Business
Harbour BioMed Announces Positive Phase II Results for HBM4003 and Tislelizumab Combination in MSS mCRC
Harbour BioMed (HKEX: 02142), a global biopharmaceutical company focused on the discovery and development of novel antibody therapeutics in immunology and oncology, today announced positive Phase II clinical data for porustobart (HBM4003), a next-generation, fully human heavy-chain-only anti-CTLA-4 antibody, in combination with tislelizumab, in patients with microsatellite stable (MSS) metastatic colorectal cancer (mCRC).
About this update from Hbm Holdings Ltd.
[{"type":"text","content":"CAMBRIDGE, Mass., ROTTERDAM, Netherlands and SHANGHAI, Oct. 22, 2025 /PRNewswire/ -- Harbour BioMed (HKEX: 02142), a global biopharmaceutical company focused on the discovery and development of novel antibody therapeutics in immunology and oncology, today announced positive Phase II clinical data for porustobart (HBM4003), a next-generation, fully human heavy-chain-only anti-CTLA-4 antibody, in combination with tislelizumab, in patients with microsatellite stable (MSS) metastatic colorectal cancer (mCRC). ","length":520,"tagName":"p"},{"type":"image","alt":"Logo (PRNewsfoto/Harbour BioMed)","displaySize":"","headline":null,"caption":"Logo (PRNewsfoto/Harbour BioMed)","className":"","disableSlideshowImg":false,"size":{"original":{"width":400,"height":159,"url":"https://media.zenfs.com/en/prnewswire.com/47f569ac406a18e992467aae42c1112a"},"resized":{"url":"https://s.yimg.com/ny/api/res/1.2/QANxnzzeBFHKxcqoWHourA--/YXBwaWQ9aGlnaGxhbmRlcjt3PTcwNTtoPTI4MDtjZj13ZWJw/https://media.zenfs.com/en/prnewswire.com/47f569ac406a18e992467aae42c1112a","width":400,"height":159}},"href":"https://mma.prnewswire.com/media/1096360/HB_for_email_Logo.html","hrefExternal":true,"rel":"nofollow"},{"type":"text","content":"The multicenter, open-label Phase II study (NCT05167071) enrolled 24 heavily pretreated patients with non-liver-metastatic (NLM) MSS mCRC. Patients received HBM4003 (0.3 mg/kg) plus tislelizumab (200 mg) every 21 days. The primary efficacy endpoint was objective response rate (ORR) per RECIST 1.1 criteria. The findings showed promising antitumor activity and a manageable safety profile for the combination therapy in this difficult-to-treat population.","length":455,"tagName":"p"},{"type":"text","content":"Key findings include:","length":21,"tagName":"p"},{"type":"list","items":[{"val":[{"type":"text","content":"Baseline: All patients (N=24) had received ≥2 prior lines of therapy; 16/24 (66.7%) had lung metastases.","length":104,"tagName":"p"}]},{"val":[{"type":"text","content":"Efficacy: Among the 23 evaluable patients, the combination therapy achieved:","length":76,"tagName":"p"},{"type":"list","items":[{"val":[{"type":"text","content":"Objective Response Rate (ORR): 34.8% (8 partial responses)","length":58,"tagName":"p"}]},{"val":[{"type":"text","content":"Disease Control Rate (DCR): 60.9% (8 partial responses + 6 stable disea...