On Jun 15th, RemeGen (688331.SH/09995.HK) announced that the first patient has been dosed in its Phase II/III clinical study of RC148 (RC148-C303), a novel bispecific antibody independently developed by RemeGen, in combination with chemotherapy as first-line therapy for unresectable or metastatic colorectal cancer (CRC).
This is a randomized, multicenter Phase II/III clinical study to evaluate the efficacy and safety of RC148 in combination with chemotherapy as first-line therapy for unresectable or metastatic CRC. The study consists of two phases: Phase II and Phase III. Phase II will preliminarily evaluate the efficacy and safety of RC148 in combination with chemotherapy as first-line therapy for unresectable or metastatic CRC, with objective response rate (ORR) as the primary endpoint. Phase III aims to evaluate the efficacy and safety of RC148 in combination with chemotherapy versus bevacizumab in combination with chemotherapy as first-line therapy for unresectable or metastatic CRC, with progression-free survival (PFS) as the primary endpoint. Phase II will initially be conducted across 17 medical institutions nationwide, with Prof. Shen Lin from Peking University Cancer Hospital serving as the principal investigator.
CRC is one of the most prevalent malignancies worldwide. According to GLOBOCAN 2022 data, there are approximately 2 million new cases and 900,000 deaths annually worldwide. In China, based on 2022 data from the National Cancer Center, there are approximately 520,000 new cases and 240,000 deaths per year, highlighting a substantial disease burden. Due to the lack of obvious early symptoms, approximately half of patients are diagnosed at an advanced stage, and about one-quarter present with distant metastasis at diagnosis. Consequently, the 5-year survival rate remains below 15%.
Metastatic colorectal cancer (mCRC) is classified into two categories based on microsatellite instability (MSI) status or mismatch repair (MMR) protein expression: MSI-H/dMMR type accounts for approximately 5%, and patients in this category respond significantly to immunotherapy; while the MSS or MSI-L/pMMR type, which accounts for as high as 95%, is referred to as “cold tumors” due to poor response to existing immuno-monotherapy (such as PD-1 monoclonal antibodies), and has limited clinical treatment options, with significant unmet needs.
The primary target population for the RC148-C303 study is patients with MSS or MSI-L/pMMR mCRC. Multiple studies have shown that the combination of bispecific antibody drugs targeting PD-1/VEGF and chemotherapy have demonstrated promising efficacy in first-line treatment for MSS or MSI-L/pMMR type CRC patients, and are expected to become a new therapeutic strategy. The progress of the RC148-C303 study will further verify the efficacy and safety of RC148 in combination with chemotherapy in the treatment of patients with CRC.
About RC148
RC148 is a novel PD-1/VEGF-targeted bispecific antibody developed by RemeGen, designed to activate the anti-tumor immune response and inhibit the tumor angiogenesis. RC148 is expected to enhance the anti-tumor activity of immune system through multiple mechanisms by targeting and blocking both PD-1 and VEGF simultaneously. Now, RemeGen is proceeding with the study trial of RC148 monotherapy and combination therapy in the treatment of multiple advanced malignant solid tumors.
In January 2026, RemeGen entered into an exclusive license agreement with AbbVie Inc. (hereinafter referred to as “AbbVie”) for RC148. Pursuant to the agreement, AbbVie obtained exclusive rights to develop, manufacture and commercialize RC148 outside Greater China. In consideration, RemeGen received a US$650 million upfront payment and is eligible to receive additional development, regulatory and commercial milestone payments of up to US$4.95 billion, as well as tiered double-digit royalty payments based on net sales of RC148 outside Greater China.
