Abstract: 7548 Background: Primary central nervous system lymphoma (PCNSL) is known as an uncommon and extremely aggressive type of non-Hodgkin lymphoma of brain tumors. Tirabrutinib (TIR), a second-generation oral Bruton’s tyrosine kinase inhibitor, was approved for the treatment of relapsed or refractory PCNSL (rrPCNSL) based on the results of phase I/II study in Japan (Trial registration: JapicCTI-173646) in 2020. Methods: In this study, 44 Japanese patients with rrPCNSL received TIR QD at doses of 320 mg (n = 20), 480 mg (n = 7), or 480 mg while fasting (480 mg fasted: n = 17). The International PCNSL Collaborative Group criteria were used to assess the primary endpoint, which was the overall response rate (ORR). We previously reported the interim results with 14.9 (range:1.4–27.7) months of median follow-up in 2020 (Mishima et al., the 25th Society for Neuro-Oncology 2020). The final analysis results with a three-year follow-up are reported here (data cutoff: April 27 th , 2022). Results: For the entire population, the ORR was 63.6% with 36.4% of complete response, the median duration of response was 9.2 months, the median progression-free survival was 2.9 months, and the median overall survival was not reached (median follow-up: 37.1 months). The most frequent adverse events (AEs) were skin and subcutaneous tissue disorders and blood and lymphatic system disorders at any grade, including rash (36.4%) and neutropenia (27.3%), leukopenia (25.0%), lymphopenia (18.2%), and thrombocytopenia (11.4%). Grade ≥3 AEs were neutropenia (9.1%), leukopenia (9.1%), lymphopenia (6.8%), and erythema multiforme (6.8%). One patient with 480 mg had grade 5 AEs (Pneumocystis jirovecii pneumonia and Interstitial lung disease), while neither new grade 5 AEs nor new safety profiles were observed since the last data cutoff. As of the current data cutoff, 15 and 6 of 44 patients had been receiving TIR for more than one and three years, respectively, and 5 of the 6 patients continued receiving TIR, including 4 patients who were receiving 480 mg fasted. Conclusions: In conclusion, TIR showed long-lasting effectiveness in a subset of patients with a tolerable safety profile of rrPCNSL. Clinical trial information: JapicCTI-173646. [Table: see text]

Abstract: The ONO-4059-02 phase 1/2 study showed favorable efficacy and acceptable safety profile of tirabrutinib, a second-generation Bruton’s tyrosine kinase inhibitor, for relapsed/refractory primary central nervous system lymphoma (PCNSL). Here, we report the long-term efficacy and safety after a 3-year follow-up. Methods Eligible patients were aged ≥20 years with histologically diagnosed PCNSL and KPS of ≥70. Patients received oral tirabrutinib once daily at 320 mg or 480 mg, or 480 mg under fasted condition. Results Between October 19, 2017, and June 13, 2019, 44 patients were enrolled: 33 and 9 had relapse and refractory, respectively. The 320 mg, 480 mg, and 480 mg fasted groups included 20, 7, and 17 patients, respectively. The median follow-up was 37.1 months. The overall response rate was 63.6% (95% CI, 47.8–77.6) with complete response, unconfirmed complete response, partial response in 9, 7, and 12 patients, respectively. The median duration of response (DOR) was 9.2 months, with a DOR rate of 19.8%; the median progression-free survival (PFS) and median overall survival (OS) were 2.9 months and not reached, respectively, with PFS and OS rates of 13.9% and 56.7%, respectively. Adverse events occurred in 38 patients (86.4%): grade ≥3 in 23 (52.3%) including 1 patient with grade 5 events. KPS and quality of life (QoL) scores were well maintained among patients receiving long-term treatment. Conclusions The results demonstrated the long-term clinical benefit of tirabrutinib, with deep and durable response in a subset of patients and acceptable safety profile, while KPS and QoL scores being maintained.

Abstract: Tirabrutinib is a Bruton’s tyrosine kinase inhibitor for treating B-cell malignancies. We report the final results of a Phase I study of tirabrutinib in 17 Japanese patients with B-cell malignancies. Patients were administered tirabrutinib at a dose of 160 mg, 320 mg, or 480 mg once daily, or 300 mg twice daily ( N  = 3, 3, 4, and 7, respectively). Three patients continued tirabrutinib until study completion (November 30, 2020). Adverse events (AEs) occurred in all 17 patients, with Grade 3–4 AEs in 8 (47.1%), serious AEs in 7 (41.2%), drug-related AEs in 16 (94.1%), and Grade 3–4 drug-related AEs in 6 (35.3%). Drug-related AEs reported in 3 or more patients were rash, vomiting, neutropenia, arthralgia, and malaise. One additional serious AE (benign neoplasm of the lung, unrelated to tirabrutinib) occurred after the previous data cutoff (January 4, 2018). Tirabrutinib administration and response assessment were continued for over 4 years in 4 patients. The overall response rate was 76.5% (13/17 patients). The median (range) time to response and duration of response were 0.9 (0.9–5.9) months and 2.59 (0.08–5.45) years, respectively. These findings demonstrate the long-term safety and efficacy of tirabrutinib in Japanese patients with B-cell malignancies. Clinical trial registration: JapicCTI-142682 ( http://www.clinicaltrials.jp/ ).

Abstract: Tirabrutinib, a second-generation inhibitor of Bruton’s tyrosine kinase, was approved in March 2020 for the treatment of relapsed or refractory primary central nervous system lymphoma (r/r PCNSL) based on phase I/II studies in Japan. We previously reported the overall response rate and safety profile. We describe Karnofsky Performance Status (KPS) and the quality of life (QoL) in patients with r/r PCNSL receiving tirabrutinib based on more than 1-year follow-up data. Methods Patients with r/r PCNSL, age ≥20 years, and KPS ≥70 were treated with tirabrutinib once daily at a dose of 320, 480, or 480 mg under fasted conditions. QoL was assessed using questionnaires issued by the European Organization for Research and Treatment of Cancer (EORTC), namely EORTC QLQ-C30, EORTC QLQ-BN20, and EuroQol 5 dimensions 3-level (EQ-5D-3L) along with KPS. Results Forty-four patients (mean age, 60 years [range 29–86]) were enrolled. The median follow-up period was 14.9 months (range, 1.4–27.7). The median KPS of the patients at baseline was 80.0 (range, 70–100), and this remained constant during the treatment. The global health status/QoL in the QLQ-C30 showed significant improvements from baseline through cycles 3–17 and remained relatively constant thereafter until cycle 23. Improvements were also seen in emotional functioning and constipation in the QLQ-C30 segments. Other items of QLQ-C30 and QLQ-BN20, EQ-5D visual analog scales, and EQ-5D index were maintained during the treatment. Conclusions Tirabrutinib generally maintains KPS and QoL scores with some improvements in specific QoL items in patients with r/r PCNSL.

Abstract: This study aimed to explore the analgesic effects of fosphenytoin (fPHT) on pain-related behaviours in mouse models of subacute herpetic neuralgia (subAHN) and postherpetic neuralgia (PHN). SubAHN refers to pain experienced immediately after the disappearance of a skin rash, while PHN is characterized by persistent pain long after skin rash resolution. Methods Our experimental approach involved the induction of acute herpes zoster-like skin lesions and pain-related responses (mechanical allodynia and hyperalgesia) in the hind paws of mice through cutaneous inoculation with herpes simplex virus type 1 (HSV-1). Subsequently, subAHN and PHN developed in the mice. Key findings Intravenous administration of fPHT (30 mg/kg) effectively mitigated HSV-1-induced subAHN and PHN. The suppressive effect of fPHT on subAHN was comparable to that of pregabalin (3 mg/kg, oral), a commonly used positive control. However, fPHT exhibited a slightly more potent effect than pregabalin in alleviating PHN. Conclusions These findings suggest that intravenous fPHT could serve as a promising alternative for pain relief in both subAHN and PHN.

Abstract: Primary central nervous system lymphoma (PCNSL) is known as one of the incurable brain tumors. In March 2020, Tirabrutinib (TIR), a second-generation oral Bruton’s tyrosine kinase inhibitor, was approved for the indication of relapsed or refractory PCNSL (rrPCNSL) based on the results of a phase I/II study in Japan (Trial registration: JapicCTI-173646). In this study, 44 Japanese patients with rrPCNSL were treated with TIR QD at 320 mg, 480 mg, or 480 mg in the fasted condition (480 mg fasted QD). The primary endpoint was overall response rate (ORR) assessed by an independent review committee according to International PCNSL Collaborative Group criteria. We previously reported the results of this study with data cutoff on June 13, 2019 (Nagane et al., the 61st American Society of Hematology Annual Meeting and Exposition in 2019). In the report, 17 of 44 patients were treated with TIR at 480 mg fasted QD which is an approved dose, and had ORR of 52.9%, median progression-free survival of 5.8 months, and median overall survival of not reached (median follow-up: 3.8 months). In 44 patients, ORR was similar among patients harboring either of the oncogenic mutants CARD11, MYD88, CD79B, or wild type. Throughout the whole patients, most common adverse events (AEs) at any grade were rash (32%), neutropenia (23%), leukopenia (18%), and lymphopenia (16%), and grade ≥3 AEs were neutropenia (9.1%), lymphopenia, leukopenia, and erythema multiforme (6.8% each). One patient with 480 mg QD had grade 5 AEs (pneumocystis jirovecii pneumonia and interstitial lung disease). We will present one-year follow-up data of this study at the meeting. As of data cutoff (February 25, 2020), 11 of 44 patients continued to receive TIR, including 6 patients with 480 mg fasted QD. Updated data for OS, duration of response, and time to onset of AEs will also be presented.

Abstract: The safety, tolerability, efficacy, and pharmacokinetics of tirabrutinib, a second-generation, highly selective oral Bruton’s tyrosine kinase inhibitor, were evaluated for relapsed/refractory primary central nervous system lymphoma (PCNSL). Methods Patients with relapsed/refractory PCNSL, Karnofsky performance status ≥70, and normal end-organ function received tirabrutinib 320 and 480 mg once daily (q.d.) in phase I to evaluate dose-limiting toxicity (DLT) within 28 days using a 3 + 3 dose escalation design and with 480 mg q.d. under fasted conditions in phase II. Results Forty-four patients were enrolled; 20, 7, and 17 received tirabrutinib at 320, 480, and 480 mg under fasted conditions, respectively. No DLTs were observed, and the maximum tolerated dose was not reached at 480 mg. Common grade ≥3 adverse events (AEs) were neutropenia (9.1%), lymphopenia, leukopenia, and erythema multiforme (6.8% each). One patient with 480 mg q.d. had grade 5 AEs (pneumocystis jirovecii pneumonia and interstitial lung disease). Independent review committee assessed overall response rate (ORR) at 64%: 60% with 5 complete responses (CR)/unconfirmed complete responses (CRu) at 320 mg, 100% with 4 CR/CRu at 480 mg, and 53% with 6 CR/CRu at 480 mg under fasted conditions. Median progression-free survival was 2.9 months: 2.1, 11.1, and 5.8 months at 320, 480, and 480 mg under fasted conditions, respectively. Median overall survival was not reached. ORR was similar among patients harboring CARD11, MYD88, and CD79B mutations, and corresponding wild types. Conclusion These data indicate favorable efficacy of tirabrutinib in patients with relapsed/refractory PCNSL. Trial registration JapicCTI-173646.

Abstract: We evaluated the safety, efficacy, pharmacokinetics, pharmacodynamics and predictive biomarkers of tirabrutinib, a second‐generation, enhanced‐selectivity Bruton's tyrosine kinase inhibitor in Japanese patients with relapsed/refractory B‐cell non−Hodgkin lymphoma (B‐cell NHL ) and chronic lymphocytic leukemia ( CLL ). This was an open‐label, multicenter, phase I study. Seventeen patients (male N   =   8) with a median age of 70 years were enrolled in 4 dose cohorts (160 mg once daily [N   =   3], 320 mg once daily [N   =   3], 480 mg once daily [N   =   4] and 300 mg twice daily [N   =   7]); 4 patients had continued tirabrutinib administration as of 4 January 2018. The maximum tolerated dose was not reached. Pneumonitis (N   =   1) was the dose‐limiting toxicity for 300 mg twice daily. Common adverse events ( AE s) were rash (35.3%) and vomiting (29.4%). Eight patients (47.1%) developed grade ≥3 AE s: neutropenia (23.5%), anemia (11.8%) and leukopenia (11.8%) were frequent. The overall response rate (≥ PR ) was 76.5% (13/17 patients), including 4 DLBCL patients with no CD 79A/B or MYD 88 mutations, and 1 CLL patient with a TP 53 mutation, providing promising data for future developments. Of 16 patients with measurable lesions during the screening period, 12 showed ≥50% reductions in tumor diameter. In many patients, the tumor size decreased soon after beginning treatment. The maximum serum concentration for tirabrutinib was 611, 1220, 1280 and 886 ng/ mL on Day 1 and 484, 971 1940, and 961 ng/ mL on Day 28 for Cohorts 1‐4, respectively. Tirabrutinib pharmacokinetics were linear, with little accumulation following multiple doses. Tirabrutinib was well tolerated and showed promising efficacy for B‐cell NHL /CLL.

Abstract: BACKGROUND The first-generation Bruton's tyrosine kinase (BTK) inhibitor ibrutinib is effective in patients with relapsed/refractory (r/r) primary central nervous system lymphoma (PCNSL). Tirabrutinib is a second-generation oral BTK inhibitor with greater selectivity than ibrutinib. We evaluated the safety, tolerability, efficacy, and pharmacokinetics (PK) of tirabrutinib once daily (QD) as monotherapy in patients with PCNSL to investigate BTK targeting as a novel therapeutic strategy. This multicenter clinical trial was sponsored by Ono Pharmaceutical Co., Ltd. and was conducted in Japan. METHODS Patients with r/r PCNSL, at least 1 parenchymal disease, Karnofsky performance status (KPS) ≥70, and normal end-organ function were treated with tirabrutinib 320 and 480 mg QD in the phase 1 portion to evaluate dose-limiting toxicity (DLT) within 28 days using a 3+3 dose escalation design, and with 480 mg QD in a fasted condition in the phase 2 portion to assess the safety, efficacy, and PK of tirabrutinib. The primary objective of the phase 2 portion was to evaluate overall response rate (ORR) as assessed by an independent review committee (IRC) according to International PCNSL Collaborative Group (IPCG) criteria. RESULTS Forty-four patients were enrolled; 20 received tirabrutinib at 320 mg, 7 at 480 mg, and 17 at 480 mg under fasted conditions as of June 13, 2019. The median patient age and KPS were 60 years (range 29-86) and 80, respectively. The median number of prior therapies was 2 (range 1-14); all patients had received methotrexate; and 28 had isolated parenchymal disease, 14 cerebrospinal fluid (CSF) involvement, and 3 intraocular involvement. No DLTs were observed, and the maximum tolerated dose (MTD) was not reached up to 480 mg. Commonly observed events (AEs) at any grade were rash (32%), neutropenia (23%), leukopenia (18%), and lymphopenia (16%). Commonly observed grade ≥3 AEs were neutropenia (9.1%), lymphopenia, leukopenia, and erythema multiforme (6.8% each). Two grade 5 AEs (pneumocystis jirovecii pneumonia and interstitial lung disease) were observed in a patient 33 days after starting tirabrutinib at 480 mg QD. IRC-assessed ORR was 64% (28/44); 60% (12/20) with 5 complete response (CR)/unconfirmed complete response (CRu) at 320 mg, 100% (7/7) with 4 CR/CRu at 480 mg, and 53% (9/17) with 6 CR/CRu at 480 mg under fasted conditions. Median progression-free survival (PFS) was 2.9 months (95% confidence interval [CI]: 1.8-11.1); 2.1 months (95% CI: 1.8-NA) at 320 mg, 11.1 months (95% CI: 1.4-NA) at 480 mg, and 5.8 months (95% CI: 1.0-5.8) at 480 mg under fasted conditions. Median overall survival was not reached (95% CI: NA-NA). ORR was similar among patients harboring the oncogenic mutants CARD11, MYD88, CD79B, and wild type (Table 1). Mean values of maximum observed plasma concentration of tirabrutinib after multiple administration on Day 28 at 320 mg, 480 mg, and 480 mg under fasting conditions were 1360, 2270, and 2690 ng/mL, respectively. The area under the plasma concentration time curve over a dosing interval was 6370, 11800, and 11800 ng*h/mL, respectively. The exposure of tirabrutinib increased with increasing dose, regardless of fasting status. Mean trough concentration of tirabrutinib in CSF/plasma at 320 mg and 480 mg on Day 28 was 2.19/16.3 ng/mL and 14.0/89.3 ng/mL, respectively. This indicated that CSF concentration increased with increasing plasma concentration at trough, while the trough concentration ratios between CSF and plasma at each dose were comparable with the free fraction of tirabrutinib in plasma. CONCLUSION Tirabrutinib had a tolerable safety profile and MTD was not reached in patients with PCNSL. IRC-assessed ORR was 64%, despite the presence of CARD11 mutation. Median PFS was longer with the increasing dose. Further investigation is warranted. Disclosures Nagane: Tsumura: Research Funding; Takeda: Research Funding; Astellas: Research Funding; Pfizer: Research Funding; Otsuka: Research Funding; Bristol-Myers-Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; Dainippon-Sumitomo: Honoraria; NovoCure: Honoraria; UCB Japan: Honoraria; Daiichi-Sankyo: Honoraria, Research Funding; Nippon-Kayaku: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; MSD: Honoraria, Research Funding; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Ono: Honoraria, Research Funding; Chugai: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding; Shionogi: Research Funding; Sanofi: Research Funding. Narita:Ono: Honoraria, Research Funding; Chugai: Honoraria, Research Funding; AbbVie: Honoraria, Research Funding; Dainippon-Sumitomo: Honoraria, Research Funding; Daiichi-Sankyo: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; Stella-pharma: Honoraria, Research Funding; Otsuka: Honoraria, Research Funding; Meiji-seika: Honoraria, Research Funding; SBI pharma: Honoraria, Research Funding. Mishima:Ono: Research Funding; Chugai: Research Funding; MSD: Research Funding; Eisai: Research Funding; Teijin Pharma: Research Funding; Medical U and A: Research Funding; AbbVie: Research Funding; Otsuka: Research Funding; Daiichi-Sankyo: Research Funding; Nihon-Medi-Physics: Research Funding. Terui:Bristol-Myers Squibb, Celgene, Janssen, Takeda, MSD, Eisai, Ono, and Chugai-Roche Pharmaceuticals Co.,Ltd.: Honoraria; Bristol-Myers Squibb K.K.: Research Funding. Arakawa:UCB: Honoraria; Otsuka: Honoraria; AbbVie: Honoraria; NovoCure: Honoraria; CSL Behring: Honoraria; Nippon-Kayaku: Honoraria; Pfizer: Research Funding; Takeda: Research Funding; CLS: Research Funding; Daiichi-Sankyo: Honoraria, Research Funding; Meiji Seika: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; Chugai: Honoraria, Research Funding; Merck: Honoraria, Research Funding; TanabeMitsubishi: Research Funding; Zeiss: Research Funding; Brainlab: Honoraria, Research Funding; Nihon Medi-Physics: Research Funding; Sanofi: Research Funding; Philips: Research Funding; Siemens: Research Funding; Ono: Research Funding. Yonezawa:Ono: Research Funding. Asai:Ono: Research Funding. Fukuhara:Mundi: Honoraria; Takeda Pharmaceutical Co., Ltd.: Honoraria, Research Funding; Nippon Shinkyaku: Honoraria; Kyowa-Hakko Kirin: Honoraria; Mochida: Honoraria; Bayer: Research Funding; Gilead: Research Funding; Chugai Pharmaceutical Co., Ltd.: Honoraria; Ono Pharmaceutical Co., Ltd.: Honoraria; Eisai: Honoraria, Research Funding; Celgene Corporation: Honoraria, Research Funding; Janssen Pharma: Honoraria; Zenyaku: Honoraria; AbbVie: Research Funding; Solasia Pharma: Research Funding. Sugiyama:Ono: Research Funding; Taiho: Research Funding; Daiichi-Sankyo: Research Funding; Bristol-Myers-Squibb: Research Funding; Chugai: Research Funding; Meiji Seika: Research Funding; Yakult: Research Funding. Shinojima:Ono: Research Funding. Kitagawa:Ono: Employment. Aoi:Ono: Employment. Nishikawa:Ono: Honoraria, Research Funding; MSD: Research Funding; AbbVie: Honoraria, Research Funding; Eisai: Honoraria, Research Funding; Chugai: Honoraria, Research Funding; NovoCure: Honoraria; Daiichi-Sankyo: Honoraria. OffLabel Disclosure: Tirabrutinib. Clinical trial for PCNSL.

Abstract: Theobroxide has been isolated from culture filtrates of Lasiodiplodia theobromae as a potato tuber-inducing compound. In this study, the metabolism of theobroxide was investigated using cowpea as an experimental model and [ 2 H 3 -7] theobroxide as a substrate for analyzing a metabolite, which revealed that theobroxide applied exogenously to the roots was converted into 3- O-β-D-glucopyranosyltheobroxide.