KAHR Bio Announces Positive Phase 2 Results of DSP107 in Combination with anti-PD-L1 in Colorectal Cancer

- Findings presented in an oral presentation at the 2025 ASCO Annual Meeting

- DSP107 in combination with atezolizumab in 3^rd line microsatellite stable colorectal cancer (MSS-CRC) patients elicits anti-tumor activity and extends survival including in patients with liver metastases

MODI'IN, Israel, June 2, 2025 /PRNewswire/ -- KAHR, a clinical-stage biotech company developing DSP107, a first-in-class bi-specific 4-1BB T-cell engager that activates innate and adaptive immunity to treat solid tumors, today announced positive results from the Phase 2 dose expansion cohort of DSP107 in combination with atezolizumab (Tecentriq^®), an anti-PD-L1 cancer immunotherapy, in patients with 3^rd line microsatellite stable metastatic colorectal cancer (MSS-CRC). In addition to its favorable safety profile, the combination has shown anti-tumor activity and extended survival including in patients with liver metastases. The results were presented in an oral presentation by Anwaar Saeed, MD, Associate Professor of Medicine, University of Pittsburgh Medical Center and Director, Gastrointestinal Disease Center, UPMC Hillman Cancer Center at the American Society of Clinical Oncology (ASCO) 2025 Annual Meeting, May 30 – June 3, 2025, in Chicago, IL.

"Colorectal cancer, the second largest cause of cancer deaths worldwide, is considered a 'cold' tumor that usually does not elicit an efficient immune response," said Dr. Saeed. "This immunotherapy combination showed durable results in MSS-CRC patients. Not only is the median survival of DSP107 with atezolizumab longer than current standard treatments, it is also very well tolerated by patients, without the severe, sometimes life-threatening side effects of chemotherapy in such advanced lines of treatment. Importantly, the majority of patients in the combination cohort had active liver metastases and the activity and survival benefit were also seen in these patients, who are very difficult to treat, suggesting that DSP107 in combination with a PD1/PD-L1 checkpoint inhibitor may become an effective immunotherapy treatment option for this patient population."

Yaron Pereg, Ph.D., Chief Executive Officer of KAHR, said, "We are extremely encouraged by the dose expansion data, showing objective responses and extended survival in response to DSP107 in combination with atezolizumab in patients with 3^rd line MSS-CRC. We look forward to initiating a Phase 2b, randomized, controlled study to confirm these promising efficacy signals. In addition, we expect data in 2026 from a Phase 2 dose expansion cohort in Non-small Cell Lung Cancer (NSCLC), the leading cause of cancer deaths worldwide."

Results from the completed dose expansion cohort show that DSP107 monotherapy and combination treatment with atezolizumab were well tolerated with no dose limiting toxicities. The median OS from the efficacy-evaluable patients who received DSP107 monotherapy (n=19) and combination therapy with atezolizumab (n=21) has not been reached, but currently (May 2025 cutoff) stands at 8.1 and 17 months, respectively. Disease control was demonstrated in 21% (monotherapy) and 62% (combination) of evaluable patients including a patient who achieved a complete response (> 2.5 years) and a patient with a deep (86% target lesion reduction) and durable (> 16 months) confirmed partial response and disappearance of pulmonary and hepatic metastases. Immunofluorescence analysis of baseline tumor biopsies demonstrated very high levels of CD47 expression, the DSP107 target, in all samples collected from liver metastases. 

The MSS-CRC dose expansion phase of the study was an open label, multi-center trial (NCT04440735) that enrolled patients with 3rd line MSS colorectal cancer patients, treated weekly with 10 mg/kg DSP107 infusions and atezolizumab (1200 mg) every three weeks, until disease progression. The primary objective was to determine the safety and tolerability of DSP107 in combination with atezolizumab. The secondary objective was to assess the preliminary efficacy of DSP107 in combination with atezolizumab.

Presentation information:

Abstract Title: Phase 2 dose expansion study of DSP107, a first-in-class bi-specific 4-1BB T-cell engager, with and without atezolizumab in metastatic MSS colorectal cancer patients.

Abstract Number for Publication: 3517

About DSP107

KAHR's lead drug candidate, DSP107, is a first-in-class bi-specific 4-1BB T-cell engager utilizing CD47 overexpression as a tumor anchor. DSP107 binds to CD47 that cancer cells express on their cell surface. Once bound, DSP107 converts the CD47 signal, which cancer uses to camouflage itself from the innate immune system, into a 4-1BB signal, which attracts and activates adaptive immune cells, primarily cancer cytotoxic CD8 T-cells. In this way, DSP107 engages both parts of the immune system in a wholistic anti-cancer response. This is particularly relevant in colorectal cancer, where 70%+ of the metastatic patients have metastases in the liver, and where liver metastases highly express CD47 in response to first- and second-line chemotherapy treatments. Previous attempts to treat colorectal cancer with immunotherapy have failed as there is a lack of immune cells in the tumor. DSP107 is unique in that it takes advantage of CD47 expression to drive immune cells into the tumor. DSP107 is also being tested in Phase 2 expansion cohort in 2L/3L PD1-experienced NSCLC.

About microsatellite stable metastatic colorectal cancer (MSS-CRC)

Microsatellite stable metastatic colorectal cancer (MSS-CRC) is a subtype of colorectal cancer that lacks deficiencies in the DNA mismatch repair system, resulting in stable microsatellite regions within the genome. Unlike microsatellite instability-high (MSI-H) tumors, MSS-CRC exhibits lower tumor mutational burden and is less responsive to immunotherapy. MSS tumors represent the majority of colorectal cancer cases and are typically more challenging to treat. Standard treatment for metastatic MSS-CRC often involves a combination of chemotherapy, targeted therapy, and in select cases, surgical intervention.

About KAHR

KAHR develops novel, dual-targeting fusion protein therapeutics engineered to activate both the innate and adaptive immune systems simultaneously and localize that response in the tumor microenvironment. The Company is developing multifunctional fusion proteins that boost the immune systems' response to cancer. KAHR Bio was founded based on technology developed at the University of Pennsylvania and Thomas Jefferson University. For more information, please visit kahrbio.com/.

Media contact:
Tsipi Haitovsky
Global Media Liaison
KAHR
+972-52-598-9892
[email protected]

SOURCE KAHR Medical