KAHR Bio's DSP107 Shows Promising 17.5-Month Survival in Advanced Colorectal Cancer Phase 2 Trial
核心洞察
KAHR Bio (搜索)'s Phase 2a trial of DSP107 combined with atezolizumab demonstrated a median overall survival of 17.5 months in advanced microsatellite stable colorectal cancer (搜索) patients, significantly exceeding current approved therapies.
The bispecific T-cell engager showed efficacy even in patients with liver metastases (搜索), a population historically refractory to immunotherapy, with approximately 75% of enrolled patients having liver involvement.
The company secured $22 million in financing to advance DSP107 into a randomized Phase 2b trial, which has already initiated enrollment across 18 sites in Australia and the United States.
KAHR Bio (搜索) announced compelling topline results from its Phase 2a dose-expansion cohort evaluating DSP107, a first-in-class bispecific T-cell engager, in combination with atezolizumab for late-line metastatic microsatellite stable colorectal cancer (搜索) (MSS-CRC). The combination therapy demonstrated a median overall survival of 17.5 months, substantially exceeding the 6.4-10.8 months reported for currently approved therapies in this challenging patient population.
Strong Efficacy in Difficult-to-Treat Population
The Phase 2a trial (NCT04440735) enrolled heavily pretreated patients with advanced, chemo-refractory MSS-CRC, with approximately 75% having liver metastases (搜索)—a population historically refractory to immunotherapy. Despite this challenging patient profile, DSP107 in combination with atezolizumab demonstrated favorable safety, clinical evidence of antitumor activity, and extended survival.
"Observing efficacy with an immunotherapy approach in late line MSS-CRC patients with liver metastases (搜索) is unexpected," said Anwaar Saeed, M.D., Chief of GI Oncology at the University of Pittsburgh and Co-Leader of the Cancer Therapeutics Program at UPMC Hillman Cancer Center, who co-led the Phase 2a trial. "DSP107's mechanism is particularly suited to this setting as it utilizes CD47 (搜索) overexpression on cancer cells to anchor a 4-1BB (搜索) ligand to those cells, thereby attracting and activating T cells."
Novel Mechanism of Action
DSP107 represents a unique approach to cancer immunotherapy as a bispecific CD47 (搜索)×4-1BB (搜索) targeting, next-generation T-cell engager. The therapy utilizes tumor-expressed CD47 as an anchor, selectively binding CD47 on cancer cells while sparing red blood cells, thereby overcoming safety challenges previously seen with other CD47-directed agents. Once bound, DSP107 converts the tumor's immune-evasion signal into a potent 4-1BB co-stimulatory activation signal, recruiting and activating CD8 cytotoxic T cells.
This mechanism is particularly relevant in colorectal cancer (搜索), where more than 70% of metastatic patients develop liver metastases (搜索) that commonly upregulate CD47 (搜索) following earlier-line chemotherapy. Dr. Saeed noted that "CD47 expression increases in liver metastases following chemotherapy, creating a therapeutic window uniquely addressable by DSP107."
Advancing to Phase 2b with Strong Financial Support
Based on these encouraging results, KAHR Bio (搜索) has secured $22 million in equity financing led by Flerie AB (搜索), Peregrine Ventures (搜索), Oriella Ltd. of the Consensus Business Group, aMoon Growth Fund (搜索), and the Cancer Focus Fund (搜索). The proceeds are expected to fully fund the company's randomized, controlled Phase 2b trial of DSP107 in combination with atezolizumab versus fruquintinib in fourth-line metastatic MSS-CRC.
The Phase 2b trial was initiated in December 2025 following FDA investigational new drug (IND) clearance and is expected to enroll patients at 18 sites across Australia and the United States. The first patient was enrolled in December 2025, with interim results anticipated in late 2026 and topline data expected in the second half of 2027.
Safety Profile Across Multiple Indications
Across more than 130 patients treated with DSP107 to date in a variety of solid tumors and hematological malignancies, the therapy continues to demonstrate a favorable safety and tolerability profile. This broad safety experience supports the advancement of DSP107 into larger, controlled trials.
Addressing Significant Unmet Need
Colorectal cancer (搜索) ranks among the top three most frequently diagnosed cancers globally, with approximately 1.9 million new cases and nearly 900,000 deaths annually. Among metastatic colorectal cancer (搜索) cases, approximately 85-90% are microsatellite stable (MSS). MSS-CRC is characterized by low tumor mutational burden and limited inherent immune activation, making tumors typically unresponsive to current immunotherapies, including immune checkpoint inhibitors.
"Following these compelling topline results demonstrating anti-tumor activity and meaningful survival outcomes in heavily pretreated MSS-CRC patients, including those with liver metastases (搜索), we have made MSS-CRC our primary development focus," said Yaron Pereg, Ph.D., Chief Executive Officer of KAHR Bio (搜索).
The company has also entered into a $10 million on-demand debt facility with SPRIM Global Investments (搜索), which can be drawn down based on eligible research and development activity under the Australian Government's R&D tax rebate scheme, providing additional financial flexibility as the program advances.