Preclinical Analysis of JAA-F11, a Specific Anti–Thomsen-Friedenreich Antibody via Immunohistochemistry and In Vivo Imaging

Abstract

The tumor specificity of JAA-F11, a novel monoclonal antibody specific for the Thomsen-Friedenreich cancer antigen (TF-Ag-alpha linked), has been comprehensively studied by in vitro immunohistochemical (IHC) staining of human tumor and normal tissue microarrays and in vivo biodistribution and imaging by micro-positron emission tomography imaging in breast and lung tumor models in mice. The IHC analysis detailed herein is the comprehensive biological analysis of the tumor specificity of JAA-F11 antibody performed as JAA-F11 is progressing towards preclinical safety testing and clinical trials. Wide tumor reactivity of JAA-F11, relative to the matched mouse IgG3 (control), was observed in 85% of 1269 cases of breast, lung, prostate, colon, bladder, and ovarian cancer. Staining on tissues from breast cancer cases was similar regardless of hormonal or Her2 status, and this is particularly important in finding a target on the currently untargetable triple-negative breast cancer subtype. Humanization of JAA-F11 was recently carried out as explained in a companion paper “Humanization of JAA-F11, a Highly Specific Anti–Thomsen-Friedenreich Pancarcinoma Antibody and In Vitro Efficacy Analysis” (Neoplasia 19: 716-733, 2017), and it was confirmed that humanization did not affect chemical specificity. IHC studies with humanized JAA-F11 showed similar binding to human breast tumor tissues. In vivo imaging and biodistribution studies in a mouse syngeneic breast cancer model and in a mouse-human xenograft lung cancer model with humanized 124I- JAA-F11 construct confirmed in vitro tumor reactivity and specificity. In conclusion, the tumor reactivity of JAA-F11 supports the continued development of JAA-F11 as a targeted cancer therapeutic for multiple cancers, including those with unmet need.

The challenges of glycan recognition with natural and artificial receptors

“…21 Tumour-associated carbohydrates, such as the Tn (GalNAca1-Ser/Thr), Sialyl-Tn, (Siaa2-3GalNAca1-Ser/Thr), and the Thomsen-Friedenreich (TF) antigen (Galb1-3GalNAca1-Ser/Thr), have been particularly targeted for AGA development. 63,64 There is also a good number of AGAs for ABH blood group antigens, Lewis antigens and glycolipids. [65][66][67] Indeed, these developed antibodies are either currently in clinical trials or already employed in disease treatment.…”

Antibody-Drug Conjugates Targeting Tumor-Specific Mucin Glycoepitopes

“…Indeed, when conjugated to the microtubulin inhibitor DM1 (N2 ′ -deacetyl-N2 ′ -(3-mercapto-1-oxopropyl)-maytansine), the hJAA-F11 H2aL2a-DM1 ADC demonstrated in vitro cytotoxic activity against various triple negative human breast cancer and lung cancer cell lines and significantly reduced MDA-MB-231 tumor growth in a mouse xenograft model [71]. This ADC has the potential to treat a significant number of patients, given the widespread expression of the T-antigen (up to 80% positive breast tumors) and its expression by a variety of cancer types including breast, lung, prostate, colon, bladder, and ovarian cancers [69,70]. Although the ability to kill xenografted tumors appears quite promising, this effect required an intense dose regimen (15 mg/kg 3 times a week for the first week followed by weekly injections for 5 weeks) and the study did not include a non-targeting ADC raising concerns of the specific efficacy of antibodymediated tumor killing in this study [71].…”

Targeting cancer metastasis with antibody therapeutics

“…Immunization of mice with a TF‐Ag fusion protein led to discovery of a murine mAb denoted JAA‐F11 that specifically recognizes TF‐Ag on tumor cells, but does not recognize this disaccharide structure on normal tissues and natural killer (NK) cells (Chaturvedi et al, 2008; Heimburg et al, 2006; Karacosta et al, 2018; Rittenhouse‐Diakun et al, 1998). JAA‐F11 thus circumvents the off‐target binding complications observed in clinical trials with a previously isolated anti‐TF‐Ag antibody denoted 170H.82 (Ferguson et al, 2014; McQuarrie et al, 1997).…”

“…H2aL2a effectively inhibited breast cancer cell adhesion to human endothelial cells, and also significantly reduced tumor growth in a mouse xenograft model of breast cancer (Tati et al, 2017). Moreover, in a mouse syngeneic breast cancer model and a mouse xenograft lung cancer model, H2aL2a specifically localized to the tumor and persisted at the tumor site for more than 7 days (Karacosta et al, 2018). These biodistribution results support future clinical development of H2aL2a as a candidate antibody therapeutic that specifically targets cancer metastasis.…”