2022 SABCS | Kelun-Biotech TROP2-ADC (SKB264, MK-2870) Phase 2 Study Poster

The 45th Annual San Antonio Breast Cancer Symposium (SABCS) will commence on December 6th, 2022. A series of groundbreaking study data is expected to be presented at this conference, and the participants will also discuss how to apply the latest findings to clinical practice in order to improve the current treatment paradigm for breast cancer patients.

The efficacy and safety data of Kelun-Biotech’s TROP2-ADC (SKB264, MK-2870) in the Phase II expansion study in patients with locally advanced or metastatic triple-negative breast cancer (TNBC) were presented in a scientific poster, which was released on the official SABCS website and displayed and exchanged at the conference site, and the detailed contents are provided below.


Main contents of the Presented Poster

This was a Phase 2 expansion study that enrolled 59 patients with previously treated locally advanced or metastatic triple-negative breast cancer to receive SKB264 monotherapy (23 patients in the 4 mg/kg group and 36 patients in the 5 mg/kg group) with a 2-week treatment cycle. The data cut-off was October 10th, 2022, with a median follow-up of 12.8 months.

Baseline characteristics: 59 patients were enrolled (23 in 4 mg/kg group, 36 in 5 mg/kg group); 88% had previously received 3 or more regimens, 40.7% had previously received 5 or more regimens, and 28.8% of patients had previously received anti-PD-1/L1 therapy. 57 patients were available for TROP2 testing, and 54.2% had high TROP2 expression (defined as H-score >200-300).
Efficacy: Among 55 patients with evaluable response (21 in 4 mg/kg group, 34 in 5 mg/kg group), confirmed objective response rate (ORR) was 40% (22/55), disease control rate (DCR) was 80% (44/55), and confirmed ORR was 55.2% (16/29) in patients with high TROP2 expression. The confirmed ORR was as high as 62.5% in the high TROP2-expressing group dosed at 5 mg/kg. Median duration of sustained response (DoR) was 11.5 months, median PFS was 5.7 months, median OS was 14.6 months, and 12-month OS was 66.4%.

Safety: Treatment-related adverse events (TRAEs) ≥Grade 3 were reported in 57.6% (34/59) of patients. The most common ≥Grade 3 TRAEs (≥10%) were neutrophil count decrease (25.4%), white blood cell count decrease (23.7%), and platelet count decrease (16.9%). TRAEs led to dose reductions in 10.2% (6/59) of patients. No deaths due to TRAEs occurred and no interstitial lung disease (ILD) was observed.

In patients with metastatic TNBC treated with multiple prior lines of therapy, SKB264 demonstrated a manageable safety and promising antitumor activity. CDE has granted Breakthrough Therapy Designation for SKB264 as a single agent in locally advanced or metastatic TNBC, and this year will mark the debut of SKB264 clinical data being shared at an international conference for breast cancer. Currently, SKB264 monotherapy is rapidly advancing in a Phase III registrational study for the treatment of locally advanced or metastatic TNBC (NCT05347134), and also as a combination therapy with KL-A167 (anti-PD-L1 monoclonal antibody) for metastatic TNBC in the first-line setting (NCT05445908). Further clinical data for SKB264 in the treatment of breast cancer is expected to be shared in the near future.

About SKB264 (TROP2-ADC)
SKB264 is a new generation of antibody-drug conjugates (ADCs) composed of a humanized monoclonal antibody targeting TROP2, an enzymatically cleavable linker, and a new topoisomerase I inhibitor that Kelun-Biotech has independent intellectual property rights, which combines the specificity of monoclonal antibodies to target antigens on the surface of tumor cells and the high efficacy of cytotoxic drugs.

Based on preliminary clinical data, SKB264 is currently conducting Phase II and Phase III clinical trials of single drug/combination for multiple tumor types. In 2022, the research and development of SKB264 is progressing rapidly. Since January, 6 clinical studies have been approved (5 in China and 1 in the United States).


About Kelun-Biotech
Kelun Biotech is a clinical-stage biotech company established in 2016, a holding subsidiary of Sichuan Kelun Pharmaceutical Co., Ltd, engaged in biologic therapeutics as well as small molecule discovery and development. The company focuses on unmet medical needs such as oncology and autoimmune conditions and strives to be a leader in novel therapeutic discovery and development. Since its inception, Kelun-Biotech has established multi-modal drug discovery platforms based on global standards and made important development breakthroughs in antibody-drug conjugation, immuno-oncology, bispecific antibody and novel small molecule targeting and designs.
Kelun-Biotech’s current pipeline includes 55 therapeutic programs for the treatment of cancers, autoimmune conditions, infectious diseases, and metabolic syndromes. Fourteen programs are in clinical development in China, two of which have entered into clinical development in the US. Most notably, Kelun-Biotech has built out a proprietary ADC platform which is protected by a complex patent portfolio. Our comprehensive ADC capabilities range from novel target discovery, payload screening, linker design, as well as GMP manufacturing. As of today, Kelun-Biotech is advancing 10 novel ADC programs in varying stages of development.