Pharmacology studies using immunosuppressed pigs
Pharmacology studies using immunosuppressed pigs are now available!
In the field of regenerative medicine, we can now offer you pharmacology studies using immunosuppressed pigs with data that can be highly clinically extrapolated.
We contribute to your success in clinical studies.
In the field of regenerative medicine, it is desirable to verify the efficacy and safety of regenerated organs produced with human cells, using large animals in which it is possible to use the same interventions as in clinical use, before they are transplanted into humans. On the other hand, when a regenerated organ produced with human cells is transplanted into a pig, which is similar in body size to humans, an immune response to xenograft occurs. Before this immunosuppressed pig model was developed, it was considered impossible to verify the safety and efficacy of human cell-derived regenerative medicine products with pigs.
We, Axcelead Drug Discovery Partners (hereinafter referred to as Axcelead DDP), adopt surgical procedures and pharmacokinetic(PK) measurement of immunosuppressants as a basic procedure to prepare immunosuppressed pigs with data that can be highly clinically extrapolated, by controlling the level of immunosuppression appropriate for individual animals, supporting your success in clinical studies.
Preparation of the immunosuppressed pig model
- An immunosuppressed state is induced by the surgical removal of the immune organs such as the thymus and spleen, and administration of immunosuppressants. The dosage of immunosuppressants is adjusted based on in vitro studies using porcine peripheral blood mononuclear cells (PBMC). We confirm after administration that the target blood concentration level has been achieved.
- The model enables the evaluation of xenotransplantation and human cell-derived regenerative medicine products. From the number of transplanted cells that are effective in pig studies, we can predict the number of transplanted cells that will be clinically effective.
- The model also enables of cell viability by pathological evaluation and the degree of cell differentiation using specific cell markers can be assessed.
Examples of pathological model preparation
♦Immunosuppressed heart failure pig model:
・This model is prepared by ligating the left coronary artery of immunosuppressed pig model to induce heart failure.
・This model can be used to evaluate cardiac function and efficacy of cell transplantation by 3D-echocardiograpy.
♦Immunosuppressed type 1 diabetes mellitus pig model:
・The type 1 diabetes mellitus model is produced by treating the immunosuppressed pig model with streptozotocin.
・This model can be used to evaluate the anti-diabetic effect of cell transplantation by monitoring the daily blood glucose and intravenous glucose tolerance test.
Please consult with us about the preparation of other pathological models.
■ A study on the production of the immunosuppressed pig model co-authored by Toshiyuki Maki and Keiko Igaki, researchers at Axcelead DDP, has been published in “Nature Research Protocol Exchange”.
“Surgically produced, controllable immunocompromised pigs” (information on the publication by Nature Research Protocol Exchange)
Eiji Kobayashi et al., Posted 03 Oct 2019
Applications in the field of regenerative medicine
At the International Society for Stem Cell Research (ISSCR) Annual Meeting, the results of a study in which human iPS cell-derived cardiomyocytes were successfully grafted in the heart of an immunosuppressed pig model were presented on a poster.
“A PHARMACOLOGICAL APPROACH FOR IMMUNOSUPPRESSION REGIMEN IN PIGS TO ACCEPT HUMAN iPSC-DERIVED CELLS”
Norihisa Tamura (T-CiRA Discovery, Takeda Pharmaceutical Company Limited), et al.
The study was co-authored by Nobuyuki Amano, Manami Kaneko, Toshiyuki Maki, Noriyasu Sano, and Teruki Hamada from Axcelead DDP.
<Summary of the presentation>
For patients with severe heart failure, heart transplantation is their final means of survival, awaiting the development of new treatment options. Human iPS cell-derived cardiomyocyte transplantation is expected to be one of the treatment options. The size and heart rate of small animal hearts are significantly different to those of humans. The clinical efficacy should be evaluated in large animals. Since it is essential to produce an immunosuppressed large animal model for the grafting of human-derived cells, we investigated optimal types and dosages of immunosuppressants. In a comparison between cyclosporin and tacrolimus, clinically-used calcineurin inhibitors, cyclosporin was more effective in pigs based on the results of the studies on porcine PBMC proliferation and measurement of in vivo PK profiles. A pig underwent surgical removal of its immune system organs, was administered several immunosuppressants including cyclosporin, and then human iPS cell-derived cardiomyocytes were transplanted into the heart. The successful engraftment of human-derived cardiomyocytes in the heart was confirmed about 3 weeks later.
<Remarkable advantages of immunosuppressed pig model used in the study!>
- Differences in response to immunosuppressants among lineages were confirmed by the in vitro proliferation study using PBMC collected from several pig lineages.
(Drug response varies among lineages as well as among species!)
- The target blood concentration of immunosuppressants was calculated using the results of the PMBC study, the unbound fraction of each drug, and the blood/plasma concentration ratio.
- Confirmation of the target blood concentration is achieved in vivo
(We have discovered that it is practically impossible for tacrolimus to achieve the target blood concentration set by Axcelead DDP in vivo!)
- In addition to administration of optimal immunosuppressants, immune system organs (spleen, thymus) are removed to induce a robust immunosuppressed state and produce an immunosuppressed pig model.
- Long-term rearing is possible under an immunosuppressed state.
(The animal’s cage and environment are maintained in a clean state with daily cleaning and a supply/exhaust unit with a built-in HEPA filter to protect the animal from infection.)
- Successful engraftment of human iPS cell-derived cardiomyocytes was confirmed.