Pixantrone Dimaleate

Cancer stem cells (CSCs) contribute to therapy resistance in HCC. Linear ubiquitin chain assembly complex (LUBAC) has been reported to accelerate the progression of cancers, yet its role in the sorafenib response of HCC is poorly defined. Herein, we investigated the impact of LUBAC on sorafenib resistance and the CSC properties of HCC, and explored the potential targeted drugs.

We found that HOIL-1, but not the other components of LUBAC, played a contributing role in LUBAC-mediated HCC sorafenib resistance, independent of its ubiquitin ligase activity. Both in vitro and in vivo assays revealed that the upregulated HOIL-1 expression enhanced the CSC properties of HCC. Mechanistically, HOIL-1 promoted sorafenib resistance and the CSC properties of HCC through Notch1 signaling. Mass spectrometry, co-immunoprecipitation, western blot, and immunofluorescence were used to determine that the A64/Q65 residues of HOIL-1 bound with the K78 residue of Numb, resulting in impaired Numb-mediated Notch1 lysosomal degradation. Notably, pixantrone was screened out by Autodock Vina, which was validated to disrupt HOIL-1/Numb interaction to inhibit Notch1 signaling and CSC properties by targeting the Q65 residue of HOIL-1. Moreover, pixantrone exerted synergistic effects with sorafenib for the treatment of HCC in different HCC mouse models.

HOIL-1 is critical in promoting sorafenib resistance and CSC properties of HCC through Notch1 signaling. Pixantrone targeting HOIL-1 restrains the sorafenib resistance and provides a potential therapeutic intervention for HCC.

The prognosis of diffuse large B‐cell lymphoma (DLBCL) patients with refractory or multiply relapsed (R/R) disease is disappointing. Pixantrone is currently approved as third or fourth line regimen, with encouraging results, even if long‐term follow‐up data are limited.

In this post‐hoc analysis of our observational study, we retrospectively investigated disease outcome and clinical characteristics of 16 R/R DLBCL patients who achieved a complete response with pixantrone.

Pixantrone was administered as third or fourth line in 12/16 (75%) and 4/16 (25%) cases. After a median follow‐up of 24 months, 14/16 patients (87.5%) were alive (causes of death were progressive disease and secondary acute myeloid leukemia, one case each). Median progression‐free survival was 23.8 months, median duration of response was 17.8 months and median overall survival (OS) was not reached (2‐years OS was 84%). A significant proportion of patients achieved a long‐lasting response >12 months (7/16 cases). Response to prior therapy did not influence long‐term remission after pixantrone.

In this real‐life experience, pixantrone demonstrated long‐term efficacy in a cohort of R/R DLBCL cases who had previously received at least two prior regimens; many of whom had characteristics associated with poor prognosis.