Frank Dittmer

Preclinical efficacy of the auristatin-based antibody-drug conjugate BAY 1187982 for the treatment of FGFR2-positive solid tumors.

The fibroblast growth factor receptor FGFR2 is overexpressed in a variety of solid tumors, including breast, gastric, and ovarian tumors, where it offers a potential therapeutic target. In this study, we present evidence of the preclinical efficacy of BAY 1187982, a novel antibody-drug conjugate (ADC). It consists of a fully human FGFR2 monoclonal antibody (mAb BAY 1179470), which binds to the FGFR2 isoforms FGFR2-IIIb and FGFR2-IIIc, conjugated through a noncleavable linker to a novel derivative of the microtubule-disrupting cytotoxic drug auristatin (FGFR2-ADC). In FGFR2-expressing cancer cell lines, this FGFR2-ADC exhibited potency in the low nanomolar to subnanomolar range and was more than 100-fold selective against FGFR2-negative cell lines. High expression levels of FGFR2 in cells correlated with efficient internalization, efficacy, and cytotoxic effects in vitro Pharmacokinetic analyses in mice bearing FGFR2-positive NCI-H716 tumors indicated that the toxophore metabolite of FGFR2-ADC was enriched more than 30-fold in tumors compared with healthy tissues. Efficacy studies demonstrated that FGFR2-ADC treatment leads to a significant tumor growth inhibition or tumor regression of cell line-based or patient-derived xenograft models of human gastric or breast cancer. Furthermore, FGFR2 amplification or mRNA overexpression predicted high efficacy in both of these types of in vivo model systems. Taken together, our results strongly support the clinical evaluation of BAY 1187982 in cancer patients and a phase I study (NCT02368951) has been initiated. Cancer Res; 76(21); 6331-9. ©2016 AACR.

Identification and function probing of an antithrombin IIIβ conformation-specific antibody.

Essentials Antithrombin III (AT)β binds heparin with higher affinity than ATα. A conformation‐specific antibody against ATβ, TPP2009, was made to investigate ATβ in hemostasis. TPP2009 bound specifically to heparin–ATβ and greatly reduced the anticoagulant effect of AT. This antibody was effective in elucidating the importance of ATβ in hemostasis.

Abstract DDT02-01: In vitro and in vivo characterization of a novel anti-fibroblast growth factor receptor (FGFR) 2 antibody (BAY 1179470) for the treatment of gastric cancer

Proceedings: AACR Annual Meeting 2014; April 5-9, 2014; San Diego, CA Gastric cancer is the second most common cause of cancer-related mortality worldwide, thus new treatment options are urgently needed. In a subset of gastric cancers, over-expression of fibroblast growth factor receptor 2 (FGFR2), a receptor tyrosine kinase, has been described and may represent a potential therapeutic target for the treatment of FGFR2-positive gastric cancer patients. To this end, we have generated a fully human anti-FGFR2 antibody (BAY 1179470) using the BioInvent Phage Display library. BAY 1179470 binds to a unique FGFR2-specific epitope that is present in all FGFR2 isoforms. Upon binding to FGFR2, BAY 1179470 induces receptor dimerization, internalization and degradation, resulting in significant tumor growth inhibition in vivo in cell line-based and patient-derived gastric cancer models overexpressing FGFR2. Additive anti-tumor efficacy in vivo was achieved by combining BAY 1179470 with either cisplatin or paclitaxel. BAY 1179470 is fully cross-reactive with FGFR2 orthologues of mouse, rat, pig, cynomolgus monkey and rhesus macaque. No significant safety findings have been seen in animal studies. Thus, BAY 1179470 represents a novel anti-FGFR2 antibody with high anti-tumor activity in gastric cancer models and an excellent preclinical safety profile. BAY 1179470 is currently being tested in a first-in-man study in all-comers ([NCT01881217][1]) in Japan. Citation Format: Charlotte Kopitz, Anette Sommer, Stefanie Hammer, Axel Harrenga, Beatrix Stelte-Ludwig, Frank Dittmer, Frank Reetz, Ekkehard May, Ruprecht Zierz, Sabine Wittemer-Rump, Christoph Schatz, H. T. Huynh, Karl Ziegelbauer, Bertolt Kreft. In vitro and in vivo characterization of a novel anti-fibroblast growth factor receptor (FGFR) 2 antibody (BAY 1179470) for the treatment of gastric cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr DDT02-01. doi:10.1158/1538-7445.AM2014-DDT02-01 [1]: /lookup/external-ref?link_type=CLINTRIALGOV&access_num=NCT01881217&atom=%2Fcanres%2F74%2F19_Supplement%2FDDT02-01.atom

Abstract 5445: Preclinical anti-tumor efficacy of an anti-C4.4a (LYPD3) antibody drug conjugate for the treatment of lung squamous cell carcinoma

C4.4a (LYPD3) has been identified previously as a cancer- and metastasis-associated internalizing cell surface protein. Targeting C4.4a with a specific antibody-drug conjugate (ADC) represents an unique opportunity to treat tumors with high unmet medical need such as squamous cell carcinomas SCC, in particular lung SCC. We have generated an anti-C4.4a ADC consisting of a fully human monoclonal antibody linked to a non cell-permeable tubulin-binding auristatin cytotoxic agent (technology licensed from Seattle Genetics). In vitro, anti-C4.4a ADC showed an anti-proliferative efficacy (IC50) in the nanomolar range in cell lines endogenously expressing C4.4a (e.g. human lung cancer cell lines NCI-H292 and NCI-H322). High ADC stability and selectivity was observed in transfected A549 lung cancer cells over-expressing C4.4a compared to mock-transfected cells. In vivo, anti-C4.4a ADC exhibited a potent and selective antitumor activity in various human xenograft models (NCI-H292, NCI-H322, SCC-4) as well as in two SCC (Lu7433, Lu7343) and one pleomorphic (Lu7064) patient-derived lung cancer xenograft models. The in vivo efficacy is strictly target-dependent and selective as no efficacy was observed in C4.4a negative models (Fadu, Lu 7700) or using a non-specific isotype antibody ADC (NCI-H292, NCI-H322). A minimal effective dose (MED) as low as 1.9 mg/kg, response rates of up to 100%, and additive anti-tumor efficacy in combination with cisplatin were observed in the NCI-H292 xenograft model. Furthermore, it has been demonstrated that NCI-H292 were still sensitive to ADC treatment when tumors were allowed to regrow after the initial treatment cycle(). The anti-C4.4a ADC, which is fully cross-reactive with the mouse orthologue of C4.4a, was well tolerated at efficacious doses. Reversible skin reddening was observed only at doses markedly higher than the MED. In summary, anti-C4.4a ADC is a promising therapeutic candidate for the treatment of C4.4a-expressing squamous cell carcinomas, andpreclinical development has been initiated. Citation Format: Joerg Willuda, Lars Linden, Hans-Georg Lerchen, Charlotte Kopitz, Sven Golfier, Ute Bach, Joachim Schumacher, Beatrix Stelte-Ludwig, Oliver Von Ahsen, Claudia Schneider, Frank Dittmer, Rudolf Beier, Sherif El-Sheik, Jan Tebbe, Gabriele Leder, Heiner Apeler, Rolf Jautelat, Bertolt Kreft, Karl Ziegelbauer. Preclinical anti-tumor efficacy of an anti-C4.4a (LYPD3) antibody drug conjugate for the treatment of lung squamous cell carcinoma. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5445. doi:10.1158/1538-7445.AM2014-5445