Safety and Immunogenicity of Recombinant Human Thrombin: A Pooled Analysis of Results from 10 Clinical Trials

Thrombin and Thrombin-Incorporated Biomaterials for Disease Treatments

Thrombin, a coagulation-inducing protease, has long been used in the hemostatic field. During the past decades, many other therapeutic uses of thrombin have been developed. For instance, burn treatment, pseudoaneurysm therapy, wound management, and tumor vascular infarction (or tumor vasculature blockade therapy) can all utilize the unique and powerful function of thrombin. Based on their therapeutic effects, many thrombin-associated products have been certificated by the Food and Drug Administration, including bovine thrombin, human thrombin, recombinant thrombin, fibrin glue, etc. Besides, several thrombin-based drugs are currently undergoing clinical trials. In this article, the therapeutic uses of thrombin (from the initial hemostasis to the latest cancer therapy), the commercially available drugs associated with thrombin, and the pros and cons of thrombin-based therapeutics (e.g., adverse immune responses related to bovine thrombin, thromboinflammation, and vasculogenic "rebounds") are summarized. Further, the current challenges and possible future research directions of thrombin-incorporated biomaterials and therapies are discussed. It is hoped that this review may provide a valuable reference for researchers in this field and help them to design safer and more effective thrombin-based drugs for fighting against various intractable diseases.

DNA-nanorobot-guided thrombin-inducing tumor infarction: raising new potential clinical concerns

DNA-nanorobot-guided thrombin-inducing tumor infarction (DNA NanorobotTh-ITI) is emerging as a powerful therapeutic strategy for treatment of solid cancers. The technology represents a major advance in the application of DNA nanotechnology for anticancer therapy. More importantly, the technology is being translated from preclinical studies to the clinic owing to its promising anticancer effects with fewer toxicities demonstrated in preclinical settings. However, despite these beneficial effects of the technology, it is important to point out that some important potential clinical concerns remain to be addressed. Here, we raise these clinical concerns along with these beneficial effects of the technology. Hopefully, these newly raised potential clinical concerns could drive forward research in this field to expedite its clinical translation.

Adverse drug reactions of Yunnan Baiyao capsule: a multi-center intensive monitoring study in China

Background

Yunnan Baiyao capsule (YBC), a marketed herbal medicine in mainland China, is widely used to control bleeding. This study's aim was to determine the occurrence of YBC-related adverse drug reactions (ADRs) among users of the medicine.

Methods

This hospital-intensive monitoring study was conducted in 163 hospitals across China. Consumers who used YBC (Z53020799) between June 2015 and December 2016 were included. By face-to-face interview or telephone, the circumstances and experiences of their adverse events (AEs), during drug taking and 14 days after drug withdrawal, were recorded at follow-up and later encoded by International Conference on Harmonisation (ICH) 1997. The Naranjo Adverse Reaction Probability Scale (APS) was used to determine the likelihood of ADRs.

Results

A total of 31,556 participants were included (follow-up rate 99.40%). AEs occurred in 742 participants, of which 561 were reported as "not related with drug use" by their physician-in-charge. Based on the remaining 181 cases, the overall ADR incidence was 1.17% (intention to treat) and 0.58% (per protocol), with abnormal findings mainly concentrated in the digestive system, skin and respiratory system. The top 5 frequently reported reactions were nausea and vomiting (0.1785%, 56 cases of 31,367 participants), functional diarrhea (0.1180%, 37 of 31,367 participants), stomach discomfort (0.0893%, 28 of 31,367 participants), rash (0.0574%, 18 of 31,367 participants) and gastro-esophageal reflux (0.0383%, 12 of 31,367 participants). Among them, functional diarrhea and stomach discomfort were judged as definite ADRs of YBC.

Conclusions

In this large study, treatment of YBC was found to be associated with ADRs with an incidence of 1.17%, although most were relatively mild and not considered to be life-threatening.

A totally recombinant human fibrin sealant

BACKGROUND

Applications of plasma-derived human fibrin sealants (pdhFS) have been limited because of cost, limited supply of pathogen-screened plasma, the need for bioengineering improvements, and regulatory issues associated with federal approval. We describe a totally recombinant human fibrin sealant (rhFS), which may engender an abundant, safe, and cost-effective supply of efficacious fibrin sealant.

MATERIALS AND METHODS

A first-generation rhFS made from recombinant human fibrinogen (rhFI; produced in the milk of transgenic cows), activated recombinant human factor XIII (rhFXIIIa; produced in yeast), and recombinant human thrombin (rhFIIa; purchased, made in animal cell culture) was formulated using thromboelastography (TEG). The hemostatic efficacy of rhFS versus commercial pdhFS was compared in a nonlethal porcine hepatic wedge excision model.

RESULTS

The maximal clot strength of rhFS measured in vitro by TEG was not statistically different than that of pdhFS. TEG analysis also showed that the rhFS gained strength more quickly as reflected by a steeper α angle; however, the rhFS achieved this clot strength with a 5-fold lower factor I content than the pdhFS. When these fibrin sealants were studied in a porcine hepatic wedge excision model, the hemostatic scores of the rhFS were equivalent or better than that of the pdhFS.

CONCLUSIONS

The bioengineered rhFS had equivalent or better hemostatic efficacy than the pdhFS in a nonlethal hemorrhage model, despite the factor I concentration in the rhFS being about one-fifth that in the pdhFS. Because the rhFS is amenable to large-scale production, the rhFS has the potential to be more economical and abundant than the pdhFS, while having a decreased risk of blood-borne pathogen transmission.