Afamitresgene autoleucel for advanced synovial sarcoma and myxoid round cell liposarcoma (SPEARHEAD-1): an international, open-label, phase 2 trial

BACKGROUND

Afamitresgene autoleucel (afami-cel) showed acceptable safety and promising efficacy in a phase 1 trial (NCT03132922). The aim of this study was to further evaluate the efficacy of afami-cel for the treatment of patients with HLA-A*02 and MAGE-A4-expressing advanced synovial sarcoma or myxoid round cell liposarcoma.

METHODS

SPEARHEAD-1 was an open-label, non-randomised, phase 2 trial done across 23 sites in Canada, the USA, and Europe. The trial included three cohorts, of which the main investigational cohort (cohort 1) is reported here. Cohort 1 included patients with HLA-A*02, aged 16-75 years, with metastatic or unresectable synovial sarcoma or myxoid round cell liposarcoma (confirmed by cytogenetics) expressing MAGE-A4, and who had received at least one previous line of anthracycline-containing or ifosfamide-containing chemotherapy. Patients received a single intravenous dose of afami-cel (transduced dose range 1·0 × 109-10·0 × 109 T cells) after lymphodepletion. The primary endpoint was overall response rate in cohort 1, assessed by a masked independent review committee using Response Evaluation Criteria in Solid Tumours (version 1.1) in the modified intention-to-treat population (all patients who received afami-cel). Adverse events, including those of special interest (cytokine release syndrome, prolonged cytopenia, and neurotoxicity), were monitored and are reported for the modified intention-to-treat population. This trial is registered at ClinicalTrials.gov, NCT04044768; recruitment is closed and follow-up is ongoing for cohorts 1 and 2, and recruitment is open for cohort 3.

FINDINGS

Between Dec 17, 2019, and July 27, 2021, 52 patients with cytogenetically confirmed synovial sarcoma (n=44) and myxoid round cell liposarcoma (n=8) were enrolled and received afami-cel in cohort 1. Patients were heavily pre-treated (median three [IQR two to four] previous lines of systemic therapy). Median follow-up time was 32·6 months (IQR 29·4-36·1). Overall response rate was 37% (19 of 52; 95% CI 24-51) overall, 39% (17 of 44; 24-55) for patients with synovial sarcoma, and 25% (two of eight; 3-65) for patients with myxoid round cell liposarcoma. Cytokine release syndrome occurred in 37 (71%) of 52 of patients (one grade 3 event). Cytopenias were the most common grade 3 or worse adverse events (lymphopenia in 50 [96%], neutropenia 44 [85%], leukopenia 42 [81%] of 52 patients). No treatment-related deaths occurred.

INTERPRETATION

Afami-cel treatment resulted in durable responses in heavily pre-treated patients with HLA-A*02 and MAGE-A4-expressing synovial sarcoma. This study shows that T-cell receptor therapy can be used to effectively target solid tumours and provides rationale to expand this approach to other solid malignancies.

FUNDING

Adaptimmune.

Abstract A038: Enrollment of pediatric and adolescent patients with MAGE-A4+ advanced synovial sarcoma into cohort 2 of SPEARHEAD-1: a phase 2 trial of afamitresgene autoleucel (“afami-cel” [formerly ADP-A2M4])

Background: Afami-cel is an autologous, specific peptide enhanced affinity receptor T-cell therapy genetically engineered to target MAGE-A4+ solid tumors in HLA-A*02+ patients. SPEARHEAD-1 (NCT04044768) is a Phase 2, two-cohort, single-arm, open-label trial evaluating afami-cel in patients with advanced/metastatic synovial sarcoma or myxoid/round cell liposarcoma (MRCLS) and is the largest trial in metastatic synovial sarcoma to date. Preliminary data from Cohort 1 in 47 heavily pre-treated patients aged 16–75 years from 22 centers in North America and Europe, showed an overall response rate (ORR) per independent review of 34.0% (14/39 [35.9%] in synovial sarcoma; 2/8 [25%] in MRCLS) and a favorable benefit–risk profile with mainly low-grade cytokine release syndrome and tolerable/reversible hematologic toxicities.1 The reported ORR in synovial sarcoma in Cohort 1 was higher than reported ORRs for current standard-of-care therapies, such as pazopanib and trabectedin, in the second-line metastatic setting.2 As synovial sarcoma is the most common malignant nonrhabdomyosarcoma soft-tissue sarcoma in children and adolescents with few treatment options, especially for recurrent disease, the trial opened a second cohort to allow enrollment of pediatric patients with MAGE-A4+ synovial sarcoma who experienced disease progression post first-line chemotherapy, and to better understand MAGE-A4 tumor expression in children. Methods: Cohort 2 of the SPEARHEAD-1 trial is enrolling patients with advanced synovial sarcoma who are at least 10 years old and weigh at least 40 kg. The planned enrollment is 45 patients, including up to 13 children, to enable a pooled analysis of ORR in >90 patients across Cohorts 1 and 2. HLA and MAGE-A4+ screening in Cohort 2 is conducted at a central laboratory using the same method as Cohort 1; MAGE-A4 testing is done using a clinical trial assay. All patients enrolled in Cohort 2 undergo apheresis and their isolated T-cells are then transduced with the MAGE-A4c1032 TCR using a lentivirus vector, followed by ex vivo expansion. Prior to afami-cel infusion of 1–10 × 109 transduced T-cells, patients will receive lymphodepleting chemotherapy consisting of fludarabine (30 mg/m2/day for 4 days) and cyclophosphamide (600 mg/m2/day for 3 days). Disease will be assessed by independent review per RECIST v1.1 using computerized tomography or magnetic resonance imaging at weeks 4, 8, 12, 16, 24, and every 2 months thereafter until confirmed disease progression. Patients enter long-term follow-up for 15 years. 1. Van Tine BA, et al. Paper 30: CTOS 2021; Virtual 2. Carroll C, et al. Cancer Res 2021;81(13_Suppl): Abstract nr 2630.

Citation Format: Colin Lunt, Sandra P. D’Angelo, Albiruni Ryan Abdul Razak, Michael J. Wagner, Brian A. Van Tine, Kristen Ganjoo, Jean-Yves Blay, Dejka M. Araujo, Mark Agulnik, John W. Glod, Erin Van Winkle, Erica Elefant, Swethajit Biswas, Dennis Williams, Axel Le Cesne. Enrollment of pediatric and adolescent patients with MAGE-A4+ advanced synovial sarcoma into cohort 2 of SPEARHEAD-1: a phase 2 trial of afamitresgene autoleucel (“afami-cel” [formerly ADP-A2M4]) [abstract]. In: Proceedings of the AACR Special Conference: Sarcomas; 2022 May 9-12; Montreal, QC, Canada. Philadelphia (PA): AACR; Clin Cancer Res 2022;28(18_Suppl):Abstract nr A038.

Protocol for PIT: a phase III trial of prophylactic irradiation of tracts in patients with malignant pleural mesothelioma following invasive chest wall intervention

INTRODUCTION

Histological diagnosis of malignant mesothelioma requires an invasive procedure such as CT-guided needle biopsy, thoracoscopy, video-assisted thorascopic surgery (VATs) or thoracotomy. These invasive procedures encourage tumour cell seeding at the intervention site and patients can develop tumour nodules within the chest wall. In an effort to prevent nodules developing, it has been widespread practice across Europe to irradiate intervention sites postprocedure--a practice known as prophylactic irradiation of tracts (PIT). To date there has not been a suitably powered randomised trial to determine whether PIT is effective at reducing the risk of chest wall nodule development.

METHODS AND ANALYSIS

In this multicentre phase III randomised controlled superiority trial, 374 patients who can receive radiotherapy within 42 days of a chest wall intervention will be randomised to receive PIT or no PIT. Patients will be randomised on a 1:1 basis. Radiotherapy in the PIT arm will be 21 Gy in three fractions. Subsequent chemotherapy is given at the clinicians' discretion. A reduction in the incidence of chest wall nodules from 15% to 5% in favour of radiotherapy 6 months after randomisation would be clinically significant. All patients will be followed up for up to 2 years with monthly telephone contact and at least four outpatient visits in the first year.

ETHICS AND DISSEMINATION

PIT was approved by NRES Committee North West-Greater Manchester West (REC reference 12/NW/0249) and recruitment is currently on-going, the last patient is expected to be randomised by the end of 2015. The analysis of the primary end point, incidence of chest wall nodules 6 months after randomisation, is expected to be published in 2016 in a peer reviewed journal and results will also be presented at scientific meetings and summary results published online. A follow-up analysis is expected to be published in 2018.

TRIAL REGISTRATION NUMBER

ISRCTN04240319; NCT01604005; Pre-results.

Familial hypercholesterolaemia: pilot study to identify children at risk

AIMS

To evaluate a more effective method of identifying children with familial hypercholesterolaemia by screening a population at high risk.

METHODS

Domiciliary measurement of random cholesterol concentration was made in 200 children who were first or second degree relatives of subjects with premature onset coronary artery disease. Measurements were taken by a health visitor using a portable analyser.

RESULTS

Twelve new cases of familial hypercholesterolaemia were identified during the first nine months of the study. Random cholesterol concentrations were within the normal range (< 5.2 mmol/l) in 70.5% of samples tested. Forty two (21%) of patients tested had a borderline cholesterol (5.2-5.9 mmol/l) but 50% of these fell within the normal range when fasting capillary samples were analysed. Children with significant hypercholesterolaemia on random testing (concentrations of > 5.9 mmol/l) (8.5%) also had fasting venous blood assayed for high density lipoprotein (HDL) cholesterol and tri-glyceride in the laboratory. Results indicated that 6.5% of patients screened were at high risk of cardiovascular disease (ratio of total: HDL cholesterol of > 4.5), and 1% had a moderately increased risk (ratio 3.5-4.5).

CONCLUSIONS

Children with familial hypercholesterolaemia can be identified from a selected "high risk" population by measuring random capillary cholesterol concentration.