Dataset Information

Systematic Review of the Therapeutic Efficacy of Bladder-preserving Treatments for Non-muscle-invasive Bladder Cancer Following Intravesical Bacillus Calmette-Guerin.

ABSTRACT:

Context

There is a critical need for effective bladder-sparing therapies for bacillus Calmette-Guérin (BCG)-unresponsive non-muscle-invasive bladder cancer (NMIBC). Owing to the current lack of effective agents that can be used as a control, the US Food and Drug Administration began to accept single-arm trials for patients with carcinoma in situ (CIS), using complete response rate (CRR) and duration of response as the primary endpoints to support marketing applications. Despite the ensuing growth of clinical trials in this space, no consensus exists on a clinically relevant benchmark for CRR.

Objective

To elucidate the CRR and recurrence-free rate (RFR) using bladder-sparing agents after BCG failure in order to provide a frame of reference for future clinical trial results.

Evidence acquisition

We performed a systematic review of clinical trials utilizing bladder-sparing therapeutics for NMIBC recurring after intravesical BCG (PROSPERO CRD42019130553). The search was performed in MEDLINE, EMBASE, and Cochrane Library. Relevant studies identified from bibliography search and conference abstracts were searched to complement the systematic review. A total of 42 studies utilizing 24 treatment options and consisting of 2254 patients were included for final analysis.

Evidence synthesis

Median CRRs in the treatment of CIS-containing tumors were 26% at 6 mo, 17% at 12 mo, and 8% at 24 mo after treatment. In comparison, median RFRs in the papillary-only studies were 67% at 6 mo, 44% at 12 mo, and 10% at 24 mo. Specifically in the BCG-unresponsive population, 6- and 12-mo CRRs in CIS-containing patients treated with Mycobacterium phlei cell wall-nucleic acid complex were 45% and 27%, respectively, and the median 6-, 12-, and 24-mo disease-free rates in the other studies were 43%, 35%, and 18%, respectively. The median progression-free rate was 91%: 95% in the CIS-containing studies and 89% in studies restricted to papillary-only recurrences. Toxicities of intravesical agents were generally mild, with very few dose limiting toxicities.

Conclusions

We demonstrate that, to date, bladder-sparing therapies achieved modest efficacy in patients with NMIBC after BCG. Results from the current study will serve as a frame of reference for emerging trial results in the BCG-unresponsive space.

Patient summary

In this study, we found that bladder-sparing therapies achieved modest efficacy in patients with non-muscle-invasive bladder cancer after bacillus Calmette-Guérin (BCG). These results will serve to inform future clinical trial results for salvage agents used to treat BCG-unresponsive bladder cancer.

SUBMITTER: Li R

PROVIDER: S-EPMC7771323 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:IntroductionIntravesical therapy (IVT), including Bacillus Calmette-Guérin (BCG), is the standard of care for high grade (HG) non-muscle invasive bladder cancer (NMIBC). Despite the use of IVT, many patients recur after treatment. The bladder microbiome and its role in disease processes has recently risen to prominence. We aim to characterize changes that occur in the bladder microbiome over the course of intravesical therapy and assess whether these changes correlate with outcomes in patients with NMIBC.MethodsPatients with NMIBC undergoing induction BCG or intravesical therapy were prospectively enrolled from January 2019 to March 2020. Patients with clinical T2 or greater pathology or active urinary tract infection at enrollment were excluded. Twenty-nine patients had catheterized (bladder) urine samples collected prior to induction intravesical therapy and prior to each IVT instillation. Twenty-seven received BCG while 2 received intravesical gemcitabine. Bacteria were identified using 16S ribosomal RNA gene sequencing. Bladder microbiome changes were evaluated and differences between patients who recurred and patients who did not recur after IVT were investigated.ResultsAcross the 29 patients analyzed, bacterial richness decreased significantly following intravesical therapy (Richness, P=0.01). Evenness and overall diversity did not change significantly (Pielou, P=0.62; Shannon, P=0.13). Patients who experienced recurrence had a higher relative abundance of Aerococcus in their urine (P<0.01), while those who did not recur had significantly more Ureaplasma (P=0.01) and Escherichia/Shigella species (P=0.05). Patients with decreased levels of alpha diversity were more likely to fall within the non-recurrence cohort.ConclusionIVT for NMIBC appears to change the urinary microbiome by decreasing richness while not altering evenness or overall diversity. The presence of Aerococcus species may be predictive of a poor cancer response to IVT, while the presence of Ureaplasma and Escherichia/Shigella may predict a favorable response to IVT. Further studies are warranted to elucidate and confirm the significance of changes in the bladder microbiome.

Project description:BackgroundIntravesical Bacillus Calmette-Guerin (BCG) is an effective treatment for bladder superficial carcinoma and it is being tested in interstitial cystitis patients, but its precise mechanism of action remains poorly understood. It is not clear whether BCG induces the release of a unique set of cytokines apart from its pro-inflammatory effects. Therefore, we quantified bladder inflammatory responses and alterations in urinary cytokine protein induced by intravesical BCG and compared the results to non-specific pro-inflammatory stimuli (LPS and TNF-alpha). We went further to determine whether BCG treatment alters cytokine gene expression in the urinary bladder.MethodsC57BL/6 female mice received four weekly instillations of BCG, LPS, or TNF-alpha. Morphometric analyses were conducted in bladders isolated from all groups and urine was collected for multiplex analysis of 18 cytokines. In addition, chromatin immune precipitation combined with real-time polymerase chain reaction assay (CHIP/Q-PCR) was used to test whether intravesical BCG would alter bladder cytokine gene expression.ResultsAcute BCG instillation induced edema which was progressively replaced by an inflammatory infiltrate, composed primarily of neutrophils, in response to weekly administrations. Our morphological analysis suggests that these polymorphonuclear neutrophils are of prime importance for the bladder responses to BCG. Overall, the inflammation induced by BCG was higher than LPS or TNF-alpha treatment but the major difference observed was the unique granuloma formation in response to BCG. Among the cytokines measured, this study highlighted the importance of IL-1beta, IL-2, IL-3, IL-4, IL-6, IL-10, IL-17, GM-CSF, KC, and Rantes as discriminators between generalized inflammation and BCG-specific inflammatory responses. CHIP/Q-PCR indicates that acute BCG instillation induced an up-regulation of IL-17A, IL-17B, and IL-17RA, whereas chronic BCG induced IL-17B, IL-17RA, and IL-17RB.ConclusionTo the best of our knowledge, the present work is the first to report that BCG induces an increase in the IL-17 family genes. In addition, BCG induces a unique type of persisting bladder inflammation different from TNF-alpha, LPS, and, most likely, other classical pro-inflammatory stimuli.

Project description:BackgroundA phase 1b study of photosensitizer TLD-1433-mediated photodynamic therapy (PDT) was performed in bacillus Calmette-Guérin (BCG)-unresponsive non-muscle-invasive bladder cancer (NMIBC) patients.ObjectiveThe primary objectives were safety and tolerability of PDT, with secondary objectives of (1) pharmacokinetic (PK) properties of TLD-1433 and (2) efficacy, as evaluated by recurrence-free survival and complete response (CR) at 90 and 180 d for patients treated at the maximum recommended starting dose (0.35 mg/cm2 bladder surface area) and the therapeutic dose (0.70 mg/cm2).Design setting and participantsSix BCG-unresponsive patients were enrolled in an open-label, single-arm, dose-escalating study of PDT. TLD-1433 was instilled intravesically for 60 min preoperatively. PDT was performed under general anesthesia using intravesically delivered irradiation of the bladder wall with green light (520 nm) to a dose of 90 J/cm2.Outcome measurements and statistical analysisPatients were followed by standard cystoscopy and cytology for up to 18 mo to assess time to recurrence.Results and limitationsPDT was well tolerated by all patients. All patients experienced at least one grade ≤2 adverse event (AE). There were no patient deaths or light sensitivity reactions. The most common AE was moderate bladder irritability, which resolved within the first weeks after treatment. AEs were independent of the TLD-1433 dose. TLD-1433 was cleared in the urine and from the plasma within 24 and 72 h, respectively. Of three patients treated at the therapeutic dose, two achieved a CR at 180 d, which was durable at 18 mo. The other patient was diagnosed with metastatic disease at 138 d.ConclusionsPDT with TLD-1433 appears safe for the treatment of BCG-unresponsive NMIBC. Early efficacy signals from full-dose photosensitizer are encouraging and warrant phase 2 trial investigation. The safety and PK results obtained support the potential for administration of consecutive PDT treatments as required.Patient summaryPhotodynamic therapy with TLD-1433 appears to be safe and effective for the treatment of bacillus Calmette-Guérin (BCG)-unresponsive bladder cancer.