Presented at the SITC 38th Annual Meeting, 3-5 November 2023, San Diego, CA, USA, and online | Abstract 1145 |
Lymph Node Targeted AMP-peptide Vaccines Generate Functional
T cell Immunity Against Mutant p53 and BRAF
Martin P. Steinbuck1, Xavier Cabana-Puig1, Erica Palmer1, Mimi M. Jung1, Thomas Williams1, Kristen Osaer1, Jeff Zhang1,
Christopher M. Haqq1, and Peter C. DeMuth1
1 Elicio Therapeutics, Inc. 451 D St., Ste 501, Boston, MA 02210
Clinical Relevance: p53 and BRAF Mutations in Cancer
Repeat-dose Immunization Strategy | ELI-008 Is Designed to Target >30% of p53 Mutations | |
Mutant p53
Nearly 60% of human tumors exhibit dysregulated p53[1]
including mutations, copy number alterations, upstream deregulation
~50% of those tumors have missense mutations in p53[2,3]
Annual incidence: 5.2M patients worldwide and 700K patients in the US
Prevalent in nearly all tumor types; sign of advanced disease Poor clinical prognosis[4]
p53 Mutations by Cancer Type
Estimated Worldwide Annual Incidence[2,3]
Brain
Mutant BRAF
Mutations are concentrated in one hotspot[5-11]
Up to 97% of BRAF mutations occur at the V600 location
High prevalence in melanoma and thyroid tumors[10,11]
Overall, BRAF mutations are present in 8% of solid tumors Representing approx. 1 million cases globally each year
BRAF Mutation Hotspots
Melanoma[11]Thyroid[5]5%
8%
V600E | V600E |
V600K | |
V600X | Other |
Preclinical Murine Doses: | Mutant | % Patients | |||||||||||||||||
AMP-CpG | AMP-Peptide | 1 | R248W | 3.53% | |||||||||||||||
Day | Day | Day | Day | Day | Day | ELI-007 | 10 nmol | + | 20 nmol | 2 | R248Q | 4.37% | |||||||
Schema | C57BL/6 | -ELI008 | Adjuvant [TLR9 Agonist] | 3 | R175H | 5.60% | |||||||||||||
1 | 7 | 14 | 21 | 28 | 35 | ELI-008 | 5 nmol | + | 1.25 nmol | ||||||||||
Potential candidates: 12 of the most | 4 | R273H | 3.95% | ||||||||||||||||
ICS, Luminex | |||||||||||||||||||
AMP-CpG 7909 | |||||||||||||||||||
*Dose | Preclinical Assays: | 5 | R273C | 3.31% | ~30% of all | ||||||||||||||
Antigen [30mer Peptides] | 6 | R282W | 2.83% | patients with | |||||||||||||||
ELISpot, FluoroSpot | AMP-p53 Mutant Peptides | 7 | G245S | 2.11% | |||||||||||||||
Assay | Spleen | p53 mutations | |||||||||||||||||
8 | R249S | 2.04% | |||||||||||||||||
Blood | ICS | frequently occurring p53 mutations[21]. | 9 | Y220C | 1.83% | ||||||||||||||
*Control groups were immunized with equivalent amounts | 10 | C135Y | 0.43% | ||||||||||||||||
Lung | ELISpot, ICS | ||||||||||||||||||
of unmodified "soluble (SOL)" CpG and antigen peptide. | 11 | R158H | 0.52% | ||||||||||||||||
12 | H214R | 0.39% |
Ovary | Total Cancer Incidence |
Melanoma | |
Kidney | |
Leukemia | ~30% |
Pancreas | |
Non-Hodgkin | |
Bladder | ~60% |
Thyroid | |
Esophagus | p53 Mutation |
Cervix | |
Liver | p53 Dysregulation |
Stomach | |
Prostate | |
Colorectum | |
Lung | |
Breast | |
1 | 2 |
Incidence of most common cancers
(in millions)
84% | Other | 95% |
Most Frequently BRAF-Mutated Cancer Types[10]
100% | Hairy Cell |
Leukemia[7] | |
Thyroid[6] |
60%
11%
Melanoma[8]Colorectal[9]54%
ELI-007 is Designed to Address ~95% of BRAF Mutations
007 | Adjuvant [TLR9 Agonist] | Mutant | % Patients | |
1 | V600E | ~90% | ||
AMP-CpG 7909 | ||||
2 | V600K | ~5% | ||
ELI- | Antigen [29mer Peptides] | |||
AMP-BRAF V600E | ~95% of all patients | |||
AMP-BRAF V600K | with BRAF mutations |
ELI-007 Generates Strong Immune Responses to V600E and V600K
AMP-p53 R248W Produces Strong T Cell Responses in Mice
The 10mer, 18mer, and 30mer AMP-peptides are centered around the same R248W mutation.
T Cell IFNγ Response: Spleen Day 21 | T Cell IFNγ Response: Spleen Day 35 | |||||||
Stim: p53 R248W OLPs | Stim: p53 R248W OLPs | |||||||
splenocytes | 12000 | splenocytes | 25000 | |||||
7000 | ||||||||
15000 | ||||||||
2000 | >9x | >50x | >28x | >26x | >530x | >10x | ||
2000 | ||||||||
6 | 6 | 10000 | ||||||
/ 1x10 | / 1x10 | |||||||
1500 | ||||||||
1000 | ||||||||
SFC | SFC | 5000 | ||||||
500 | ||||||||
IFNγ | IFNγ | |||||||
0 | 0 |
Therapeutic Vaccination: Benefits of Targeting Mutated p53 & BRAF
Peptide | SOL AMP SOL AMP SOL AMP | Peptide | SOL AMP SOL AMP SOL AMP |
Truncal Mutation
Driver Mutation
High Prevalence
Public Neoantigen
Proven Clinical MOA
Mutant p53 | Mutant BRAF |
These mutations are present early on in tumor progression and shared among all progeny as they apply positive selection for survival in the cancer cell population and allow for clonal expansion[12].
Signaling is required for tumor survival and growth, making loss of
these mutations unlikely, thus preventing immune escape.
Major driver in [10] | |
Occurs in nearly all types of | 100% of hairy cell leukemia |
tumors and is involved in | 60% of thyroid cancer |
~30% of overall cancer cases[3]. | 54% of melanoma |
11% of colorectal cancer |
Mutant peptides are not centrally tolerized;
cognate TCRs are present in naïve repertoire[13-16]
Mutant p53- and BRAF-specific T cells are
known to mediate anti-tumor efficacy[14,15]
T Cell IFNγ Response: Spleen Day 21 | T Cell IFNγ Response: Spleen Day 21 | |||||||
splenocytes | Stim: BRAF V600E OLPs | splenocytes | Stim: BRAF V600K OLPs | |||||
1200 | 1000 | |||||||
900 | 800 | |||||||
6x | 5x | 11x | 4x | 7x | 6x | |||
600 | ||||||||
6 | 6 | |||||||
1x10 | 600 | 1x10 | ||||||
400 | ||||||||
/ | / | |||||||
SFC | 300 | SFC | ||||||
Antigen | Mock | 18mer | 30mer | Antigen | Mock | 18mer | 30mer |
10mer | 10mer |
Longer antigen peptides contain greater numbers of potential epitopes, increasing the probability of a strong immune response in various HLA haplotypes.
Potent T cell responses are observed after only two doses with AMP-p53 R248W, which are further improved upon after a third bi-weekly dose.
200 | |||||||||
IFNγ | IFNγ | ||||||||
0 | 0 | ||||||||
Peptide | SOL AMP | SOL AMP SOL AMP | Peptide | SOL AMP | SOL AMP SOL AMP | ||||
Mock | V600E + | Mock | V600E + | ||||||
Antigen | V600E | V600K | Antigen | V600E | V600K | ||||
V600K | V600K | ||||||||
T cell responses are detectable after only two doses of the AMP-BRAF V600E, V600K, and combination (ELI-007) vaccines.
T Cell IFNγ Response: Spleen Day 35 | T Cell IFNγ Response: Spleen Day 35 | ||||||
splenocytes | Stim: BRAF V600E OLPs | splenocytes | Stim: BRAF V600K OLPs | ||||
20000 | 15000 | ||||||
15000 | |||||||
10000 | |||||||
10000 | 24x | 18x | 10000 | 27x | 10x | ||
16x | 11x | ||||||
6 | 7500 | 6 | 7500 | ||||
1x10 | 1x10 | ||||||
5000 | 5000 | ||||||
/ | / | ||||||
12000 | ||
6 | 10000 | |
/SFCCytokine1x10 | splenocytes | |
8000 | ||
6000 | ||
4000 | ||
2000 | ||
0 |
Peptide
Antigen
Overlay
Percent Polyfunctional
T Cell Cytokine Response: Spleen Day 35
Stim: p53 R248W OLPs
Triple+
IFNγ+ IL2+
IFNγ+ TNFα+
IL2+
TNFα+
IFNγ+
Mock | SOL | AMP | SOL | AMP | SOL | AMP |
10mer | 18mer | 30mer | ||||
1x10/SFCCytokine | lymphocytesresident-lung | 8000 |
6 | ||
6000 | ||
4000 | ||
2000 | ||
0 | ||
Peptide | ||
Antigen |
Overlay
Percent Polyfunctional
T Cell Cytokine Response: Lung Day 35
Stim: p53 R248W OLPs
Triple+
IFNγ+ IL2+
IFNγ+ TNFα+
IL2+
TNFα+
IFNγ+
Mock | SOL AMP SOL AMP SOL AMP | ||
10mer | 18mer | 30mer |
1 Cytokine
2 Cytokines
3 Cytokines
SFC | 2500 | SFC | 2500 | ||||||||
IFNγ | 0 | IFNγ | 0 | ||||||||
Peptide | SOL AMP | SOL AMP SOL AMP | Peptide | SOL AMP | SOL AMP SOL AMP | ||||||
Mock | V600E + | Mock | V600E + | ||||||||
Antigen | V600E | V600K | Antigen | V600E | V600K |
Vaccine:
5000 |
pg/ml |
Multiplexed Immune Proteomics: Spleen Day 35 | |||||||||
Stim: p53 R248W OLPs | |||||||||
R248W 10mer | R248W 18mer | R248W 30mer | |||||||
200 | 30000 | 2000 | 100000 | ||||||
Mock | SOL | AMP | Mock | SOL | AMP | Mock | SOL | AMP | |
80000 |
2500
2000
[IL2, |
The AMP-Platform Delivers Cargo Directly to the Lymph Nodes[17,18]
Smart trafficking to the lymph nodes after subcutaneous dosing generates immune responses with increased magnitude, function, and durability.
Takes advantage of potent lymph node immune mechanisms, including activation of innate and adaptive immune cells, antigen-spreading,and improved tumor T cell trafficking / infiltration.
Mutant p53/BRAF peptides provide validated antigens for application of the Amphiphile platform.
Lymph node delivery of potent adjuvants minimizes systemic exposure to improve safety.
Lymph Node Biodistribution | AMP Platform Design | |||||||||||||
120 | O | O | x | |||||||||||
Nodes | Antigen | Albumin Binding Lipid | Peptide Antigen | |||||||||||
PEG Linker | ||||||||||||||
100 | Albumin | O | ||||||||||||
(65 kDa) | O | |||||||||||||
Lymph | 80 | |||||||||||||
60 | ||||||||||||||
O | ||||||||||||||
Dose% in | ||||||||||||||
40 | Adjuvant | NH | ||||||||||||
O | ||||||||||||||
NH | ||||||||||||||
20 | ||||||||||||||
Peptide Antigens | Albumin Binding Lipid | CpG-DNA | ||||||||||||
0 | Molecular Adjuvants | |||||||||||||
0 | 20 | 40 | 60 | 80 | ||||||||||
Molecular Weight (kDa) | ||||||||||||||
AMP MOA | Tissue Injection Site | Lymph Node | ||||||||||||
Amphiphiles | Endogenous Albumin |
Albumin-bound Amphiphiles
1 Subcutaneous | 2 | Albumin | 3 | Lymph node | 4 | Adaptive |
injection | binding | targeting | immune response |
Biodistribution of AMP Vaccines[17]
Soluble CpG | AMP-CpG | ||||
2 | T Cells B Cells | T Cells B Cells | |||
0h | 24h | |||||
1 | lymph node | lymph node | ||||
3.3nmol | ||||||
AMP-CpG-FITC or | ||||||
Soluble CpG-FITC | ||||||
Clinical Experience[19,20]
ELI-002,an AMP-vaccinetargeting mKRAS, is currently being investigated in clinical trials for treatment of pancreatic and colorectal cancer (AMPLIFY-201: NCT04853017 and AMPLIFY-7P: NCT05726864).
ELI-002has shown preliminary safety / tolerability, and significant increases in mKRAS T cell responses, associated with reduction / clearance of tumor biomarkers, and reduced risk of progression and death.
Vaccine candidates targeting mutant p53 / BRAF have been built from the AMP-platform, and utilize the ELI-002 adjuvant, AMP-CpG, providing the potential for favorable clinical tolerability and activity.
V600K | V600K |
Further immunization with the AMP-BRAF vaccines increases the T cell response substantially.
Polyfunctional T Cell Responses: Cytokines and Granzyme
Left Y-Axes | 4000 | |
γ, GzmB] | 3000 | |
2000 | ||
[IFN | 1000 | |
0 |
150 | 1500 | ||||||||||||||
20000 | |||||||||||||||
60000 | |||||||||||||||
100 | 1000 | ||||||||||||||
40000 | |||||||||||||||
10000 | |||||||||||||||
50 | 500 | 20000 | |||||||||||||
GM-CSF | 0 | 0 | GM-CSF | 0 | 0 | GM-CSF | |||||||||
IFNγ | TNFα | IL2 | GzmB | IFNγ | TNFα | IL2 | GzmB | IFNγ | TNFα | IL2 | GzmB | ||||
Mock | 2 | Mock | 2 | Mock | 2 | ||||||||||
1 | 1 | 1 | |||||||||||||
SOL | 0 | SOL | 0 | SOL | 0 | ||||||||||
-1 | -1 | -1 |
1500
1000
500
0
Baseline Average Z-
TNFα, GM-CSF] | Right Y-Axes |
pg/ml |
Rel. Protein
Multiplexed Immune Proteomics: Spleen Day 35 |
Stim: BRAF V600 OLPs |
AMP | AMP | AMP | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
-2 | -2 | -2 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Subtracted score
Expression
Vaccine:
80000 | Mock | |
Axes-YLeftpg/mlGzmB],γ | 60000 | |
15000 | ||
10000 | ||
[IFN | 5000 | |
0 | ||
IFNγ |
Mock
SOL
AMP
V600E
SOL
TNFα | IL2 | GM-CSF | |||||||
V600K | V600E + V600K | ||||||||||||
1500 | 1500 | ||||||||||||
AMP | 40000 | Mock | SOL | AMP | 40000 | Mock | SOL | AMP | |||||
10000 | 10000 | ||||||||||||
1000 | 1000 | ||||||||||||
7500 | |||||||||||||
500 | 5000 | 500 | 5000 | ||||||||||
2500 | |||||||||||||
0 | 0 | GM-CSF | 0 | 0 | GM-CSF | ||||||||
GzmB | IFNγ | TNFα | IL2 | GzmB | IFNγ | TNFα | IL2 | GzmB | |||||
1 . 5 | Mock | 1.5 | Mock | 1.5 | |||||||||
0 | SOL | 0 | SOL | 0 | |||||||||
- 1 . 5 | AMP | -1.5 | AMP | -1.5 |
400
300
200
100
0
Average ZBaseline Subtracted -score
[IL2, TNFα, GM-CSF] | Right Y-Axes |
pg/ml |
Rel. Protein Expression
Polyfunctional T cells reside not only in secondary lymphoid tissues like spleen, but in peripheral organs such as the lung, which is one of the predominant sites for metastatic spread in melanoma and colorectal carcinoma.
AMP-p53 R248W Generates Cytotoxic T Cells
T Cell Cytotoxic Response: Spleen Day 35 | In Vivo Target Cell Killing: Spleen Day 35 | ||||||||
splenocytes | Stim: p53 R248W OLPs | Stim: p53 R248W OLPs | |||||||
20000 | 80 | 54% | 46% | ||||||
Killing | Low [Tag-it Violet] | ||||||||
Unspecific Targets | |||||||||
15000 | 36x | 14x | 20x | 60 | High [Tag-it Violet] | ||||
p53-specific Targets | |||||||||
6 | % Target Cell | ||||||||
SFC / 1x10 | 10000 | 40 | Mock | ||||||
5000 | 20 | 52% | 48% | 74% | |||||
26% |
Cytotoxic Response: Spleen Day 35 | Cytotoxic Response: Spleen Day 35 | |||||||||
Stim: BRAF V600E OLPs | Stim: BRAF V600K OLPs | |||||||||
cells | 12 | cells | 8 | |||||||
CD3+ | 2.4x | 2.7x | 1.9x | CD3+ | 6 | 2.1x | 2.2x | 2.4x | ||
among | 8 | among | ||||||||
4 | ||||||||||
GzmB+% | 4 | GzmB+% | ||||||||
2 | ||||||||||
BL | BL | |||||||||
0 | 0 | |||||||||
Peptide | SOL AMP SOL AMP SOL AMP | Peptide | SOL AMP | SOL AMP | SOL AMP | |||||
Mock | V600E + | Mock | V600E + | |||||||
Antigen | V600K | Antigen | V600E | V600K | ||||||
V600E | V600K | V600K | ||||||||
Polyfunctional T cells induced by AMP-BRAF vaccines produce high levels of cytokines as well as cytolytic GzmB.
➢ AMP enhances vaccine potency via targeted lymph node delivery.
MESSAGES | ➢ ELI-007 and ELI-008 substantially improved T cell responses over | |
soluble comparator vaccines: | ||
• Polyfunctional T cells that produce TH1-associated cytokines: | ||
HOME | (IFNγ / TNFα / IL2 / GM-CSF). | |
• Secretion of Granzyme B, potent cytolytic function | ||
➢ AMP-vaccines have the potential to address a high, unmet medical | ||
TAKE | need for millions of patients with BRAF / p53 mutations annually. | |
➢ | The AMP-platform technology is simple, rapid and scalable for broad | |
clinical application.
GzmB | 0 | 0 | |||||
Peptide | SOL AMP SOL AMP SOL AMP | SOL AMP | |||||
Antigen | Mock | 18mer | 30mer | Mock | SOL | AMP | |
10mer | 18mer |
AMP-p53 R248W generates GzmB producing, cytotoxic T cells capable of killing p53 R248W-pulsed target cells in vivo.
AMP-vaccination Generates Immunity to Common p53 Mutants
T Cell IFNγ Response: Spleen Day 35 Stim: respective p53 OLPs
R248W | R175H | R273H | G245S | |||||||||||
splenocytes | 25000 | splenocytes | 8000 | splenocytes | splenocytes | 2000 | ||||||||
6000 | ||||||||||||||
6000 | ||||||||||||||
15000 | 10x | 3000 | 70x | 3000 | 100x | 1500 | 7x | |||||||
6 | 6 | 6 | 6 | |||||||||||
1x10/ | 10000 | 1x10/ | 2000 | 1x10/ | 2000 | 1x10/ | 1000 | |||||||
SFCγ | 5000 | SFCγ | 1000 | SFCγ | 1000 | SFCγ | 500 | |||||||
IFN | 0 | IFN | 0 | IFN | 0 | IFN | 0 | |||||||
Mock | SOL | AMP | Mock SOL | AMP | Mock | SOL AMP | Mock SOL | AMP | ||||||
splenocytes | Y220C | splenocytes | C135Y | splenocytes | R158H | splenocytes | H214R | |||||||
15000 | ||||||||||||||
21000 | 25000 | |||||||||||||
18x | 5x | 2000 | 37x | 8x | ||||||||||
10000 | 20000 | |||||||||||||
10000 | ||||||||||||||
6 | 7500 | 6 | 15000 | 6 | 6 | |||||||||
1x10 | 1x10 | 1x10 | 1x10 | |||||||||||
5000 | 10000 | 1000 | ||||||||||||
/ | / | / | / | 5000 | ||||||||||
SFC | SFC | SFC | SFC | |||||||||||
2500 | 5000 | |||||||||||||
IFNγ | IFNγ | IFNγ | IFNγ | |||||||||||
0 | 0 | 0 | 0 | |||||||||||
Mock SOL | AMP | Mock SOL | AMP | Mock SOL AMP | Mock SOL | AMP |
8 candidate p53 mutant 30mer AMP-peptides elicit strong T cell responses upon immunization, demonstrating the versatility, ease of application and potency of the AMP-platform.
References | 6. | Agrawal N, et al. Cell. (2014) 159:676-90 | 14. | Yu Y, et al. Hum Vaccin Immunother. (2022) 18(1):1-11. | Funded by: | |
7. | Ahmadzadeh A, et al. Oncol Rev. (2014) 8(2):253 | 15. | Veatch JR, et al. J Clin Invest. (2018) 128(4):1563-68. | |||
1. | Ciriello G, et al. Nat Genetics. (2013) 45(10):1127-33 | 8. | Hodis E, et al. Cell. (2012) 150(2):251-63 | 16. | Sharkey MS et al. Cancer Res. (2004) 64(5):1595-9 | |
2. | IARC Global Cancer Observatory. gco.iarc.fr. 2023 | 9. | CGNA, et al. Nature. (2012) 487, 330-337. | 17. | Liu H, et al. Nature. (2014) 27;507(7493):519-22 | |
3. | The TP53 Database. tp53.isb-cgc.org. 2023 | 10. | Yi Q, et al. Front Bioeng Biotechnol. (2022) 10:806851 | 18. | Moynihan KD, et al. Nat Med. (2016) 22(12):1402-1410 | |
4. | Robles AI, et al. CSH Perspect Biol. (2010) 2(3):a001016 | 11. | Ihle MA, et al. BMC Cancer. (2014) 10;14:13 | 19. | O'Reilly EM, et al. J Clin Oncol. (2023) 41(16): 2528 | |
5. | Nikiforov YE, et al. Mod Pathol. (2011) 24 Suppl 2:S34-43 | 12. | Levine, A.J. Oncogene (2021) 40, 5975-5983 | 20. | Wainberg Z, et al. AACR Pancreatic (2023) | |
13. | Houbiers JG, et al. Eur J Immunol. (1993) 23(9):2072-7 | 21. | Baugh EH, et al. Cell Death Differ. (2018) 25(1):154-160 |
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Elicio Therapeutics Inc. published this content on 03 November 2023 and is solely responsible for the information contained therein. Distributed by Public, unedited and unaltered, on 10 November 2023 14:37:54 UTC.