A Study to Evaluate the Safety and Efficacy of A2B694, a Logic-gated CAR T, in Subjects With Solid Tumors That Express MSLN and Have Lost HLA-A*02 Expression

Cancer Clinical Trial

— EVEREST-2  

Official title:

A Seamless Phase 1/2 Study to Evaluate the Safety and Efficacy of A2B694, an Autologous Logic-gated Tmod™ CAR T, in Heterozygous HLA-A*02 Adults With Recurrent Unresectable, Locally Advanced, or Metastatic Solid Tumors That Express MSLN and Have Lost HLA-A*02 Expression

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT06051695
• Other study ID #: A2B694-101
• Status: Recruiting
• Phase: Phase 1/Phase 2
• Start date: April 3, 2024
• Est. completion date: June 2029

Study information

• Verified date: June 2024
• Source: A2 Biotherapeutics Inc.
• Contact: Clinical Trials
• Phone: 310-431-9180
• Email: ClinicalTrials[@]a2bio.com
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

The goal of this study is to test A2B694, an autologous logic-gated Tmod™ CAR T-cell product in subjects with solid tumors including colorectal cancer (CRC), pancreatic cancer (PANC), non-small cell lung cancer (NSCLC), ovarian cancer (OVCA), mesothelioma (MESO), and other solid tumors that express MSLN and have lost HLA-A*02 expression.

The main questions this study aims to answer are:

Phase 1: What is the recommended dose of A2B694 that is safe for patients

Phase 2: Does the recommended dose of A2B694 kill the solid tumor cells and protect the patient's healthy cells

Participants will be required to perform study procedures and assessments, and will also receive the following study treatments:

Enrollment and Apheresis in BASECAMP-1 (NCT04981119)

Preconditioning Lymphodepletion (PCLD) Regimen

A2B694 Tmod CAR T cells at the assigned dose

Description:

This is a seamless phase 1/2, multi-center, open-label study that enrolls adults with recurrent unresectable, locally advanced, or metastatic (considered non-curative) CRC, NSCLC, PANC, OVCA, MESO or other solid tumors with MSLN expression. Subjects must be germline HLA-A*02 heterozygous, with tumors that express MSLN and have lost HLA-A*02 expression. The purpose of Phase 1 of this study is to determine the safety and the optimal dose of A2B694 (after PCLD) in participants with solid tumor disease. The purpose of Phase 2 of this study is to determine the further safety and efficacy (how well it treats the solid tumor disease) of A2B694.

The treatment available for these cancers and other solid tumors can be toxic, debilitating, and fatal. In the recurrent unresectable, locally advanced, or metastatic setting, the intent of standard of care treatment is typically palliative rather than curative, and has not changed significantly in several decades. A2 Bio hypothesizes that A2B694 Tmod CAR T-cell therapy will enable the killing of tumor target cells (those cells that express MSLN and have LOH for HLA-A*02 protein). Additionally, normal healthy cells that maintain HLA-A*02 expression and co-express MSLN (eg, lung tissue) will not be targeted due to the blocker portion of the Tmod CAR T cell that acts as a self-regulated safety switch that protects normal tissue from damage. A2 Bio believes this will provide a therapeutic safety window compared to previous solid tumor targeting therapies. This hypothesis will be explored in the study.

Participants for this study must enroll and have their T cells collected (apheresis) in the pre-screening BASECAMP-1 study (NCT04981119). T cells are collected, processed and stored for each participant. Upon disease progression the participant may screen for this study (EVEREST-2) and the participant's T cells are manufactured and then infused following PCLD regimen. There is no time requirement between the studies, and patients may go directly from BASECAMP-1 to EVEREST-2 based on their own disease course.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 230
• Est. completion date: June 2029
• Est. primary completion date: June 2028
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

Key Inclusion Criteria:

1. Appropriately enrolled in the BASECAMP-1 A2 Biotherapeutics, Inc. study, with tissue demonstrating LOH of HLA-A*02 by NGS (whenever possible from the primary site), successful apheresis and PBMC processing, and with sufficient stored cells available for Tmod CAR T-cell therapy

2. Histologically confirmed recurrent unresectable, locally advanced, or metastatic CRC, NSCLC, PANC, OVCA, MESO, or other solid tumors with MSLN expression. Measurable disease is required with lesions of >1.0 cm by CT.

3. Received previous required therapy for the appropriate solid tumor disease as described in the protocol

4. Has adequate organ function as described in the protocol

5. ECOG performance status of 0 to 1

6. Life expectancy of =3 months

7. Willing to comply with study schedule of assessments including long term safety follow up

Key Exclusion Criteria:

1. Has disease that is suitable for local therapy or able to receive standard of care therapy that is therapeutic and not palliative

2. Prior allogeneic stem cell transplant

3. Prior solid organ transplant

4. MESO with pleural involvement extending into the peritoneum

5. Cancer therapy within 3 weeks or 3 half lives of A2B694 infusion

6. Radiotherapy within 28 days of A2B694 infusion

7. Unstable angina, arrhythmia, myocardial infarction, or any other significant cardiac disease within the last 6 months

8. Any new symptomatic pulmonary embolism (PE) or a deep vein thrombosis (DVT) within 3 months of enrollment. Therapeutic dosing of anticoagulants is allowed for history of PE or DVT if greater than 3 months from time of enrollment, and adequately treated

9. History of interstitial lung disease including drug-induced interstitial lung disease and radiation pneumonitis that requires treatment with prolonged steroids or other immune suppressive agents within 1 year

10. Requires supplemental home oxygen

11. Females of childbearing potential who are pregnant or breastfeeding

12. Subjects, both male and female, of childbearing potential who are not willing to practice birth control from the time of consent through 6 months post infusion of A2B694

Related Conditions & MeSH terms

• Cancer
• Colon Cancer
• Colorectal Adenocarcinoma
• Colorectal Cancer
• Colorectal Neoplasms
• CRC
• Lung Cancer
• Lung Neoplasms
• Mesothelioma
• Mesothelioma, Malignant
• Neoplasms
• Non Small Cell Lung Cancer
• NSCLC
• NSCLC, Recurrent
• Ovarian Cancer
• Ovarian Neoplasms
• Ovary Cancer
• Pancreas Cancer
• Pancreatic Neoplasm
• Pancreatic Neoplasms
• Rectal Cancer
• Solid Tumor, Adult

Intervention

Biological:
• A2B694
Autologous logic-gated Tmod CAR T cells

Diagnostic Test:
• xT CDx with HLA-LOH Assay
An investigational next generation sequencing (NGS) in vitro diagnostic (IVD) medical device

Locations

Country	Name	City	State
United States	Massachusetts General Hopsital/Dana Farber Cancer Center	Boston	Massachusetts
United States	Mayo Clinic	Jacksonville	Florida
United States	UCSD Moores Cancer Center	La Jolla	California
United States	UCLA Medical Center	Los Angeles	California
United States	NYU Langone Medical Center	New York	New York
United States	Mayo Clinic Rochester	Rochester	Minnesota
United States	Washington University	Saint Louis	Missouri
United States	Stanford University	Stanford	California
United States	Moffitt Cancer Center	Tampa	Florida

Sponsors (2)

Lead Sponsor	Collaborator
A2 Biotherapeutics Inc.	Tempus AI

Country where clinical trial is conducted

United States, 

References & Publications (4)

Beroukhim R, Mermel CH, Porter D, Wei G, Raychaudhuri S, Donovan J, Barretina J, Boehm JS, Dobson J, Urashima M, Mc Henry KT, Pinchback RM, Ligon AH, Cho YJ, Haery L, Greulich H, Reich M, Winckler W, Lawrence MS, Weir BA, Tanaka KE, Chiang DY, Bass AJ, Loo A, Hoffman C, Prensner J, Liefeld T, Gao Q, Yecies D, Signoretti S, Maher E, Kaye FJ, Sasaki H, Tepper JE, Fletcher JA, Tabernero J, Baselga J, Tsao MS, Demichelis F, Rubin MA, Janne PA, Daly MJ, Nucera C, Levine RL, Ebert BL, Gabriel S, Rustgi AK, Antonescu CR, Ladanyi M, Letai A, Garraway LA, Loda M, Beer DG, True LD, Okamoto A, Pomeroy SL, Singer S, Golub TR, Lander ES, Getz G, Sellers WR, Meyerson M. The landscape of somatic copy-number alteration across human cancers. Nature. 2010 Feb 18;463(7283):899-905. doi: 10.1038/nature08822. — View Citation

Hamburger AE, DiAndreth B, Cui J, Daris ME, Munguia ML, Deshmukh K, Mock JY, Asuelime GE, Lim ED, Kreke MR, Tokatlian T, Kamb A. Engineered T cells directed at tumors with defined allelic loss. Mol Immunol. 2020 Dec;128:298-310. doi: 10.1016/j.molimm.2020.09.012. Epub 2020 Oct 1. — View Citation

Hwang MS, Mog BJ, Douglass J, Pearlman AH, Hsiue EH, Paul S, DiNapoli SR, Konig MF, Pardoll DM, Gabelli SB, Bettegowda C, Papadopoulos N, Vogelstein B, Zhou S, Kinzler KW. Targeting loss of heterozygosity for cancer-specific immunotherapy. Proc Natl Acad Sci U S A. 2021 Mar 23;118(12):e2022410118. doi: 10.1073/pnas.2022410118. — View Citation

Tokatlian T, Asuelime GE, Mock JY, DiAndreth B, Sharma S, Toledo Warshaviak D, Daris ME, Bolanos K, Luna BL, Naradikian MS, Deshmukh K, Hamburger AE, Kamb A. Mesothelin-specific CAR-T cell therapy that incorporates an HLA-gated safety mechanism selectively kills tumor cells. J Immunother Cancer. 2022 Jan;10(1):e003826. doi: 10.1136/jitc-2021-003826. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Phase 1: Rate of adverse events and dose limiting toxicities (DLTs) by dose level	Adverse Events and toxicity will be evaluated according to the Cancer Therapy Evaluation Program Common Terminology Criteria for Adverse Events version (CTCAE) 5.0 (or current version). Cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS) events will be graded according to the criteria described in the current protocol.	From the time of Informed consent until 24 months (2 years) post A2B694 infusion
Primary	Phase 1: Recommended Phase 2 Dose (RP2D)	The RP2D will be identified utilizing a BOIN study design in addition to considering safety and biomarker analysis.	21 days post A2B694 infusion
Primary	Phase 2: The Overall Response Rate (ORR) for patients	The ORR will be evaluated per RECIST v1.1 and assessed by independent central review.	24 months post A2B694 infusion
Secondary	Persistence of A2B694	Number of A2B694 Tmod CAR T cells present in patients treated with A2B694 as assessed by Polymerase Chain Reaction (PCR) (or similar method) on participant blood samples	up to 24 months post A2B694 infusion
Secondary	Cytokine analysis	Cytokine levels such as interferon-gamma (IFN-?) and interleukin-6 (IL-6) in patients treated with A2B694 assessed by cytokine analysis on participant blood samples	up to 24 months post A2B694 infusion

External Links

•   A2 Biotherapeutics Inc.