Mitoxantrone Hydrochloride Liposome Injection-containing Bridging Regimen and CD19-targeting CAR-T Therapies

Chimeric antigen receptor T-cell (CAR-T) therapy has been approved for a variety of relapsed/refractory hematologic malignancies and has significantly improved patient outcomes. The preparation of CAR-T cells, including a variety of relevant individual factors, usually takes at least 3-4 weeks, or more, so patients may require bridging therapy (BT) to control disease progression and prevent the rapid exacerbation of systemic cancer. Clinical trial data have shown that about 7% of patients do not survive while waiting for CAR-T cell preparation to be completed, so individual bridging therapy can be given after apheresis and 4-6 weeks before CAR-T infusion to achieve effective CAR-T cell therapy.

Mitoxantrone, a traditional anthracycline quinone, is an antibiotic antineoplastic drug. It exerts antitumor effects by interfering with DNA, RNA, and inhibition of topoisomerase II, and is a cell cycle non-specific drug\[\]. Liposomes are excellent carriers of anti-tumor drugs, which can reduce the distribution of drugs in normal tissues and increase the accumulation of drugs in tumor tissues, thereby reducing toxicity and improving treatment efficacy. To reduce the toxicity of mitoxantrone and improve its efficacy, CSPC Pharmaceutical Group has developed the liposomal formulation of mitoxantrone, which is based on liposomal R\&D technology. A new technical upgrade has been carried out on the mitoxantrone liposome, making it the only liposome with a higher dosage than the ordinary preparation, and it is a new anthracycline liposome that has been comprehensively upgraded. In the pivotal phase II study of liposomal mitoxantrone, monotherapy with PTCL was associated with an ORR of 41.7%, a CR rate of 23.1%, a median PFS of 8.5 months, a median OS not reached, and a high incidence of adverse events such as neutropenia and pigmentation, with a good cardiac safety profile and no progression of cardiotoxicity. Single-agent 16mg/m2 and 20mg/m2 doses were also explored in DLBCL, and 35 patients with relapsed and refractory DLBCL were enrolled, with an overall objective response rate of 38.5% in the 26 full analysis sets, which had certain activity in DLBCL.