839P - Preliminary results from a phase II study of amulirafusp alfa (IMM0306) in patients with relapsed or refractory CD20-positive B-cell non-Hodgkin's lymphoma

Background

Amulirafusp alfa (IMM0306) is a fusion protein of CD20 monoclonal antibody with the CD47 binding domain of SIRPα on both heavy chains. It exerts excellent cancer killing effect by activating both macrophages and natural killer cells via blockade of CD47-SIRPα interaction and FcɣR engagement. Here, we report the safety and efficacy results in patients (pts) with relapsed or refractory follicular lymphoma (R/R FL) from a phase II study (NCT05805943).

Methods

Eligible patients with FL Grade 1-3a received intravenous Amulirafusp alfa once a week of a 28-day treatment cycle with dose of 2.0 mg/kg until disease progression or intolerable toxicity. Safety was evaluated per the Common Terminology Criteria for Adverse Events version 5.0. Tumor assessments were performed by Lugano 2014. The primary endpoint was objective response rate (ORR). The secondary endpoints including disease control rate (DCR), progression free survival (PFS), and safety.

Results

As of Mar 14, 2024, 16 pts with FL were enrolled. The median age was 61 years old with 10 (62.5%) males. The median prior lines of therapy were 4. All 16 pts received previous anti-CD20 therapy. The most common treatment related adverse events (TRAEs) were lymphocyte (LYM) decreased (68.8%), platelet (PLT) decreased (50.0%), white blood cell (WBC) decreased (43.8%), anemia (43.8%) and absolute neutrophil count (ANC) decreased (31.3%). ≥ Grade 3 TRAEs occurred in 62.5% of pts. The most common ≥ grade 3 TRAEs were LYM decreased (50.0%), PLT decreased (18.8%), ANC decreased (18.8%) and pneumonia (18.8%). 18.8% of pts experienced serious TRAEs, all was pneumonia, in which 2 pts were recovering and 1 pts recovered without sequelae. No adverse event led to drug reduction, discontinuation or death. Among 15 efficacy evaluable pts with R/R FL, the ORR and DCR assessed by investigator was 33.3% and 66.7%, respectively. With a median follow-up of 5.72 months, the PFS rate at 9 months was 58.3%.

Conclusions

Amulirafusp alfa (IMM0306) was well-tolerated and presented robust preliminary anti-tumor activity in pts with R/R FL. This phase II study is ongoing.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

ImmuneOnco Biopharmaceuticals (Shanghai) Inc.

Funding

ImmuneOnco Biopharmaceuticals (Shanghai) Inc.

Disclosure

W. Meng: Financial Interests, Personal, Affiliate: ImmuneOnco Biopharmaceuticals (Shanghai) Inc. Z. Wang: Financial Interests, Personal, Full or part-time Employment: ImmuneOnco Biopharmaceuticals (Shanghai) Inc. All other authors have declared no conflicts of interest.