Durable immunogenicity of ELI-002 2P in AMPLIFY-201: Lymph node targeted mKRAS-specific amphiphile vaccine in pancreatic and colorectal cancer

Public neoantigen:

repertoire4-5

Driver:

Truncal:

Presented at the AACR Annual Meeting, 5-10 April 2024, San Diego, CA, USA, and online	Abstract CT107
Durable immunogenicity of ELI-002 2P in AMPLIFY-201: Lymph node targeted
mKRAS-specific amphiphile vaccine in pancreatic and colorectal cancer

James R. Perry, Haley VanWyk, Amy M. Tavares, Thian Kheoh, Esther Welkowsky, Christopher M. Haqq, Peter C. DeMuth, and Lisa K. McNeil

Elicio Therapeutics, Inc. Boston, MA, USA.

Why Target mutated KRAS with Therapeutic Vaccination?

mKRAS T Cell Responses Correlate with Reduction in Risk of Relapse or Death12

ELI-002 2P Vaccination Amplifies Cytotoxic mKRAS-specific CD4+ T cells

68% of patients (13/19) have cytotoxic mKRAS-specific CD4+ T cells

1 Mutant KRAS Drives 25% of Solid Human Cancers

Prevalent among numerous tumor types1-2

Overall poor clinical prognosis3

Limited therapeutic options

Pancreatic Ductal

Adenocarcinoma

93%(PDAC)

US Incidence: ~56k

5%
	Colorectal Cancer
52%	(CRC)
US Incidence: 151k

KRAS mutant NRAS mutant

2 Mutant KRAS is a Promising Tumor Antigen

mutations occur early, expressed uniformly in all tumor cells mKRAS signaling is required for tumor growth and survival

Highly prevalent: involved in ~25% of solid tumors1-2

not centrally tolerized, cognate TCRs present in naïve

Promiscuous HLA presentation: potential off-the-shelf use in diverse patient population6-8

Proven Clinical MOA: mKRAS-specific T cells known to mediate anti-tumorefficacy4-5

Multi-targetingpotential: recognition of clonal and subclonal mKRAS variants to prevent escape9

Strength of T Cell Response	86% Reduced Risk of Relapse or Death	Best Overall Tumor Biomarker Response
			≥ Median T Cell Response (n = 13)	P = 0.0167	Clearance Reduction Non-Responder
			< Median T Cell Response (n = 12)	HR: 0.14 (0.03 - 0.63)

			300
100	Median RFS: not reached
			200	P = 0.0014
75
			100
50	Median RFS: 4.01 months
SurvivalRelapsefree(%)-	ResponseBiomarkerOverall	Baseline)(%of	0
25

CD4+ IL2+	CD4+ IL2+ T cells	CD4+ Cytotoxic T cells		CD4+ Memory Phenotype
mKRAS-specific T cells		Cytotoxic+		Memory
	GrB+	GrB+Perf+	CM	Naive		CM EM TEMRA Naive
	9.38	1.88	23.1	62.8	80

Baseline								Baseline	Week 9
IL2+						23	63
	0.31					60
	DN	Perf+	EM	TEMRA	T cells
	88.1	0.62	12.2	1.88
	GrB+	GrB+Perf+	CM	Naive	+	40
	CD4
	56.7	6.44	51.5	13.4
	B				%			13

The AMP-Platform: Enhanced Lymph Node Delivery

Smart trafficking to the lymph nodes after subcutaneous dosing generates immune responses with increased magnitude, function, and durability10-11

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

Lymph Node Biodistribution	AMP Platform Design
120	O

							Best
0							-100
						≥ Median	< Median
0	3	6	9	12	15	18
			Months				T Cell Response
							(Fold change from baseline)

Expansion of T cells Targeting mKRAS and Antigen Spreading

Week 9	IL2+	Granzyme			CCR7			20 33
CD4	1.00
	DN	Perf+	EM	TEMRA
			35.4	1.49		32.9	2.23	0
IL2			Perforin			CD45RA

Ex Vivo mKRAS-specific cytotoxic CD4+ T cells

• mKRAS-specific cytotoxic CD4+ T cells secrete

Granzyme B and Perforin

2200

0.1 mg

32

+

						O	x
		100	Albumin		Antigen	O
		(65 kDa)		O
	Nodes
	80			PEG Linker	Peptide Antigen
Vaccine	in Lymph				Albumin Binding Lipid
60
Design	40				O
	% Dose				NH
	20			Adjuvant	O
			NH
			Peptide Antigens
	0		Molecular Adjuvants
			Albumin Binding Lipid	CpG-DNA

change from baseline

Max Fold-change

450
50
40
30
20	Median:
10	12.75x
5

IFNγ and/or GrB SFC / 1x106 PBMC

Ex Vivo Fluorospot

4500

200

200

150

100

50

among	T cells
+
+	CD4
%Cytokine	or
+
CD8

5

3

1

1.0

0.8

0.6

0.4

Ex Vivo ICS

0.1 mg

0.5 mg

2.5 mg

5.0 mg

10.0 mg

CD4/8 T cell Correlation to

Tumor Biomarker Response

Clearance Reduction Non-Responder

Response	300
200				P = 0.0101

Fold change from baseline

1500

800

25

15

5

5

2

0 Baseline

Week 9

0.5 mg	32
2.5 mg	68
5.0 mg
10.0 mg		Cytotoxic CD4+ T cells
		Non-cytotoxic CD4+ T cells

• Cytotoxic CD4 T cells are predominantly central

and effector memory post vaccination shifting from

naïve T cells at baseline

• Of the 68% of patients who had mKRAS-specific

CD4+ cytotoxic T cells, the median fold change was

7.4, ranging from 2.23 to 2183, with 66.7% (4/6)

cytotoxic responders at the RP2D

• CD4+ regulatory T cells are not observed in any

patients (0/19)

0

20

40

60

80

Molecular Weight (kDa)

Fold

2

0.2

Biomarker Baseline)	100

ELI-002 2P Vaccination Amplifies Cytotoxic mKRAS-specific CD8+ T cells

1	Subcutaneous	2	Albumin	3	Lymph Node	4	Delivery to	5	Immune
Injection	Binding	Targeting	Immune Cells	Response

0	Max
Baseline
Response

0

Baseline Max Response

0.0

Baseline Max Response

84% of patients (16/19) have cytotoxic mKRAS-specific CD8+ T cells

AMP	Endogenous Albumin	Albumin-bound AMP

APC Activation

Mechanism	T Cell Activation
Expansion
of
Action	Persistence
	Effector function

Ex Vivo mKRAS T Cell Response	CD4 / CD8 T Cell Response	mKRAS Specificity
16			Responder		18		CD4 + CD8	14			7 antigens
			Non-responder				CD8	10			5-6 antigens
	84			59	24		CD4	52			2-4 antigens
					24

1 antigen

Best
-100
Both	CD4, CD8,
CD4 + CD8	or None

T Cell Response

mKRAS-specific T cells

Cytotoxic+

Memory

	GrB+	GrB+Perf+	CM	Naive	CM	EM	TEMRA Naive
	8.4	60.5	2.52	17.6
	100
Baseline						Baseline	Week 9
				80
CD137+	DN	Perf+	EM	TEMRA
0.24	cells
	21.0	10.1	23.5	56.3

		Phenotype
		Metabolic function
Albumin-bound AMP	Antigen Presenting Cell	T Cell
Tissue Injection Site	Lymph Node

AMPLIFY 201: Trial Design12

	Patient 11 Antigen Spreading	Patient 11: NIP 5	• 84% of patients generated mKRAS-specific T
	cell responses following ELI-002 2P
Non-Immunizing Peptide (NIP): Ex vivo ICS			immunization; 100% responders at the highest
T cells	1.25		Baseline	Week 9	dose levels (5.0 and 10.0 mg)
Baseline	Week 9			• 59% of patients induced both CD4+ and CD8+ T
+	1.00				cell responses, 76% of patients induced
CD8
				responses to ≥5 mKRAS antigens
among	0.75
			• Response to both CD4+ and CD8+ T cells

								T	60
			GrB+	GrB+Perf+		CM	Naive	+
				CD8
			0.18	88.6		0.31	1.11	40
		B						%
Week 9		Granzyme							20
CD8				CCR7
CD137+	DN	Perf+	EM	TEMRA
3.38
			1.91	9.36		22.2	76.4		0

Prior Therapy

Locoregional

Screening Period

mKRAS+

Amph-Peptides 2P 1.4 mg + 0.1, 0.5, 2.5, 5 or 10 mg Amph-CpG-7909

Prime

No Dosing

Booster

Follow-up

+

0.50

CD8

TNFα+

TNFα+

correlated with overall tumor biomarker

Cytokine

0.25

0.16

0.80

response

CD137

Perforin

CD45RA

Ex Vivo mKRAS-specific cytotoxic CD8+ T cells

Therapy:

Surgery

+

Neoadjuvant /

G12R+ or G12D+

NED

Imaging Negative

MRD+

Immunization

Period

Immunization

Period

Week S/B 0 1 2 3 4 5 6 7 8 9 17 20 21 22 23 24 25

105

Dose

	TNFα	• ELI-002 2P vaccination induces antigen
%	0.00	spreading to non-immunizing antigens in 66.7%
	NIP 1 NIP 2 NIP 3 NIP 4 NIP 5 NIP 6	(6/9) of patients

Durable mKRAS-Specific Immunogenicity after ELI-002 2P Booster Vaccinations

from baseline

400

200

50

35

20

0.1 mg	16
0.5 mg
2.5 mg	84
5.0 mg

• Cytotoxic CD8+ T cells secrete high levels of both

Granzyme B and Perforin

• After vaccination, cytotoxic CD8+ T cells are

predominantly TEMRA memory which are known for

lower proliferative capacity but increased cytotoxic

function

Adjuvant

Chemotherapy

ctDNA+ or

serum biomarker+

ctDNA

Serum biomarkers

PBMC

	2100	100	CM	EM	TEMRA	Naive
SFC	1400	80
700

• 86% (6/7) of patients maintained elevated

T cell response relative to baseline levels

Fold change

5

5

2

10.0 mg		Cytotoxic CD8+ T cells
		Non-cytotoxic CD8+ T cells

• Of the 84% of patients who had mKRAS-specific

CD8+ cytotoxic T cells, the median fold change was

10.4, ranging from 2.73 to 407, with 66.7% (4/6)

Patients

Baseline Characteristics: 20 Pancreatic (PDAC), 5 Colorectal (CRC) were evaluated for safety as of data cutoff: Sept. 6th, 202312

GrB PBMC	600	T cells	60
6		+

or increased response after boost

• Post-boostmKRAS-specific CD4+ T cells

0

Baseline

Week 9

cytotoxic responders at the RP2D

Safety	Safety: No TEAEs ≥ Grade 3, no Dose Limiting Toxicities, no Cytokine Release Syndrome observed across all dose levels;
44% had Grade 1-2 TEAEs: e.g. injection site reaction, fatigue, headache, nausea12

AMPLIFY 201: Immunogenicity Methods

IFNand/orγ /1x10	400					%CD4	40
200					20
	0						0
	0	5	10	15	20	25

had increased central and effector

memory cells and decreased naïve T cells

compared to baseline

MESSAGES		T Cell Response MOA Correlated to:	 86% Reduced Risk of Relapse or Death
		Tumor Biomarker Response
	Direct ex vivo mKRAS-specific T cell responses observed in 84% of patients
	86% (6/7) of patients had durable T cell responses with memory T cells increased from baseline

• Immunogenicity of ELI-002 2P was assessed using longitudinally collected peripheral blood from 23 evaluable patients to assess specificity, polyfunctionality, and antigen breadth. Phenotype of mKRAS-specificT cells was assessed in 19 evaluable patients.
• PBMCs from each patient were individually stimulated with overlapping peptides for each of the seven mKRAS antigens (G12R, G12D, G12V, G12C, G12A, G12S and G13D) for evaluation of mKRAS-specific T cell responses using direct ex vivo assaysγ .
• T cell responses and polyfunctionality were determined by a direct ex vivo IFN /Granzyme B (GrB) Fluorospot, where a positive immune response was defined as >2- fold over baseline and at least 50 SFC per million PBMCs.
• Polyfunctionality and phenotype of patient T cells were further characterized using an ex vivo intracellular cytokine staining (ICS) assay, where responder populations were defined as >2-foldγ overα baseline and a frequency of at least 0.1% Cytokine+. The ICS assay included markers for CD3, CD4, CD8, Memory (CCR7, CD45RA, CD45RO), cytokines (IFN , TNF , IL2), cytolysis (GrB, Perforin, CD107a), activation markers (CD69, CD137, CD154), and proliferation (Ki67).

Weeks post-vaccination	Baseline	Post-boost

References

1.	Bianken A, et al. Nature. 2012; 491(7424): 399-405	5.	Tran E, et al. NEJM. 2016; 375(23): 2255-2262	9.	Awad MM, et al. Cancer Cell. 2022; 40(9): 1010-1026
2.	Prior IA, et al. Cancer Research. 2012; 72(10): 2457-	6.	Bear AS, et al. Nat. Commun. 2021; 12(1): s41467-021-	10.	Liu H, et al. Nature. 2014; 507: 519-522
	2467		24562-2	11.	Moynihan KD, et al. Nature Medicine. 2016; 22(12):
3.	Siegel RL, et al. Cancer J. Clin. 2021; 71(1): 7-33	7.	Carbone DP, et al. J Clin Oncol. 2005; 23(22): 5099-5107		1402-1410
4.	Leidner R, et al. NEJM. 2022; 386(22): 2112-2119	8.	Palmer CD, et al. Br. J. Cancer 2020; 122(7): 971-977	12.	Pant S, et al. Nature Medicine. 2024; 30: 531-542

Acknowledgements

• We are grateful to the patients who participated in the study, their families, and the investigators and staff at the participating institutions.

HOME		Ex vivo T cell responses to non-immunizing antigens are induced by ELI-002 2P vaccination
	mKRAS-specific CD4+ T cells were cytotoxic, predominantly central and effector memory phenotype
	No increases in CD4+ regulatory T cells were observed after vaccination with ELI-002 2P
	84% (16/19) of patients have cytotoxic mKRAS-specific CD8+ T cells, primarily TEMRA phenotype
TAKE
 Randomized Phase 2 Ongoing: ELI-002 7P (NCT05726864) in PDAC: targeting G12D R V C A S, G13D