Liminatus Pharma R&D Consortium Companion Diagnostic YN 1203 Demonstrates ~70% Sensitivity & Specificity in Clinical Testing

Liminatus Pharma (www.liminatuspharma.com), a leader in Guanylyl Cyclase C (GCC)-targeted immunotherapies, including CAR-T therapeutics and vaccines, recently announced its companion diagnostic to support checkpoint inhibitor therapies, YN1203 CDx liquid biopsy test (YN1203 ELISA Kit), has demonstrated ~70% sensitivity and specificity, exceeding that of PharmDx and SP263 by Agilent and Roche, respectively. YN1203 was invented by the Korea National Cancer Center established by the Korean government and the patent for YN1203 has been transferred to InnoBationBio Co., Ltd. Liminatus Pharma secured a license with InnoBationBio Co., Ltd, which provides a worldwide exclusive right to develop and market this technology.

Companion diagnostics are required, or recommended, to guide therapy with immune checkpoint inhibitors. In part, this reflects the expense and heterogeneous efficacy of FDA-approved immune checkpoint inhibitors for cancer therapy, such as Keytruda^® and Opdivo^®, which imposes a significant economic burden on healthcare systems. Currently, Agilent in Santa Clara, CA, and Roche in Switzerland cover most of the companion diagnostic market from the sale of their products, PharmDx and SP263, respectively, to predict immune checkpoint inhibitor therapy responses.

Data on the companion diagnostic kit, YN1203, revealed its superiority to PharmDx and SP263 with respect to results, costs, screening methods, time, and sampling. For example, YN1203 uses an enzyme-linked immunosorbent assay (ELISA), a plate-based assay technique designed to detect and quantify soluble substances, for example in plasma. In contrast, PharmDx and SP263 use tissue immunostaining, an antibody-based method to detect a specific protein in biopsy specimens. Thus, YN1203 interrogates plasma obtained non-invasively by blood sampling, while PharmDx and SP263 are applied to cancer specimens obtained by invasive biopsies. Beyond incurring additional costs, biopsies have additional risks of bleeding or bruising, and infection of the biopsy site or damage to neighboring tissues is possible.

The present study evaluated the predictive power of YN1203 in plasma for non-small cell lung cancer (NSCLC) patients treated with immune checkpoint inhibitors, including Keytruda (pembrolizumab), Opdivo (nivolumab) and Tecentriq^® (atezolizumab). Plasma samples were collected from lung cancer patients before treatment with immune checkpoint inhibitors. Sixty-nine (64 NSCLC + 5 small cell lung cancer) and 100 (all NSCLC) patients were enrolled from two of the largest hospitals in Korea.

According to Dr. Yoo, technical advisor of InnoBationBio Co., Ltd, the licensor of the blood-based CDx technology, “the YN1203 test was applied to 169 plasma samples, and optimum discrimination of responders and non-responders was achieved at 215 µg/ml (Responder < 215 µg/ml YN1203, Non-responder >= 215 µg/ml YN1203) by statistical assessment (CRO, Synex Consulting Ltd, Seoul, Republic of Korea) using Receiver Operating Characteristics (ROC) and Area Under Curve (AUC) analyses. Using that threshold, YN1203 exhibited a sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of ~70%.”

This study clearly demonstrated YN1203 as a sensitive biomarker to predict clinical responses to immune checkpoint inhibitors. Advantages of YN1203 include:

• NON-INVASIVE: Compared to previous tissue staining methods such as PharmDx or SP263, quantification of YN1203 is performed in plasma samples.
• STRONG PREDICTIVE POWER: PD-L1 expression in tissues (PharmDx or SP263) as a predictive biomarker has limitations. YN1203 is superior to those of other previous methods.
• REAL TIME PREDICTION: In some cases, archived tissues are used to measure the expression of PD-L1. Thus, the expression level of PD-L1 may not reflect the status of patients before immune checkpoint inhibitor treatment. YN1203 assay reveals the status of patients at the actual time of treatment.
• VERSATILE: YN1203 can be used to predict responses to various immune checkpoint inhibitors. Also, it may useful to predict responses to other types of immunotherapy.
• EASE OF USE and FASTER PREDICTIONS: YN1203 in plasma is quantified using established ELISA protocols, with results available within ~4 hours.

Chris Kim, CEO of Liminatus Pharma and Liminatus R&D Consortium, indicated that following discussions with members of the Consortium, including InnoBationBio Co., Ltd. and Ewon Comfortech Co., Ltd, that upon publication of results of these studies, Liminatus will begin regulatory clearance procedures with the FDA by initiating clinical trials with YN1203, led by a major university medical center in the United States.

In addition, Liminatus R&D Consortium will start its YN522 cancer screening kit test (a multi-cancer liquid biopsy test requiring only 20 microliters of plasma) in the United States and pursue its FDA approval in 2022. Liminatus Pharma is planning on an initial public offering (IPO) in 2021 with its pipelines including YN1203 and YN522, along with its existing GCC-related CAR T and vaccine technologies. For this, Liminatus is now in due diligence with a well-known hedge fund in the US and a conglomerate in Asia.