Kling Biotherapeutics to Present Discoveries on its Primary B-Cell Screening Platform at the ESMO Targeted Anticancer Therapies Congress

Kling reports on advancing pipeline of therapeutic antibodies targeting novel antigens discovered with its best-in-class B-cell screening platform, Kling-Select

Progress on in vitro and in vivo validation of two highly specific tumor antigens is reported: CD43s, a sialylated-glyco epitope, and U5snRNP200, an ectopically expressed antigen highly specific for AML blast

Lead program KBA1412 is advancing in a Phase 1 clinical study, targeting advanced solid malignant tumors

AMSTERDAM, Feb. 22, 2024 /PRNewswire/ -- Kling Biotherapeutics ("Kling" or "the Company"), a clinical stage biotech company developing antibody-based drugs against targets identified from its primary B-cell screening platform, today announces that it will be presenting findings demonstrating the power of its clinically validated, best-in-class, B cell screening platforms, Kling-Select and Kling-Evolve, at the ESMO Targeted Anticancer Therapies Congress, in Paris, France on 26 February.

Michael Koslowski, Chief Executive Officer at Kling Bio, said: "Our findings consistently highlight and validate our world class, proprietary primary B cell screening platform and its ability to efficiently identify novel therapeutic targets and antibodies. Our aim is to maximise disease fighting antibodies and find a cure for all patients battling illnesses which include cancer and infectious diseases. Our lead clinical candidate KBA1412, a unique and previously undiscovered epitope of CD9, is advancing in a Phase 1 study, demonstrating a clean and safe profile in patients with advanced solid tumors. We look forward to sharing data in the foreseeable future and exploring the therapeutic potential of snRNP200 and our uniquely identified CD43 glycoform."

Poster one, entitled "KBA1413, an antibody derived from a cured AML patient, recognizes a unique CD43 glycoform shared by AML, MDS and solid cancer cells," details the identification of KBA1413, a fully human antibody screened from a single acute myeloid leukemia (AML) patient who remains in long term remission following allogeneic hematopoietic stem cell transplantation. The antibody identified using Kling's proprietary B cell screening platform, Kling-Select, recognised a unique, previously undescribed, sialylated epitope on CD43 that is reactive to freshly isolated blasts of over 60 randomly selected AML and myelodysplastic syndrome (MDS) patients. It also recognised CD43 on several solid tumor indications, including melanoma and breast cancer. KBA1413 triggered TR NK-mediated antibody dependent cell-mediated cytotoxicity (ADCC) against AML cells both in vitro and in vivo, suggesting that the antibody played a role in the graft versus leukemia response of the original donor patient. KBA1413 was made into a bispecific T-cell engaging antibody (bTCE), to increase its therapeutic potential and induced potent cytotoxicity in vitro and in vivo on cell lines in primary AML. Data demonstrates that KBA1413 warrants further development as a potent and promising treatment candidate for AML, MDS and solid tumors.

Poster two, entitled "snRNP200 reactive antibodies isolated from multiple AML patients show promise for targeted therapy," details how Kling's proprietary Kling-Select platform has the ability to identify new therapeutic target-antibody pairs to improve patient outcomes by interrogating the B cell repertoire of patients that have achieved remission via a strong tumor-directed immune response.

The Kling-Select platform was used to discover and characterise anti-snRNP200 antibodies from three AML patients that have achieved complete response after allogeneic stem cell transplantation, establishing that anti-snRNP200 specifically and selectively bind to AML cell lines that display snRNP200 on the outer cell surface. These findings have been independently confirmed^[2] and show that snRNP200 surface expression is limited to malignant cells and not expressed on normal hematopoietic stem cell progenitors. Kling will further explore the therapeutic potential of anti-snRNP200 with affinity matured variants produced with Kling-Evolve.

A first-in-human, Phase 1 clinical trial on Kling's first-in-class anti-CD9 antibody in patients with advanced solid malignant tumors is ongoing and can be found on www.clinicaltrials.gov under the identifier NCT05501821.

All accepted abstracts will be published online only in the ESMO TAT 2024 Abstract Book, a supplement to the ESMO journal, ESMO open.

Details of the conference and poster presentations are as follow:

Poster Title: KBA1413, an antibody derived from a cured AML patient, recognizes a unique CD43 glycoform shared by AML, MDS and solid cancer cells
Authors: V. Clerico Mosina, M. Kedde, B. Pieters, B. Monica, K. Maijoor, R. Schotte, A. Bakker, M. Koslowski, S. Gullà^[1]
Date and Time: 26 February, 17:15-18:15 CET
Session: Cocktail and Poster Display Session
Location: Hall Bordeaux
Presentation Number: 11P

Poster Title: snRNP200 reactive antibodies isolated from multiple AML patients show promise for targeted therapy
Authors: S. Baumann, M. Kedde, B. Monica, K. Maijoor, R. Schotte, A. Bakker, J. M. Koslowski, S. Gullà^[1]
Date and Time: 26 February, 17:15-18:15 CET
Session: Cocktail and Poster Display Session
Location: Hall Bordeaux
Presentation Number: 11P

^1. Kling Biotherapeutics, Amsterdam, Netherlands
^2. National Library of Medicine.

About Kling Biotherapeutics

Kling Biotherapeutics is a clinical-stage, privately held biotech company focused on discovery and development of antibody based therapeutics. The company is headquartered in Amsterdam, Netherlands with a fully owned IP portfolio that covers platform technologies Kling-Select and Kling-Evolve for the simultaneous discovery of novel targets and identification of fully human antibodies directly from patient-derived B cells.

Kling-Select relies on a fully-owned and clinically-validated B cell immortalization and screening technology to identify novel therapeutic targets and antibody binders from patients with exceptional clinical responses. This technology has successfully identified novel neutralising antibodies for various infectious diseases such as RSV (nirsevimab/Beyfortus), Covid, and Influenza. More recently, Kling-Select has been applied to peripheral and tumor-infiltrating B cells derived from cancer patients and produced a portfolio of novel and selective target-antibody pairs. The unbiased nature of this discovery platform allows identification of novel targets and unique epitopes inaccessible to traditional target discovery approaches.

Kling-Evolve enables the ex vivo affinity maturation of B cell clones against targets of interest. This powerful technology can be used for the rapid evolution of neutralizing antibodies against emerging viral variants or for affinity and selectivity improvement of oncology assets.

Kling Biotherapeutics is progressing a unique pipeline of oncology programs with KBA1412, a first-in-class CD9 antibody, being tested in a Phase 1 clinical trial. Details of the trial can be found on clinicaltrials.gov under identifier NCT05501821.

About ESMO

ESMO's core mission is to improve the quality of cancer care, from prevention and diagnosis all the way to palliative care and patient follow-up. It is to educate – doctors, cancer patients and the general public – on the best practices and latest advances in oncology. And it is to promote equal access to optimal cancer care for all patients.