Transition of the PD-1 occupancy of nivolumab on T cells after discontinuation and response of nivolumab re-challenge.

Although nivolumab is administered every two or four weeks, high programmed cell death-1 (PD-1) binding of nivolumab on T cells lasting for several months has been reported. A relationship between the PD-1 occupancy rate on T-cells and the efficacy of nivolumab is not yet fully understood. The present study used flow cytometric analyses to determine the time-dependence of PD-1 occupancy in five patients who discontinued nivolumab. The relationship between PD-1 occupancy at relapse and the efficacy of re-challenge was also studied. Occupancies after discontinuation were measured at a total of 32 points. The data indicated that it took 32.4 and 48.9 weeks to decrease occupancy by 50 and 70%, respectively. Subsequently, two patients had recurrence and were re-challenged with nivolumab. At that time, one patient had 70.8% occupancy while the other had 6.6%. Treatment was effective only for the patient with lower occupancy. Overall, the present study suggests that re-challenge with nivolumab may be efficacious in patients with low occupancy at recurrence.

Apixaban in Japanese patients with cancer-associated venous thromboembolism: a multi-center phase II trial.

BACKGROUND: Recent pivotal phase III trials involving direct oral anticoagulant (DOAC) versus low molecular weight heparin have demonstrated the utility of DOACs in Western patients with cancer-associated venous thromboembolism (VTE). However, these trials did not include Japanese patients. This phase II trial evaluated the safety and efficacy of apixaban in Japanese patients with cancer-associated VTE (UMIN000028447). METHOD AND RESULTS: Apixaban was initiated at 10 mg twice daily for 7 days, followed by 5 mg twice daily for 23 weeks. The primary endpoint was the incidence of major or clinically relevant non-major (CRNM) bleeding events during the treatment period. The study was terminated due to safety concerns after enrolling 27 patients. Median age was 71 years; median body weight was 51.3 kg; and major primary tumor sites were the gastrointestinal tract (26%) and lung (19%). During the median follow-up period of 5.4 months, major or CRNM bleeding occurred in in 26% of patients (major, n = 5; CRNM, n = 2; 95% confidence interval, 11-46%). No recurrent VTE or VTE-related death occurred. Estimated overall survival at 6 months was 68%. CONCLUSION: This study demonstrated the excessive bleeding risk of apixaban at the standard dose in Japanese patients with cancer-associated VTE.

Safety and immunogenicity of the COVID-19 vaccine BNT162b2 in patients undergoing chemotherapy for solid cancer.

BACKGROUND: Although COVID-19 severity in cancer patients is high, the safety and immunogenicity of the BNT162b2 mRNA COVID-19 vaccine in patients undergoing chemotherapy for solid cancers in Japan have not been reported. METHODS: We investigated the safety and immunogenicity of BNT162b2 in 41 patients undergoing chemotherapy for solid cancers and in healthy volunteers who received 2 doses of BNT162b2. We evaluated serum IgG antibody titers for S1 protein by ELISA at pre-vaccination, prior to the second dose and 14 days after the second vaccination in 24 cancer patients undergoing cytotoxic chemotherapy (CC group), 17 cancer patients undergoing immune checkpoint inhibitor therapy (ICI group) and 12 age-matched healthy volunteers (HV group). Additionally, inflammatory cytokine levels were compared between the HV and ICI groups at pre and the next day of each vaccination. RESULTS: Anti-S1 antibody levels were significantly lower in the ICI and CC groups than in the HV group after the second dose (median optimal density: 0.241 [0.063-1.205] and 0.161 [0.07-0.857] vs 0.644 [0.259-1.498], p = 0.0024 and p < 0.0001, respectively). Adverse effect profile did not differ among the three groups, and no serious adverse event occurred. There were no differences in vaccine-induced inflammatory cytokines between the HV and ICI groups. CONCLUSION: Although there were no significant differences in adverse events in three groups, antibody titers were significantly lower in the ICI and CC groups than in the HV group. Further protection strategies should be considered in cancer patients undergoing CC or ICI.

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.

Retroperitoneal Bulky Histiocytic Sarcoma Successfully Treated with Induction Chemotherapy Followed by Curative Surgery.

Histiocytic sarcoma (HS) is a rare hematopoietic neoplasm. We report a patient with HS treated with induction chemotherapy followed by curative surgery. A 50-year-old man was referred to our hospital because of a retroperitoneal tumor. A computed tomography scan revealed a bulky retroperitoneal mass, infiltrating the surrounding organ. An excisional biopsy confirmed the diagnosis of HS. The tumor shrunk after multidrug chemotherapy. However, positron emission tomography showed uptake of fludeoxyglucose in the residual tumor. He underwent right nephrectomy to remove the tumor. Pathological examination showed complete response. Surgery combined with induction chemotherapy may be an effective way to manage HS.