The efficacy and toxicity of cabazitaxel for treatment of docetaxel-resistant prostate cancer correlating with the initial doses in Japanese patients

The efficacy of sequential therapy with docetaxel and cabazitaxel for castration-resistant prostate cancer: A retrospective multi-institutional study in Japan

OBJECTIVE

This study investigated the efficacy of docetaxel (DOC) and cabazitaxel (CBZ) and examined the factors associated with the prognosis of patients with castration-resistant prostate cancer (CRPC) receiving DOC-CBZ sequential treatment in Japanese real-world data.

METHODS

We retrospectively evaluated data for 146 patients who received DOC followed by CBZ. The correlations of prostate specific antigen (PSA) decrease rate and time to progression between DOC and CBZ treatment were examined. Combined progression-free survival (PFS) of DOC-CBZ and overall survival (OS) from the initiation of DOC and the diagnosis of CRPC were evaluated and compared between patients with high and low PSA levels at the start of DOC and CBZ treatment.

RESULTS

No correlations of PSA decrease rate and time to progression were observed between DOC and CBZ. The patients for whom DOC was started in higher PSA levels had significantly shorter combined PFS (p = 0.003) and OS from the initiation of DOC (p = 0.002). In patients who started DOC at high PSA levels, those who switched to CBZ at low PSA levels had longer OS than those who switched at high PSA levels (p = 0.048). The OS from CRPC of patients who started DOC at low PSA levels was significantly longer than those that started at high PSA levels (p = 0.030).

CONCLUSIONS

For patients for whom DOC was not effective, sequential CBZ might have change to be effective. The PSA levels at the start of DOC and CBZ might be a potential prognostic biomarker.

Efficacy of cabazitaxel and androgen splicing variant-7 status in circulating tumor cells in Asian patients with metastatic castration-resistant prostate cancer

Androgen receptor splice variant-7 (AR-V7) expression in circulating tumor cells (CTCs) in metastatic castration-resistant prostate cancer (mCRPC) is associated with abiraterone and enzalutamide resistance. We determine whether cabazitaxel (CBZ) is equally effective in AR-V7-positive and -negative CRPC and whether AR-V7-positive patients retain CBZ sensitivity. This is the first prospective, open-label, Asian validation study of CBZ in Japanese patients with mCRPC after docetaxel (n = 48; four CBZ cycles; 2017-2020, Juntendo University Hospitals). Primary endpoint was prostate-specific antigen response rate (PSA-RR); secondary endpoints included overall survival (OS), bone scan index (BSI) PSA-RR (≥ 50% decline from baseline) for CTC-/ARV7-, CTC+ /ARV7-, and CTC +/ARV7+ groups. PSA-RR ≥ - 30% was 38% (18/48) and ≥ - 50% was 26% (12/48). BSI-change rate ≥ - 30% was 19% (9/41) and ≥ - 50% was 17% (8/41). Median OS was 13.7(12.2-18.9) months. PSA decline in early CBZ treatment associated with OS (p = 0.00173). BSI decline associated with OS (p = 0.0194). PSA-RR(≥ 50%) was 43%(6/14) in CTC-/ARV7-, 19%(5/26) in CTC+ ARV7-, and 12%(1/8) in CTC+/ARV7+ ( p > 0.05). AR-V7 in CTCs at baseline not associated with OS. AR-V7 was not associated with CBZ resistance in CTCs. Reductions in BSI and PSA in early stages of CBZ treatment may predict OS.

[LONG TERM ADMINISTRATION OF RELATIVE DOSE INTENSITY-ADJUSTED CABAZITAXEL FOR METASTATIC CASTRATION-RESISTANT PROSTATE CANCER: A CASE REPORT]

We report the case of a 74-year-old man with metastatic castration-resistant prostatic cancer (CRPC), who underwent treatment with cabazitaxel. Initially, he underwent docetaxel treatment for 2 years and exhibited severe neuropathy in his hands caused by its toxicity. As a result, we replaced docetaxel with cabazitaxel. On receiving 100% of the dose of cabazitaxel in the first course, febrile neutropenia (FN) was observed on the seventh day. However, he soon recovered from the FN and we began relative dose intensity (RDI) treatment with an adequate dose-volume and interval of treatments. He was successfully administered 51 cabazitaxel treatment courses without severe adverse effects. Cabazitaxel is a highly effective drug used as second-line chemotherapy following docetaxel, and it causes fewer adverse effects compared with docetaxel. Cabazitaxel may be a suitable alternative for outpatient treatment. Given that the patient in this case had a long overall survival of more than 3.5 years and received over 50 courses of cabazitaxel, it is crucial for RDI to be taken very seriously.

Active targeting of orthotopic glioma using biomimetic liposomes co-loaded elemene and cabazitaxel modified by transferritin

BACKGROUND

Effective treatment of glioma requires a nanocarrier that can cross the blood-brain barrier (BBB) to target the tumor lesion. In the current study, elemene (ELE) and cabazitaxel (CTX) liposomes were prepared by conjugating liposomes with transferrin (Tf) and embedding the cell membrane proteins of RG2 glioma cells into liposomes (active-targeting biomimetic liposomes, Tf-ELE/CTX@BLIP), which exhibited effective BBB infiltration to target glioma.

RESULTS

The findings showed that Tf-ELE/CTX@BLIP was highly stable. The liposomes exhibited highly significant homologous targeting and immune evasion in vitro and a 5.83-fold intake rate compared with classical liposome (ELE/CTX@LIP). Bioluminescence imaging showed increased drug accumulation in the brain and increased tumor penetration of Tf-ELE/CTX@BLIP in orthotopic glioma model nude mice. Findings from in vivo studies indicated that the antitumor effect of the Tf-ELE/CTX@BLIP led to increased survival time and decreased tumor volume in mice. The average tumor fluorescence intensity after intravenous administration of Tf-ELE/CTX@BLIP was 65.2, 12.5, 22.1, 6.6, 2.6, 1.5 times less compared with that of the control, CTX solution, ELE solution, ELE/CTX@LIP, ELE/CTX@BLIP, Tf-ELE/CTX@LIP groups, respectively. Histopathological analysis showed that Tf-ELE/CTX@BLIP were less toxic compared with administration of the CTX solution.

CONCLUSION

These findings indicate that the active-targeting biomimetic liposome, Tf-ELE/CTX@BLIP, is a promising nanoplatform for delivery of drugs to gliomas.

Prognostic significance of third-line treatment for patients with metastatic castration-resistant prostate cancer: comparative assessments between cabazitaxel and other agents

BACKGROUND

Cabazitaxel has played an important role in the treatment of patients with metastatic castration-resistant prostate cancer (mCRPC); however, several types of sequential therapy against mCRPC have been performed in routine clinical practice. The objective of this study was to investigate the impact of third-line treatment on prognostic outcomes of mCRPC patients.

METHODS

This study retrospectively analyzed the clinical outcomes of 166 patients who received 3 agents following the diagnosis of mCRPC, consisting of 81 sequentially treated with either abiraterone or enzalutamide and then docetaxel, followed by third-line cabazitaxel (group A) and 85 treated with 3 agents, including abiraterone, enzalutamide, and docetaxel (group B).

RESULTS

There were no significant differences in major characteristics at the introduction of the third-line agent between these 2 groups. The proportion of patients with prostate-specific antigen (PSA) reduction > 50% by cabazitaxel in group A was significantly greater than that by either third-line agent in group B. Both PSA progression-free survival (PFS) and overall survival (OS) following third-line therapy in group A were significantly longer than those in group B. Furthermore, OS after the diagnosis of mCRPC in group A was significantly longer than that in group B. Multivariate analysis identified independent predictors of favorable prognostic outcomes after third-line therapy as follows: high-performance status (PS), low PSA level and third-line cabazitaxel for PSA PFS, and high PS, low lactate dehydrogenase level and third-line cabazitaxel for OS.

CONCLUSIONS

The introduction of cabazitaxel as a third-line agent could markedly improve the prognostic outcomes of mCRPC patients.

Sarcopenia and Visceral Metastasis at Cabazitaxel Initiation Predict Prognosis in Patients With Castration-resistant Prostate Cancer Receiving Cabazitaxel Chemotherapy

BACKGROUND/AIM

Cabazitaxel is recommended as first-line treatment after docetaxel for metastatic castration-resistant prostate cancer. However, the efficacy, adverse events and prognostic factors associated with cabazitaxel are unclear.

PATIENTS AND METHODS

This single-centre retrospective study including 30 patients with CRPC treated with cabazitaxel between 2014 and 2020 investigated efficacy, outcomes and prognostic factors.

RESULTS

Fourteen patients had visceral metastases. The median cabazitaxel dose was 20 mg/m² The prostate-specific antigen response rate, time to prostate-specific antigen response, and overall survival were 13.3%, 3.48 months, and 7.92 months, respectively. The rates of grade 3 or more neutropenia and febrile neutropenia were 20% and 6.7%, respectively. By multivariate analysis, sarcopenia and visceral metastasis at the time of cabazitaxel initiation were independent and significant factors conferring a poor prognosis.

CONCLUSION

The early introduction of cabazitaxel, prior to the development of sarcopenia and visceral metastasis, might contribute to improved prognosis in CRPC.

Utility of prophylactic antibiotics for preventing febrile neutropenia during cabazitaxel therapy for castration-resistant prostate cancer

The aim was to investigate the efficacy of prophylactic antibiotics for the prevention of febrile neutropenia (FN) during cabazitaxel therapy for castration-resistant prostate cancer (CRPC) with G-CSF. We retrospectively studied 443 cycles of cabazitaxel therapy given to 56 patients with CRPC at Keio University Hospital between May 2012 and August 2018. Statistical analysis was conducted to determine whether the combination of prophylactic G-CSF and antibiotics was more effective in preventing FN, compared with prophylactic G-CSF alone. Prophylactic PEG-G-CSF or G-CSF was administered in all 443 cycles. Only fluoroquinolones were used as prophylactic antibiotics and were administered in 328 cycles (74.0%). FN occurred in 5 cycles (1.1%). Prophylactic antibiotics were administered in 327 cycles (74.6%) in the FN-negative group and in only 1 cycle (20.0%) in the FN-positive group. Chi-square test indicated the incidence of FN was significantly lower in the group that received prophylactic antibiotics compared with the group that did not receive prophylactic antibiotics (P = 0.017). Compared with prophylactic G-CSF alone, prophylactic G-CSF and antibiotics significantly suppressed the occurrence of FN.

Prognostic value of ECOG performance status and Gleason score in the survival of castration-resistant prostate cancer: a systematic review

Eastern Cooperative Oncology Group (ECOG) performance status and Gleason score are commonly investigated factors for overall survival (OS) in men with castration-resistant prostate cancer (CRPC). However, there is a lack of consistency regarding their prognostic or predictive value for OS. Therefore, we performed this meta-analysis to assess the associations of ECOG performance status and Gleason score with OS in CRPC patients and compare the two markers in patients under different treatment regimens or with different chemotherapy histories. A systematic literature review of monotherapy studies in CRPC patients was conducted in the PubMed database until May 2019. The data from 8247 patients in 34 studies, including clinical trials and real-world data, were included in our meta-analysis. Of these, twenty studies reported multivariate results and were included in our main analysis. CRPC patients with higher ECOG performance statuses (≥ 2) had a significantly increased mortality risk than those with lower ECOG performance statuses (<2), hazard ratio (HR): 2.10, 95% confidence interval (CI): 1.68-2.62, and P < 0.001. The synthesized HR of OS stratified by Gleason score was 1.01, with a 95% CI of 0.62-1.67 (Gleason score ≥ 8 vs <8). Subgroup analysis showed that there was no significant difference in pooled HRs for patients administered taxane chemotherapy (docetaxel and cabazitaxel) and androgen-targeting therapy (abiraterone acetate and enzalutamide) or for patients with different chemotherapy histories. ECOG performance status was identified as a significant prognostic factor in CRPC patients, while Gleason score showed a weak prognostic value for OS based on the available data in our meta-analysis.

The Wnt non-canonical signaling modulates cabazitaxel sensitivity in prostate cancer cells

Background

Despite new drugs, metastatic prostate cancer remains fatal. Growing interest in the latest approved cabazitaxel taxane drug has markedly increased due to the survival benefits conferred when used at an earlier stage of the disease, its promising new therapeutic combination and formulation, and its differential toxicity. Still cabazitaxel’s mechanisms of resistance are poorly characterized. The goal of this study was thus to generate a new model of acquired resistance against cabazitaxel in order to unravel cabazitaxel’s resistance mechanisms.

Methods

Du145 cells were cultured with increasing concentrations of cabazitaxel, docetaxel/ taxane control or placebo/age-matched control. Once resistance was reached, Epithelial-to-Mesenchymal Translation (EMT) was tested by cell morphology, cell migration, and E/M markers expression profile. Cell transcriptomics were determined by RNA sequencing; related pathways were identified using IPA, PANTHER or KEGG software. The Wnt pathway was analyzed by western blotting, pharmacological and knock-down studies.

Results

While age-matched Du145 cells were sensitive to both taxane drugs, docetaxel-resistant cells were only resistant to docetaxel and cabazitaxel-resistant cells showed a partial cross-resistance to both drugs concomitant to EMT. Using RNA-sequencing, the Wnt non-canonical pathway was identified as exclusively activated in cabazitaxel resistant cells while the Wnt canonical pathway was restricted to docetaxel-resistant cells. Cabazitaxel-resistant cells showed a minimal crossover in the Wnt-pathway-related genes linked to docetaxel resistance validating our unique model of acquired resistance to cabazitaxel. Pharmacological and western blot studies confirmed these findings and suggest the implication of the Tyrosine kinase Ror2 receptor in cabazitaxel resistant cells. Variation in Ror2 expression level altered the sensitivity of prostate cancer cells to both drugs identifying a possible new target for taxane resistance.

Conclusion

Our study represents the first demonstration that while Wnt pathway seems to play an important role in taxanes resistance, Wnt effectors responsible for taxane specificity remain un-identified prompting the need for more studies.

miR-103a-3p Suppresses Cell Proliferation and Invasion by Targeting Tumor Protein D52 in Prostate Cancer

Growing evidence points at an association between microRNAs and tumor development. Although dysregulation of microRNA-103a-3p (miR-103a-3p) in multiple human cancers has been reported, its expression in prostate cancer (PCa) remains unknown and there is currently no research on the relationship between miR-103a-3p and tumor protein D52 (TPD52) in PCa. Our aim in this study was to explore the effect and potential mechanism of miR-103a-3p in PCa. qRT-PCR was performed to detected the level of miR-103a-3p in PCa tissues and cells, and in normal tissues. Colony, wound-healing, invasion, proliferation, and apoptosis assays were performed in search miR-103a-3p effect in PCa. TargetScan was used to predict potential targets of miR-103a-3p. Additionally, dual-luciferase reporter, western blot, and immunofluorescence assays were performed to detected the target gene of miR-103a-3p. Finally, we explore the differences in tumor xenograft experiments between nude mice injected with stably miR-103a-3p expressing cells and those expressing a miR-negative control. Low level of miR-103a-3p was detected in PCa tissues and cells, when compared with normal tissues. Enhancement of miR-103a-3p significantly inhibited migration and invasion of PCa cells, and negatively regulated expression of the oncogenic tumor protein D52 (TPD52) through direct binding to its 3'-UTR. Interestingly, overexpression of TPD52 significantly attenuated the effect of mir-103a-3p on PCa. Our study provides the first evidence that miR-103a-3p directly targets TPD52 and inhibits the proliferation and invasion of PCa. This finding helps clarify the role of mir-103a-3p-TPD52 axis in PCa and may provide new therapeutic targets for the disease.