Enterome Phase 1/2 data show EO2463-induced CD8 T-cell expansion was associated with longer progression-free survival in indolent non-Hodgkin lymphoma.

Enterome has reported new interim Phase 1/2 data suggesting that CD8 T-cell expansion induced by its investigational cancer immunotherapy EO2463 is associated with longer progression-free survival (PFS) in patients with indolent non-Hodgkin lymphoma (iNHL) managed in a watch-and-wait setting.

The findings, presented at the Pan Pacific Lymphoma Conference, also showed a statistically significant association between EO2463-induced CD8 T-cell expansion and complete response rates in patients with relapsed or refractory iNHL who received the treatment in combination with lenalidomide and rituximab.

The results support further investigation of EO2463-induced CD8 T-cell expansion as a potential predictive biomarker for clinical benefit, according to Enterome.

In the EO2463 monotherapy cohort, which included patients with iNHL in a watch-and-wait setting, higher CD8 T-cell expansion was significantly associated with longer PFS. The analysis reported a hazard ratio of 0.18, with a 95% confidence interval of 0.03–0.82 and a log-rank p-value of 0.020.

In a separate cohort involving patients with relapsed or refractory disease treated with EO2463 in combination with lenalidomide and rituximab, higher CD8 T-cell expansion was significantly associated with complete response, with a p-value of 0.0073.

The data come from the ongoing open-label Phase 1/2 SIDNEY trial, which is evaluating the safety, tolerability, immunogenicity and preliminary efficacy of EO2463 as a monotherapy and in combination regimens in patients with follicular lymphoma and marginal zone lymphoma.

The study includes a dedicated monotherapy cohort for patients managed under a watch-and-wait approach, a first-line low-tumour-burden cohort combining EO2463 with rituximab, and relapsed or refractory cohorts receiving EO2463 with lenalidomide and rituximab.

The watch-and-wait setting is used for some patients with indolent lymphoma who do not require immediate treatment. Enterome is investigating whether EO2463 could have a role in this setting, where patients are monitored without active therapy until treatment is considered necessary.

The latest findings build on earlier analyses of the SIDNEY study. Data presented at the European Hematology Association Congress in 2026 showed that EO2463-induced CD8 T-cell expansion was significantly associated with clinical outcomes across monotherapy, rituximab and lenalidomide plus rituximab cohorts.

The company also reported at the American Society of Hematology meeting in 2025 that the EO2463 and lenalidomide plus rituximab combination produced a higher complete response rate than lenalidomide and rituximab alone. Earlier data presented in 2024 showed that EO2463 monotherapy generated a 46% objective response rate in patients in the watch-and-wait cohort.

Pierre Belichard, CEO of Enterome, said: “The correlation between the robust CD8 T cell expansion induced by EO2463 and PFS is a landmark finding that creates an imperative for further study and offers new hope for patients suffering from iNHL.”

He added that the findings support further investigation of EO2463 as a potential treatment for patients with iNHL in a watch-and-wait setting.

EO2463 is an off-the-shelf immunotherapy comprising four synthetic microbial-derived peptides designed to mimic the B-cell lineage markers CD20, CD22, CD37 and CD268, also known as BAFF receptor, alongside a helper peptide known as UCP2.

The approach is intended to stimulate the expansion of pre-existing memory CD8 T cells that can recognise malignant B cells. By targeting multiple B-cell lineage markers, the treatment is designed to broaden target coverage and reduce the potential for tumour cells to evade treatment through loss of a single antigen.

Enterome said the OncoMimics approach uses peptide antigens derived from bacteria that mimic tumour-associated antigens or B-cell lineage markers. The peptides are designed to stimulate an immune response against cancer cells by activating CD8 T cells.

The latest findings provide an early indication that the degree of CD8 T-cell expansion may be linked to clinical benefit, although further studies will be needed to establish whether the biomarker can reliably predict treatment response and progression-free survival.

In May 2026, the US Food and Drug Administration granted Orphan Drug Designation to EO2463 for the treatment of patients with follicular lymphoma.

Enterome also plans to present data on its solid-tumour OncoMimics candidate EO4010 at the European Society for Medical Oncology Congress 2026 in Madrid, Spain, in October. The presentation will examine CD8 T-cell expansion and its association with survival in patients with treated mismatch repair-proficient metastatic colorectal cancer.