Enhanced fusogenicity and pathogenicity of SARS-CoV-2 Delta P681R mutation.

During the current coronavirus disease 2019 (COVID-19) pandemic, a variety of mutations have accumulated in the viral genome of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and, at the time of writing, four variants of concern are considered to be potentially hazardous to human society1. The recently emerged B.1.617.2/Delta variant of concern is closely associated with the COVID-19 surge that occurred in India in the spring of 2021 (ref. 2). However, the virological properties of B.1.617.2/Delta remain unclear. Here we show that the B.1.617.2/Delta variant is highly fusogenic and notably more pathogenic than prototypic SARS-CoV-2 in infected hamsters. The P681R mutation in the spike protein, which is highly conserved in this lineage, facilitates cleavage of the spike protein and enhances viral fusogenicity. Moreover, we demonstrate that the P681R-bearing virus exhibits higher pathogenicity compared with its parental virus. Our data suggest that the P681R mutation is a hallmark of the virological phenotype of the B.1.617.2/Delta variant and is associated with enhanced pathogenicity.

SARS-CoV-2 B.1.617.2 Delta variant replication and immune evasion.

The B.1.617.2 (Delta) variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first identified in the state of Maharashtra in late 2020 and spread throughout India, outcompeting pre-existing lineages including B.1.617.1 (Kappa) and B.1.1.7 (Alpha)1. In vitro, B.1.617.2 is sixfold less sensitive to serum neutralizing antibodies from recovered individuals, and eightfold less sensitive to vaccine-elicited antibodies, compared with wild-type Wuhan-1 bearing D614G. Serum neutralizing titres against B.1.617.2 were lower in ChAdOx1 vaccinees than in BNT162b2 vaccinees. B.1.617.2 spike pseudotyped viruses exhibited compromised sensitivity to monoclonal antibodies to the receptor-binding domain and the amino-terminal domain. B.1.617.2 demonstrated higher replication efficiency than B.1.1.7 in both airway organoid and human airway epithelial systems, associated with B.1.617.2 spike being in a predominantly cleaved state compared with B.1.1.7 spike. The B.1.617.2 spike protein was able to mediate highly efficient syncytium formation that was less sensitive to inhibition by neutralizing antibody, compared with that of wild-type spike. We also observed that B.1.617.2 had higher replication and spike-mediated entry than B.1.617.1, potentially explaining the B.1.617.2 dominance. In an analysis of more than 130 SARS-CoV-2-infected health care workers across three centres in India during a period of mixed lineage circulation, we observed reduced ChAdOx1 vaccine effectiveness against B.1.617.2 relative to non-B.1.617.2, with the caveat of possible residual confounding. Compromised vaccine efficacy against the highly fit and immune-evasive B.1.617.2 Delta variant warrants continued infection control measures in the post-vaccination era.

[A case of giardiasis diagnosed from a high output stoma after surgery for obstructive colorectal cancer].

This report describes a case of giardiasis detected through stool smear analysis of postoperative stool fluid collected from a high output stoma for obstructive colorectal cancer. The patient, a 67-year-old male, underwent right hemicolectomy with ileostomy for obstructive colorectal cancer. The persistent excessive excretion of postoperative stool fluid from the stoma prompted a stool smear test. The findings revealed the presence of Giardia intestinalis. Fecal output decreased when metronidazole was administered orally. The study strongly recommends that patients with prolonged gastrointestinal symptoms need to undergo stool smear tests.

Difference of compliance rates for the recommendations in Japanese Guideline on Febrile Neutropenia according to respondents' attributes: the second report on a questionnaire survey among hematology-oncology physicians and surgeons.

PURPOSE: The Japanese Society of Medical Oncology (JSMO) published a guideline (GL) on febrile neutropenia (FN) in 2017. This study aims to identify promoting factors and disincentives for complying with GL recommendations according to attributes of doctors providing chemotherapy. METHODS: A questionnaire survey was conducted with SurveyMonkey™ for physician members of the Japanese Association of Supportive Care in Cancer and relevant academic organizations. Each question had four options (always do, do in more than half of patients, do in less than half, do not at all) and a free description form. Responses were analyzed according to the respondents' attributes. RESULT: Seven hundred eighty-eight out of retrieved 801 responses were available for analysis. Multivariable analysis demonstrated that the percentage of GL users was higher among women and Japanese Society of Clinical Oncology members. The overall compliance rate was higher among women, JSMO members, and board-certified medical oncologists. Internists emphasized the significance of collecting blood cultures at FN onset, and surgeons stressed the importance of G-CSF prophylaxis. Hematologists were less likely to adhere to recommendations on risk assessment of FN by the Multinational Association of Supportive Care in Cancer score and administration of gammaglobulin products. However, those are acceptable due to the characteristics of their practice. Eight recommendations had no difference in compliance rates between users and non-users, some of whose statements were ambiguous and discretionary. CONCLUSION: Women were more likely to use and adhere to GL. The recommendations should be developed considering the characteristics of specialty and subspecialty and avoiding ambiguity and discretionary statements.

Consolidation with 90 Yttrium-ibritumomab tiuxetan after bendamustine and rituximab for relapsed follicular lymphoma.

Bendamustine and rituximab (BR) are widely used in patients with follicular lymphoma (FL) previously treated with conventional immunochemotherapy, but the role of consolidation radioimmunotherapy in these patients is unknown. This study evaluated the efficacy and safety of consolidation with 90 Yttrium-ibritumomab tiuxetan (90 Y-IT) after re-induction therapy with BR in patients with previously treated FL. This study included adult patients with relapsed FL who had undergone one or two prior therapies. Re-induction therapy with BR was administered every 4 weeks up to 4-6 cycles. If patients achieved at least partial response, 90 Y-IT was administered as consolidation therapy. The primary endpoint was 2-year progression-free survival (PFS) after consolidation. A total of 24 FL patients (median age 60 years) who had undergone one (n = 17) or two (n = 7) prior treatments received BR. After BR therapy, 22 patients proceeded to consolidation with 90 Y-IT, resulting in an overall 88% response rate to the protocol treatment. Within a median observation period of 46.8 months, the estimated 2-year PFS rate after the consolidation among the 22 patients receiving 90 Y-IT was 59% (95% confidence interval [CI], 38%-77%). Patients whose remission after previous treatment had lasted ≥2 years had a significantly higher 2-year PFS rate than patients whose remission after previous treatment had been <2 years (68% vs. 33%, Wilcoxon p = 0.0211). Major adverse events during the protocol treatment and within 2 years after the consolidation were hematological toxicities, but they were generally acceptable. Consequently, the estimated 2-year overall survival after the consolidation was 95% (95% CI, 74%-99%). In conclusion, in a subset of patients with previously treated FL, 90 Y-IT consolidation after BR re-induction conferred a durable remission, indicating that consolidation therapy using 90 Y-IT may be a novel therapeutic option for patients with relapsed FL (UMIN000008793).

Single response assessment of transplant-ineligible multiple myeloma: a supplementary analysis of JCOG1105 (JCOG1105S1).

BACKGROUND: The International Myeloma Working Group response criteria require two consecutive assessments of paraprotein levels. We conducted an exploratory analysis to evaluate whether a single response assessment could be a substitute for the International Myeloma Working Group criteria using data from JCOG1105, a randomized phase II study on melphalan, prednisolone and bortezomib. METHODS: Of 91 patients with transplant-ineligible newly diagnosed multiple myeloma, 79 patients were included. We calculated the kappa coefficient to evaluate the degree of agreement between the International Myeloma Working Group criteria and the single response assessment. RESULTS: Based on the International Myeloma Working Group criteria, 11 (13.9%), 20 (25.3%), 36 (45.6%) and 12 (15.2%) patients had stringent complete response/complete response, very good partial response, partial response and stable disease, respectively. Based on the single response assessment, 17 (21.5%), 19 (24.1%), 35 (44.3%) and 8 (10.1%) patients had stringent complete response/complete response, very good partial response, partial response and stable disease, respectively. The kappa coefficient was 0.76 (95% confidence interval, 0.65-0.88), demonstrating good agreement. The single response assessment was not inferior to the International Myeloma Working Group criteria in the median progression-free survival (3.8 and 2.9 years) in stringent complete response/complete response patients, suggesting that the single response assessment was not an overestimation. CONCLUSIONS: The single response assessment could be a substitute for the current International Myeloma Working Group criteria for transplant-ineligible newly diagnosed multiple myeloma.

A questionnaire survey on evaluation for penetration and compliance of the Japanese Guideline on Febrile Neutropenia among hematology-oncology physicians and surgeons.

PURPOSE: The Japanese Society of Medical Oncology published a guideline (GL) on febrile neutropenia (FN) in 2017. The study's purpose is to reveal how widely GL penetrated among physicians and surgeons providing chemotherapy. METHODS: A questionnaire survey was conducted with SurveyMonkey™ for members of the Japanese Association of Supportive Care in Cancer and relevant academic organizations. Each question had four options (always do, do in more than half of patients, do in less than half, do not at all) and a free description form. Responses were analyzed with statistical text-analytics. RESULT: A total of 800 responses were retrieved. Major respondents were experts with more than 10-year experience, physicians 54%, and surgeons 46%. Eighty-seven percent of respondents knew and used GL. Forty-eight percent assessed FN with Multinational Association of Supportive Care in Cancer (MASCC) score "always" or "more than half." Eighty-one percent chose beta-lactam monotherapy as primary treatment in high-risk patients. Seventy-seven percent did oral antibacterial therapy in low-risk patients ambulatorily. Seventy-eight percent administered primary prophylactic G-CSF (ppG-CSF) in FN frequency ≥ 20% regimen. Fifty-nine percent did ppG-CSF for high-risk patients in FN frequency 10-20% regimen. Ninety-seven percent did not use ppG-CSF in FN frequency < 10% regimen. The medians of complete and complete plus partial compliance rates were 46.4% (range 7.0-92.8) and 77.8% (range 35.4-98.7). The complete compliance rates were less than 30% in seven recommendations, including the MASCC score assessment. CONCLUSION: GL is estimated to be widely utilized, but some recommendations were not followed, presumably due to a mismatch with actual clinical practices in Japan.

Does the SARS-CoV-2 rapid antigen test result correlate with the viral culture result?

Rapid antigen tests (RATs) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have advantages over viral culture in terms of cost and rapidity of testing, but they have low sensitivity. In addition, RATs tend to be negative from approximately 11 days after symptom onset. To determine whether the antigen-negative state indicates a lack of infectiousness, we assessed the association between viral culture and RAT results. Viral culture, reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and rapid antigen testing were performed on stored nasopharyngeal samples with threshold cycle values < 30, based on previous RT-qPCR testing. SARS-CoV-2 was isolated by viral culture from nine samples (45%) and one sample (17%) with positive and negative RAT results, respectively. The RAT and viral culture results were both associated with the viral load level and their cutoffs were similar, but the associations were not statistically significant. RAT might be a useful indicator of infectiousness, which can be helpful to control infection. However, further studies with larger sample size are warranted to confirm this observation.

DA-EPOCH-R combined with high-dose methotrexate in patients with newly diagnosed stage II-IV CD5-positive diffuse large B-cell lymphoma: a single-arm, open-label, phase II study.

CD5-positive diffuse large B-cell lymphoma (CD5+ DLBCL) is characterized by poor prognosis and a high frequency of central nervous system relapse after standard immunochemotherapy. We conducted a phase II study to investigate the efficacy and safety of dose-adjusted (DA)- EPOCH-R (etoposide, prednisone, vincristine, cyclophosphamide, doxorubicin, and rituximab) combined with high-dose methotrexate (HD-MTX) in newly diagnosed patients with CD5+ DLBCL. Previously untreated patients with stage II to IV CD5+ DLBCL according to the 2008 World Health Organization classification were eligible. Four cycles of DA-EPOCH-R followed by two cycles of HD-MTX and four additional cycles of DAEPOCH- R (DA-EPOCH-R/HD-MTX) were planned as the protocol treatment. The primary end point was 2-year progression-free survival (PFS). Between September 25, 2012, and November 11, 2015, we enrolled 47 evaluable patients. Forty-five (96%) patients completed the protocol treatment. There were no deviations or violations in the DA-EPOCH-R dose levels. The complete response rate was 91%, and the overall response rate was 94%. At a median follow up of 3.1 years (range, 2.0-4.9 years), the 2- year PFS was 79% [95% confidence interval (CI): 64-88]. The 2-year overall survival was 89% (95%CI: 76-95). Toxicity included grade 4 neutropenia in 46 (98%) patients, grade 4 thrombocytopenia 12 (26%) patients, and febrile neutropenia in 31 (66%) patients. No treatment-related death was noted during the study. DA-EPOCH-R/HD-MTX might be a first-line therapy option for stage II-IV CD5+ DLBCL and warrants further investigation. (Trial registered at: UMIN-CTR: UMIN000008507.).

An internet-based survey exploring the awareness of febrile neutropenia in patients with malignant lymphoma.

PURPOSE: Febrile neutropenia (FN) is associated with infection-related mortality and a reduction of relative dose intensity during chemotherapy of malignant lymphoma. To prevent deaths and recover the attenuated efficacy of chemotherapies caused by FN, guidelines for the management of FN are published. The aim of this study is to clarify the degree to how much patients understand the FN. METHODS: An internet-based survey was employed to investigate the awareness of FN in Japanese patients who had received chemotherapies for malignant lymphoma. RESULTS: A total of 105 subjects were enrolled, of whom 64 (61.0%) received ambulatory treatment and 41 (39.0%) received primarily inpatient services. Sixty-four (61.0%) remembered receiving explanations of FN and 61 (95.3%) understood FN very well or almost well. Respondents who reported understanding received explanations from multiple medical staff that were similar to those from single medical staff. A total of 31 (29.5%) experienced FN and 17 of them developed FN at home. Only 8 (47.1%) visited or made contact with their hospitals within 3 h after onset at home. CONCLUSIONS: Explanatory procedures need to be addressed, since subjects' levels of understanding were not proportionate to the number of elucidators. Although medical professionals made preliminary explanations, in fact, no more than half of those respondents who developed FN at home had made contact to their hospitals immediately. In conclusion, these results suggest that medical professionals should make more effort to lead patients to an understanding of the proper correspondences in case of FN onset.

Intravenous itraconazole compared with liposomal amphotericin B as empirical antifungal therapy in patients with neutropaenia and persistent fever.

BACKGROUND: Fungal infections are a major complication of neutropaenia following chemotherapy. Their early diagnosis is difficult, and empirical antifungal treatment is widely used, and uses of less toxic drugs that reduce breakthrough infection are required. OBJECTIVE: We conducted a multicentre, open-label, randomised, non-inferiority trial to compare the safety and efficacy of intravenous itraconazole (ivITCZ) and liposomal amphotericin B (LAmB) as empirical antifungal therapy in patients with haematological malignancies with neutropaenia and persistent fever. METHODS: Patients with haematological malignancies who developed fever refractory to broad-spectrum antibacterial agents under neutropaenia conditions were enrolled. Patients were randomised for treatment with LAmB (3.0 mg/kg/d) or ivITCZ (induction: 400 mg/d, maintenance: 200 mg/d). RESULTS: Observed overall favourable response rates of 17/52 (32.7%) and 18/50 (36.0%) in the LAmB and ivITCZ groups, with a model-based estimate of a 4% difference (90% CI, -12% to 20%), did not fulfil the statistical non-inferiority criterion. In the LAmB group, there were two cases of breakthrough infection and five cases of probable invasive fungal disease, whereas in the itraconazole group, neither breakthrough infection nor probable invasive fungal disease occurred. Patients in the ivITCZ group had significantly fewer grade 3-4 hypokalaemia-related events than LAmB group patients (P < .01). The overall incidence of adverse events tended to be lower in the ivITCZ group (P = .07). CONCLUSION: ivITCZ showed similar efficacy and safety as LAmB as empirical antifungal therapy in haematological malignancy patients with febrile neutropaenia, although the small sample size and various limitations prevented demonstration of its non-inferiority.

Multicenter phase 1/2 study of forodesine in patients with relapsed peripheral T cell lymphoma.

Peripheral T cell lymphomas are an aggressive group of non-Hodgkin lymphomas with poor outcomes for most subtypes and no accepted standard of care for relapsed patients. This study evaluated the efficacy and safety of forodesine, a novel purine nucleoside phosphorylase inhibitor, in patients with relapsed peripheral T cell lymphomas. Patients with histologically confirmed disease, progression after ≥ 1 prior treatment, and an objective response to last treatment received oral forodesine 300 mg twice-daily. The primary endpoint was objective response rate (ORR). Secondary endpoints included duration of response, progression-free survival (PFS), overall survival (OS), and safety. Forty-eight patients (median age, 69.5 years; median of 2 prior treatments) received forodesine. In phase 1 (n = 3 evaluable), no dose-limiting toxicity was observed during the first 28 days of forodesine treatment. In phase 2 (n = 41 evaluable), the ORR for the primary and final analyses was 22% (90% CI 12-35%) and 25% (90% CI 14-38%), respectively, including four complete responses (10%). Median PFS and OS were 1.9 and 15.6 months, respectively. The most common grade 3/4 adverse events were lymphopenia (96%), leukopenia (42%), and neutropenia (35%). Dose reduction and discontinuation due to adverse events were uncommon. Secondary B cell lymphoma developed in five patients, of whom four were positive for Epstein-Barr virus. In conclusion, forodesine has single-agent activity within the range of approved therapies in relapsed peripheral T cell lymphomas, with a manageable safety profile, and may represent a viable treatment option for this difficult-to-treat population.

Phase II Trial Using Romidepsin after Gemcitabine, Dexamethasone, and Cisplatin Therapy in Elderly Transplant-Ineligible Patients with Relapsed/Refractory Peripheral T-Cell Lymphoma: Study Protocol.

Romidepsin is an important therapeutic option for patients with peripheral T-cell lymphoma (PTCL). However, the timing of romidepsin administration remains controversial. Romidepsin was launched in Japan as a consolidation therapy agent after conventional salvage chemotherapy with gemcitabine, dexamethasone, and cisplatin (GDP). GDP therapy will be administered every 3 weeks. If complete response, partial response, or stable disease is confirmed after 2-4 GDP cycles, romidepsin will be administered every 4 weeks. The primary endpoint is a 2-year progression-free survival rate. Patients participating in this study and undergoing treatment can expect results similar to or better than those of conventional therapies.

[Acute myeloid leukemia with sudden onset bilateral lower extremity paralysis caused by disseminated mucormycosis following unrelated bone marrow transplantation].

A 63-year-old woman was admitted to our hospital with relapsed acute myeloid leukemia. On day10 after reinduction therapy, she became febrile. Computed tomography on day15 revealed right upper lobe consolidation. Because the ß-D glucan and Aspergillus galactomannan antigen tests were negative, we considered pulmonary mucormycosis as a breakthrough infection under voriconazole administration. Liposomal amphotericin B was initiated, and the patient underwent unrelated bone marrow transplantation although not in complete remission. She developed right shoulder pain on day1, and her pneumonia worsened on day3. She reported right lower extremity paralysis on day15, and developed bilateral lower extremity motor and sensory paralysis the next day. T2-enhanced magnetic resonance imaging revealed hyperdense lesions in the spinal cord at Th11. Transverse myelitis was diagnosed, and she underwent antiviral therapy. After engraftment, she died of pneumonia on day24. Postmortem examination revealed disseminated mucormycosis involving the lungs, liver, diaphragm, blood vessels, and dura matter of the spinal cord; it also revealed that the sudden bilateral lower extremity paralysis was caused by disseminated mucormycosis. This case stresses the possibility of mucormycosis, particularly in prolonged neutropenic patients with pain, fever, and focal neurological findings.

Correction to: Multicenter phase 1/2 study of forodesine in patients with relapsed peripheral T cell lymphoma.

The original version of this article contained a mistake in Fig. 4. The horizontal axis should be 36 instead of 60.

R-mini CHP in ≥80-year-old Patients with Diffuse Large B-cell Lymphoma: A Multicenter, Open-label, Single-arm Phase II Trial Protocol.

In very-elderly diffuse large B-cell lymphoma (DLBCL) patients, treatment intensities must be lowered due to the risks of comorbidities and organ function deterioration, and treatment outcomes are worse compared to younger patients. Very-elderly patients are often excluded from DLBCL clinical trials, and optimal treatments and dosages are not established. In this clinical trial, we examined the efficacy and safety of 6 courses of R-mini CHP therapy (cf., CHOP [cyclophosphamide, doxorubicin, vincristine, and prednisone]) in which vincristine is omitted to avoid the peripheral neuropathy that reduces elderly patients' quality of life, as remission induction therapy in DLBCL patients aged≥80 years.

High-dose Dexamethasone Therapy as the Initial Treatment for Idiopathic Thrombocytopenic Purpura: Protocol for a Multicenter, Open-label, Single Arm Trial.

Standard therapy for idiopathic thrombocytopenic purpura (ITP) has not been established. We are conducting a multicenter, prospective trial to determine the efficacy and safety of short-term, high-dose dexamethasone therapy in ITP patients aged 18-80 years with platelet counts of <20, 000 /µL, or with <50, 000/ µL and bleeding symptoms. The primary endpoints of this trial are the proportion of responses (complete plus partial response) on day 180 (day 46+180) after the completion of the 46-day high-dose dexamethasone therapy. The results of this investigation of the effectiveness and safety of this regimen will be essential for the establishment of standard therapy for ITP.

Dose-adjusted EPOCH chemotherapy for untreated peripheral T-cell lymphomas: a multicenter phase II trial of West-JHOG PTCL0707.

The standard CHOP therapy for peripheral T-cell lymphoma has resulted in unsatisfactory outcomes and it is still not clear what is the optimal front-line therapy. We conducted a multicenter phase II study of dose-adjusted etoposide, doxorubicin, and cyclophosphamide with vincristine and prednisone (EPOCH) for untreated peripheral T-cell lymphoma patients. In this prospective study, 41 patients were treated with dose-adjusted-EPOCH as initial therapy: peripheral T-cell lymphoma-not otherwise specified, n=21; angioimmunoblastic T-cell lymphoma, n=17; anaplastic lymphoma kinase-positive anaplastic large cell lymphoma, n=2; and anaplastic lymphoma kinase-negative anaplastic large cell lymphoma, n=1. Median patient age was 64 years (range: 32-79 years). According to the International Prognostic Index criteria, 51.2% were at high-intermediate or high risk. The overall response and complete response rates were 78.0% [95% confidence interval (CI): 62.4-89.4%] and 61.0% (95%CI: 44.5-75.8%), respectively. At the median follow up of 24.0 months, the 2-year progression-free survival and overall survival were 53.3% (95%CI: 36.4-67.5%) and 73.2% (95%CI: 56.8-84.1%), respectively. The younger patients (≤ 60 years old) had a high response rate (overall response 94.1% and complete response 70.6%) and survival rate (progression-free survival 62.5% and overall survival 82.4%). The most common grade ≥ 3 adverse events were neutropenia (74.5%), anemia (40.8%), thrombocytopenia (22.0%), and febrile neutropenia (9.0%). Dose-adjusted-EPOCH had a high response rate with a tolerable toxicity profile. Our results indicate that dose-adjusted-EPOCH is a reasonable first-line approach for peripheral T-cell lymphoma patients and may improve outcomes.