The anti-tumor efficacy of different FGFR2-ADC BAY 1187982 treatment schedules on MFM-223 human TNBC mouse model.

The FGFR2-ADC BAY 1187982 inhibits microtubule polymerization resulting in induction of apoptosis.

The expression of FGFR2 on tumor cell surface and half maximal inhibitory concentration of cell viability for FGFR2-ADC BAY 1187982 and control ADC.

Supplementary Materials and Methods and Supplementary Figure Legends

Fibroblast growth factor receptor (FGFR) 2 is overexpressed in several tumor types, including triple-negative breast cancer and gastric cancer, both of which have a high unmet medical need. Aprutumab ixadotin (BAY 1187982) is the first antibody–drug conjugate (ADC) to target FGFR2 and the first to use a novel auristatin-based payload. This first-in-human trial was conducted to determine the safety, tolerability, and maximum tolerated dose (MTD) of aprutumab ixadotin in patients with advanced solid tumors from cancer indications known to be FGFR2-positive. In this open-label, multicenter, phase I dose-escalation trial (NCT02368951), patients with advanced solid tumors received escalating doses of aprutumab ixadotin (starting at 0.1 mg/kg body weight), administered intravenously on day 1 of every 21-day cycle. Primary endpoints included safety, tolerability, and the MTD of aprutumab ixadotin; secondary endpoints were pharmacokinetic evaluation and tumor response to aprutumab ixadotin. Twenty patients received aprutumab ixadotin across five cohorts, at doses of 0.1–1.3 mg/kg. The most common grade ≥ 3 drug-related adverse events were anemia, aspartate aminotransferase increase, proteinuria, and thrombocytopenia. Dose-limiting toxicities were thrombocytopenia, proteinuria, and corneal epithelial microcysts, and were only seen in the two highest dosing cohorts. The MTD was determined to be 0.2 mg/kg due to lack of quantitative data following discontinuations at 0.4 and 0.8 mg/kg doses. One patient had stable disease; no responses were reported. Aprutumab ixadotin was poorly tolerated, with an MTD found to be below the therapeutic threshold estimated preclinically; therefore, the trial was terminated early. NCT02368951.

Abstract Background: FGFR2-ADC (BAY 1187982) consists of an anti-FGFR2 antibody (BAY 1179470) and a stably linked, highly potent and non-cell permeable microtubule-binding auristatin toxophore. A phase I study was conducted in patients (pts) with advanced solid tumors focusing on tumor types with a described expression of FGFR2. Methods: Eligible pts with solid tumors, known to express FGFR2 and refractory to standard treatment, adequate organ function, and ECOG performance status (PS) ≤ 1 were enrolled. BAY 1187982 was administered by an one hour intravenous infusion on an every 21 days (q3w) schedule in 20 pts (5 cholangiocarcinoma, 5 colon, 2 gastric, 2 breast cancer and 6 others) at doses ranging from 0.1 to 1.3 mg/kg. Dose escalation followed the continous reassessment design treating 3-4 pts per cohort. Pts were assessed for AEs weekly in C1-C3 and on D1 in subsequent cycles. Tumor response was assessed every 6 weeks. Blood samples for a full pharmacokinetic profile were collected after dosing on D1 of C1 and C3 and thereafter every second cycle pre-dose and at the end of infusion. Results: A total of 20 pts were evaluable: 55% female, mean age 52 yrs (range 24-76), PS 0/1 75% / 25%. No drug-related serious adverse events were reported at dose levels 0.1 and 0.2 mg/kg. At 0.4 mg/kg drug-related serious adverse events were similar to other ADCs, including reversible asymptomatic liver function test increases, and gastrointestinal disorders. Dose limiting toxicities (DLTs) were observed at dose level 0.8 and 1.3 mg/kg, respectively: 0.8 mg/kg cohort grade 3 thrombocytopenia (N=1); 1.3 mg/kg cohort grade 3 corneal epitheliopathy (N=1), grade 4 thrombocytopenia (N=1) and proteinuria progressing to nephrotic syndrome after treatment in C2 or C3 (N=2) with signs of reversibility after discontinuation. In dose level 0.4 and 0.8 mg/kg the majority of pts discontinued study drug treatment already in C1 or C2 due to disease progression and data on proteinuria at these dose levels were absent or spare. As a consequence only doses below 0.4 mg/kg were considered safe. Exposures of BAY 1187982 increased in a dose-proportional manner in the investigated dose range from 0.1 to 1.3 mg/kg. Conclusion: While this drug was tolerated well at lower dose levels, dose-limiting toxicities occurred below the expected therapeutic dose level. As the predicted human efficacious dose level based on the majority of animal models was above 0.4 mg/kg (Wittemer-Rump et al. AACR; Cancer Res 2015;75, 15 Suppl: Abstract nr 1683) a Phase II dose cannot be recommended and a successful clinical development of the compound was regarded as unlikely. The data from the preclinical safety analysis in monkey and rat will be submitted as abstract to AACR 2017. Citation Format: Sung-Bae Kim, Funda Meric-Bernstam, Jordan Berlin, Sabine Wittemer-Rump, Motonobu Osada, Ray Valencia, Aleksei Babich, Rong Liu, Andy Hwang, Takahiko Tanigawa, Frank Reetz, Dirk Laurent, Aparna Kalyan. Phase I study of fibroblast growth factor receptor 2 antibody-drug conjugate (FGFR2-ADC) BAY 1187982 in patients with advanced cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT094. doi:10.1158/1538-7445.AM2017-CT094

Abstract 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.

Abstract Antibody-drug conjugates (ADC) represent a promising therapeutic approach for treatment of cancer. We have developed a novel ADC directed against fibroblast growth factor receptor 2 (FGFR2). FGFR2 is overexpressed in several cancer indications, such as gastric, breast, and ovarian cancer and thus represents a potential therapeutic target for treatment of FGFR2-positive cancer patients with ADC-based therapy. FGFR2-ADC consists of a fully human anti-FGFR2-Ab (BAY 1179470) conjugated via a stable linker to a novel auristatin cytotoxic agent licensed from Seattle Genetics. FGFR2-ADC exhibits low nM to sub-nM potency in vitro in a panel of FGFR2-positive cancer cells lines (SNU-16, MFM-223, NCI-H716) while being inactive against FGFR2-low or -negative cell lines (MDA-MB-231, HEK-293, BaF/3) and highly selective versus a control ADC. FGFR2-ADC is highly efficacious in monotherapy and results in tumor growth inhibition in the gastric cancer xenograft model SNU-16 and tumor regression in the breast cancer xenograft model MFM-223. FGFR2-ADC induces tumor stasis in the colorectal cancer xenograft model NCI-H716 and regrown tumors are sensitive to a second treatment cycle of FGFR2-ADC. FGFR2-ADC shows high efficacy in vivo in monotherapy in patient-derived (PDX) FGFR2-positive murine xenograft models, e.g. in the ovarian cancer model OV30-0511A. FGFR2-ADC is also efficacious in the gastric cancer PDX model GC10-0608 and the breast cancer model MAXF857. The toxophore metabolite of FGFR2-ADC was more than 30-fold enriched in tumors versus other organs (liver, spleen, kidneys) in NCI-H716 tumor-bearing mice. Based on the preclinical efficacy, PK and tolerability data, evaluation of FGFR2-ADC in cancer patients appears warranted. A Phase I study is planned. Citation Format: Anette Sommer, Charlotte Kopitz, Christoph Schatz, Ruprecht Zierz, Joachim Schuhmacher, Sabine Wittemer-Rump, Klaas Prins, Manuela Braun, Frank Reetz, Bertolt Kreft, Hung T. Huynh, Karl Ziegelbauer. Preclinical anti-tumor efficacy of FGFR2-ADC BAY 1187982 in patient-derived gastric, breast and ovarian cancer models. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1684. doi:10.1158/1538-7445.AM2015-1684

Abstract 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) 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

Abstract Antibody-drug conjugates (ADCs) represent a promising therapeutic approach for treatment of cancer. We have developed a novel ADC directed against fibroblast growth factor receptor 2 (FGFR2). FGFR2 is overexpressed in several cancer indications, such as gastric cancer and breast cancer, thus representing an interesting therapeutic target for the treatment of FGFR2 positive cancer patients with an ADC-based therapy. The FGFR2-ADC consists of the fully human anti-FGFR2-mAb BAY 1179470 conjugated via a stable linker to a novel auristatin cytotoxic agent (technology licensed from Seattle Genetics). The FGFR2-mAb BAY 1179470, which is cross-reactive with human, mouse, rat and monkey, induces internalization of FGFR2. Quantitative data on FGFR2 antibody bound per cell (ABC) were determined with the QuantiBrite assay using BAY 1179470. FGFR2-ADC has a potency in the single digit nM to sub nM range in a panel of FGFR2-positive cells lines (e.g., SNU-16, KatoIII, SUM52-PE, MFM-223) and shows more than 100-fold selectivity versus FGFR2-negative cell lines. High levels of FGFR2 on cancer cells correlate with internalization efficacy and cytotoxic activity in vitro. FGFR2-ADC is highly efficacious in monotherapy and results in tumor growth inhibition in the gastric cancer xenograft model SNU-16 and tumor regression in the breast cancer xenograft model MFM-223. At doses efficacious in mice, FGFR2-ADC is well tolerated. The pre-clinical efficacy and tolerability data obtained for FGFR2-ADC suggest a therapeutic index and support clinical testing. Citation Format: Anette Sommer, Carl F. Nising, Christoph Mahlert, Charlotte C. Kopitz, Hans-Georg Lerchen, Simone Greven, Beatrix Stelte-Ludwig, Joachim Schuhmacher, Ruprecht Zierz, Sabine Wittemer-Rump, Christoph Schatz, Frank Reetz, Heiner Apeler, Rolf Jautelat, Bertolt Kreft, Karl Ziegelbauer. FGFR2-ADC potently and selectively inhibits growth of gastric and breast cancer xenograft models. [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 4491. doi:10.1158/1538-7445.AM2014-4491