SITC 2023: Preclinical development of LYL119, a ROR1-targeted CAR T-cell product incorporating four novel T-cell reprogramming technologies to overcome barriers to effective cell therapy for solid tumors

Phase 1 Trial of LYL797, a ROR1-Targeted CAR T-Cell Therapy Enhanced With Genetic and Epigenetic Reprogramming, in

Advanced Triple-Negative Breast Cancer (TNBC) and Non-SmallAbstract 754 Cell Lung Cancer (NSCLC)

David R. Spigel1, Erika Hamilton1, Babar Bashir2, Usama Gergis2, Hemant S. Murthy3, Saranya Chumsri3, Yazan Migdady4, Jennifer M. Specht5, Lubna N. Chaudhary6, Haven R. Garber7, Chul Kim8, Hirva Mamdani9, Amer Beitinjaneh10, Jonathan Goldman11, Roberto A. Leon-Ferre12, R. Alejandro Sica13, Brenda J. Ernst14, Michael Hurwitz15, Roisin E. O'Cearbhail16, Sarah Fitzsimmons17, Bishwa Ganguly17, Hajime Hiraragi17, Helle Jensen17, Yeonhee Kim17, Mary C. Lessig17, and Heidi H. Gillenwater17

1Sarah Cannon Research Institute and Tennessee Oncology, Nashville, TN; 2Thomas Jefferson University Hospital, Philadelphia, PA; 3Mayo Clinic, Jacksonville, FL; 4Oregon Health & Science University Hospital, Portland, OR;

5Fred Hutchinson Cancer Center, Seattle, WA; 6Medical College of Wisconsin, Milwaukee, WI; 7MD Anderson Cancer Center, Houston, TX; 8Georgetown University Medical Center, Washington, DC; 9Karmanos Cancer Institute, Wayne State University, Detroit, MI; 10University of Miami, Coral Gables, FL; 11David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA; 12Mayo Clinic, Rochester, MN; 13Montefiore Medical Center, New York, NY; 14Mayo Clinic, Phoenix, AZ; 15Yale School of Medicine, New Haven, CT; 16Memoral Sloan Kettering Cancer Center, New York, NY; 17Lyell Immunopharma, Inc., South San Francisco, CA

Background

Targeting ROR1 in solid tumors

• Receptor tyrosine kinase-like orphan receptor (ROR1) is a cell surface antigen expressed during embryogenesis that is involved in cell migration, proliferation, and resistance to apoptosis1

• While not expressed in most postpartum tissues1, ROR1 is highly expressed in multiple solid tumors, including approximately 60% of TNBC2 and 40% of NSCLC3 tumors (Figure 1) and is, therefore, an attractive target in patients with limited effective treatment options4,5

• High ROR1 expression has been associated with poor prognosis and metastasis in solid tumors1

LYL797: A novel approach to CAR T-cell therapy

• CAR T-cell therapy has been successful for the treatment of hematologic malignancies but remains challenging for solid tumors due to T-cell exhaustion and lack of durable stemness, key barriers to effective T-cell therapy in solid tumors5,6
• LYL797 is an investigational, autologous ROR1-targeted CAR T-cell product enhanced with epigenetic (Epi-R) and genetic (c-Jun overexpression) reprogramming technologies designed to create more potent and durable T cells to overcome barriers to effective cell therapy in solid tumors (Figures 2 - 4)

Lyell's T-cell reprogramming technologies: Epi-R and c-Jun overexpression

• Epi-R manufacturing protocols are designed to generate populations of stem-like T cells with reduced exhaustion and improved proliferation and antitumor activity (Figure 3)

• Reprogramming T cells through c-Jun overexpression delays exhaustion and results in increased proliferation, sustained cytokine production, and durable antitumor activity in nonclinical models6-8 (Figure 4)

• In nonclinical models, the combined use of Epi-R protocols and c-Jun overexpression further improved CAR T-cell expansion and cytotoxicity, as well as antitumor activity compared with conventional CAR T-cell preparations6,8

Figure 1: ROR1 expression in TNBC and NSCLC6

TNBCNSCLC

ROR1

Isotype IgG

Representative images of IHC staining are shown for ROR1-positive TNBC (BR1301: US Biomax,

Biomax, Inc.) and NSCLC (LC2801; US Biomax, Inc.). Scale bar: 100 µm.

Figure 2: LYL797, ROR1-targeted CAR T Cell

Optimized variant	ROR1-specific CAR
of epidermal growth				Anti-ROR1
factor receptor
			single-chain
					variable fragment

4-1BB

CD3ζ

c-Jun overexpression

Figure 3: Lyell's Epi-R protocol versus standard expansion

Short-lived effector cells	Long-livedstem-like cells

Standard expansion protocol

Control product

Patient-derived

T cells

Lyell Epi-R protocol comprises:

LYL product

 Proprietary media

• Optimized cytokine compositions
• Well-definedcell activation and expansion protocols

Figure 4: Effects of c-Jun overexpression on T-cell activity

 Maintains effector function longer	 Decreases exhaustion markers
 Maintains proliferation	 Blocks inhibitory pathways
 Maintains cytokine secretion	 Delays cellular exhaustion

• Maintains cytotoxic granule secretion

		Reduced exhaustion
	Inflammatory	Cytotoxic granules
	cytokines
c-Jun
T-cell therapy product	Reduced exhaustion markers	TIM3
	LAG3
		TIGIT	Proliferation
		PD-1

Objectives

• LYL797-101 is a phase 1, single-arm,open-label,multi-center,dose-escalation and -expansion study that will evaluate the safety and efficacy of LYL797 in adults with relapsed and/or refractory ROR1-positive TNBC or NSCLC

Primary objectives	Exploratory objectives
• Evaluate safety and tolerability	• Evaluate the effects of c-Jun overexpression
• Determine the RP2D	and Epi-R protocols on T-cell phenotype
Secondary objectives	and activity
• Evaluate the relationship between ROR1
• Evaluate anti-tumor activity	expression and LYL797 activity
• Evaluate pharmacokinetics

Key Eligibility Criteria

• Locally advanced or metastatic ROR1-positive (centrally determined) TNBC or NSCLC

• Measurable disease by RECIST v1.1, including a target lesion and an additional lesion for biopsy • Prior therapies:

͵ TNBC: at least two prior lines of systemic therapy; participants with PD-L1-positive disease must have progressed on an anti-PD-1 antibody therapy

͵ NSCLC: at least one prior line of systemic therapy, including a checkpoint inhibitor and targeted therapy if applicable

• ECOG PS of 0 or 1

• Life expectancy of 3 months or greater

• Participants with active, untreated brain metastases or leptomeningeal disease are excluded; however, participants with successfully treated brain metastases are allowed if stable after completion of therapy for at least 3 months

• No prior ROR1-targeted therapies

LYL797-101 Design: NCT05274451

• The dose-escalation phase includes participants with TNBC and NSCLC and will investigate four dose levels to determine the RP2D using a modified toxicity probability interval 2 design with a 28-daydose-limiting toxicity period. In the dose-expansion phase, 15 - 30 participants will be enrolled in each of the TNBC and NSCLC cohorts at the RP2D (Figure 5)

• Enrolled participants will undergo leukapheresis for LYL797 manufacturing, during which bridging anti-cancer therapy is allowed for disease control. Participants will then receive lymphodepleting chemotherapy followed by LYL797 infusion at the assigned dose level (Figure 6)

Figure 5: Dose-escalation and dose-expansion study design

Dose escalation				Dose expansion
			The RP2D moves	n = 15 - 30 per cohorta
Dose Level 4
			forward to
Dose Level 3			expansion cohort	TNBC
Dose Level 2				NSCLC
Dose Level 1
De-escalation if required
Dose Level -1				aIncluding dose-escalation patients at RP2D

Figure 6: Timeline of screening, treatment, and disease/safety assessments

Optional

Main

Enroll

Pre-screening of ROR1 expression, using an investigational clinical trial assay,

pre-screen ICF

ICF

may occur before patients meet the prior line of therapy eligibility requirement.

Bridging therapy

Optional

Patient

Lymphodepletion

LTFU

LYL797 post-treatmentfollow-up

protocol;

pre-screening

screen

(flu/cy)

Leukapheresis

years 2 - 15

Single-dose infusion of LYL797

						Disease/safety assessments
	LYL797 manufacturing

1 - 3 weeks

~4 weeks

1 month

1 month - 2 years

Tumor assessments (baseline,	Biopsies (archive baseline [at pre-screening or screening],	Post-treatment assessments (2d, 3d, 4d, 8d, 11d,
1m, 2m, 3m, 6m, 12m, 18m, 24m)	22d post-treatment required, post-progression optional)	15d, 22d, 29d, 2m, 3m, 6m, 9m, 12m, 18m, 24m)

Participating Sites

Participating study locations

• Mayo Clinic, Phoenix, AZ

• University of California, Los Angeles, Los Angeles, CA

• Yale New Haven Hospital, New Haven, CT • Georgetown University, Washington, DC • Mayo Clinic, Jacksonville, FL • University of Miami, Coral Gables, FL • Karmanos Cancer Institute, Detroit, MI • Mayo Clinic, Rochester, MN

• Memorial Sloan Kettering Cancer Center, New York, NY

• Montefiore Medical Center, Bronx, NY

• Oregon Health and Science University Hospital, Portland, OR

• Thomas Jefferson University Hospital, Philadelphia, PA

• Sarah Cannon Research Institute and Tennessee Oncology, Nashville, TN

• MD Anderson Cancer Center, Houston, TX

• Fred Hutchinson Cancer Research Center, Seattle, WA

• Medical College of Wisconsin, Milwaukee, WI

Abbreviations

CAR, chimeric antigen receptor; CD, cluster of differentiation; d, days; ECOG PS, Eastern Cooperative Oncology Group performance status; flu/cy, fludarabine/cyclophosphamide; ICF, informed consent form; IgG, immunoglobulin G; IHC, immunohistochemistry; LAG3, lymphocyte activation gene-3; LTFU, long-term follow up; m, months; n, number of patients; NSCLC, non-small cell lung cancer; PD-1, programmed cell death 1; PD-L1, programmed cell death ligand 1; RECIST, Response Evaluation Criteria In Solid Tumors; ROR1, receptor tyrosine kinase-like orphan receptor; RP2D, recommended phase 2 dose; TIGIT, T cell immunoreceptor with immunoglobulin and ITIM domain; TIM3, T-cell immunoglobulin and mucin domain 3; TNBC, triple-negative breast cancer.

References

1. Zhao Y, et al. Front Oncol. 2021;11:680834. 2. Zhang S, et al. PLoS One. 2012;7(3):e31127. 3. Zheng Y-Z, et al. Sci Rep. 2016;6:36447. 4. Balakrishnan A, et al. Clin Cancer Res. 2017;23(12):3061-3071.5. Krishna S, et al. Science. 2020;370(6522):1328-1334.6. Park S, et al. Poster presented at the AACR Annual Meeting 2022, April 8-13, 2022. Abstract 2754. 7. Lynn RC, et al. Nature. 2019;576(7786):293-300.8. Park S, et al. Poster presented at the ASGCT Annual Meeting 2022, May 16-18, 2022. Abstract 661.

Acknowledgments

We would like to thank the patients, their families, and their caregivers for participation in this study as well as the study site staff for their contributions. Medical writing and editorial support were funded by Lyell Immunopharma and provided by Madison Fagan, PhD of BOLDSCIENCE, Inc.

Presented at SITC Annual Meeting 2023; Nov 1 - 5; San Diego, CA, USA