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AKS-452 is a biologically-engineered vaccine comprising an Fc fusion protein of the SARS-CoV-2 viral spike protein receptor binding domain antigen (Ag) and human IgG1 Fc (SP/RBD-Fc) in clinical development for the induction and augmentation of neutralizing IgG titers against SARS-CoV-2 viral infection to address the COVID-19 pandemic. The Fc moiety is designed to enhance immunogenicity by increasing uptake via Fc-receptors (FcγR) on Ag-presenting cells (APCs) and prolonging exposure due to neonatal Fc receptor (FcRn) recycling. AKS-452 induced approximately 20-fold greater neutralizing IgG titers in mice relative to those induced by SP/RBD without the Fc moiety and induced comparable long-term neutralizing titers with a single dose vs. two doses. To further enhance immunogenicity, AKS-452 was evaluated in formulations containing a panel of adjuvants in which the water-in-oil adjuvant, Montanide™ ISA 720, enhanced neutralizing IgG titers by approximately 7-fold after one and two doses in mice, including the neutralization of live SARS-CoV-2 virus infection of VERO-E6 cells. Furthermore, ISA 720-adjuvanted AKS-452 was immunogenic in rabbits and non-human primates (NHPs) and protected from infection and clinical symptoms with live SARS-CoV-2 virus in NHPs (USA-WA1/2020 viral strain) and the K18 human ACE2-trangenic (K18-huACE2-Tg) mouse (South African B.1.351 viral variant). These preclinical studies support the initiation of Phase I clinical studies with adjuvanted AKS-452 with the expectation that this room-temperature stable, Fc-fusion subunit vaccine can be rapidly and inexpensively manufactured to provide billions of doses per year especially in regions where the cold-chain is difficult to maintain.

Background Treatment of diabetes mellitus (DM) in cats typically requires insulin injections q12h‐q24h, posing a major compliance barrier for caregivers. Novel treatments enabling decreased injection frequency while maintaining safety are highly desirable. Insulin fused with feline immunoglobulin fragment crystallizable (Fc) has an ultra‐long plasma half‐life because it recycles through cells where it is protected from proteolysis. Hypothesis Glycemic control can be achieved in diabetic cats with a recombinant fusion protein of a synthetic insulin and feline Fc (AKS‐267c) administered SC weekly. Animals Five cats with spontaneous DM. Methods Cats previously controlled using insulin glargine q12h were transitioned to once‐weekly injection of AKS‐267c. The dose of AKS‐267c was titrated weekly for 7 weeks based on continuous glucose monitoring. Clinical signs, body weight, fructosamine concentrations, and mean interstitial glucose concentrations (IG) were compared between baseline (week 0, on insulin glargine) and the last week of treatment. Data were assessed for normality and compared using parametric or nonparametric paired tests (as appropriate). Results After 7 weeks of once‐weekly injections, compared to baseline, there were no significant changes in clinical signs, body weight (median [range] gain, 0.1 kg [−0.1 to +0.7]; P = .5), fructosamine (−60 mmol/L [−338 to +206]; P = .6), and mean IG concentrations (change = −153 mmol/L [−179 to +29]; P = .3), and no adverse reactions were reported. Conclusion Successful control of clinical signs and maintenance of glycemia was achieved with this once‐weekly novel insulin treatment. The efficacy and safety of this novel formulation should be further assessed in a large clinical trial.

A link between obesity, metabolic dysfunction, and an increased risk in cancer mortality has been well established in several cancer types including, breast, colon, pancreatic, and prostate cancers. A likely mechanism driving this elevated risk is the associated increase in circulating insulin and insulin-like growth factor (IGF), which are known promoters of cancer growth and have been linked to shorter progression-free survival, and increased risk of metastatic disease and death in breast cancer patients. IGF receptor (IGF1R) targeting has been unsuccessful as insulin receptor (IR) also is functional in breast cancers. To address IR targeting, Akston Biosciences developed a novel insulin-Fc fusion protein (AKS-130) with the goal of lowering patient blood glucose levels without causing clinical hypoglycemia. AKS-130 was also found to downregulate IR expression in models of colon cancer (HCT-116) and malignant melanoma (WM266.4). Further, AKS-130 suppressed xenograft growth in fed and fasted states. We examined if AKS-130 had similar effects on estrogen receptor (ER) positive breast cancer cells as ER+ breast cancers may have elevated expression or activation of IGF1R and IR. Data from our lab show that development of endocrine therapy resistance in ER+ breast cancer cell lines is associated with loss of IGF1R expression and subsequently increased sensitivity to insulin signaling, which supports overlapping pro-tumorigenic signaling pathways to IGF1R. To test the hypothesis that resistance to endocrine therapy increases the reliance of ER+ breast cancer cells on IR signaling, we used the ER+ breast cancer cell line, MCF-7L, and a Tam resistant derivative, MCF-7L TamR, to assess IR/IGF1R activation and growth in response to AKS-130. Similar to HCT-116 and WM266.4 cells, MCF-7L parental and TamR cells showed that AKS-130 was an agonist of IR. But after 72 hours of exposure, a marked reduction in IR was seen and associated with partially suppressed downstream signaling to Akt. Interestingly, AKS-130 induced proliferation at similar levels to insulin treatment in MCF-7L parental cells at three and five days post treatment. However, pre-treatment of cells with AKS-130 suppressed further insulin-stimulated growth in MCF-7L TamR cells. Ongoing studies are evaluating the effects of AKS-130 on ER+ breast cancer xenografts in vivo to determine if the ability of the drug to downregulate IR expression results in decreased tumor growth. Taken together these data show that novel agents, such as AKS-130, can target IR function in cancer cells. AKS-130 is a drug which may serve as way to disrupt IR in cancer cells without affecting host glucose metabolism. Targeting of IR signaling may represent a new strategy to overcome endocrine therapy resistance in breast cancer. Citation Format: Lynsey M Fettig, Xihong Zhang, Kelly LaPara, Sylaja Murikipudi, Andrea R Delpero, Thomas M Lancaster, Todd C Zion, Douglas Yee. A novel long-acting insulin for cancer therapy reduces xenograft tumor growth [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P1-21-05.

Partial or even complete cancer regression can be achieved in some patients with current cancer treatments. However, such initial responses are almost always followed by relapse, with the recurrent cancer being resistant to further treatments. The discovery of therapeutic approaches that counteract relapse is, therefore, essential for advancing cancer medicine. Cancer cells are extremely heterogeneous, even in each individual patient, in terms of their malignant potential, drug sensitivity, and their potential to metastasize and cause relapse. Indeed, hypermalignant cancer cells, termed cancer stem cells or stemness-high cancer cells, that are highly tumorigenic and metastatic have been isolated from cancer patients with a variety of tumor types. Moreover, such stemness-high cancer cells are resistant to conventional chemotherapy and radiation. Here we show that BBI608, a small molecule identified by its ability to inhibit gene transcription driven by Stat3 and cancer stemness properties, can inhibit stemness gene expression and block spherogenesis of or kill stemness-high cancer cells isolated from a variety of cancer types. Moreover, cancer relapse and metastasis were effectively blocked by BBI608 in mice. These data demonstrate targeting cancer stemness as a novel approach to develop the next generation of cancer therapeutics to suppress cancer relapse and metastasis.

Endothelial cells (EC) are potent bioregulatory cells, modulating thrombosis, inflammation and control over mural smooth muscle cells and vascular health. The biochemical roles of EC are retained when cells are embedded within three-dimensional (3D) denatured collagen matrices. Though substrate mechanics have long been known to affect cellular morphology and function and 3D-EC systems are increasingly used as therapeutic modalities little is known about the effect of substrate mechanics on EC in these 3D systems. In this work, we examined the effect of isolated changes in modulus on EC growth and morphology, extracellular matrix gene expression, modulation of smooth muscle cell growth, and immunogenicity. EC growth, but not morphology was dependent on scaffold modulus. Increased scaffold modulus reduced secretion of smooth muscle cell growth inhibiting heparan sulfate proteoglycans (HSPGs), but had no effect on secreted growth factors, resulting in a loss of smooth muscle cell growth inhibition by EC on high modulus scaffolds. Expression of ICAM-1, VCAM-1 and induction of CD4[superscript +] T cell proliferation was reduced by increased scaffold modulus, and correlated with changes in integrin α5 expression. Expression of several common ECM proteins by EC on stiffer substrates dropped, including collagen IV(α1), collagen IV(α5), fibronectin, HSPGs (perlecan and biglycan). In contrast, expression of elastin and TIMPs were increased. This work shows even modest changes in substrate modulus can have a significant impact on EC function in three-dimensional systems. The mechanism of these changes is not clear, but the data presented here within suggests a model wherein EC attempt to neutralize changes in environmental force balance by altering ECM and integrin expression, leading to changes in effects on downstream signaling and function., National Institutes of Health (U.S.) (R01 GM49039), Else Kroner-Fresenius Stiftung (P36/07//A45/07)

Cancer cells are extremely heterogeneous, even in each individual patient, in terms of their malignant potential, drug-senstivity, and their potential to metastasize and cause relapse. Subpopulations of cancer cells with extremely high tumorigenic potential have been isolated from cancer patients with a variety of tumor types and found to have high stemness properties termed cancer stem cells. These stemness-high cancer cells are extremely tumorigenic and are resistant to conventional therapeutics due to activation of pro-survival and anti-apoptotic pathways, overexpression of drug efflux pumps, and increased DNA repair capacity. Moreover, chemotherapy and radiation have been found to induce stemness genes in cancer cells, converting stemness-low cancer cells to stemness-high cancer cells. Such highly tumorigenic and drug-resistant stemness-high cancer stem cells are, therefore, likely to be “left-over” following chemotherapy or radiotherapy and ultimately responsible for relapse. We hypothesized that cancer stemness inhibition is sufficient to suppress metastasis and relapse. Stemness, initially defined by the expression of stem cells genes, is a property shared by embryonic stem cells and adult stem cells. It has been demonstrated that the gene expression profiles of cancer stem cells more closely resemble embryonic stem cells than adult stem cells, suggesting the feasibility to identify molecular targets that are required for cancer stemness, but not (or less so) by normal adult stem cells. Through gene-silencing approaches, we have identified Stat3 as critically important for maintaining cancer stemness, yet largely dispensable for adult stem cells. Here we show that BBI608, a small molecule identified by its ability to inhibit gene-transcription driven by Stat3 and cancer cell stemness properties, displays anticancer properties that are highly different from chemotherapeutics agents. Stemness-high cancer cells enriched by multiple techniques are resistance to chemotherapeutics, yet highly sensitive to the stemness inhibitor BBI608. Blockade of spherogenesis and reduction of stemness gene expression by BBI608 were observed in stemness-high cancer cells isolated from a variety of cancer types. While treatment of xenografted tumor models with chemotherapeutics enriched stemness-high cancer cells, BBI608 induced significant depletion of stemness-high populations in vivo. Moreover, the inhibition of stemness by BBI608 is sufficient to suppress cancer relapse and metastasis in xenografted human cancers in mice. These data demonstrate targeting cancer stemness as an effective way to suppress cancer relapse and metastasis. Citation Format: Youzhi Li, Harry A. Rogoff, Sarah Keates, Yuan Gao, Sylaja Murikipudi, Keith Mikule, David Leggett, Wei Li, Arthur Pardee, Chiang J. Li. Inhibition of stemness by BBI608 is sufficient to suppress cancer relapse and metastasis. [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 LB-253. doi:10.1158/1538-7445.AM2015-LB-253