Date
14.12.2018
Time
12:30 - 13:00
Authors
  • Y. Yang (Beijing, China)
  • Y. Guo (Beijing北京, China)
  • Y. Shen (Beijing北京, China)
  • J. Ni (Beijing, China)

Abstract

Background

4-1BB, also called TNF receptor super family member 9 or CD137, is mainly expressed on the surface of activated T, NK, and mononuclear cells. 4-1BB is activated by its ligand 4-1BBL or an activating 4-1BB monoclonal antibody, and stimulates T cell activation, proliferation and cytokine production. This co-stimulatory signal can also multiply antigen presenting cells and result in enhanced cell factor secretion. Experiments show that 4-1BB co-stimulation regulates T cell and antigen presenting cell function for antitumor immunity, providing new targets for tumor immunological therapies.

Methods

Here, we developed a cohort of 4-1BB specific antibodies using the classic hybridoma technology. Then, we utilized humanized 4-1BB mice (B-h-4-1BB) and implanted syngeneic tumors subcutaneously, followed by treating mice with purified testing antibodies. Via this approach, we are able to discern several clones that effectively inhibited tumor growth without prior knowledge of their in vitro activities. These clones were further selected for humanization. The cohort of recombinant humanized 4-1BB antibodies were screened in B-h4-1BB mice.

Results

A cohort of 4-1BB specific antibodies were successfully generated and purified. These purified antibodies were screened by their efficacy to stimulate anti-tumor activity in live animals using Biocytogen’s humanized mouse platform. Top clones were humanized and screened by using B-h4-1BB mice. Both the Fv and Fc portion of the lead antibody were optimized using the B-h4-1BB mice, leading to the humanized form of the antibodies.

Conclusions

We adopted an in vivo screen approach to discover candidates of 4-1BB specific antibodies that have potent anti-tumor activity. We discovered the leads with the most potent anti-tumor activity.

Legal entity responsible for the study

Biocytogen Boston Corp.

Funding

Biocytogen Boston Corp.

Disclosure

All authors have declared no conflicts of interest.

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Poster Display session Poster Display session

104P - PIG-C and SOCS3: Potential immunotargets regulated by non-coding RNAs in TNBC (ID 429)

Presentation Number
104P
Lecture Time
12:30 - 12:30
Speakers
  • M. M. Armanios (Cairo, Egypt)
Session Name
Poster Display session
Location
Room B, Geneva Palexpo, Geneva, Switzerland
Date
14.12.2018
Time
12:30 - 13:00
Authors
  • M. M. Armanios (Cairo, Egypt)
  • R. Abdel Tawab (Cairo, Egypt)
  • H. M. El Tayebi (Cairo, Egypt)

Abstract

Background

Among the crucial proteins having dual role in cancer and immunity is suppressor of cytokine-signaling3 (SOCS3) protein regulating JAK/STAT and IL 6/STAT3/NF-κB pathways, respectively. Another pivotal membrane anchoring protein; PIG-C, that anchors several proteins involved in carcinogenesis. Previous studies proved that miR-34a regulates PDL1. Also, our previous work proved that lncRNAs XIST and TSIX were able to manipulate PDL1 expression in triple negative breast cancer (TNBC). Therefore, this study aims at studying the impact of miR-34a, XIST/TSIX on SOCS3 and PIGC as novel targets to be added to the picture of molecular targeted immunotherapy.

Methods

Twenty pairs of BC tissues and adjacent non-BC tissues were collected from patients undergoing tumor resection surgery. MDA-MB-231 cell line was cultured, transfected for manipulation of gene expression purposes. Total RNA was extracted using Biozol followed by reverse transcription cDNA synthesis, amplification and quantification using quantitative-real-time PCR.

Results

PIG-C was up-regulated in BC compared to controls (p = 0.0017). MiR-34a decreased PIG-C expression in BC cells lines (p < 0.0001) while anti-miR-34a increased PIG-C (p = 0.0259). MiR-34a increased SOCS3 (p = 0.0192) while anti-miR-34a decreased SOCS-3 (p = 0.0003). Upon XIST knockdown, PIG-C was up-regulated (p = 0.0243) and surprisingly SOCS3 was also up-regulated (p = 0.0092). Oppositely, siTSIX decreased PIG-C (p = 0.0320) and it significantly decreased SOCS3 (p = 0.0005) ensuring the previous results with siXIST. Co-transfection of miR-34a and siXIST decreased PIGC (p < 0.0001). Similarly, PIG-C decreased upon co-transfection of miR-34a and siTSIX (p < 0.0001). SOCS3 increased upon co-transfection of miR-34a with siTSIX (p = 0.0017). Synergistically, SOCS3 increased in the cells co-transfected with miR-34a and siXIST (p = 0.0201).

Conclusions

Here, PIG-C and SOCS3 are introduced as new immunotargets in TNBC. In the context of epigenetic regulation, the cross-talk between non-coding RNAs revealed miR-34a to have the lead over XIST and TSIX in regulating PIG-C and SOCS3. These data pave the road for establishing new proteins for molecular targeted immunotherapy along with their key upstream non-coding RNA regulators.

Legal entity responsible for the study

German University in Cairo, Egypt.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.

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Combinations with other modalities Educational session

Radiotherapy to boost the immune system (ID 21)

Lecture Time
16:50 - 17:10
Speakers
  • D. De Ruysscher (Maastricht, Netherlands)
Location
Room C, Geneva Palexpo, Geneva, Switzerland
Date
13.12.2018
Time
16:30 - 18:00
Authors
  • D. De Ruysscher (Maastricht, Netherlands)
What’s new in melanoma & Merkel cell carcinoma (MCC) Educational session

Adoptive cell therapy in melanoma (ID 43)

Lecture Time
15:15 - 15:35
Speakers
  • J. B. Haanen (Amsterdam, Netherlands)
Location
Room C, Geneva Palexpo, Geneva, Switzerland
Date
14.12.2018
Time
14:15 - 15:45
Authors
  • J. B. Haanen (Amsterdam, Netherlands)