Drug review process advancement and required manufacturer and contract research oraganization responses.

The United States Senate passed the "FDA Modernization Act 2.0." on September 29, 2022. Although the effectiveness of this Bill, which aims to eliminate the mandatory use of laboratory animals in new drug development, is limited, it represents a significant trend that will change the shape of drug applications in the United States and other countries. However, pharmaceutical companies have not taken major steps towards the complete elimination of animal testing from the standpoint of product safety, where they prioritize patient safety. Nonetheless, society is becoming increasingly opposed to animal testing, and efforts will be made to use fewer animals and conduct fewer animal tests as a natural and reasonable response. These changes eventually alter the shape of new drug applications. Based on the assumption that fewer animal tests will be conducted or fewer animals will be used in testing, this study explored bioinformatics and new technologies as alternatives to compensate for reduced information and provide a picture of how future new drug applications may look. The authors also discuss the directions that pharmaceutical companies and nonclinical contract research organizations should adopt to promote the replacement, reduction, and refinement of animals used in research, teaching, testing, and exhibitions.

First Successful Delivery after Uterus Transplantation in MHC-Defined Cynomolgus Macaques.

Delivery following uterus transplantation (UTx)-an approach for treating uterine factor infertility-has not been reported in nonhuman primate models. Here, six female major histocompatibility complex (MHC)-defined cynomolgus macaques that underwent allogeneic UTx were evaluated. Antithymocyte globulin and rituximab were administered to induce immunosuppression and a triple maintenance regimen was used. Menstruation resumed in all animals with long-term survival, except one, which was euthanized due to infusion associated adverse reaction to antithymocyte globulin. Donor-specific antibodies (DSA) were detected in cases 2, 4, and 5, while humoral rejection occurred in cases 4 and 5. Post-transplant lymphoproliferative disorder (PTLD) developed in cases 2 and 3. Pregnancy was attempted in cases 1, 2, and 3 but was achieved only in case 2, which had haploidentical donor and recipient MHCs. Pregnancy was achieved in case 2 after recovery from graft rejection coincident with DSA and PTLD. A cesarean section was performed at full-term. This is the first report of a successful livebirth following allogeneic UTx in nonhuman primates, although the delivery was achieved via UTx between a pair carrying haploidentical MHCs. Experimental data from nonhuman primates may provide important scientific knowledge needed to resolve unsolved clinical issues in UTx.

Experimental techniques for the development of a uterus transplantation model in cynomolgus macaques.

Uterus transplantation (UTx) is now a treatment for women with uterine factor infertility to have a child. However, UTx is still largely at the experimental stage, and many medical issues remain unsolved. Therefore, adequate studies in large animals including non-human primates are required for validation of these issues. UTx research, especially in non-human primates, can provide important information for its full establishment in humans due to the anatomical and physiological similarities between the two. We accumulated data from UTx studies using cynomolgus macaques since 2009 and established autologous and allogeneic UTx models which led to deliveries after performing the procedure. In this paper, we summarized key points to develop UTx models in cynomolgus macaques based on our experience. UTx models in non-human primates can surely contribute new and beneficial knowledge in this field and can be useful for the further development of UTx in humans.

Clinical features of irreversible rejection after allogeneic uterus transplantation in cynomolgus macaques.

Uterus transplantation (UTx) is a potential option for women with uterine factor infertility to have a child. The clinical features indicating irreversible rejection of the uterus are unknown. In our experimental series of allogeneic UTx in cynomolgus macaques, six female macaques were retrospectively examined, which were unresponsive to treatment with immunosuppressants (i.e. irreversible rejection). Clinical features including general condition, hematology, uterine size, indocyanine green (ICG) fluorescence imaging by laparotomy, and histopathological findings of the removed uterus were evaluated. In all cases, general condition was good at the time of diagnosis of irreversible rejection and thereafter. Laboratory evaluation showed temporary increases in white blood cells, lactate dehydrogenase and C-reactive protein, then these levels tended to decrease gradually. In transabdominal ultrasonography, the uterus showed time-dependent shrinkage after transient swelling at the time of diagnosis of irreversible rejection. In laparotomy, a whitish transplanted uterus was observed and enhancement of the transplanted uterus was absent in ICG fluorescence imaging. Histopathological findings in each removed uterus showed hyalinized fibrosis, endometrial deficit, lymphocytic infiltration and vasculitis. These findings suggest that uterine transplantation rejection is not fatal, in contrast to rejection of life-supporting organs. Since the transplanted uterus with irreversible rejection atrophies naturally, hysterectomy may be unnecessary.

Impact of altered dietary calcium-phosphorus ratio caused by high-phosphorus diets in a rat chronic kidney disease (CKD) model created by partial ligation of the renal arteries.

This study aimed to establish a rat chronic kidney disease (CKD) model by studying the effects of a high-phosphorus diet in rats that had undergone partial ligation of the renal arteries (RL). Separate groups of 10-week-old male Slc:Sprague-Dawley rats underwent RL and were fed diets with varying phosphorous levels for a period of 48 days. A marked suppression of body weight gain necessitating humane euthanization occurred on day 28 in rats that had undergone RL and were given high-phosphorus feed. By contrast, the group of intact animals on a high-phosphorus feed exhibited a slightly decreased body weight gain from day 21 and survived until scheduled euthanization. In rats with RL, hematological, blood biochemical, and histopathological analyses demonstrated the presence of CKD-like conditions, particularly in the group that were fed a high-phosphorus diet. Hyperphosphatemia and hypocalcemia were induced by a high-phosphorus diet in both the RL and intact groups, both of which had high levels of FGF23 and parathyroid hormone in the blood. Rats with RL on a high-phosphorus diet showed decreased hematopoiesis by the hematopoietic cell area being narrower in the medullary cavity, proliferation of mesenchymal cells and osteoblasts/osteoclasts, and expansion of the osteoid area, a furthermore generalized vascular lesions, such as calcification, were observed. These findings demonstrate that the partial ligation of the renal arteries combined with a calcium-phosphorus imbalance induced by a high-phosphorus diet serves as an animal model for CKD-like conditions accompanied by bone lesions, helping to elucidate this clinical condition and its underlying molecular mechanisms.

Long-Term Outcome and Rejection After Allogeneic Uterus Transplantation in Cynomolgus Macaques.

Uterus transplantation (UTx) is an option for women with uterine factor infertility to have a child, but is still in the experimental stage. Therefore, allogeneic animal models of UTx are required for resolution of clinical issues. In this study, long-term outcomes were evaluated in four recipients (cases 1-4) after allogeneic UTx in cynomolgus macaques. Immunosuppression with antithymocyte globulin induction and a triple maintenance regimen was used. Postoperative ultrasonography and biopsy of the transplanted uterus and immunoserological examinations were performed. All four recipients survived for >3 months after surgery, but continuous menstruation did not resume, although temporary menstruation occurred (cases 1 and 2). All animals were euthanized due to irreversible rejection and no uterine blood flow (cases 1, 2 and 4) and post-transplant lymphoproliferative disorder (case 3). Donor-specific antibodies against MHC class I and II were detected in cases 1, 2 and 4, but not in case 3. Peripheral lymphocyte counts tended to elevate for CD3+, CD20+ and NK cells in conjunction with uterine rejection, and all animals had elevated stimulation indexes of mixed lymphocyte reaction after surgery. Establishment of allogeneic UTx in cynomolgus macaque requires further exploration of immunosuppression, but the clinicopathological features of uterine rejection are useful for development of human UTx.

Surgical technique for allogeneic uterus transplantation in macaques.

No study has reported an animal model of uterus transplantation (UTx) using cynomolgus macaques. We aimed to establish a surgical technique of allogeneic UTx assuming the recovery of a uterus from a deceased donor in cynomolgus macaques. Four allogeneic UTxs were performed in female cynomolgus macaques. Donor surgeries comprised en bloc recovery of organs with iliac vessels on both sides, and/or abdominal aorta/vena cava after sufficient perfusion from one femoral artery or external iliac artery. Before perfusion, 150 mL of whole blood was obtained from the donor for subsequent blood transfusion to the recipient. Four uterine grafts were orthotopically transplanted to recipients. End-to-side anastomosis was performed to the iliac vessels on one side in case 1 and iliac vessels on both sides in case 2; aorto-aorto/cavo-caval anastomosis was performed in cases 3 and 4. Arterial blood flow of the uterine grafts was determined by intraoperative indocyanine green (ICG) angiography. ICG angiography results showed sufficient blood flow to all uterine grafts, and anaemia did not progress. Under appropriate immune suppression, all recipients survived for more than 90 days post-transplantation, without any surgical complications. We describe a surgical technique for allogeneic UTx in cynomolgus macaques.

Depressed levels of interferon-gamma and HLA-DR+CD3+ T cells in infants with transient hyperferritinemia.

Familial hemophagocytic lymphohistiocytosis (FHL), which typically has its onset during infancy, is uniformly fatal if not treated. It therefore requires prompt therapeutic intervention. Although hyperferritinemia has been emphasized as a useful marker for FHL, some nonfatal cases in infants with spontaneous remission also manifest with hyperferritinemia. However, distinguishing them is difficult because initial clinical features of these infants are similar. The authors encountered 14 infants with hyperferritinemia (serum ferritin >674 ng/mL), which normalized within 3 weeks following a benign clinical course. The authors compared the levels of HLA-DR+CD3+ T-cell subsets and interferon-gamma (IFN-γ) in the peripheral blood between these infants and FHL cases: one of the authors' own patients and others from the literature. Serum IFN-γ was not detected in infants with hyperferritinemia. Moreover, levels of HLA-DR+CD3+ T cells were extremely depressed. In contrast, serum IFN-γ was elevated and HLA-DR+CD3+ T cells were not depressed in FHL. Measurement of activated T cells and serum IFN-γ might help differentiate FHL in febrile infants with transient hyperferritinemia.