P1480 A case of triple left ventricular aneurysms diagnosed by CT and echocardiography

【Background】

Left ventricular aneurysms is complication of myocardial infarction (MI) that can lead to death or serious morbidity. False aneurysm is rare complications of myocardial infarction or iatrogenic perforation and represent a contained myocardial rupture. False aneurysm does not contain all the three layers of the myocardium and is frequently lined by pericardium and mural thrombus. Definitive diagnosis is achieved by echocardiography, computed tomography (CT), angiography, or magnetic resonance imaging. Coexistence of true and false aneurysms is rare.

【Case】 A 58 years old man with a history of hypertension and MI was referred to our hospital for aneurysmectomy. During the course of prior MI, he got fever and pericardial effusion.

CT revealed that three left ventricular aneurysms were present. Also, three aneurysms were connected by narrow ducts each other. Transthoracic echocardiography (TTE) revealed that three ventricular aneurysms were connected via acceleration blood flow which swirling in the spherical aneurysm. We determined that this triple ventricular aneurysms were at high risk for rupture, so we performed surgery.

The postoperative course was good and he was discharged without any complications.

【Discussion】

False aneurysms occur after hemorrhagic dissection into an area of transmural infarction and most commonly result in free intrapericardial rupture of the heart, cardiac tamponade, and death. Rarely, if the overlying pericardium becomes adherent to the epicardium along the surface of the infarct, it can contain the rupture.

We were able to evaluate the mechanism of development with triple left ventricular aneurysms using CT and TTE. We could know about spatial comprehension of triple aneurysms using CT. False aneurysms were restricted enlargement due to stiff pericardium because of complicating Dressler syndrome. We hypothesis that aneurysms were enlarging in the direction of the base of heart in the adhered pericardium space.

We were able to evaluate the thickness of aneurysms and blood flow condition using TTE. TTE revealed that the wall of aneurysm was fragile. Multimodality imaging like TTE or cardiac CT are useful diagnostic methods in this case.

Abstract P1480 Figure. Triple aneurysms

1638 A case of capturing changes in interatrial blood flow and anatomical structure during percutaneous PFO closure with platypnea orthodeoxia syndrome using intra-cardiac echocardiography

Background

Platypnea–orthodeoxia syndrome (POS) is an uncommon condition characterized by positional dyspnea and hypoxemia due to intracardiac right-to-left shunting through a patent foramen ovale (PFO). The most commonly associated conditions included pneumonectomy, ascending aortic dilation, and arch surgery, as previously reported. Percutaneous closure of PFO is useful treatment for POS.

Case

A 76 year old man used home oxygen therapy because of unexplained hypoxemia. A decrease in blood oxygen saturation was observed in sitting and standing positions. The patient was diagnosed as "POS" because a shunt blood flow with PFO and atrial septal aneurysm (ASA) and eustachian valve was observed at transesophageal echocardiography. He was admitted for the purpose of percutaneous PFO closure.

He was treated with intra-cardiac echocardiography (ICE) guidance under local anesthesia because of poor lung function.

PFO closure was performed successfully with 30mm AMPLATZER Cribriform. The ICE findings prior to PFO closure showed a right-to-left shunt blood flow through the PFO in the sitting position but almost disappeared after closure. Furthermore, it was observed that the aortic artery compression was stronger in the sitting position than in the supine position with right-to-left shunt blood flow. After PFO closure, hypoxia associated with postural change improved and patient’s symptom as shortness of breath also significantly improved.

Discussion

POS is a position-dependent condition of dyspnea and hypoxemia due to right-to-left shunting. It often remains unrecognized in clinical practice, possibly because of its complex underlying pathophysiology. It is considered that the cause of POS in this patient was multiple factors such as ASA, aortic displacement, and venous valve remnant. In addition, being able to observe the change of the atrium due to compression from the aortic artery using ICE during the operation was very significant to explain the mechanism of POS.

Abstract 1638 Figure. Intra-cardiac echocardiography

P1713 A case of quadricuspid aortic valve complicated with infective endocarditis diagnosed by 3D transesophageal echocardiography

Background

Quadricuspid aortic valve (QAV) is a rare congenital heart disease with an estimated incidence of 0.008% to 1.46%. The functional status of QAV is predominantly a pure aortic regurgitation. The extensive use of echocardiography has allowed an early and accurate diagnosis of this malformation. In many cases, the transthoracic echocardiography (TTE) is suitable for the diagnosis but, transesophageal echocardiography (TEE), especially 3-dimensional (3D) TEE, is a tool for the accurate definition of the valve anatomy.

Clinical case

A 60-year-old female underwent a head CT for intermittent headaches for one month ago. She was admitted to neurosurgery in our hospital diagnosed of subarachnoid hemorrhage. Four mm aneurysm was found on the periphery of the right middle cerebral artery on CT examination, and a cerebral aneurysm coil embolization was performed with a catheter in emergency. The possibility of infectious cerebral aneurysm was pointed out, and we examined in cardiovascular internal medicine. TTE revealed moderate aortic regurgitation. The ventricular septum exhibits sigmoid septum. A mobile mass was found near the left ventricular outflow tract in the sigmoid septum. TEE revealed a hypoplasia cusp (accessory cusp) is found between non coronary cusp and right coronary cusp. Aortic valve leaflets have become thickened and regurgitation from the central part of the cusps. 3DTEE was able to more accurately visualize that only the accessory cusp was hypoplastic, and the size of the other three leaflets appears almost the same. Similarly, vegetation on the left ventricular outflow tract were clearly revealed by 3DTEE.

Based on the above, it was diagnosed that quadricuspid aortic valve complicated with infective endocarditis (IE) with aortic valve regurgitation. After treatment with antibiotics according to IE, surgical treatment was scheduled.

Discussion

QAV is a rare congenital heart disease, and TTE is an important imaging tool for accurate diagnosis. Furthermore, TEE, especially 3DTEE, was a more appropriate diagnostic method in QAV and IE.

Abstract P1713 Figure. 3DTEE

Clinical Pig Kidney Xenotransplantation: How Close Are We?

Patients with ESKD who would benefit from a kidney transplant face a critical and continuing shortage of kidneys from deceased human donors. As a result, such patients wait a median of 3.9 years to receive a donor kidney, by which time approximately 35% of transplant candidates have died while waiting or have been removed from the waiting list. Those of blood group B or O may experience a significantly longer waiting period. This problem could be resolved if kidneys from genetically engineered pigs offered an alternative with an acceptable clinical outcome. Attempts to accomplish this have followed two major paths: deletion of pig xenoantigens, as well as insertion of "protective" human transgenes to counter the human immune response. Pigs with up to nine genetic manipulations are now available. In nonhuman primates, administering novel agents that block the CD40/CD154 costimulation pathway, such as an anti-CD40 mAb, suppresses the adaptive immune response, leading to pig kidney graft survival of many months without features of rejection (experiments were terminated for infectious complications). In the absence of innate and adaptive immune responses, the transplanted pig kidneys have generally displayed excellent function. A clinical trial is anticipated within 2 years. We suggest that it would be ethical to offer a pig kidney transplant to selected patients who have a life expectancy shorter than the time it would take for them to obtain a kidney from a deceased human donor. In the future, the pigs will also be genetically engineered to control the adaptive immune response, thus enabling exogenous immunosuppressive therapy to be significantly reduced or eliminated.

Combination gemcitabine plus S-1 versus gemcitabine plus cisplatin for advanced/recurrent biliary tract cancer: the FUGA-BT (JCOG1113) randomized phase III clinical trial

BACKGROUND

Gemcitabine plus cisplatin (GC) is the standard treatment of advanced biliary tract cancer (BTC); however, it causes nausea, vomiting, and anorexia, and requires hydration. Gemcitabine plus S-1 (GS) reportedly has equal to, or better, efficacy and an acceptable toxicity profile. We aimed to confirm the non-inferiority of GS to GC for patients with advanced/recurrent BTC in terms of overall survival (OS).

PATIENTS AND METHODS

We undertook a phase III randomized trial in 33 institutions in Japan. Eligibility criteria included chemotherapy-naïve patients with recurrent or unresectable BTC, an Eastern Cooperative Oncology Group Performance Status of 0 - 1, and adequate organ function. The calculated sample size was 350 with a one-sided α of 5%, a power of 80%, and non-inferiority margin hazard ratio (HR) of 1.155. The primary end point was OS, while the secondary end points included progression-free survival (PFS), response rate (RR), adverse events (AEs), and clinically significant AEs defined as grade ≥2 fatigue, anorexia, nausea, vomiting, oral mucositis, or diarrhea.

RESULTS

Between May 2013 and March 2016, 354 patients were enrolled. GS was found to be non-inferior to GC [median OS: 13.4 months with GC and 15.1 months with GS, HR, 0.945; 90% confidence interval (CI), 0.78-1.15; P = 0.046 for non-inferiority]. The median PFS was 5.8 months with GC and 6.8 months with GS (HR 0.86; 95% CI 0.70-1.07). The RR was 32.4% with GC and 29.8% with GS. Both treatments were generally well-tolerated. Clinically significant AEs were observed in 35.1% of patients in the GC arm and 29.9% in the GS arm.

CONCLUSIONS

GS, which does not require hydration, should be considered a new, convenient standard of care option for patients with advanced/recurrent BTC.

CLINICAL TRIAL NUMBER

This trial has been registered with the UMIN Clinical Trials Registry (http://www.umin.ac.jp/ctr/index.htm), number UMIN000010667.

Decellularization methods for developing porcine corneal xenografts and future perspectives

Corneal transplantation is the only option to cure corneal opacities. However, there is an imbalance between supply and demand of corneal tissues in the world. To solve the problem of corneal shortage, corneal xenotransplantation studies have been implemented in the past years using porcine corneas. The corneal xenografts could come from (a) wild-type pigs, (b) genetically engineered pigs, (c) decellularized porcine corneas, and (d) decellularized porcine corneas that are recellularized with human corneal cells, eventually with patients' own cells, as in all type of xenografts. All approaches except, the former would reduce or mitigate recipient immune responses. Although several techniques in decellularization have been reported, there is still no standardized protocol for the complete decellularization of corneal tissue. Herein, we reviewed different decellularization methods for porcine corneas based on the mechanism of action, decellularization efficacy, biocompatibility, and the undesirable effects on corneal ultrastructure. We compared 9 decellularization methods including: (a) sodium dodecyl sulfate, (b) triton x-100, (c) hypertonic saline, (d) human serum with electrophoresis, (e) high hydrostatic pressure, (f) freeze-thaw, (h) nitrogen gas, (h) phospholipase A₂ , and (i) glycerol with chemical crosslinking methods. It appears that combined methods could be more useful to perform efficient corneal decellularization.

P3535Prognostic value of congestion status by bioelectrical impedance analysis and natriuretic peptide levels in acute heart failure with preserved versus reduced left ventricular ejection fraction

Background

N-terminal pro-brain natriuretic peptide (NT-proBNP) is a well-known predictor of acute heart failure (HF). Congestion volume status estimated by bioelectrical impedance analysis (BIA) is also associated with adverse cardiovascular events in HF patients. However, it is unclear whether these biomarkers reflecting pathophysiological pathways are different between HF with preserved (HFpEF) and reduced ejection fraction (HFrEF).

Purpose

The aim of this study was to investigate whether the prognostic value of NT-proBNP and extracellular water/free fat mass (ECW%) assessed by BIA is different between HFrEF and HFpEF in acute HF patients.

Methods and results

One hundred-and-forty-three patients admitted for acute HF between November 2013 and January 2015 were estimated for NT-proBNP levels and ECW% by BIA on admission. A total of 49 HFrEF (LVEF<40%) and 75 HFpEF (LVEF≥50%) patients were included in this study (mean age: 76±14 years, male: 63%). The median of NT-proBNP levels in HFrEF patients was higher than in HFpEF (6022 [IQR: 2531–9163] pg/mL and 3179 [1076–6054] pg/mL, respectively, p=0.012). Conversely, ECW% was similar between HFrEF and HFpEF (29.0 [25.7–33.7] % and 31.7 [27.3–38.8] %, respectively, p=0.088). The primary endpoint was the composite of all-cause mortality and/or hospitalisation due to HF. During a median follow-up of 5.9 months, 16 (35.6%) and 35 (50.7%) patients were observed to have composite events in HFrEF and HFpEF, respectively, (p=0.111). Elevated NT-proBNP levels in HFrEF patients were associated with an increased risk of composite events after adjustment for traditional risk factors (hazard ratio [HR]: 2.39; 95% Confidence interval [CI]; 1.04–5.47; p=0.040), but not in HFpEF (p=0.063). Meanwhile, a high ECW% in HFrEF patients was associated with increasing composite events risk (HR: 3.30; 95% CI; 1.32–8.25; p=0.011), as well as in HFpEF patients (HR: 1.62; 95% CI; 1.03–2.55; p=0.037). Furthermore, the ECW% in addition to NT-proBNP in HFpEF patients resulted in a significant improvement in prediction for composite events (net reclassification improvement 0.67 [95% CI 0.24–1.11]; p=0.002 and integrated discrimination improvement 0.12 [0.004–0.20]; p=0.004).

Conclusion

Elevated levels of NT-proBNP in acute HF were predictive for mortality and hospitalisation due to HF in HFrEF but may not be for HFpEF patients, and ECW% had a better predictive value than NT-proBNP in HFpEF patients.

Life-supporting Kidney Xenotransplantation From Genetically Engineered Pigs in Baboons: A Comparison of Two Immunosuppressive Regimens

BACKGROUND

The aims of this study were to evaluate the efficacy of US Food and Drug Administration-approved drugs in genetically engineered pig-to-baboon kidney xenotransplantation and compare the results with those using an anti-CD40 monoclonal antibody (mAb)-based regimen.

METHODS

Ten life-supporting kidney transplants were carried out in baboons using α1,3-galactosyltransferase gene-knockout/CD46 pigs with various other genetic manipulations aimed at controlling coagulation dysregulation. Eight transplants resulted in informative data. Immunosuppressive therapy consisted of induction with antithymocyte globulin and anti-CD20mAb, and maintenance based on either (1) CTLA4-Ig and/or tacrolimus (+rapamycin or mycophenolate mofetil) (GroupA [US Food and Drug Administration-approved regimens], n = 4) or (2) anti-CD40mAb + rapamycin (GroupB, n = 4). All baboons received corticosteroids, interleukin-6R blockade, and tumor necrosis factor-α blockade. Baboons were followed by clinical and laboratory monitoring of kidney function, coagulation, and immune parameters. At euthanasia, morphological and immunohistochemical studies were performed on the kidney grafts.

RESULTS

The median survival in GroupB was 186 days (range 90-260), which was significantly longer than in GroupA; median 14 days (range 12-32) (P < 0.01). Only GroupA baboons developed consumptive coagulopathy and the histopathological features of thrombotic microangiopathic glomerulopathy and interstitial arterial vasculitis.

CONCLUSIONS

Recognizing that the pig donors in each group differed in some genetic modifications, these data indicate that maintenance immunosuppression including anti-CD40mAb may be important to prevent pig kidney graft failure.

The complex functioning of the complement system in xenotransplantation

The role of complement in xenotransplantation is well-known and is a topic that has been reviewed previously. However, our understanding of the immense complexity of its interaction with other constituents of the innate immune response and of the coagulation, adaptive immune, and inflammatory responses to a xenograft is steadily increasing. In addition, the complement system plays a function in metabolism and homeostasis. New reviews at intervals are therefore clearly warranted. The pathways of complement activation, the function of the complement system, and the interaction between complement and coagulation, inflammation, and the adaptive immune system in relation to xenotransplantation are reviewed. Through several different mechanisms, complement activation is a major factor in contributing to xenograft failure. In the organ-source pig, the detrimental influence of the complement system is seen during organ harvest and preservation, for example, in ischemia-reperfusion injury. In the recipient, the effect of complement can be seen through its interaction with the immune, coagulation, and inflammatory responses. Genetic-engineering and other therapeutic methods by which the xenograft can be protected from the effects of complement activation are discussed. The review provides an updated source of reference to this increasingly complex subject.

Circulating pig-specific DNA as a novel biomarker for monitoring xenograft rejection

Monitoring for immune rejection is crucial for long-term survival of pig xenografts. Circulating DNA is a promising non-invasive biomarker for either organ injury or response to therapy. In this study, circulating pig-specific DNA (cpsDNA) was monitored during xenograft rejection. Potential targets of cpsDNA were selected by in silico analysis, and species specificity of selected primers was confirmed by PCR. Subsequently, cpsDNA as a biomarker was evaluated using a complement-dependent cytotoxicity (CDC) assay in vitro. Then, early diagnosis and response to rapamycin were assessed by an in vivo imaging model of pig-to-mouse cell transplantation. Finally, cpsDNA was monitored in a pig-to-monkey artery patch transplantation model. The results showed that (a) a method of cpsDNA quantitation was established for application in mouse and nonhuman primate models; (b) cpsDNA reflected CDC in vitro; (c) cpsDNA in vivo mirrored xenograft rejection, and correlated with xenograft loss in pig-to-mouse cell transplantation; (d) cpsDNA was significantly reduced when rapamycin was administered; and (e) dynamic cpsDNA was detectable in pig-to-monkey artery patch transplantation. In conclusion, measurement of cpsDNA could prove to be a less invasive, but more specific and sensitive low-cost biomarker enabling monitoring of xenograft rejection and the response to immunosuppressive therapy.

Justification of specific genetic modifications in pigs for clinical organ xenotransplantation

Xenotransplantation research has made considerable progress in recent years, largely through the increasing availability of pigs with multiple genetic modifications. We suggest that a pig with nine genetic modifications (ie, currently available) will provide organs (initially kidneys and hearts) that would function for a clinically valuable period of time, for example, >12 months, after transplantation into patients with end-stage organ failure. The national regulatory authorities, however, will likely require evidence, based on in vitro and/or in vivo experimental data, to justify the inclusion of each individual genetic modification in the pig. We provide data both from our own experience and that of others on the advantages of pigs in which (a) all three known carbohydrate xenoantigens have been deleted (triple-knockout pigs), (b) two human complement-regulatory proteins (CD46, CD55) and two human coagulation-regulatory proteins (thrombomodulin, endothelial cell protein C receptor) are expressed, (c) the anti-apoptotic and "anti-inflammatory" molecule, human hemeoxygenase-1 is expressed, and (d) human CD47 is expressed to suppress elements of the macrophage and T-cell responses. Although many alternative genetic modifications could be made to an organ-source pig, we suggest that the genetic manipulations we identify above will all contribute to the success of the initial clinical pig kidney or heart transplants, and that the beneficial contribution of each individual manipulation is supported by considerable experimental evidence.

Carbohydrate antigen expression and anti-pig antibodies in New World capuchin monkeys: Relevance to studies of xenotransplantation

BACKGROUND

Old World non-human primates (OWNHPs) are used for preclinical pig-to-NHP studies. However, like pigs, OWNHPs express Neu5Gc, and therefore do not develop natural anti-Neu5Gc antibodies. New World NHPs (NWNHPs) have been reported not to express Neu5Gc. We investigated the potential of NWNHPs in xenotransplantation research.

METHODS

We investigated expression of Gal, Neu5Gc, and Sd^a antigens on RBCs and PBMCs from humans, selected OWNHPs, and capuchin monkeys (a NWNHP). Serum anti-Gal and anti-Neu5Gc IgM and IgG levels were measured by ELISA. Binding of primate serum IgM and IgG to pig RBCs was measured by flow cytometry.

RESULTS

(a) Neither humans, OWNHPs, or capuchin monkeys expressed Gal on their RBCs, but capuchins expressed Gal on PBMCs. Humans and capuchins did not express Neu5Gc on either RBCs or PBMCs, but OWNHPs expressed Neu5Gc on both cells. Sd^a was not expressed on any RBCs or PBMCs. (b) By ELISA, human and OWNHP, but not capuchin, sera showed IgM and IgG binding to Gal. Human and capuchin, but not OWNHP, sera demonstrated some binding to Neu5Gc. (c) Anti-Sd^a IgM/IgG antibodies were detected in OWNHP sera. Knockout of Sd^a on pig RBCs did not significantly reduce human and capuchin antibody binding.

CONCLUSION

Capuchin monkeys could be surrogates for humans in experiments using RBCs, islets, neuronal cells, etc, from triple-knockout pigs (but may be too small to be used as recipients of pig organ grafts).

Abstract P3-10-16: Predicting pathological complete response by the combination of microRNAs in patients with HER2-positive primary breast cancer who received neoadjuvant combination therapy of trastuzumab, lapatinib and paclitaxel: Results from JBCRG-16 (NeoLath) study

[Background] JBCRG-16 (NeoLath) study is a five-arm study to evaluate the efficacy and safety of lapatinib and trastuzumab (6 weeks) followed by lapatinib and trastuzumab plus weekly paclitaxel (12 weeks) with/without prolongation of anti-HER2 therapy prior to chemotherapy (18 vs. 6 weeks), and with/without endocrine therapy in patients with HER2+ and/or estrogen receptor (ER)+ disease. The primary endpoint was pathological complete response (pCR) rate and pCR rate was 47.9% (Masuda N, et al. Breast Cancer, 2018). It is recently reported that microRNAs (miRNAs) are stably present in serum and potentially useful in the diagnosis and evaluation of treatment of cancer. We performed exploratory analysis of detecting pCR by comprehensive analysis of serum miRNAs.

[Materials and Methods] Serum samples were obtained from study participants who received neoadjuvant systemic therapy with trastuzumab, lapatinib and paclitaxel. Before profiling of miRNAs, the overall serum samples were randomly devided in two sets, namely the training set and the testing set with pCR or non-pCR. Pathological complete response (pCR) was defined as the absence of residual invasive cancer of the resected breast specimen and all sampled regional lymph nodes. Total RNA was extracted from a 300 ul serum sample using 3D-Gene® RNA extraction reagent from a liquid sample kit. A comprehensive quantitative expression analysis of miRNA was performed using the by DNA chip 3D-Gene®, which was designed to detect 2565 miRNA sequences registered in miRBase release 21 (http://www.mirbase.org/). The expression level of miRNAs were normalized by internal control (miR-2861, miR-149-3p and miR-4463). Clinicopathological data was retrieved from trial data.

[Results] A total of 112 samples were obtained. Seventy were used in the training set and others were used in the testing set. Median age was 54 years (range 26-70). Sixty-five (58%) patients were pre-menopausal. ER was positive in 59 patients (52.7%). Fourteen (12.5%) were T1c, 78 (69.6%) were T2 and 20 (17.9%) were T3. Fifty-seven (50.9%) patients were node-positive. Fifty-nine (52.7%) patients achieved pCR. The formula with the combination of three miRNAs (miR-A, miR-B, miR-C) was found to be able to predict pCR. This set had a sensitivity of 62.5%, specificity of 86.7% and accuracy of 71.8% in the testing cohort. Area under curve of receiver operationg characteristic curve was 0.753.

[Conclusion] The combination of three miRNAs has potential to predict pCR in patients who received neoadjuvant combination therapy of trastuzumab, lapatinib and paclitaxel in HER2-positive primary breast cancer. The further analysis of changing expression of miRNAs during neoadjuvant therapy is underway and further results will be presented in the symposium.

Citation Format: Shimomura A, Masuda N, Kawauchi J, Takizawa S, Ichikawa M, Matasuzaki J, Kuroi K, Hara H, Yamamoto N, Inoue K, Suganuma N, Aogi K, Ohno S, Tamura K, Ochiya T, Toi M. Predicting pathological complete response by the combination of microRNAs in patients with HER2-positive primary breast cancer who received neoadjuvant combination therapy of trastuzumab, lapatinib and paclitaxel: Results from JBCRG-16 (NeoLath) study [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-10-16.

Safety and efficacy of nivolumab in combination with S-1/capecitabine plus oxaliplatin in patients with previously untreated, unresectable, advanced, or recurrent gastric/gastroesophageal junction cancer: interim results of a randomized, phase II trial (ATTRACTION-4)

BACKGROUND

Nivolumab is approved as an option for third- or later-line treatment of advanced gastric/gastroesophageal junction (G/GEJ) cancer in several countries after ATTRACTION-2. To further improve the therapeutic efficacy of first-line therapy, exploration of a nivolumab-chemotherapy combination is warranted. In part 1 (phase II) of ATTRACTION-4, the safety and efficacy of nivolumab combined with S-1 plus oxaliplatin (SOX) or capecitabine plus oxaliplatin (CapeOX) as first-line therapy for unresectable advanced or recurrent human epidermal growth factor receptor 2 (HER2)-negative G/GEJ cancer were evaluated.

PATIENTS AND METHODS

Patients were randomized (1 : 1) to receive nivolumab (360 mg intravenously every 3 weeks) plus SOX (S-1, 40 mg/m2 orally twice daily for 14 days followed by 7 days off; oxaliplatin, 130 mg/m2 intravenously on day 1 every 3 weeks) or CapeOX (capecitabine, 1000 mg/m2 orally twice daily for 14 days followed by 7 days off; oxaliplatin, 130 mg/m2 intravenously on day 1 every 3 weeks) until disease progression, unacceptable toxicity, or consent withdrawal.

RESULTS

Of 40 randomized patients, 39 (nivolumab plus SOX, 21; nivolumab plus CapeOX, 18) and 38 (21 and 17, respectively) comprised the safety and efficacy populations, respectively. Most frequent (>10%) grade 3/4 treatment-related adverse events were neutropenia (14.3%) in the nivolumab plus SOX group, and neutropenia (16.7%), anemia, peripheral sensory neuropathy, decreased appetite, type 1 diabetes mellitus, and nausea (11.1% each) in the nivolumab plus CapeOX group. No treatment-related death occurred. Objective response rate was 57.1% (95% confidence interval 34.0-78.2) with nivolumab plus SOX and 76.5% (50.1-93.2) with nivolumab plus CapeOX. Median overall survival was not reached (NR) in both groups. Median progression-free survival was 9.7 months (5.8-NR) and 10.6 months (5.6-12.5), respectively.

CONCLUSION

Nivolumab combined with SOX/CapeOX was well tolerated and demonstrated encouraging efficacy for unresectable advanced or recurrent HER2-negative G/GEJ cancer. ATTRACTION-4 has proceeded to part 2 (phase III) to compare nivolumab plus SOX/CapeOX versus placebo plus SOX/CapeOX.

CLINICALTRIALS.GOV ID

NCT02746796.

The Case for Cardiac Xenotransplantation in Neonates: Is Now the Time to Reconsider Xenotransplantation for Hypoplastic Left Heart Syndrome?

Neonatal cardiac transplantation for hypoplastic left heart syndrome (HLHS) is associated with excellent long-term survival compared to older recipients. However, heart transplantation for neonates is greatly limited by the critical shortage of donor hearts, and by the associated mortality of the long pre-transplant waiting period. This led to the development of staged surgical palliation as the first-line surgical therapy for HLHS. Recent advances in genetic engineering and xenotransplantation have provided the potential to replicate the excellent results of neonatal cardiac allotransplantation while eliminating wait-list-associated mortality through genetically modified pig-to-human neonatal cardiac xenotransplantation. The elimination of the major pig antigens in addition to the immature B-cell response in neonates allows for the potential to induce B-cell tolerance. Additionally, the relatively mature neonatal T-cell response could be reduced by thymectomy at the time of operation combined with donor-specific pig thymus transplantation to "reprogram" the host's T-cells to recognize the xenograft as host tissue. In light of the recent significantly increased graft survival of genetically-engineered pig-to-baboon cardiac xenotransplantation, we propose that now is the time to consider devoting research to advance the potential clinical application of cardiac xenotransplantation as a treatment option for patients with HLHS. Employing cardiac xenotransplantation could revolutionize therapy for complex congenital heart defects and open a new chapter in the field of pediatric cardiac transplantation.

Genetically-engineered pigs as sources for clinical red blood cell transfusion: What pathobiological barriers need to be overcome?

An alternative to human red blood cells (RBCs) for clinical transfusion would be advantageous, particularly in situations of massive acute blood loss (where availability and compatibility are limited) or chronic hematologic diseases requiring frequent transfusions (resulting in alloimmunization). Ideally, any alternative must be neither immunogenic nor pathogenic, but readily available, inexpensive, and physiologically effective. Pig RBCs (pRBCs) provide a promising alternative due to their several similarities with human RBCs, and our increasing ability to genetically-modify pigs to reduce cellular immunogenicity. We briefly summarize the history of xenotransfusion, the progress that has been made in recent years, and the remaining barriers. These barriers include prevention of (i) human natural antibody binding to pRBCs, (ii) their phagocytosis by macrophages, and (iii) the T cell adaptive immune response (in the absence of exogenous immunosuppressive therapy). Although techniques of genetic engineering have advanced in recent years, novel methods to introduce human transgenes into pRBCs (which do not have nuclei) will need to be developed before clinical trials can be initiated.