KAHR Reports Dose Escalation Results from Phase I Trial of DSP107 in Combination with anti-PD-L1 in Patients with Advanced Solid Tumors

DSP107, a first-in-class CD47 and 4-1BB targeting fusion protein, in combination with atezolizumab, was well tolerated and demonstrated durable responses

Dose was determined for Phase II expansion cohorts in 3rd line MSS-CRC and 2nd/3rd line NSCLC

Data to be presented at ASCO 2023

Modi’in, Israel, May 31, 2023 — KAHR, a clinical-stage biotech company developing DSP107, a novel, bi-specific CD47x4-1BB targeting immunotherapy that activates innate and adaptive immunity to treat solid tumors and blood cancers, today announced positive results from the dose escalation Phase I study of DSP107 in combination with atezolizumab (anti-PD-L1) in patients with advanced solid tumors. The results will be presented as a poster in the American Society of Clinical Oncology (ASCO) 2023 Annual Meeting, to be held June 2-6, in Chicago, IL.

Yaron Pereg, Ph.D., Chief Executive Officer of KAHR said, “We are extremely encouraged by the dose escalation data, showing significant tumor shrinkage and durable responses to DSP107 in combination with atezolizumab in patients with microsatellite stable colorectal cancer (MSS-CRC), which is considered a “cold” tumor that usually does not elicit an efficient immune response. The highest dose of DSP107 (10 mg/kg) in the dose escalation phase was selected for the Phase II expansion cohorts in 3rd line MSS-CRC patients and 2nd/3rd line non-small cell lung carcinoma (NSCLC) patients. In light of DSP107’s latest and previously demonstrated favorable safety profile, and the deep and long-lasting responses seen in the combination therapy dose escalation stage of the trial, we believe that DSP107 has the potential to benefit patients who are non-responsive or refractory to existing cancer treatments.”

Results of the completed dose escalation part of the study show that DSP107 in combination with atezolizumab was well tolerated (n=19) with no dose limiting toxicities (DLT’s) and no hematological or hepato-toxicities up to and including the highest dose tested (10 mg/kg).

At the highest dose (10 mg/kg) of DSP107, which was selected for the expansion cohorts, the combined treatment demonstrated a disease control rate (DCR) of 57% (4/7 patients with objective response or stable disease). Deep and durable objective responses were observed in 2 of 3 patients with MSS-CRC, with target lesion shrinkage of 73% and 83% including disappearance of pulmonary and hepatic target lesions in one patient and response durability currently standing at 10 and 9 months, respectively. The third MSS-CRC patient achieved stable disease (16% target lesion shrinkage) lasting for 6.5 months until progression. Another patient with adrenal carcinoma from the highest dose cohort also remains stable on treatment after 11 months.

The combination therapy dose escalation phase of the study was an open label, multi-center trial (NCT04440735) that enrolled 19 patients with advanced solid tumors, with a median of 3 prior lines of therapy. Patients were treated weekly with 1, 3 or 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

Date: June 3rd, 2023, 8:00 am- 4:00 pm

Session: Developmental Therapeutics – Immunotherapy

Abstract #2632

Poster #474

Abstract available on the ASCO website.