上田 真寿

BACKGROUND: Despite its promising outcome, anti-BCMA CAR-T is the most expensive myeloma treatment that has ever been developed, and its cost-effectiveness is an important issue. OBJECTIVE: This study aimed to assess the cost-effectiveness of anti-BCMA CAR-T in comparison with standard anti-myeloma therapy in RRMM patients. STUDY DESIGN: The model assumed myeloma patients in Japan and the US who have received ≥3 prior lines of anti-myeloma therapies including PIs, IMiDs, and anti-CD38 mAbs. A Markov model was constructed to compare the 'CAR-T' strategy, in which patients receive either idecabtagene vicleucel (ide-cel) or ciltacabtagene autoleucel (cilta-cel) followed by three lines of multiagent chemotherapy after relapse, to the 'no CAR-T' strategy, in which patients only receive chemotherapies. The data from the LocoMMotion, KarMMa, and CARTITUDE-1 trials were extracted. Several assumptions were made regarding long-term progression-free survival (PFS) with CAR-Ts. Extensive scenario analyses were made regarding regimens for 'no CAR-T' strategies. The outcome was an incremental cost-effectiveness ratio (ICER) with willingness-to-pay thresholds of \ 7,500,000 in Japan and $150,000 in the US. RESULTS: When a 5-year PFS of 40% with cilta-cel was assumed, the ICER of the 'CAR-T' versus 'no CAR-T' strategies was \7,603,823 in Japan and $112,191 in the US per QALY over a 10-year time horizon. When a 5-year PFS of 15% with ide-cel was assumed, the ICER was \20,388,711 in Japan and $261,678 in the US per QALY over a 10-year time horizon. The results were highly dependent on the PFS assumption with CAR-T and were robust to changes in most other parameters and scenarios. CONCLUSION: Although anti-BCMA CAR-T can be cost-effective even under current pricing, a high long-term PFS is necessary.

Aprepitant (Apr) is an effective antiemetic agent for chemotherapy-induced nausea and vomiting (CINV). Current CINV guidelines recommend the antiemetic combination of a 5-HT3 receptor antagonist, Apr, and dexamethasone (Dex) for highly emetogenic chemotherapies. Apr inhibits CYP3A4 dose-dependently. Since Dex is metabolized by CYP3A4, the combined use of Apr and Dex inhibits Dex metabolism. CINV guidelines therefore recommend dose-reduction of Dex when Apr and Dex are used together. However, there is some controversy over whether or not Dex should be reduced when administered as an antitumor agent for lymphoid malignancies. We retrospectively compared the antitumor effect of Dex-containing chemotherapy in which Dex is administered at the usual dose without Apr (group A) or administered at a half-dose in combination with Apr (group B). We analyzed 62 consecutive patients with refractory or relapsed CD20 + B cell lymphoma who received R-DHAP therapy in our hospital, including 29 and 33 cases in groups A and B, respectively. The response rate at the end of the first course of R-DHAP was 62.1% and 54.5%, respectively (P = 0.61). As another endpoint to evaluate the effect of Dex, group B tended to show greater suppression of the lymphocyte count (P = 0.05). Therefore, decreasing the dose of Dex by half appeared to be reasonable when combined with Apr.

Triplet regimens such as lenalidomide, bortezomib, and dexamethasone (RVd) or thalidomide, bortezomib, and dexamethasone (VTd) are standard induction therapies for transplant-eligible newly diagnosed multiple myeloma (NDMM) patients. The addition of daratumumab to RVd and VTd has been investigated in the GRIFFIN and CASSIOPEIA trials, respectively, resulting in improvement in the rate of minimal residual disease (MRD) negativity. In this study, we conducted a cost-effectiveness analysis with a 10-year time horizon to compare first-line and second-line use of daratumumab for transplant-eligible NDMM patients. Since long-term follow-up data for these clinical trials are not yet available, we developed a Markov model that uses MRD status to predict PFS. Daratumumab was used either in the first-line setting in combination with RVd or VTd, or in the second-line setting with carfilzomib plus dexamethasone (Kd). Quality-adjusted life years (QALYs) and incremental cost-effectiveness ratios (ICERs) were calculated from a Japanese and US payer perspective. In the Japanese analysis, D-RVd showed higher QALYs (5.43 vs 5.18) and lower costs (\ 64,479,793 vs 71,287,569) compared to RVd, and D-VTd showed higher QALYs (5.67 vs 5.42) and lower costs (\ 43,600,310 vs \ 49,471,941) compared to VTd. Similarly, the US analysis demonstrated dominance of a strategy incorporating daratumumab in first-line treatment regimens. Given that overall costs are reduced and outcomes are improved when daratumumab is used as part of a first-line regimen, the economic analysis indicates that addition of daratumumab to first-line RVd and VTd regimens is a dominant strategy compared to reserving its use for the second-line setting.

The cost of tyrosine kinase inhibitors (TKIs) in the treatment of chronic myeloid leukemia (CML) is a substantial economic burden. In Japan, imatinib, dasatinib, and nilotinib are now approved as first-line treatment of CML in chronic phase. Recent "stop TKI" trials have shown that TKIs can be safely discontinued in nearly one-half of patients with sustained deep molecular response (DMR). In this study, we analyzed the cost-effectiveness of a simulated 10 years of CML treatment including stop TKI in both the United States and Japan. We constructed Markov models to compare 4 strategies in which treatment was initiated with imatinib, dasatinib, nilotinib, or any of these TKIs at the physician's discretion. Treatment was switched to another TKI in the case of intolerance or resistance to the initial TKI, and TKIs were discontinued if DMR persisted for 2 years. "Imatinib first" offered 7.34 quality-adjusted life years (QALYs) at the cost of $1 022 148 in the United States (US dollars) and \32 526 785 in Japan (Japanese yen). In comparison with imatinib first, the incremental cost-effectiveness ratio per QALY of "dasatinib first" (7.68 QALY, $1 236 052, \51 506 254), "nilotinib first" (7.64 QALY, $1 245 667, \39 635 598), and "physician's choice" (7.55 QALY, $1 167 818, \41 187 740) was $641 324, $696 717, and $666 634 in the United States and \54 456 325, \23 154 465, and \39 635 615 in Japan, respectively. None of the 3 strategies met the willingness-to-pay threshold. The results were robust to univariate and multivariate sensitivity analyses. Imatinib first was shown to be the most cost-effective approach even with the incorporation of stop TKI.

Objectives: Increasing numbers of reports have described hematopoietic improvement after iron chelation therapy in iron-overloaded patients. These observations indicate that excess iron could affect hematopoiesis unfavorably. To investigate how excess iron affects hematopoiesis in vivo, we generated iron-overloaded mice and examined hematopoietic parameters in these mice. Methods: We generated iron-overloaded mice by injecting 200 mg of iron dextran into C57BL/6J mice, and immature hematopoietic cells in the bone marrow were evaluated by flow cytometric analyses, colony-forming assays, and bone marrow transplantation analyses. We also examined changes in molecular profiles of the hematopoietic microenvironment. Results and Conclusions: Iron-overloaded (IO) mice did not show significant defects in the hematopoietic data of the peripheral blood. Myeloid progenitor cells in the bone marrow were increased in IO mice, but the number and function of the erythroid progenitors and hematopoietic stem cells were not significantly affected. However, bone marrow transplantation from normal donors to IO recipients showed delayed hematopoietic reconstitution, which indicates that excess iron impacts the hematopoietic microenvironment negatively. Microarray and quantitative RT-PCR analyses on the bone marrow stromal cells demonstrated remarkably reduced expression of CXCL12, VCAM-1, Kit-ligand, and IGF-1 in the iron-overloaded mice. In addition, erythropoietin and thrombopoietin levels were significantly suppressed, and increased oxidative stress was observed in the IO bone marrow and liver. Consequently, our findings indicate that excess iron can damage bone marrow stromal cells and other vital organs, disrupting hematopoiesis presumably by increased oxidative stress.