Enterome's EO2463 Receives FDA Orphan Drug Designation for Watch-and-Wait Indolent Non-Hodgkin Lymphoma
核心洞察
The U.S. FDA granted Orphan Drug Designation to Enterome's EO2463 OncoMimics immunotherapy for treating indolent non-Hodgkin lymphoma (搜索) patients in the watch-and-wait setting.
EO2463 demonstrated a 52.6% objective response rate in follicular lymphoma (搜索) patients and 47.6% in the overall watch-and-wait population during the SIDNEY Phase 1/2 trial.
The designation provides seven years of market exclusivity upon approval and validates the unmet medical need for active treatment options in watch-and-wait patients.
Enterome SA announced that the U.S. Food and Drug Administration has granted Orphan Drug Designation to EO2463 for treating patients with indolent non-Hodgkin lymphoma (搜索) in the low-tumor-burden "watch-and-wait" setting. The designation follows the FDA's Fast Track designation granted in October 2025 for follicular lymphoma (搜索) in the same patient population, highlighting the significant unmet medical need in this indication.
Regulatory Advantages and Market Exclusivity
The FDA orphan drug designation confers substantial financial, regulatory, and strategic advantages for therapies targeting rare diseases affecting fewer than 200,000 people in the United States. Upon marketing approval, orphan-designated products receive seven years of market exclusivity in the U.S.
"Receiving FDA Orphan Drug Designation is an important regulatory milestone for EO2463 and re-affirms our strong commercial potential," said Pierre Belichard, Chief Executive Officer of Enterome. "Today, the only option for non-symptomatic low tumor burden 'watch-and-wait' iNHL patients is to go without treatment and be observed until the cancer progresses."
Clinical Efficacy in Watch-and-Wait Population
Data from the ongoing SIDNEY trial demonstrate EO2463's potential as a disease-modifying therapy for watch-and-wait patients. In the low-tumor-burden watch-and-wait population of SIDNEY Cohort 2, EO2463 monotherapy produced a 52.6% objective response rate in 19 evaluable patients with follicular lymphoma (搜索) and a 47.6% objective response rate in the overall group of 21 evaluable patients with follicular lymphoma or marginal zone lymphoma (搜索), including 14.3% complete responses and 33.3% partial responses.
The treatment rapidly induced extensive in vivo expansion of B-cell-target-specific CD8 T cells, with Enterome establishing a correlation between EO2463-induced CD8 T-cell expansion and Lugano objective response. This immune readout may serve as a predictive biomarker in indolent NHL, potentially helping physicians decide which patients to monitor more closely and alleviating anxiety in watch-and-wait patients.
Combination Therapy Results
Beyond monotherapy efficacy, EO2463 demonstrated complementary activity when combined with established cancer therapeutics. In relapsed/refractory patients, EO2463 combined with lenalidomide and rituximab achieved a 60% complete response rate in 20 patients with follicular and marginal zone lymphoma (搜索). The combination was well tolerated and showed CD8 T-cell expansion correlating with the probability of complete remission.
OncoMimics Technology Platform
EO2463 represents Enterome's OncoMimics technology, an off-the-shelf active immunotherapy composed of four synthetic microbial-derived peptides designed to mimic B-cell lineage markers CD20 (搜索), CD22 (搜索), CD37 (搜索), and CD268 (搜索) (BAFF receptor (搜索)), plus the helper peptide UCP2. This multi-target approach is intended to expand pre-existing memory CD8 T cells, selectively target malignant B cells, broaden target coverage, and reduce the risk of antigen escape.
OncoMimics consist of bacteria-derived peptide antigens that closely mimic tumor-associated antigens or cell lineage markers. These antigens induce fast and potent in vivo expansion of cytotoxic memory CD8 T-cells, primed by gut bacteria and cross-reactive with tumor markers. Because the peptides are "non-self," OncoMimics avoid the self-tolerance that limits many cancer immunotherapies, enabling rapid, potent, and durable responses to tumors.
Ongoing Development and Partnership Strategy
SIDNEY is an ongoing open-label Phase 1/2 study evaluating the safety, tolerability, immunogenicity, and preliminary efficacy of EO2463 as monotherapy and in combination regimens in up to 55 patients with follicular lymphoma (搜索) and marginal zone lymphoma (搜索). The trial includes a dedicated watch-and-wait monotherapy cohort, a first-line low-tumor-burden combination cohort with rituximab, and relapsed/refractory cohorts treated with EO2463 plus lenalidomide and rituximab.
Enterome is actively engaging with potential partners and investors to advance EO2463 development toward registrational studies in the watch-and-wait population. The company's drug discovery platform mines a proprietary database of 23 million commensal bacteria genes to identify OncoMimics with high similarity to tumor-associated antigens.