Pharmacokinetics (PK) of Tiragolumab in First-in-Human Study in Patients with Mixed Solid Tumors (GO30103)

Tiragolumab is a first-in-class, fully human IgG1/kappa anti-TIGIT monoclonal antibody that blocks the binding of TIGIT to CD155 (the poliovirus receptor). We summarize the pharmacokinetics (PK) data from the phase 1a/1b GO30103 study of Q3W (every 3 weeks) sequential dosing of tiragolumab (2, 8, 30, 100, 400, 600, or 1200 mg) followed by atezolizumab (1200 mg), Q4W (every 4 weeks) sequential dosing (tiragolumab 840 mg followed by atezolizumab 1680 mg), and Q4W co-infusion (tiragolumab 840 mg plus atezolizumab 1680 mg). Serum samples were collected at multiple time points following tiragolumab and atezolizumab intravenous infusion in patients with solid tumors for PK and immunogenicity assessment. The serum PK profile of tiragolumab appeared to be biphasic, with a rapid distribution phase followed by a slower elimination phase when administered alone or in combination with atezolizumab. In phase 1a, across doses of tiragolumab ranging from 2 to 1200 mg (cycle 1), the geometric mean (GM), coefficient of variation (CV%), serum tiragolumab Cmax ranged from 0.682 to 270 µg/mL (18.6% to 36.5%) and Cmin ranged from 0.0125 to 75.3 µg/mL (0.0% to 24.2%). The GM systemic exposure (area under the plasma drug concentration-time curve, AUC0-21) ranged from 310 to 2670 µg day/mL (20.5% to 27.0%); interindividual variability in AUC0-21 ranged from 20.5% to 43.9%. Tiragolumab exposure increased in an approximately dose-proportional manner when administered alone or with atezolizumab at doses ≥100 mg. Postbaseline, 4/207 patients (1.9%) were positive for treatment-emergent antidrug antibodies (ADA) against tiragolumab, each at a single time point. Tiragolumab combined with atezolizumab demonstrated desirable PK properties, with no drug-drug interactions or immunogenicity liability. There were no meaningful differences in tiragolumab or atezolizumab exposure between the Q4W co-infusion and sequential dosing cohorts. ClinicalTrials.gov: NCT02794571 (date of registration June 6, 2016).

The role of anti-EGFR rechallenge in metastatic colorectal cancer, from available data to future developments: A systematic review

Despite recent molecular and immunological advancements, prognosis of metastatic colorectal cancer (mCRC) patients remains poor. In this context, several retrospective and phase II studies suggested that after failure of an upfront anti-EGFR based regimen, a subset of patients can still benefit from further anti-EGFR blockade. Several translational studies involving circulating tumor DNA (ctDNA) analysis demonstrated that cancer clones harboring mutations driving anti-EGFR resistance, which can arise under anti-EGFR agents selective pressure, often decay after anti-EGFR discontinuation potentially restoring sensitivity to this therapeutic strategy. Accordingly, several retrospective analyses and a recent prospective trial demonstrated that ctDNA RAS and BRAF wild-type mCRC patients are those benefitting the most from anti-EGFR rechallenge. Indeed, in molecularly selected patients, anti-EGFR rechallenge strategy achieved up to 30 % response rate, with a progression free survival longer than 4 months and an overall survival longer than 1 year, which favorably compared with other standard therapeutic options available for heavily pretreated patients. Anti-EGFR is also well tolerated with no unexpected toxicities compared to the upfront setting. However, several open questions remain to be addressed towards a broader applicability of anti-EGFR strategy in the everyday clinical practice such as the identification of the best rechallenge regimen, the right placement in mCRC therapeutic algorithm, the best ctDNA screening panel. In our systematic review, we revised available data from clinical trials assessing anti-EGFR rechallenge activity in chemo-refractory mCRC patients, discussing as well potential future scenarios and development to implement this therapeutic approach. Particularly, we discussed the role of ctDNA as a safe, timely and comprehensive tool to refine patient's selection and the therapeutic index of anti-EGFR rechallenge.

Pan-Asian adapted ESMO Clinical Practice Guidelines for the diagnosis, treatment and follow-up of patients with gastric cancer

The European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, treatment and follow-up of patients with gastric cancer (GC), published in late 2022 and the updated ESMO Gastric Cancer Living Guideline published in July 2023, were adapted in August 2023, according to previously established standard methodology, to produce the Pan-Asian adapted (PAGA) ESMO consensus guidelines for the management of Asian patients with GC. The adapted guidelines presented in this manuscript represent the consensus opinions reached by a panel of Asian experts in the treatment of patients with GC representing the oncological societies of China (CSCO), Indonesia (ISHMO), India (ISMPO), Japan (JSMO), Korea (KSMO), Malaysia (MOS), the Philippines (PSMO), Singapore (SSO), Taiwan (TOS) and Thailand (TSCO), coordinated by ESMO and the Japanese Society of Medical Oncology (JSMO). The voting was based on scientific evidence and was independent of the current treatment practices, drug access restrictions and reimbursement decisions in the different Asian regions represented by the 10 oncological societies. The latter are discussed separately in the manuscript. The aim is to provide guidance for the optimisation and harmonisation of the management of patients with GC across the different regions of Asia, drawing on the evidence provided by both Western and Asian trials, whilst respecting the differences in screening practices, molecular profiling and age and stage at presentation. Attention is drawn to the disparity in the drug approvals and reimbursement strategies, between the different regions of Asia.

Divarasib plus cetuximab in KRAS G12C-positive colorectal cancer: a phase 1b trial

KRAS G12C mutation is prevalent in ~4% of colorectal cancer (CRC) and is associated with poor prognosis. Divarasib, a KRAS G12C inhibitor, has shown modest activity as a single agent in KRAS G12C-positive CRC at 400 mg. Epidermal growth factor receptor has been recognized as a major upstream activator of RAS-MAPK signaling, a proposed key mechanism of resistance to KRAS G12C inhibition in CRC. Here, we report on divarasib plus cetuximab (epidermal growth factor receptor inhibitor) in patients with KRAS G12C-positive CRC (n = 29) from arm C of an ongoing phase 1b trial. The primary objective was to evaluate safety. Secondary objectives included preliminary antitumor activity. The safety profile of this combination was consistent with those of single-agent divarasib and cetuximab. Treatment-related adverse events led to divarasib dose reductions in four patients (13.8%); there were no treatment withdrawals. The objective response rate was 62.5% (95% confidence interval: 40.6%, 81.2%) in KRAS G12C inhibitor-naive patients (n = 24). The median duration of response was 6.9 months. The median progression-free survival was 8.1 months (95% confidence interval: 5.5, 12.3). As an exploratory objective, we observed a decline in KRAS G12C variant allele frequency associated with response and identified acquired genomic alterations at disease progression that may be associated with resistance. The manageable safety profile and encouraging antitumor activity of divarasib plus cetuximab support the further investigation of this combination in KRAS G12C-positive CRC.ClinicalTrials.gov identifier: NCT04449874.

Sequencing paired tumor DNA and white blood cells improves circulating tumor DNA tracking and detects pathogenic germline variants in localized colon cancer

BACKGROUND

In the setting of localized colon cancer (CC), circulating tumor DNA (ctDNA) monitoring in plasma has shown potential for detecting minimal residual disease (MRD) and predicting a higher risk of recurrence. With the tumor-only sequencing approach, however, germline variants may be misidentified as somatic variations, precluding the possibility of tracking in up to 11% of patients due to a lack of known somatic mutations. In this study, we assess the potential value of adding white blood cells (WBCs) to tumor tissue sequencing to enhance the accuracy of sequencing results.

PATIENTS AND METHODS

A total of 148 patients diagnosed with localized CC were prospectively recruited at the Hospital Clínico Universitario in Valencia (Spain). Employing a custom 29-gene panel, sequencing was conducted on tumor tissue, plasma and corresponding WBCs. Droplet digital PCR and amplicon-based NGS were performed on plasma samples post-surgery to track MRD. Oncogenic somatic variants were identified by annotating with COSMIC, OncoKB and an internal repository of pathogenic mutations database. A variant prioritization analysis, mainly characterized by the match of oncogenic mutations with the evidence levels defined in OncoKB, was carried out to select specific targeted therapies.

RESULTS

Utilizing paired tumor and WBCs sequencing, we identified somatic mutations in all patients (100%) within our cohort, compared to 89% using only tumor tissue. Consequently, the top 10 most frequently mutated genes for plasma monitoring were altered. The sequencing of WBCs identified 9% of patients with pathogenic mutations in the germline, with APC and TP53 being the most frequently mutated genes. Additionally, mutations in genes related to clonal hematopoiesis of indeterminate potential were detected in 27% of the cohort, with TP53, KRAS, and KMT2C being the most frequently altered genes. There were no observed differences in the sensitivity of monitoring MRD using ddPCR or amplicon-based NGS (p = 1). Ultimately, 41% of the patients harbored potentially targetable alterations at diagnosis.

CONCLUSION

The germline testing method not only enhanced sequencing results and raised the proportion of patients eligible for plasma monitoring, but also uncovered the existence of pathogenic germline variations, thereby aiding in the identification of patients at a higher risk of hereditary cancer syndromes.

Leucovorin and Fluorouracil With or Without Oxaliplatin as First-Line Treatment in Advanced Colorectal Cancer

PURPOSE

In a previous study of treatment for advanced colorectal cancer, the LV5FU2 regimen, comprising leucovorin (LV) plus bolus and infusional fluorouracil (5FU) every 2 weeks, was superior to the standard North Central Cancer Treatment Group/Mayo Clinic 5-day bolus 5FU/LV regimen. This phase III study investigated the effect of combining oxaliplatin with LV5FU2, with progression-free survival as the primary end point.

PATIENTS AND METHODS

Four hundred twenty previously untreated patients with measurable disease were randomized to receive a 2-hour infusion of LV (200 mg/m2/d) followed by a 5FU bolus (400 mg/m2/d) and 22-hour infusion (600 mg/m2/d) for 2 consecutive days every 2 weeks, either alone or together with oxaliplatin 85 mg/m2 as a 2-hour infusion on day 1.

RESULTS

Patients allocated to oxaliplatin plus LV5FU2 had significantly longer progression-free survival (median, 9.0 v 6.2 months; P = .0003) and better response rate (50.7% v 22.3%; P = .0001) when compared with the control arm. The improvement in overall survival did not reach significance (median, 16.2 v 14.7 months; P = .12). LV5FU2 plus oxaliplatin gave higher frequencies of National Cancer Institute common toxicity criteria grade 3/4 neutropenia (41.7% v 5.3% of patients), grade 3/4 diarrhea (11.9% v 5.3%), and grade 3 neurosensory toxicity (18.2% v 0%), but this did not result in impairment of quality of life (QoL). Survival without disease progression or deterioration in global health status was longer in patients allocated to oxaliplatin treatment (P = .004).

CONCLUSION

The LV5FU2-oxaliplatin combination seems beneficial as first-line therapy in advanced colorectal cancer, demonstrating a prolonged progression-free survival with acceptable tolerability and maintenance of QoL.

Pamiparib in combination with tislelizumab in patients with advanced solid tumours: results from the dose-expansion stage of a multicentre, open-label, phase I trial

BACKGROUND

The aim of this study was to investigate the antitumour activity, safety, and tolerability of pamiparib plus tislelizumab in patients with previously treated advanced solid tumours.

METHODS

In this study, patients were enrolled into eight arms by tumour type. All received pamiparib 40 mg orally twice daily plus tislelizumab 200 mg intravenously every 3 weeks. The primary endpoint was objective response rate (ORR), assessed by the investigator per Response Evaluation Criteria in Solid Tumours v1.1. Secondary endpoints included duration of response (DoR), safety, and tolerability.

RESULTS

Overall, 180 patients were enrolled. In the overall population, the ORR was 20.0% (range: 0-47.4 across study arms), with median DoR of 17.1 months (95% confidence interval [CI]: 6.2, not estimable [NE]). The highest ORR was observed in the triple-negative breast cancer (TNBC) arm (patients with BRCA1/2 mutations and/or homologous recombination deficiency) (ORR: 47.4%; median DoR: 17.1 months [95% CI: 3.0, NE]). Treatment-emergent adverse events (TEAEs) of ≥Grade 3 occurred in 61.7% of patients. Serious TEAEs occurred in 50.0% of patients.

CONCLUSIONS

Pamiparib plus tislelizumab showed a variable level of antitumour activity in patients with advanced solid tumours, with the highest ORR in TNBC and was associated with a manageable safety profile.

CLINICAL TRIAL REGISTRATION

ClinicalTrial.gov: NCT02660034.

Pan-Asian adapted ESMO Clinical Practice Guidelines for the diagnosis, treatment and follow-up of patients with metastatic colorectal cancer

The European Society for Medical Oncology (ESMO) Clinical Practice Guidelines for the diagnosis, treatment and follow-up of patients with metastatic colorectal cancer (mCRC), published in late 2022, were adapted in December 2022, according to previously established standard methodology, to produce the Pan-Asian adapted (PAGA) ESMO consensus guidelines for the management of Asian patients with mCRC. The adapted guidelines presented in this manuscript represent the consensus opinions reached by a panel of Asian experts in the treatment of patients with mCRC representing the oncological societies of China (CSCO), Indonesia (ISHMO), India (ISMPO), Japan (JSMO), Korea (KSMO), Malaysia (MOS), the Philippines (PSMO), Singapore (SSO), Taiwan (TOS) and Thailand (TSCO), co-ordinated by ESMO and the Japanese Society of Medical Oncology (JSMO). The voting was based on scientific evidence and was independent of the current treatment practices, drug access restrictions and reimbursement decisions in the different Asian countries. The latter are discussed separately in the manuscript. The aim is to provide guidance for the optimisation and harmonisation of the management of patients with mCRC across the different countries of Asia, drawing on the evidence provided by both Western and Asian trials, whilst respecting the differences in screening practices, molecular profiling and age and stage at presentation, coupled with a disparity in the drug approvals and reimbursement strategies, between the different countries.

The management of hepatocellular carcinoma. Current expert opinion and recommendations derived from the 24th ESMO/World Congress on Gastrointestinal Cancer, Barcelona, 2022

This article summarises expert discussion on the management of patients with hepatocellular carcinoma (HCC), which took place during the 24th World Gastrointestinal Cancer Congress (WGICC) in Barcelona, July 2022. A multidisciplinary approach is mandatory to ensure an optimal diagnosis and staging of HCC, planning of curative and therapeutic options, including surgical, embolisation, ablative strategies, or systemic therapy. Furthermore, in many patients with HCC, underlying liver cirrhosis represents a challenge and influences the therapeutic options.

Safety and clinical activity of atezolizumab plus erlotinib in patients with non-small-cell lung cancer

BACKGROUND

Acquired resistance limits long-term epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) efficacy in patients with EGFR mutation-positive non-small-cell lung cancer (NSCLC) in whom anti-programmed death-ligand 1 (PD-L1) efficacy is also limited. We hypothesized that combining atezolizumab with erlotinib could enhance antitumor immunity and extend efficacy in these patients.

PATIENTS AND METHODS

This open-label phase Ib trial was conducted in adults aged ≥18 years who had advanced, unresectable NSCLC. Stage 1 (safety evaluation) enrolled EGFR TKI-naive patients regardless of EGFR status. Stage 2 (expansion) enrolled patients with EGFR-mutant NSCLC treated with ≤1 prior non-EGFR TKI therapy. Patients received 150 mg erlotinib orally once daily. After a 7-day erlotinib run-in, atezolizumab 1200 mg was administered intravenously every 3 weeks. The primary endpoint was the safety and tolerability of the combination in all patients; secondary endpoints included antitumor activity per RECIST 1.1 in stage 2 patients.

RESULTS

At the data cut-off on 7 May 2020, 28 patients (8 in stage 1, 20 in stage 2) were assessable for safety. No dose-limiting toxicities or grade 4 or 5 treatment-related adverse events occurred. Grade 3 treatment-related adverse events occurred in 46% of patients; the most common were increased alanine aminotransferase, diarrhea, pyrexia, and rash (each in 7% of patients). Serious adverse events occurred in 50% of patients. Pneumonitis (grade 1) was reported in a single patient (4%). The objective response rate was 75% [95% confidence interval (CI) 50.9% to 91.3%]), median response duration was 18.9 months (95% CI 9.5-40.5 months), median progression-free survival was 15.4 months (95% CI 8.4-39.0 months), and median overall survival was not estimable (NE) (95% CI 34.6-NE).

CONCLUSIONS

Atezolizumab combined with erlotinib demonstrated a tolerable safety profile and encouraging, durable clinical activity in patients with advanced EGFR mutation-positive NSCLC.

European expert panel consensus on the clinical management of BRAFV600E-mutant metastatic colorectal cancer

Metastatic colorectal cancer (mCRC) is a heterogenous disease caused by various genetic alterations. The BRAF^V600E mutation occurs in approximately 8-12% of patients and is characterised by an aggressive clinical course and poor prognosis. Here we review the current knowledge on BRAF^V600E-mutant mCRC and provide a series of consensus statements on its clinical management. The treatment landscape for BRAF^V600E-mutant mCRC has changed greatly due to the emergence of molecular targeted therapies (including BRAF inhibitors) and immune checkpoint inhibitors. A scientific literature search identified available data on molecular testing, treatments, and clinical monitoring of patients with BRAF^V600E-mutant mCRC. Consensus statements were discussed and developed by a European expert panel. This manuscript provides consensus management guidance for different clinical presentations of BRAF^V600E-mutant mCRC and makes recommendations regarding treatment sequencing choices. To guide appropriate clinical management and treatment decisions for mCRC patients, tumour tissue analysis for DNA mismatch repair/microsatellite status and, at a minimum, KRAS, NRAS, and BRAF mutational status is mandatory at the time of diagnosis. Finally, we discuss the rapidly evolving treatment landscape for BRAF^V600E-mutant mCRC and define priorities for the development of novel therapeutic strategies that are needed to improve patient outcomes.

The value of post-operative chemotherapy after chemoradiotherapy in patients with high-risk locally advanced rectal cancer-results from the RAPIDO trial

BACKGROUND

Pre-operative chemoradiotherapy (CRT) rather than radiotherapy (RT) has resulted in fewer locoregional recurrences (LRRs), but no decrease in distant metastasis (DM) rate for patients with locally advanced rectal cancer (LARC). In many countries, patients receive post-operative chemotherapy (pCT) to improve oncological outcomes. We investigated the value of pCT after pre-operative CRT in the RAPIDO trial.

PATIENTS AND METHODS

Patients were randomised between experimental (short-course RT, chemotherapy and surgery) and standard-of-care treatment (CRT, surgery and pCT depending on hospital policy). In this substudy, we compared curatively resected patients from the standard-of-care group who received pCT (pCT+ group) with those who did not (pCT- group). Subsequently, patients from the pCT+ group who received at least 75% of the prescribed chemotherapy cycles (pCT ≥75% group) were compared with patients who did not receive pCT (pCT-/- group). By propensity score stratification (PSS), we adjusted for the following unbalanced confounders: age, clinical extramural vascular invasion, distance to the anal verge, ypT stage, ypN stage, residual tumour, serious adverse event (SAE) and/or readmission within 6 weeks after surgery and SAE related to pre-operative CRT. Cumulative probability of disease-free survival (DFS), DM, LRR and overall survival (OS) was analysed by Cox regression.

RESULTS

In total, 396/452 patients had a curative resection. The number of patients in the pCT+, pCT >75%, pCT- and pCT-/- groups was 184, 112, 154 and 149, respectively. The PSS-adjusted analyses for all endpoints demonstrated hazard ratios between approximately 0.7 and 0.8 (pCT+ versus pCT-), and 0.5 and 0.8 (pCT ≥75% versus pCT-/-). However, all 95% confidence intervals included 1.

CONCLUSIONS

These data suggest a benefit of pCT after pre-operative CRT for patients with high-risk LARC, with approximately 20%-25% improvement in DFS and OS and 20%-25% risk reductions in DM and LRR. Compliance with pCT additionally reduces or improves all endpoints by 10%-20%. However, differences are not statistically significant.

Napabucasin Plus FOLFIRI in Patients With Previously Treated Metastatic Colorectal Cancer: Results From the Open-Label, Randomized Phase III CanStem303C Study

PURPOSE

Napabucasin is an investigational, orally administered reactive oxygen species generator bioactivated by intracellular antioxidant NAD(P)H:quinone oxidoreductase 1 that has been evaluated in various solid tumors, including metastatic colorectal cancer (mCRC). Phosphorylated signal transducer and activator of transcription 3 (pSTAT3) is hypothesized to predict response in napabucasin-treated patients with mCRC.

PATIENT AND METHODS

In the multi-center, open-label, phase III CanStem303C (NCT02753127) study, adults with histologically confirmed mCRC that progressed on first-line fluoropyrimidine plus oxaliplatin ± bevacizumab were randomized to twice-daily napabucasin plus FOLFIRI (napabucasin) or FOLFIRI alone (control). The primary endpoint was overall survival (OS) in the general study population and in patients with pSTAT3-positive tumors (biomarker-positive).

RESULTS

In the general study population (napabucasin, n = 624; control, n = 629), median OS was 14.3 months for napabucasin and 13.8 months for control (hazard ratio [HR], 0.976, one-sided P = .74). Overall, 44% of patients were biomarker-positive (napabucasin, n = 275; control, n = 272). In the biomarker-positive population, median OS was 13.2 months for napabucasin and 12.1 months for control (HR, 0.969; one-sided P > .99). In the control arm, median OS was shorter for biomarker-positive versus biomarker negative patients (12.1 vs. 18.5 months; HR, 1.518; nominal 2-sided P = .0002). The most common treatment-emergent adverse events (TEAEs) were diarrhea (napabucasin, 84.6%; control, 53.9%), nausea (60.5%, 50.5%), vomiting (41.2%, 29.3%), and abdominal pain (41.0%, 25.2%). Grade ≥3 TEAEs occurred in 73.8% of napabucasin-treated and 66.7% of control-treated patients, most commonly diarrhea (21.2%, 7.0%), neutrophil count decreased (13.7%, 19.2%), and neutropenia (13.3%, 15.2%). Safety was similar in biomarker-positive patients.

CONCLUSION

In patients with previously treated mCRC, adding napabucasin to FOLFIRI did not improve OS. Results from the control arm indicate that pSTAT3 is an adverse prognostic factor in mCRC.

Preliminary clinical outcomes of ADP-A2M4CD8, a next-generation autologous T-cell receptor T-cell therapy, in patients with advanced urothelial cancer

517

Background: ADP-A2M4CD8 is a specific peptide enhanced affinity receptor mixed CD4+ and CD8+ T-cell therapy targeting the cancer testis antigen MAGE-A4 and modified with addition of a CD8α co-receptor designed to provide additional functionality to CD4+ T-cells. ADP-A2M4CD8 has demonstrated an acceptable benefit to risk profile in the Phase 1 SURPASS trial (NCT04044859) in HLA A*02–eligible patients with unresectable or metastatic tumors positive for MAGE-A4.1 Here we report updated clinical outcomes in patients with urothelial cancer (UC). Methods: SURPASS is a first-in-human trial consisting of a modified 3+3 dose-escalation design and an expansion cohort. Autologous T-cells are obtained by leukapheresis, transduced with a self-inactivating lentiviral vector expressing the MAGE-A4-specific T-cell receptor and the CD8α co-receptor, and infused back to the patients as ADP-A2M4CD8 following lymphodepleting chemotherapy. Primary and secondary objectives are safety and anti-tumor activity, respectively. Results: At ESMO 2022, we reported promising results from SURPASS in several tumour types.2 In the 43 evaluable patients, the overall response rate was 28%, including 1 complete response and 11 partial responses (PR), and an additional 2 unconfirmed PRs awaiting confirmatory scans (as of August 1, 2022). Data from the 7 evaluable patients in the UC subset (updated September 6, 2022) showed that 3 (43%) had a best overall response of PR, and 1 (14%) had an unconfirmed PR. Disease control rate was 100% (3 PR + 1 unconfirmed PR + 3 stable disease). Adverse events have been consistent with those typically observed with lymphodepletion chemotherapy or cellular therapy. This trial is ongoing; data from additional patients with UC treated by January 2023 and updated translational data will be presented. Conclusions: ADP-A2M4CD8 continues to show an acceptable benefit to risk profile in multiple MAGE-A4+ unresectable or metastatic tumors, and preliminary encouraging evidence of efficacy in UC. An additional treatment cohort has been included in the updated trial protocol to evaluate ADP-A2M4CD8 combined with nivolumab. 1. Hong DS, et al. E-poster 540P: ESMO 2021; Virtual. 2. Hong DS, et al. Ann Oncol 33(suppl_7); S331-S355, Abstract 735MO. ESMO 2022. Clinical trial information: NCT04044859 .

The percentage of mesorectal infiltration as a prognostic factor after curative surgery for pT3 rectal cancer

AIM

The aim of this study is to evaluate the prognostic value of a novel variable - the percentage of mesorectal infiltration (PMI) - in pT3 rectal cancer.

METHOD

A cohort of 241 patients with pT3 rectal adenocarcinoma, operated on between February 2002 and May 2019, was selected for the analysis. Data concerning patient, treatment and tumour characteristics were collected. The depth of mesorectal infiltration (DMI) and the distance between the deepest invasion and the circumferential resection margin (CRM) were measured. The PMI was calculated using a formula combining these parameters.

RESULTS

Neoadjuvant therapy was administered in 33.2% of cases. A complete mesorectal excision was achieved in 74% of patients. The CRM was affected in 24 patients (9.9%). The 5-year actuarial local recurrence (LR), overall recurrence (OR) and overall survival (OS) rates were 7.5%, 22.9% and 72.4%, respectively. The PMI was significantly associated with worse oncological outcomes regarding LR (p = 0.009), OR (p = 0.001) and OS (p = 0.016) rates. A cut-off value of PMI >60% had the highest specificity (80%) for LR (p = 0.026), OR (p = 0.04) and OS (p = 0.07).

CONCLUSION

The PMI has an adverse prognostic impact on the oncological results following surgery for pT3 rectal cancer. It allows prediction of the risk of both LR and distant recurrence with higher accuracy than the DMI or the distance to the CRM. A PMI >60% may be used as a cut off value while subclassifying pT3 rectal tumours. It may influence decision-making while establishing adjuvant treatment and the follow-up schedule.

Safety and efficacy from the phase 1 SURPASS trial of ADP-A2M4CD8, a next-generation T-cell receptor T-cell therapy, in patients with advanced esophageal, esophagogastric junction, or gastric cancer

349

Background: ADP-A2M4CD8 is a specific peptide enhanced affinity receptor mixed CD4+ and CD8+ T-cell therapy targeting the cancer testis antigen MAGE-A4 and modified with addition of a CD8α co-receptor designed to provide additional functionality to CD4+ T-cells. ADP-A2M4CD8 has demonstrated a favorable benefit to risk profile in the Phase 1 SURPASS trial (NCT04044859) in HLA A*02–eligible patients (pts) with unresectable or metastatic tumors positive for MAGE-A4 (Hong DS, et al. E-poster 540P: ESMO 2021; Virtual). Here we report updated clinical outcomes in pts with esophageal, esophagogastric junction (EGJ), or gastric cancer. Methods: SURPASS is a first-in-human trial consisting of a modified 3+3 dose-escalation design and an expansion cohort. Autologous T-cells are obtained by leukapheresis, transduced with a self-inactivating lentiviral vector expressing the MAGE-A4-specific T-cell receptor and the CD8α co-receptor, and infused back to the pts as ADP-A2M4CD8 following lymphodepleting chemotherapy. Primary and secondary objectives are safety and anti-tumor activity, respectively. Results: As September 6, 2022, 13 pts (11 male, 2 female) with esophageal (3), EGJ (8), and gastric cancer (2) received ADP-A2M4CD8 (range: 1.02–9.9x109 transduced T-cells). All pts had adenocarcinoma, median age was 55 years (range: 31–71), median MAGE-A4 expression H-score was 245 (range: 160–300), and pts received median of 2 lines of prior therapy (range 1–5). Adverse events (AEs) were consistent with those typically associated with lymphodepleting chemotherapy, cellular therapy, and/or disease. One pt had a Grade 5 (fatal) AE of pancytopenia. Overall response rate per RECIST v1.1 by investigator review was 15% (2 partial response [PR]). Disease control rate was 77% (2 PR+8 stable disease). This trial is ongoing, and additional data will be presented. Conclusions: Results indicate an acceptable benefit to risk profile and encouraging anti-tumor activity of ADP-A2M4CD8. An additional treatment cohort has been included in the updated SURPASS trial protocol to evaluate ADP-A2M4CD8 combined with nivolumab. A Phase 2, open-label trial in advanced esophageal and EGJ cancers has been initiated (SURPASS-2; NCT04752358). Clinical trial information: NCT04044859 .

Will Organoids Fill the Gap towards Functional Precision Medicine?

Precision medicine approaches for solid tumors are mainly based on genomics. Its employment in clinical trials has led to somewhat underwhelming results, except for single responses. Moreover, several factors can influence the response, such as gene and protein expression, the coexistence of different genomic alterations or post-transcriptional/translational modifications, the impact of tumor microenvironment, etc., therefore making it insufficient to employ a genomics-only approach to predict response. Recently, the implementation of patient-derived organoids has shed light on the possibility to use them to predict patient response to drug treatment. This could offer for the first time the possibility to move precision medicine to a functional environment.

SMG8/SMG9 Heterodimer Loss Modulates SMG1 Kinase to Drive ATR Inhibitor Resistance

Gastric cancer represents the third leading cause of global cancer mortality and an area of unmet clinical need. Drugs that target the DNA damage response, including ATR inhibitors (ATRi), have been proposed as novel targeted agents in gastric cancer. Here, we sought to evaluate the efficacy of ATRi in preclinical models of gastric cancer and to understand how ATRi resistance might emerge as a means to identify predictors of ATRi response. A positive selection genome-wide CRISPR-Cas9 screen identified candidate regulators of ATRi resistance in gastric cancer. Loss-of-function mutations in either SMG8 or SMG9 caused ATRi resistance by an SMG1-mediated mechanism. Although ATRi still impaired ATR/CHK1 signaling in SMG8/9-defective cells, other characteristic responses to ATRi exposure were not seen, such as changes in ATM/CHK2, γH2AX, phospho-RPA, or 53BP1 status or changes in the proportions of cells in S- or G2-M-phases of the cell cycle. Transcription/replication conflicts (TRC) elicited by ATRi exposure are a likely cause of ATRi sensitivity, and SMG8/9-defective cells exhibited a reduced level of ATRi-induced TRCs, which could contribute to ATRi resistance. These observations suggest ATRi elicits antitumor efficacy in gastric cancer but that drug resistance could emerge via alterations in the SMG8/9/1 pathway.

SIGNIFICANCE

These findings reveal how cancer cells acquire resistance to ATRi and identify pathways that could be targeted to enhance the overall effectiveness of these inhibitors.

ESMO Expert Consensus Statements on Cancer Survivorship: promoting high-quality survivorship care and research in Europe

BACKGROUND

The increased number of cancer survivors and the recognition of physical and psychosocial challenges, present from cancer diagnosis through active treatment and beyond, led to the discipline of cancer survivorship.

DESIGN AND METHODS

Herein, we reflected on the different components of survivorship care, existing models and priorities, in order to facilitate the promotion of high-quality European survivorship care and research.

RESULTS

We identified five main components of survivorship care: (i) physical effects of cancer and chronic medical conditions; (ii) psychological effects of cancer; (iii) social, work and financial effects of cancer; (iv) surveillance for recurrences and second cancers; and (v) cancer prevention and overall health and well-being promotion. Survivorship care can be delivered by structured care models including but not limited to shared models integrating primary care and oncology services. The choice of the care model to be implemented has to be adapted to local realities. High-quality care should be expedited by the generation of: (i) focused and shared European recommendations, (ii) creation of tools to facilitate implementation of coordinated care and (iii) survivorship educational programs for health care teams and patients. The research agenda should be defined with the participation of health care providers, researchers, policy makers, patients and caregivers. The following patient-centered survivorship research areas were highlighted: (i) generation of a big data platform to collect long-term real-world data in survivors and healthy controls to (a) understand the resources, needs and preferences of patients with cancer, and (b) understand biological determinants of survivorship issues, and (ii) develop innovative effective interventions focused on the main components of survivorship care.

CONCLUSIONS

The European Society for Medical Oncology (ESMO) can actively contribute in the efforts of the oncology community toward (a) promoting the development of high-quality survivorship care programs, (b) providing educational material and (c) aiding groundbreaking research by reflecting on priorities and by supporting research networking.

First-In-Human Phase I Study of the OX40 Agonist MOXR0916 in Patients with Advanced Solid Tumors

PURPOSE

OX40, a receptor transiently expressed by T cells upon antigen recognition, is associated with costimulation of effector T cells and impairment of regulatory T-cell function. This first-in-human study evaluated MOXR0916, a humanized effector-competent agonist IgG1 monoclonal anti-OX40 antibody.

PATIENTS AND METHODS

Eligible patients with locally advanced or metastatic refractory solid tumors were treated with MOXR0916 intravenously once every 3 weeks (Q3W). A 3+3 dose-escalation stage (0.2-1,200 mg; n = 34) was followed by expansion cohorts at 300 mg (n = 138) for patients with melanoma, renal cell carcinoma, non-small cell lung carcinoma, urothelial carcinoma, and triple-negative breast cancer.

RESULTS

MOXR0916 was well tolerated with no dose-limiting toxicities observed. An MTD was not reached. Most patients (95%) experienced at least one adverse event (AE); 56% of AEs, mostly grade 1-2, were related to MOXR0916. Most common treatment-related AEs included fatigue (17%), diarrhea (8%), myalgia (7%), nausea (6%), decreased appetite (6%), and infusion-related reaction (5%). Pharmacokinetic (PK) parameters were dose proportional between 80 and 1,200 mg and supported Q3W administration. The recommended expansion dose based on PK and OX40 receptor saturation was 300 mg Q3W. Immune activation and upregulation of PD-L1 was observed in a subset of paired tumor biopsies. One renal cell carcinoma patient experienced a confirmed partial response. Overall, 33% of patients achieved stable disease.

CONCLUSIONS

Although objective responses were rarely observed with MOXR0916 monotherapy, the favorable safety profile and evidence of tumor immune activation in a subset of patients support further investigation in combination with complementary agents such as PD-1/PD-L1 antagonists.

Clinical management of metastatic colorectal cancer in the era of precision medicine

Colorectal cancer (CRC) represents approximately 10% of all cancers and is the second most common cause of cancer deaths. Initial clinical presentation as metastatic CRC (mCRC) occurs in approximately 20% of patients. Moreover, up to 50% of patients with localized disease eventually develop metastases. Appropriate clinical management of these patients is still a challenging medical issue. Major efforts have been made to unveil the molecular landscape of mCRC. This has resulted in the identification of several druggable tumor molecular targets with the aim of developing personalized treatments for each patient. This review summarizes the improvements in the clinical management of patients with mCRC in the emerging era of precision medicine. In fact, molecular stratification, on which the current treatment algorithm for mCRC is based, although it does not completely represent the complexity of this disease, has been the first significant step toward clinically informative genetic profiling for implementing more effective therapeutic approaches. This has resulted in a clinically relevant increase in mCRC disease control and patient survival. The next steps in the clinical management of mCRC will be to integrate the comprehensive knowledge of tumor gene alterations, of tumor and microenvironment gene and protein expression profiling, of host immune competence as well as the application of the resulting dynamic changes to a precision medicine-based continuum of care for each patient. This approach could result in the identification of individual prognostic and predictive parameters, which could help the clinician in choosing the most appropriate therapeutic program(s) throughout the entire disease journey for each patient with mCRC. CA Cancer J Clin. 2022;72:000-000.

Long-term safety of inavolisib (GDC-0077) in an ongoing phase 1/1b study evaluating monotherapy and in combination (combo) with palbociclib and/or endocrine therapy in patients (pts) with PIK3CA-mutated, hormone receptor-positive/HER2-negative (HR+/HER2-) metastatic breast cancer (BC)

1052

Background: Dysregulating mutations in PIK3CA, encoding the PI3K p110α subunit, occur in ̃40% of HR+/HER2– BCs. Inavolisib is a PI3Kα-specific inhibitor that also promotes degradation of mutant p110α. It has demonstrated encouraging preliminary antitumor activity in pts with PIK3CA-mutated HR+ BC as a monotherapy, and in combo with other anticancer agents. Methods: We included pts from NCT03006172 on treatment ≥1 year with inavolisib alone (Arm A), or in combo with palbo + letrozole (letro) (B), letro (C), fulvestrant (fulv) (D), or palbo + fulv (E; + metformin in Arm F for pts with body mass index ≥30 and/or HbA1c ≥5.7%). Inavolisib was administered orally daily (PO QD) at 3, 6, 9, or 12 mg (3+3 dose-escalation design); letro at 2.5 mg PO QD; palbo at 125 mg PO QD for 21/28 days; and fulv at 500 mg intramuscularly every 4 weeks, in 28-day cycles until intolerable toxicity/disease progression. Safety was assessed by NCI-CTCAE v4. Results: 57 female pts were included (cutoff 07/26/21; N = 1, 18, 6, 12, 15, 5 in Arms A–F); median age: 57 years (range 33–80); median lines of prior therapy: 2 (1–7). All but 2 pts, both in Arm B (3 mg), were assigned the 9 mg inavolisib recommended phase 3 dose. Overall median treatment duration: 19 months (range 12–45); median inavolisib cumulative dose intensity, 95%. The most frequent treatment-related adverse events (AEs; in ≥20 pts/35%) were hyperglycemia (68%), stomatitis (68%; grouped terms), neutropenia (58%), diarrhea (51%), nausea (39%), alopecia (35%), and rash (35%; grouped terms). The most frequent treatment-related Grade (G) 3–4 AEs (≥2 pts/4%) were neutropenia (47%), hyperglycemia (16%), leukopenia (9%), thrombocytopenia (9%), lymphopenia (7%), weight decreased, and hypokalemia (4% each). G3–4 neutropenia, leukopenia, thrombocytopenia, and lymphopenia were all reported in palbo arms. One G5 AE of pleural effusion was reported (disease progression-related). 39 pts (68%) had ≥1 AE resulting in study treatment modification (drug interruption/dose reduction/treatment withdrawal); 11 (19%) had an inavolisib dose reduction and 2 (4%) discontinued treatment due to an AE (1 related G2 diarrhea, 1 unrelated G3 cerebrovascular disorder). AEs typically occurred during the first 6 months and tended to be less frequent in later cycles. No new safety signals were observed with long-term inavolisib use. Conclusions: These data indicate acceptable long-term tolerability. The safety profile of pts on study treatment with inavolisib alone or in combo with endocrine-based anticancer therapies for ≥1 year was similar to that reported for the overall study population. Updated data will be presented. A phase 3 study of inavolisib + palbo + fulv is enrolling (NCT04191499; INAVO120). Clinical trial information: NCT03006172.

AFM24 in combination with atezolizumab in patients with advanced EGFR-expressing solid tumors: Phase 1/2a study design and rationale

TPS2673

Background: Innate Cell Engagers (ICE) are bispecific molecules that bind both a tumor cell-surface antigen and to CD16A expressed on natural killer (NK) cells and macrophages, inducing antibody-dependent cellular cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP), respectively. As epidermal growth factor receptor (EGFR) is often overexpressed in several types of solid tumors, this provides an ideal tumor-cell surface antigen which may be targeted using ICE molecules. AFM24 is a first in class, tetravalent, bispecific, novel ICE targeting EGFR. By binding to EGFR on tumor cells and CD16A on innate immune cells, AFM24 may utilize a patient’s innate immunity to induce ADCC/ADCP towards tumor cells. Anti-programmed death-ligand 1 (PD-L1) immune checkpoint inhibitors, which enhance the anti-tumor activity of a patient’s adaptive immunity, have also demonstrated efficacy as monotherapy and are playing an increasingly prominent role in treatments. The combination of AFM24 and the PD-L1 inhibitor, atezolizumab, may therefore represent a rational new treatment modality, enhancing both the innate and adaptive immune responses to target EGFR+ tumor cells. Methods: An ongoing Phase 1/2a open-label, non-randomized, multicenter, dose escalation (Phase 1) and dose expansion (Phase 2a) study was initiated in November 2021 (NCT05109442) to evaluate the safety, tolerability and efficacy of AFM24 in combination with atezolizumab. The primary aim of the Phase 1 study is to determine the maximum tolerated dose and the recommended Phase 2 dose (RP2D) of AFM24. Eligible patients must have advanced histologically confirmed EGFR+ disease and confirmed disease progression after treatment with ≥1 prior therapy. Patients undergo a safety lead-in phase with AFM24 as a single agent 7 days before receiving the combination therapy. A standard 3+3 design will be used to determine the RP2D. Escalating doses of AFM24 will be given to each cohort as weekly intravenous (IV) infusions; the starting dose and at least two planned dose escalations are based on results from the ongoing AFM24 monotherapy trial (NCT04259450). Atezolizumab will be given at a fixed dose of 840 mg as a biweekly IV infusion. Patients will receive AFM24 and atezolizumab treatment until disease progression, intolerable toxicity, patient withdrawal, or termination at the investigator’s discretion. The Phase 2a study will then establish the overall response rate (as per RECIST v1.1) and safety of combination therapy in patients with advanced/ metastatic, or treatment refractory gastric, esophagogastric, hepatocellular, hepatobiliary, pancreatic, or non-small cell lung cancer. For both phases, secondary endpoints include treatment-emergent adverse events, serious adverse events, pharmacokinetics, pharmacodynamics, and immunogenicity. Clinical trial information: NCT05109442.

First-in-human, open-label, phase 1/2 study of the monoclonal antibody programmed cell death protein-1 (PD-1) inhibitor cetrelimab (JNJ-63723283) in patients with advanced cancers

Purpose

To assess the safety, pharmacokinetics, pharmacodynamics, and preliminary efficacy of cetrelimab (JNJ-63723283), a monoclonal antibody programmed cell death protein-1 (PD-1) inhibitor, in patients with advanced/refractory solid tumors in the phase 1/2 LUC1001 study.

Methods

In phase 1, patients with advanced solid tumors received intravenous cetrelimab 80, 240, 460, or 800 mg every 2 weeks (Q2W) or 480 mg Q4W. In phase 2, patients with melanoma, non-small-cell lung cancer (NSCLC), and microsatellite instability–high (MSI-H)/DNA mismatch repair-deficient colorectal cancer (CRC) received cetrelimab 240 mg Q2W. Response was assessed Q8W until Week 24 and Q12W thereafter.

Results

In phase 1, 58 patients received cetrelimab. Two dose-limiting toxicities were reported and two recommended phase 2 doses (RP2D) were defined (240 mg Q2W or 480 mg Q4W). After a first dose, mean maximum serum concentrations (C_max) ranged from 24.7 to 227.0 µg/mL; median time to C_max ranged from 2.0 to 3.2 h. Pharmacodynamic effect was maintained throughout the dosing period across doses. In phase 2, 146 patients received cetrelimab 240 mg Q2W. Grade ≥ 3 adverse events (AEs) occurred in 53.9% of patients. Immune-related AEs (any grade) occurred in 35.3% of patients (grade ≥ 3 in 6.9%). Overall response rate was 18.6% across tumor types, 34.3% in NSCLC, 52.6% in programmed death ligand 1–high (≥ 50% by immunohistochemistry) NSCLC, 28.0% in melanoma, and 23.8% in centrally confirmed MSI-H CRC.

Conclusions

The RP2D for cetrelimab was established. Pharmacokinetic/pharmacodynamic characteristics, safety profile, and clinical activity of cetrelimab in immune-sensitive advanced cancers were consistent with known PD-1 inhibitors.

Trial registrations

NCT02908906 at ClinicalTrials.gov, September 21, 2016; EudraCT 2016–002,017-22 at clinicaltrialsregister.eu, Jan 11, 2017.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00280-022-04414-6.

Phase 2 study of 9-ING-41, a small molecule selective glycogen synthase kinase-3 beta (GSK-3β) inhibitor, with gemcitabine/nab-paclitaxel (GnP) in first-line advanced pancreatic ductal adenocarcinoma (PDAC)

578

Background: GSK-3β overexpression is associated with worse prognosis and chemotherapy resistance in PDAC. GSK-3β inhibition reverses chemotherapy-resistance by inhibiting chemotherapy-induced, ATR-mediated, DNA damage response. 9-ING-41 has significant anti-tumor activity through apoptosis induction, anti-fibrotic activity and NK/T-cell effector stimulation. We hypothesized that 9-ING-41 in combination with GnP chemotherapy would lead to anti-tumor activity, with improved tumor responses in patients with advanced PDAC in the first line setting. Methods: Primary endpoint is disease control rate (DCR). DCR = confirmed complete response (CR), partial response (PR), or stable disease (SD) ≥ 16 weeks (wks). Secondary endpoints are safety and ORR (overall response rates). Eligibility: Advanced PDAC, ECOG PS 0-2, no prior therapy in the metastatic setting and no systemic therapy in prior 6 months. Pts received 9-ING-41 15mg/kg IV twice-weekly with G 1,000 mg/m2 and nP 125 mg/m2 on days 1,8,15 of a 28-day cycle. Simon 2-Stage Design for DCR of 65% and null hypothesis of 50% (historical control), 80% power and 2 sided-significance level of.05. Up to 23 fully evaluable pts planned for stage 1 and if ≥ 12 evaluable patients achieve a DCR 37 additional pts will be enrolled on a second stage or a randomized study commenced. Results: As of Sept 27, 2021, 42 pts enrolled. Median age: 67. 24 females, 18 males. 38 pts with metastatic and 4 with locally advanced disease. Prior adjuvant therapy: 4 pts each FOLFIRINOX and gemcitabine-based. No 9-ING-41-attributable SAEs to date. 9-ING-41 attributed AEs: visual disturbance: 24 (75%) G1/2, 1 (3%) G3; infusion reactions 9 (28%) G1/2. Chemotherapy-related AEs: anemia 13 (40%) G1/2, 1 (3%) G3; neutropenia 2 (6%) G1/2, 13 (40%) G3/4; thrombocytopenia 9 (28%) G1/2, 2 (6%) G3/4; diarrhea 8 (25%) G1/2, 4 (13%) G3; fatigue 9 (28%) G1/2, 3 (9%) G3; nausea/vomiting 24 (75%) G1/2, 1 (3%) G3; constipation 9 (28%) G1/2; febrile neutropenia 5 (16%) G3/4. In 21 pts currently evaluable for response, DCR was 62% and ORR 43%. There were 2 confirmed CRs, 6 confirmed and 1 unconfirmed PRs, 4 SD and 8 disease progressions were observed. Amongst responder’s median duration of response has not yet been reached. Conclusions: 9-ING-41 plus GnP demonstrated encouraging clinical activity but chemotherapy-related AEs were significant. Based on efficacy data to date, including confirmed CRs, we have commenced a randomized phase 2 study, evaluating 9-ING-41 plus GnP vs Gn P alone. Enrollment to the randomized study is now open (NCT03678883). Clinical trial information: NCT03678883.

Circulating Tumor DNA in Stage III Colorectal Cancer, beyond Minimal Residual Disease Detection, toward Assessment of Adjuvant Therapy Efficacy and Clinical Behavior of Recurrences

PURPOSE

Sensitive methods for risk stratification, monitoring therapeutic efficacy, and early relapse detection may have a major impact on treatment decisions and patient management for stage III colorectal cancer patients. Beyond assessing the predictive power of postoperative ctDNA detection, we explored the added benefits of serial analysis: assessing adjuvant chemotherapy (ACT) efficacy, early relapse detection, and ctDNA growth rates.

EXPERIMENTAL DESIGN

We recruited 168 patients with stage III colorectal cancer treated with curative intent at Danish and Spanish hospitals between 2014 and 2019. To quantify ctDNA in plasma samples (n = 1,204), 16 patient-specific somatic single-nucleotide variants were profiled using multiplex-PCR, next-generation sequencing.

RESULTS

Detection of ctDNA was a strong recurrence predictor postoperatively [HR = 7.0; 95% confidence interval (CI), 3.7-13.5; P < 0.001] and directly after ACT (HR = 50.76; 95% CI, 15.4-167; P < 0.001). The recurrence rate of postoperative ctDNA-positive patients treated with ACT was 80% (16/20). Only patients who cleared ctDNA permanently during ACT did not relapse. Serial ctDNA assessment after the end of treatment was similarly predictive of recurrence (HR = 50.80; 95% CI, 14.9-172; P < 0.001), and revealed two distinct rates of exponential ctDNA growth, slow (25% ctDNA-increase/month) and fast (143% ctDNA-increase/month; P < 0.001). The ctDNA growth rate was prognostic of survival (HR = 2.7; 95% CI, 1.1-6.7; P = 0.039). Serial ctDNA analysis every 3 months detected recurrence with a median lead-time of 9.8 months compared with standard-of-care computed tomography.

CONCLUSIONS

Serial postoperative ctDNA analysis has a strong prognostic value and enables tumor growth rate assessment. The novel combination of ctDNA detection and growth rate assessment provides unique opportunities for guiding decision-making.See related commentary by Morris and George, p. 438.

SURPASS-2 trial design: A phase 2, open-label study of ADP-A2M4CD8 SPEAR T cells in advanced esophageal or esophagogastric junction cancers

TPS363

Background: ADP-A2M4CD8 is an autologous specific peptide enhanced affinity receptor (SPEAR) mixed CD4 and CD8 T-cell product that expresses an engineered T-cell receptor (TCR) designed to target the MAGE-A4 antigen in HLA-A*02-positive patients. These SPEAR T-cells also express wild-type CD8α co-receptors, designed to provide additional functionality to CD4 T-cells. MAGE-A4 expression has been described in several solid tumors, including esophageal and esophagogastric junction (EGJ) cancers[1]. In an ongoing phase 1 study (NCT04044859) of ADP-A2M4CD8 in patients with different tumor types, most adverse events have been consistent with those typically experienced by patients undergoing chemotherapy and/or adoptive T-cell therapies, and as of 2 August 2021, among evaluable patients with esophageal and EGJ cancers, best overall responses were 1 partial response (EGJ), 4 stable disease (2 EGJ, 2 esophageal), and 1 progressive disease (EGJ)[2]. Methods: SURPASS-2 (NCT04752358) is a phase 2, open-label, single-arm trial to assess safety and efficacy of ADP-A2M4CD8 SPEAR T-cells in HLA-A*02–positive patients with advanced esophageal or EGJ cancers that express MAGE-A4 antigen. A total of 45 patients between the ages of 18 and 75 years old will be treated across sites in North America and Europe. Key eligibility criteria include measurable disease per RECIST v1.1; ECOG performance status of 0 or 1; no active autoimmune or immune-mediated disease; no leptomeningeal disease, carcinomatous meningitis, or symptomatic CNS metastases; and ≤2 prior lines of combination or single agent systemic treatment for advanced or metastatic disease before treatment with ADP-A2M4CD8 as the next therapy. Leukapheresis can be performed before initiating or at the end of second-line treatment. Collected T-cells will be transduced with a self-inactivating lentiviral vector expressing the high affinity MAGE-A4-specific TCR and the CD8α co-receptor. Lymphodepleting chemotherapy, consisting of intravenous (IV) cyclophosphamide 600 mg/m2/day for 3 days and IV fludarabine 30 mg/m2/day for 4 days, will be given approximately 1 week prior to treatment with ADP-A2M4CD8. ADP-A2M4CD8 dose will range between 1 x 109 to 10 x 109 transduced cells administered by a single IV infusion. The primary endpoint is overall response rate per RECIST v1.1 by an independent radiological assessment committee. Safety evaluations will include adverse events (AEs); serious AEs; incidence, severity, and duration of the AEs of special interest; replication competent lentivirus; and T-cell clonality and insertional oncogenesis. All patients receiving ADP-A2M4CD8 cellular therapy will be followed for 15 years from time of last T-cell infusion for observation of delayed AEs. To date, one site is activated. [1] Ishihara et al. BMC Cancer 20, 606 (2020). [2] Hong et al. E-poster 540P: ESMO (2021). Clinical trial information: NCT04752358.