Response to mRNA SARS-CoV-2 vaccination evaluated by B-cell receptor repertoire after tixagevimab/cilgavimab administration.

The use of anti-SARS-CoV-2 antibody products like tixagevimab/cilgavimab represents an important strategy to protect immunocompromised patients with haematological malignancies from COVID-19. Although patients who receive these agents should still be vaccinated, the use of tixagevimab/cilgavimab can mask the production of anti-spike antibody after vaccination, making it hard to assess vaccine response. We have newly established a quantification method to assess the response to SARS-CoV-2 vaccination at the mRNA level using B-cell receptor (BCR) repertoire assay and the Coronavirus Antibody Database (CoV-AbDab). Repeated blood samples before and after vaccination were analysed for the BCR repertoire, and BCR sequences were searched in the database. We analysed the number and percentage frequency of matched sequences. We found that the number of matched sequences increased 2 weeks after the first vaccination and quickly decreased. Meanwhile, the number of matched sequences more rapidly increased after the second vaccination. These results show that the postvaccine immune response can be assessed at the mRNA level by analysing the fluctuation in matching sequences. Finally, BCR repertoire analysis with CoV-AbDab clearly demonstrated the response to mRNA SARS-CoV-2 vaccination even after tixagevimab/cilgavimab administration in haematological malignancy patients who underwent allogeneic haematopoietic stem cell transplantation.

Guidelines for clinical evaluation of anti-cancer drugs.

Clinical studies intended for regulatory approval must demonstrate the clinical benefits of the drug in a target population. Clinical development of a drug proceeds by stepwise clinical studies; after safety and pharmacokinetics are evaluated and the recommended dosage and administration are determined, efficacy and safety are evaluated in an exploratory manner, and finally clinical benefits are compared with conventional standard therapies. Guidelines for the clinical evaluation of anti-cancer drugs in Japan were established in 1991 and amended in 2006 after molecular-targeted drugs were introduced. Recent progress in the development of drugs acting on the immune system and cancer genomic medicine targeting rare but important molecular subtypes have altered the strategy for development of anti-cancer drugs. It is often difficult to conduct a confirmatory randomized controlled study using overall survival as the primary endpoint in rare molecular subtypes, and the primary evaluation of the efficacy of some drugs and subsequent approval is based on the tumor response. As conducting clinical studies for rare subtypes solely within Japan is difficult, drug development needs to be conducted within a global study. However, this requires robust monitoring to detect possible ethnic differences in pharmacokinetics and drug efficacy. Development using the conditional approval system for drugs enforced in 2020 may be considered, when clinical utility is evaluated based on surrogate endpoints. Because of these changes, we have revised the guidelines for the clinical evaluation of anti-cancer drugs in Japan. To promote global development of anti-cancer drugs involving Japan, the guidelines have been translated into English.

Association of antithyroglobulin antibodies with the development of thyroid dysfunction induced by nivolumab.

Thyroid dysfunction (TD) induced by immune checkpoint inhibitors is not sufficiently understood. The purpose of this retrospective observational study was to identify risk factors and the clinical course of TD induced by nivolumab. Patients with advanced solid tumors who were treated with nivolumab from March 2009 through to March 2016 at the National Cancer Center Hospital (Tokyo, Japan) were included. Thyroid function and antithyroid Abs from serum samples among all patients were evaluated at baseline and during nivolumab treatment. Overt hypothyroidism was defined as low serum-free T4 together with elevated thyroid-stimulating hormone (TSH) >10 µIU/mL. Thyrotoxicosis was defined as low TSH with elevated free T4 and/or free T3. We defined thyroid autoimmunity as the presence of antithyroid Abs at baseline, including antithyroid peroxidase Abs and antithyroglobulin Abs (TgAb). Twenty-three (14%) of a total of 168 patients developed TD, including 17 cases of hypothyroidism and 20 of thyrotoxicosis. Thyrotoxicosis followed by hypothyroidism occurred in 14 cases. Fourteen of 35 patients (40%) with thyroid autoimmunity developed TD vs 9 of 133 (7%) without (odds ratio 9.19; 95% confidence interval [CI], 3.53-23.9). In multivariate analysis, elevated TSH and TgAb at baseline were significantly associated with the development of TD, with odds ratio of 7.36 (95% CI, 1.66-32.7) and 26.5 (95% CI, 8.18-85.8), respectively. Association between TD and elevated antithyroid peroxidase Abs at baseline was not significant. These results suggest that patients with pre-existing TgAb and elevated TSH at baseline are at high risk of TD.

A case report of epithelioid inflammatory myofibroblastic sarcoma with RANBP2-ALK fusion gene treated with the ALK inhibitor, crizotinib.

Epithelioid inflammatory myofibroblastic sarcoma is a variant of inflammatory myofibroblastic tumor with aggressive clinical course associated with RANBP2-ALK fusion. The present report describes a case of a 22-year-old Japanese man with a pelvic mesenchymal neoplasm. The feature of the neoplasms, including epithelioid morphology, anaplastic lymphoma kinase staining on the nuclear membrane, and results from the reverse transcriptase-polymerase chain reaction, led to diagnosis of epithelioid inflammatory myofibroblastic sarcoma with RANBP2-ALK fusion. Despite two surgical excision procedures, local recurrence rapidly occurred, and the tumor developed resistance to conventional chemotherapy with doxorubicin. Subsequent administration of crizotinib, an oral anaplastic lymphoma kinase inhibitor, resulted in tumor shrinkage. Distinguishing epithelioid inflammatory myofibroblastic sarcoma from conventional inflammatory myofibroblastic tumor is important, and crizotinib is a promising treatment for this aggressive tumor.

[Evaluation of recurrence rates on change in hormone receptor and human epidermal growth factor receptor 2 status after neo-adjuvant chemotherapy in breast cancer patients].

BACKGROUND: Neo-adjuvant chemotherapy(NAC)may affect hormone receptor(HR)and human epidermal growth factor receptor 2(HER2)status in breast cancer patients. However, the correlation between recurrence rates and this status change remains unclear. METHODS: We evaluated 70 consecutive breast cancer patients receiving NAC with anthracyclines and taxanes, with or without trastuzumab, between January 2005 and May 2012. Pre-treatment core needle biopsy samples and specimens obtained after surgery were tested to determine HR and HER2 status. The relationship between HR and HER2 status changes and recurrence rates was then assessed. RESULTS: Pathological complete response(pCR)was observed in 13 cases and non-pCR was observed in 57 cases. Of the non-pCR cases, HR-positive status changed to HR-negative status in 6.3% of patients, but a change from negativity to positivity was not observed. HER2-positive status changed to HER2-negative status in 48.0% of patients, and a change from negativity to positivity was observed in 12.5% of cases. The recurrence rate among patients with conversion to a HR-negative status was 0%and that among patients with conversion to a HER2-negative status was 25.0%. CONCLUSION: Recurrence rates were not significantly associated with HR and HER2 status conversion after NAC. Future research is warranted to confirm out results.

Analysis of B-cell receptor repertoire to evaluate the immunogenicity of SARS-CoV-2 RBD mRNA vaccine: MAFB-7256a (DS-5670d).

A monovalent Omicron XBB.1.5 mRNA RBD analogue vaccine, MAFB-7256a (DS-5670d), was newly developed and approved in Japan in the Spring of 2024 for the prevention of COVID-19. However, clinical efficacy data for this vaccine are currently lacking. We previously established the Quantification of Antigen-specific Antibody Sequence (QASAS) method to assess the response to SARS-CoV-2 vaccination at the mRNA level using B-cell receptor (BCR) repertoire assays and the Coronavirus Antibody Database (CoV-AbDab). Here, we used this method to evaluate the immunogenicity of MAFB-7256a. We analyzed repeated blood samples using the QASAS method from three healthy volunteers before and after MAFB-7256a vaccination. BCR response increased rapidly one week post-vaccination and then decreased, as with conventional vaccine. Notably, the matched sequences after MAFB-7256a vaccination specifically bound to the receptor-binding domain (RBD), with no sequences binding to other epitopes. These results validate that MAFB-7256a is an effective vaccine that exclusively induces antibodies specific for the RBD, demonstrating its targeted immunogenic effect.

Analysis of B-cell receptor repertoire to evaluate immunogenicity of monovalent Omicron XBB.1.5 mRNA vaccines.

Monovalent Omicron XBB.1.5 mRNA vaccines were newly developed and approved by the FDA in Autumn 2023 for preventing COVID-19. However, clinical efficacy for these vaccines is currently lacking. We previously established the quantification of antigen-specific antibody sequence (QASAS) method to assess the response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination at the mRNA level using B-cell receptor (BCR) repertoire assay and the coronavirus antibody database (CoV-AbDab). Here, we used this method to evaluate the immunogenicity of monovalent XBB.1.5 vaccines. We analyzed repeated blood samples of healthy volunteers before and after monovalent XBB.1.5 vaccination (BNT162b2 XBB.1.5 or mRNA-1273.815) for the BCR repertoire to assess BCR/antibody sequences that matched SARS-CoV-2-specific sequences in the database. The number of matched unique sequences and their total reads quickly increased 1 week after vaccination. Matched sequences included those bound to the Omicron strain and Omicron XBB sublineage. The antibody sequences that can bind to the Omicron strain and XBB sublineage revealed that the monovalent XBB.1.5 vaccines showed a stronger response than previous vaccines or SARS-CoV-2 infection before the emergence of XBB sublineage. The QASAS method was able to demonstrate the immunogenic effect of monovalent XBB.1.5 vaccines for the 2023-2024 COVID-19 vaccination campaign.

GSK3 inhibitor enhances gemtuzumab ozogamicin-induced apoptosis in primary human leukemia cells by overcoming multiple mechanisms of resistance.

In acute myeloid leukemia (AML), the heterogeneity of genetic and epigenetic characteristics makes treatment difficult. The prognosis for AML is therefore poor, and there is an urgent need for new treatments for this condition. Gemtuzumab ozogamicin (GO), the first antibody-drug conjugate (ADC), targets the CD33 antigen expressed in over 90% of AML cases. GO therefore has the potential to counter the heterogeneity of AML patients. However, a major clinical problem is that drug resistance to GO diminishes its effect over time. Here, we report that the inhibition of glycogen synthase kinase 3 (GSK3) alone overcomes several forms of GO resistance at concentrations without antileukemic effects. The GSK3 inhibitors tested significantly enhanced the cytotoxic effect of GO in AML cell lines. We elucidated four mechanisms of enhancement: (1) increased expression of CD33, the target antigen of GO; (2) activation of a lysosomal function essential for hydrolysis of the GO linker; (3) reduced expression of MDR1 that eliminates calicheamicin, the payload of GO; and (4) reduced expression of the anti-apoptotic factor Bcl-2. A similar combination effect was observed against patient-derived primary AML cells. Combining GO with GSK3 inhibitors may be efficacious in treating heterogeneous AML.

Incidence of venous thromboembolism in patients with solid cancers in Japan: retrospective study of 2735 patients.

BACKGROUND: The incidence of cancer-associated venous thromboembolism (CA-VTE) in Japan has not been fully investigated. METHODS AND RESULTS: Clinicopathological information from patients with solid malignancies who first visited our department between November 2011 and March 2018 were retrospectively reviewed from medical records. The primary outcome was incidence of CA-VTE, defined as deep-vein thrombosis (DVT) and/or pulmonary embolism (PE). On median follow-up of 187 days, 91 of 2735 patients (3.3%) developed CA-VTE during their clinical course, giving an incidence rate of 40.7 per 1000 person-years. Of the 91 patients, 75 (82%) were diagnosed with DVT alone, 6 (7%) with PE alone, and 10 (11%) with both DVT and PE. CA-VTE was most frequent in non-small cell lung cancer (10.8%), followed by cancer of unknown origin (5.8%). Forty-four patients (48%) had one or more symptoms at the initial diagnosis of VTE. Five patients (6%) had a normal D-dimer level (≤ 1.0 µg/mL); of these, 2 were asymptomatic. CONCLUSIONS: In this retrospective study, the incidence of CA-VTE in Japanese patients with cancer was equivalent to that in Western populations. Approximately half of CA-VTE patients were asymptomatic and 6% had normal D-dimer levels, indicating the need for closer attention to occult CA-VTE.

Regorafenib-induced exacerbation of chronic immune thrombocytopenic purpura in remission: A case report.

Regorafenib is an oral multi-kinase inhibitor which targets tumor angiogenesis, the tumor microenvironment and oncogenesis. Based on this mode of action, regorafenib has a broad spectrum of toxicities. However, at present, few reports have focused on autoimmune adverse events. We report a first case of regorafenib-induced exacerbation of chronic immune thrombocytopenic purpura in remission during treatment for the patients with heavily treated advanced colorectal cancer. This case report highlights the need for caution with regard to regorafenib treatment in patients with cancer with concomitant immune thrombocytopenic purpura.

Secondary CIC-rearranged sarcoma responsive to chemotherapy regimens for Ewing sarcoma: A case report.

Capicua transcriptional repressor (CIC)-rearranged sarcoma is an Ewing-like sarcoma with an aggressive clinical course and poor prognosis. No standard treatment has been established. The present study describes a case of CIC-rearranged sarcoma with lung metastases developing in a 24-year-old woman as a therapy-associated malignancy following chemotherapy for anaplastic large cell lymphoma at nine years old. This was treated with palliative regimens used for Ewing sarcoma. The patient achieved disease control for one year. Of note, ifosfamide and etoposide (IE), which were used as a second line treatment lead to a partial response. The case described in the present study indicated that treatment with Ewing regimens is a reasonable option for patients with metastatic CIC-rearranged sarcoma, including those with a second malignant case.

Phase 1 study of Gemcitabine/Nab-paclitaxel/S-1 in patients with unresectable pancreatic cancer (GeNeS1S trial).

PURPOSE: We conducted a phase 1 study to determine the maximum tolerated dose and the recommended dose of gemcitabine/nab-paclitaxel/S-1 combination chemotherapy in patients with unresectable pancreatic cancer. METHODS: We enrolled patients aged 20 years or older with unresectable pancreatic cancer and who had not been treated with chemotherapy or radiation therapy. Gemcitabine and nab-paclitaxel were administered on days 1 and 8, and S-1 was administered orally twice daily for 2 weeks, repeated every 3 weeks. The starting dose was level 0 [gemcitabine 700 mg/m2, nab-paclitaxel 90 mg/m2, S-1 60/80/100 mg/day (< 1.25 m2/1.25-1.50 m2/ > 1.5 m2)]. Dose-limiting toxicities were determined during the first course, and a classical 3 + 3 dose finding design was planned. RESULTS: From March 2018 to October 2019, 20 patients were enrolled. At dose level 0, three of six patients experienced dose-limiting toxicities; one grade 3 skin rash on day 8, and two grade 3 or 4 neutropenia on day 8. At dose level-1 (gemcitabine 600 mg/m2, nab-paclitaxel 90 mg/m2, and S-1 50/70/80 mg/day), two of twelve patients experienced dose-limiting toxicities, all of which were grade 3 neutropenia on day 8. The most frequently observed toxicity during eight courses was neutropenia. Other treatment-related adverse events were mild. Eleven out of 19 (58%) patients achieved partial response. CONCLUSION: We defined the maximum tolerated dose and the recommended dose for combination therapy with gemcitabine/nab-paclitaxel/S-1 as dose level-1. Considering the observed response rate, further studies are warranted in order to determine the efficacy of this regimen (UMIN-CTR 000030007).

Immune checkpoint and inflammation as therapeutic targets in pancreatic carcinoma.

Pancreatic adenocarcinoma (PAC) is one of the most deadly malignant neoplasms, and the efficacy of conventional cytotoxic chemotherapy is far from satisfactory. Recent research studies have revealed that immunosuppression and inflammation are associated with oncogenesis, as well as tumor development, invasion, and metastasis in PAC. Thus, immunosuppression-related signaling, especially that involving immune checkpoint and inflammation, has emerged as novel treatment targets for PAC. However, PAC is an immune-resistant tumor, and it is still unclear whether immune checkpoint or anti-inflammation therapies would be an ideal strategy. In this article, we will review immune checkpoint and inflammation as potential targets, as well as clinical trials and the prospects for immunotherapy in PAC.

Rapid improvement of glucagonoma-related necrolytic migratory erythema with octreotide.

Necrolytic migratory erythema (NME) is a classical paraneoplastic symptom observed in patients with pancreatic glucagonoma. We report a 46-year-old Japanese woman with glucagonoma who presented with mucocutaneous manifestations 1 year prior to the diagnosis of the pancreatic neoplasm with multiple liver metastases. She was treated with octreotide long-acting release, a somatostatin analog, which resulted in a dramatic improvement of NME within 2 weeks after the start of treatment. Increased awareness of NME may avoid unnecessary delay in the diagnosis of pancreatic glucagonoma.