Bispecific antibody targeting both B7-H3 and PD-L1 exhibits superior antitumor activities.

Clinical application of PD-1 and PD-L1 monoclonal antibodies (mAbs) is hindered by their relatively low response rates and the occurrence of drug resistance. Co-expression of B7-H3 with PD-L1 has been found in various solid tumors, and combination therapies that target both PD-1/PD-L1 and B7-H3 pathways may provide  additional therapeutic benefits. Up to today, however, no bispecific antibodies targeting both PD-1 and B7-H3 have reached the clinical development stage. In this study, we generated a stable B7-H3×PD-L1 bispecific antibody (BsAb) in IgG1-VHH format by coupling a humanized IgG1 mAb against PD-L1 with a humanized camelus variable domain of the heavy-chain of heavy-chain antibody (VHH) against human B7-H3. The BsAb exhibited favorable thermostability, efficient T cell activation, IFN-γ production, and antibody-dependent cell-mediated cytotoxicity (ADCC). In a PBMC humanized A375 xenogeneic tumor model, treatment with BsAb (10 mg/kg, i.p., twice a week for 6 weeks) showed enhanced antitumor activities compared to monotherapies and, to some degree, combination therapies. Our results suggest that targeting both PD-1 and B7-H3 with BsAbs increases their specificities to B7-H3 and PD-L1 double-positive tumors and induces a synergetic effect. We conclude that B7-H3×PD-L1 BsAb is favored over mAbs and possibly combination therapies in treating B7-H3 and PD-L1 double-positive tumors.

Intranasal delivery of replicating mRNA encoding hACE2-targeting antibody against SARS-CoV-2 Omicron infection in the hamster.

The Omicron variant is sweeping the world, which displays striking immune escape potential through mutations at key antigenic sites on the spike protein, making broad-spectrum SARS-CoV-2 prevention or therapeutical strategies urgently needed. Previously, we have reported a hACE2-targeting neutralizing antibody 3E8, which could efficiently block both prototype SARS-CoV-2 and Delta variant infections in prophylactic mouse models, having the potential of broad-spectrum to prevent SARS-CoV-2. However, preparation of monoclonal neutralizing antibodies is severely limited by the time-consuming process and the relative high cost. Here, we utilized a modified VEEV replicon with two subgenomic (sg) promoters engineered to express the light and heavy chains of the 3E8 mAb. The feasibility and protective efficacy of replicating mRNA encoding 3E8 against Omicron infection in the hamster were demonstrated through the lung targeting delivery with the help of VEEV-VRP. Overall, we developed a safe and cost-effective platform of broad-spectrum to prevent SARS-CoV-2 infection.

Development of a variant of dinutuximab with enhanced antitumor efficacy and reduced induction of neuropathic pain.

Dinutuximab (ch14.18) was the first approved monoclonal antibody against the tumor-associated antigen disialoganglioside GD2. Despite its success in treating neuroblastoma (NB), it triggers a significant amount of neuropathic pain in patients, possibly through complement-dependent cytotoxicity (CDC). We hypothesized that modifying ch14.18 using antibody engineering techniques, such as humanization, affinity maturation, and Fc engineering, may enable the development of next-generation GD2-specific antibodies with reduced neuropathic pain and enhanced antitumor activity. In this study we developed the H3-16 IgG1m4 antibody from ch14.18 IgG1. H3-16 IgG1m4 exhibited enhanced binding activity to GD2 molecules and GD2-positive cell lines as revealed by ELISA, and its cross-binding activity to other gangliosides was not altered. The CDC activity of H3-16 IgG1m4 was decreased, and the antibody-dependent cellular cytotoxicity (ADCC) activity was enhanced. The pain response after H3-16 IgG1m4 antibody administration was also reduced, as demonstrated using the von Frey test in Sprague-Dawley (SD) rats. In summary, H3-16 IgG1m4 may have potential as a monoclonal antibody with reduced side effects.

NGF monoclonal antibody DS002 alleviates chemotherapy-induced peripheral neuropathy in rats.

Chemotherapy-induced peripheral neuropathy (CIPN) is one of the pervasive side effects of chemotherapy, leading to poor quality of life in cancer patients. Discovery of powerful analgesics for CIPN is an urgent and substantial clinical need. Nerve growth factor (NGF), a classic neurotrophic factor, has been identified as a potential therapeutic target for pain. In this study, we generated a humanized NGF monoclonal antibody (DS002) that most effectively blocked the interaction between NGF and tropomyosin receptor kinase A (TrkA). We showed that DS002 blocked NGF binding to TrkA in a dose-dependent manner with an IC50 value of 6.6 nM; DS002 dose-dependently inhibited the proliferation of TF-1 cells by blocking the TrkA-mediated downstream signaling pathway. Furthermore, DS002 did not display noticeable species differences in its binding and blocking abilities. In three chemotherapy-induced rat models of CIPN, subcutaneous injection of DS002 produced a significant prophylactic effect against paclitaxel-, cisplatin- and vincristine-induced peripheral neuropathy. In conclusion, we demonstrate for the first time that an NGF inhibitor effectively alleviates pain in animal models of CIPN. DS002 has the potential to treat CIPN pain in the clinic.