Efficacy, pharmacokinetic and pharmacodynamic evaluation of Apaziquone in the treatment of non- muscle invasive bladder cancer

Introduction: Apaziquone (also known as EO9 and Qapzola) is a prodrug that is activated to DNA damaging species by oxidoreductases (particularly NQO1) and has the ability to kill aerobic and/or hypoxic cancer cells. Areas covered: Whilst its poor pharmacokinetic properties contributed to its failure in phase II clinical trials when administered intravenously, these properties were ideal for loco-regional therapies. Apaziquone demonstrated good anti-cancer activity against non-muscle invasive bladder cancer (NMIBC) when administered intravesically to marker lesions and was well tolerated with no systemic side effects. However, phase III clinical trials did not reach statistical significance for the primary endpoint of 2-year recurrence in apaziquone over placebo although improvements were observed. Post-hoc analysis of the combined study data did indicate a significant benefit for patients treated with apaziquone, especially when the instillation of apaziquone was given 30 minutes or more after surgery. A further phase III study is ongoing to test the hypotheses generated in the unsuccessful phase III studies conducted to date. Expert opinion: Because of its specific pharmacological properties, Apaziquone is excellently suited for local therapy such as NMIBC. Future studies should include proper biomarkers

FGFR3 expression in primary and metastatic urothelial carcinoma of the bladder

While fibroblast growth factor receptor 3 (FGFR3) is frequently mutated or overexpressed in nonmuscle-invasive urothelial carcinoma (UC), the prevalence of FGFR3 protein expression and mutation remains unknown in muscle-invasive disease. FGFR3 protein and mRNA expression, mutational status, and copy number variation were retrospectively analyzed in 231 patients with formalin-fixed paraffin-embedded primary UCs, 33 metastases, and 14 paired primary and metastatic tumors using the following methods: immunohistochemistry, NanoString nCounterTM, OncoMap or Affymetrix OncoScanTM array, and Gain and Loss of Analysis of DNA and Genomic Identification of Significant Targets in Cancer software. FGFR3 immunohistochemistry staining was present in 29% of primary UCs and 49% of metastases and did not impact overall survival (P = 0.89, primary tumors; P = 0.78, metastases). FGFR3 mutations were observed in 2% of primary tumors and 9% of metastases. Mutant tumors expressed higher levels of FGFR3 mRNA than wild-type tumors (P < 0.001). FGFR3 copy number gain and loss were rare events in primary and metastatic tumors (0.8% each; 3.0% and 12.3%, respectively). FGFR3 immunohistochemistry staining is present in one third of primary muscle-invasive UCs and half of metastases, while FGFR3 mutations and copy number changes are relatively uncommon

Mocetinostat for patients with previously treated, locally advanced/metastatic urothelial carcinoma and inactivating alterations of acetyltransferase genes

BackgroundThe authors evaluated mocetinostat (a class I/IV histone deacetylase inhibitor) in patients with urothelial carcinoma harboring inactivating mutations or deletions in CREB binding protein [CREBBP] and/or E1A binding protein p300 [EP300] histone acetyltransferase genes in a singleâ arm, openâ label phase 2 study.MethodsEligible patients with platinumâ treated, advanced/metastatic disease received oral mocetinostat (at a dose of 70 mg 3 times per week [TIW] escalating to 90 mg TIW) in 28â day cycles in a 3â stage study (ClinicalTrials.gov identifier NCT02236195). The primary endpoint was the objective response rate.ResultsGenomic testing was feasible in 155 of 175 patients (89%). Qualifying tumor mutations were CREBBP (15%), EP300 (8%), and both CREBBP and EP300 (1%). A total of 17 patients were enrolled into stage 1 (the intentâ toâ treat population); no patients were enrolled in subsequent stages. One partial response was observed (11% [1 of 9 patients; the population that was evaluable for efficacy comprised 9 of the 15 planned patients]); activity was deemed insufficient to progress to stage 2 (null hypothesis: objective response rate of â ¤15%). All patients experienced â ¥1 adverse event, most commonly nausea (13 of 17 patients; 77%) and fatigue (12 of 17 patients; 71%). The median duration of treatment was 46 days; treatment interruptions (14 of 17 patients; 82%) and dose reductions (5 of 17 patients; 29%) were common. Mocetinostat exposure was lower than anticipated (doseâ normalized maximum serum concentration [Cmax] after TIW dosing of 0.2 ng/mL/mg).ConclusionsTo the authorsâ knowledge, the current study represents the first clinical trial using genomicâ based selection to identify patients with urothelial cancer who are likely to benefit from selective histone deacetylase inhibition. Mocetinostat was associated with significant toxicities that impacted drug exposure and may have contributed to modest clinical activity in these pretreated patients. The efficacy observed was considered insufficient to warrant further investigation of mocetinostat as a single agent in this setting.After the genomicâ based selection of patients with urothelial cancer with inactivating mutations/deletions in the histone acetyltransferase genes CREBBP and/or EP300, singleâ agent mocetinostat appears to be associated with significant toxicities that limit drug exposure. This may have contributed to the limited activity noted in the current phase 2 study (response rate of 11%) among heavily pretreated patients with platinumâ refractory disease.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147860/1/cncr31817_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147860/2/cncr31817.pd

FGFR3 – a Central Player in Bladder Cancer Pathogenesis?

The identification of mutations in FGFR3 in bladder tumors in 1999 led to major interest in this receptor and during the subsequent 20 years much has been learnt about the mutational profiles found in bladder cancer, the phenotypes associated with these and the potential of this mutated protein as a target for therapy. Based on mutational and expression data, it is estimated that >80% of non-muscle-invasive bladder cancers (NMIBC) and ∼40% of muscle-invasive bladder cancers (MIBC) have upregulated FGFR3 signalling, and these frequencies are likely to be even higher if alternative splicing of the receptor, expression of ligands and changes in regulatory mechanisms are taken into account. Major efforts by the pharmaceutical industry have led to development of a range of agents targeting FGFR3 and other FGF receptors. Several of these have entered clinical trials, and some have presented very encouraging early results in advanced bladder cancer. Recent reviews have summarised the drugs and related clinical trials in this area. This review will summarise what is known about the effects of FGFR3 and its mutant forms in normal urothelium and bladder tumors, will suggest when and how this protein contributes to urothelial cancer pathogenesis and will highlight areas that may benefit from further study

Examining the bleeding incidences associated with targeted therapies used in metastatic renal cell carcinoma

A systematic review was conducted to illustrate the bleeding risks associated with targeted therapies used in the treatment of metastatic renal cell carcinoma (mRCC). Eligible studies included phase II, III, or IV clinical trials using pazopanib, sunitinib, cabozantinib, lenvatinib, everolimus, temsirolimus, bevacizumab, axitinib, and/or sorafenib in the setting of mRCC. Types of bleeding event(s), bleeding event frequency, and incidence of thrombocytopenia were collected from the relevant articles. ClinicalTrials.gov was also searched for incidence of “Serious bleeding adverse effects” reported in these trials. The incidences of bleeding events ranged from 1 to 36%, and incidences of thrombocytopenia ranged from 2 to 78%. Available serious bleeding adverse events ranged from 1 to 7%. The highest percentage of bleeding incidences were seen with bevacizumab, while the lowest percentage of bleeding incidences were seen with axitinib. All of the included trials were of high quality per Jadad scoring

Abiraterone-induced rhabdomyolysis resulting in acute kidney injury: A case report and review of the literature

Abiraterone, a CYP17 inhibitor, blocks androgen biosynthesis in multiple tissue types. In combination with prednisone, it is approved as a first-line treatment for metastatic castration-resistant prostate cancer. We present a case of rhabdomyolysis associated with abiraterone therapy resulting in acute on chronic kidney injury in a patient with metastatic castration-resistant prostate cancer. Strict monitoring should be employed in patients started on abiraterone who have additional risk factors for developing rhabdomyolysis

Platinum concentration in bladder tissue treated with neoadjuvant chemotherapy and pathologic response.

341 Background: Platinum (Pt) resistance is a major limitation in the treatment of muscle-invasive bladder cancer (MIBC), for which Pt-based chemotherapy remains the standard of care. Reduced intratumoral drug accumulation is an important mechanism of platinum resistance. Our previous studies in lung cancer demonstrate significant correlation between tissue Pt concentration and tumor response to neoadjuvant chemotherapy (NAC). Tissue Pt concentration was measured in bladder specimens exposed to Pt-based NAC and correlated to pathologic response. Methods: A cohort of 19 clinically annotated, archived frozen bladder specimens from MIBC patients treated with three to four cycles of Pt-based NAC was identified [pT0 (pathologic complete response, pCR), n=4; pTis or pT1 (pathologic partial response, pPR), n=6; &gt;/= pT2 (minimal pathologic response/progression), n=9]. Two cystectomy specimens from MIBC patients treated with Pt-based adjuvant therapy were used as controls. Non-tumor bearing adjacent bladder tissue (“normal”) was identified in cystectomy specimens by a genitourinary pathologist. Total Pt concentration in normal tissue was measured by flameless atomic absorption spectrophotometry. Three group Kruskal-Wallis tests were used to compare the distributions of Pt concentrations by pathologic response (pCR, pPR, minimal response/progression). Mann-Whitney non-parametric two-sided tests were used for two group comparisons. Results: Total Pt concentration in normal adjacent bladder tissue differed by tumor pathologic response (p=0.011). Specimens with a pCR had the highest Pt concentrations compared to those with a pPR (p=0.0095) or no response/progression (p=0.0196). There was no significant difference in Pt levels between PR and no response/progression group (p=0.37). Conclusions: Our findings suggest that enhanced Pt accumulation may be an important determinant of Pt sensitivity. Studies investigating factors that modulate intracellular Pt concentration, such as expression of influx/efflux Pt transporters, may serve as predictive biomarkers and promote increased use of Pt-based NAC. </jats:p