Antennova Unveils CD73 Inhibitor ATN-037 Data with 89.5% DCR at ESMO 2024

Antennova, a clinical-stage biotechnology company centered on oncology, has revealed promising results for its CD73 small molecule inhibitor, ATN-037, during a presentation at the 2024 European Society of Medical Oncology Congress (ESMO Congress 2024). The data presented focused on the efficacy and safety of ATN-037, particularly its potential in treating patients with advanced solid tumors who have developed resistance to checkpoint inhibitors (CPIs).

ATN-037, also known as ATG-037, is an orally administered potent inhibitor of CD73. The Phase I/II STAMINA-01 study was initiated to assess the safety, pharmacokinetics, and optimal dosing of ATN-037 both as a standalone treatment and in combination with Merck’s anti-PD-1 therapy KEYTRUDA® (pembrolizumab). This study is targeted towards patients with refractory or relapsed solid tumors.

As of July 26, 2024, 43 patients were enrolled in the study and treated with ATN-037 monotherapy. Of these, 26 patients who had developed resistance to CPIs also received ATN-037 combined with pembrolizumab. Out of the total participants, 42 patients had undergone at least one tumor evaluation, with one patient remaining unevaluable.

The efficacy data revealed that among the 42 evaluable patients treated with monotherapy, 23 achieved stable disease (SD). For the 26 patients who received the combination therapy of ATN-037 and pembrolizumab, 9 had non-small cell lung cancer (NSCLC) and 10 had melanoma. Within these groups, 4 patients (2 with NSCLC and 2 with melanoma) achieved a confirmed partial response (PR). Specifically, in the subgroup of 19 patients with either NSCLC or melanoma, the overall response rate (ORR) was 21.1%, while the disease control rate (DCR) was an impressive 89.5%.

Regarding safety, all 43 patients experienced treatment-emergent adverse events (TEAEs), with 62.3% being treatment-related. Sixteen patients encountered treatment-emergent serious adverse events (TE-SAEs), of which 2 were linked to the treatment. Eighteen patients experienced Grade 3 or higher TEAEs, with 4 of these being treatment-related. Notably, at the 400 mg twice-daily dosage, one case of dose-limiting toxicity (DLT) in the form of a Grade 3 rash was observed. No Grade 5 treatment-related adverse events (TRAEs) were reported.

The preliminary data from the Phase I dose escalation study of STAMINA-01 indicate that ATN-037, especially when combined with pembrolizumab, shows promising partial responses with an excellent safety profile. This combination could offer a new therapeutic approach for patients with CPI-resistant NSCLC and melanoma.

Antennova is progressing with the dose optimization and dose expansion phase of the Phase II STAMINA trial in Australia and plans to extend the study to China by the end of October 2024. The company aims to further investigate and confirm these encouraging preliminary findings.

Antennova, a Delaware corporation and a subsidiary of Antengene, emphasizes developing innovative therapies that enhance the effectiveness of standard treatments, reverse CPI resistance, and target tumors unresponsive to current CPI therapies. The company is advancing a pipeline that includes ATN-037, along with other clinical-stage programs such as ATN-031, ATN-022, and ATN-101, with some candidates receiving Orphan Drug Designations from the U.S. FDA for various cancers.