Adaptimmune Presents MAGE-A4 Expression Data from its Screening Protocol at AACR Confirming Expression Across a Broad Range of Solid Tumors

Rhea-AI Summary

Adaptimmune Therapeutics plc (Nasdaq: ADAP) presented significant findings at the AACR annual meeting regarding its MAGE-A4-targeting SPEAR T-cell therapies. The data confirms MAGE-A4 as a viable target for multiple solid tumors, with a 67% eligibility rate in synovial sarcoma and 20%-35% across other cancers such as lung and bladder. Out of 6167 patients screened, 2729 were eligible, highlighting a robust patient pool for ongoing trials. These results build upon prior data, emphasizing Adaptimmune's commitment to advancing cancer treatment options.

Positive

• 67% of synovial sarcoma patients eligible for MAGE-A4 therapy.
• 20%-35% eligibility across various solid tumors enhances the clinical trial pool.
• Strong participation with 6167 patients screened, confirming broad applicability.

Negative

• Closed enrollment in the Phase 1 trial of afami-cel, limiting future data collection.

- Data from multiple solid tumor indications confirms that MAGE-A4 is a broadly expressed cancer target for SPEAR T-cell therapy -

- Rate of eligible MAGE-A4 expression was 67% for synovial sarcoma, and ranged from 20%-35% for squamous cell lung, bladder, esophagogastric junction, ovarian, head and neck, and esophageal cancers-

PHILADELPHIA and OXFORDSHIRE, United Kingdom, April 08, 2022 (GLOBE NEWSWIRE) -- Adaptimmune Therapeutics plc (Nasdaq: ADAP), a leader in cell therapy to treat cancer, presented data from the multinational, multicenter, screening protocol (NCT02636855) at the American Association for Cancer Research (AACR) annual meeting in a poster entitled “Identifying MAGE-A4-Positive Tumors for SPEAR T-Cell Therapies in HLA-A*02–Eligible Patients”.

“This large clinical dataset continues building the science around MAGE-A4 expression, and provides a broad, real-world understanding of patient eligibility for our clinical trials with SPEAR T-cell therapies targeting MAGE-A4,” said Elliot Norry, Adaptimmune’s Chief Medical Officer. “This information confirms the potential of our MAGE-A4 franchise and our continued commitment to patients and clinicians.”

The screening protocol prospectively evaluated HLA types and MAGE-A4 expression levels to determine eligibility for the Company’s clinical trials with SPEAR T-cells targeting MAGE-A4 across a broad range of solid tumors. To be eligible, patients are required to be HLA-A*02 positive¹ and tumor samples need to meet protocol-defined MAGE-A4 expression levels² . Data were collected for screening in the Phase 1 trial of afami-cel (formerly ADP-A2M4; closed to enrollment) as well as the ongoing Phase 1 SURPASS trial.

Results from this large dataset are consistent with data previously shared by the Company and support MAGE-A4 as an important cancer target within the tumor types currently included in ongoing clinical trials of afami-cel and ADP-A2M4CD8.

Across sites in the US, Canada, and Spain, a total of 6167 patients had their HLA-A type accurately determined and 2729 (44.3%) were eligible based on protocol-defined criteria. Among HLA-eligible patients, 1543 had tumor samples evaluable for MAGE-A4 with 313 (20%) meeting the requirements for MAGE-A4 expression.

The rate of eligible MAGE-A4 expression levels was highest in synovial sarcoma (67%) and ranged from 20% to 35% across the following solid tumor indications: squamous small cell lung (35%); bladder (32%), esophagogastric junction (26%), ovarian (24%), head and neck squamous cell (22%), and esophageal (21%) cancers.

About Adaptimmune
Adaptimmune is a clinical-stage biopharmaceutical company focused on the development of novel cancer immunotherapy products for people with cancer. The Company’s unique SPEAR (Specific Peptide Enhanced Affinity Receptor) T-cell platform enables the engineering of T-cells to target and destroy cancer across multiple solid tumors. 

Forward-Looking Statements
This release contains “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995 (PSLRA). These forward-looking statements involve certain risks and uncertainties. Such risks and uncertainties could cause our actual results to differ materially from those indicated by such forward-looking statements, and include, without limitation: the success, cost and timing of our product development activities and clinical trials and our ability to successfully advance our TCR therapeutic candidates through the regulatory and commercialization processes. For a further description of the risks and uncertainties that could cause our actual results to differ materially from those expressed in these forward-looking statements, as well as risks relating to our business in general, we refer you to our Annual Report on Form 10-K filed with the Securities and Exchange Commission for the year ended December 31, 2021, our Quarterly Reports on Form 10-Q, Current Reports on Form 8-K, and other filings with the Securities and Exchange Commission. The forward-looking statements contained in this press release speak only as of the date the statements were made and we do not undertake any obligation to update such forward-looking statements to reflect subsequent events or circumstances.

Adaptimmune Contacts:

Media Relations:

Sébastien Desprez — VP, Corporate Affairs and Communications
T: +44 1235 430 583
M: +44 7718 453 176
Sebastien.Desprez@adaptimmune.com

Investor Relations:

Juli P. Miller, Ph.D. — VP, Investor Relations
T: +1 215 825 9310
M: +1 215 460 8920
Juli.Miller@adaptimmune.com

^{__________________
1} HLA-A*02:01P, 02:02P, 02:03P, and 02:06P alleles are eligible; A*02:05P is excluded
² MAGE-A4 expression level is defined by protein (P) score, which is the percentage of tumor cells staining at 2+, 3+ by immunohistochemistry (IHC) using the clinical trial assay. Tumor samples with P scores ≥30% are considered eligible per protocol. Of note, P score is a quantification used internally at Adaptimmune. H-score is assessed as part of the Company’s translational research but is not used for eligibility.

FAQ

What were the findings of Adaptimmune's recent study on MAGE-A4?

Adaptimmune's study revealed that MAGE-A4 is a broadly expressed cancer target, with 67% eligibility in synovial sarcoma and 20%-35% across other solid tumors.

What is the significance of the AACR annual meeting presentation for ADAP stock?

The presentation at the AACR meeting highlights the potential of Adaptimmune's therapies, which may positively influence investor sentiment and ADAP stock performance.

How many patients were screened for Adaptimmune's MAGE-A4 therapy?

A total of 6167 patients were screened for eligibility in Adaptimmune's clinical trials targeting MAGE-A4.

What percentage of patients met the MAGE-A4 expression criteria?

Out of the screened patients, 2729 were eligible, with 20% of those having evaluable tumors meeting MAGE-A4 expression requirements.

What is the current status of Adaptimmune's trials related to MAGE-A4?

Adaptimmune is conducting ongoing Phase 1 trials with SPEAR T-cell therapies targeting MAGE-A4 after a successful screening process.