Safety and efficacy of up to 900 mg/day polysulfate sodium (elmiron) in patients with interstitial cystitis

[Oral therapy for interstitial cystitis: pentosan polysulfate sodium]

INTRODUCTION

It is currently assumed that interstitial cystitis/bladder pain syndrome is caused by damage to the glycosaminoglycane layer on the urothelium of the urinary bladder. This layer can be repaired by oral therapy with pentosan polysulfate sodium. The focus of this article is on the history of this drug, its efficacy, its valuation in guidelines and especially the possible correlation with maculopathy.

METHODS

Literature research in PubMed and Embase.

RESULTS

PPS has a US and European approval for the therapy of IC characterised by glomerulations or a Hunner lesion detected by endoscopy and bladder distension. Its efficacy was proven in randomised trials. This led to a recommendation as a basic pharmaceutical therapy (in addition to behavioural intervention, dietary therapy or other drug treatments such as pain therapy). After a treatment period of six months, efficacy should be re-evaluated. Side-effects include mild haemodilution, nausea and loss of hair. Two publications of a US eye clinic have recently postulated a correlation between prolonged high-dose therapy with PPS and a special kind of maculopathy. Although this correlation was rejected in a large-scale health service study in Germany, a "red-hand-letter" led to the recommendation to perform an ophthalmologic examination before and during the treatment with PPS. Due to a pending litigation between payers and the distributor, PPS is currently out of trade in Germany. However, PPS can still be prescribed but must be imported from adjacent European countries. Unfortunately, these modalities have led to a significant undersupply of patients with IC/BPS. It is feared that this undersupply will increase further as the litigation is ongoing.

CONCLUSION

Being the only causally acting compound in the therapy of IC/BPS, PPS has an exceptional status. Although an ongoing litigation is pending in Germany and the correlation with maculopathy is still unclear, PPS must remain part of the current and future therapy of IC/BPS.

Fulranumab in patients with interstitial cystitis/bladder pain syndrome: observations from a randomized, double-blind, placebo-controlled study

BACKGROUND

This study was designed to evaluate the efficacy and safety of fulranumab, a fully human monoclonal antibody directed against nerve growth factor (NGF), for pain relief in patients with interstitial cystitis/bladder pain syndrome (IC/BPS).

METHODS

In this multicenter, double-blind study, adults with IC/BPS (i.e., interstitial cystitis symptom index [ICSI] total score ≥8) accompanied by chronic, moderate-to-severe pain were randomized to fulranumab 9 mg or matching placebo, administered subcutaneously at weeks 1, 5, and 9. The primary efficacy endpoint was change from baseline to study endpoint (week 12 or at withdrawal) in average daily pain intensity score. Key secondary endpoints included change from baseline to study endpoint in worst pain intensity score, ICSI total score, Pelvic Pain and Urgency/Frequency total score, Patient Perception of Bladder Condition score, and global response assessment.

RESULTS

This study was terminated prematurely based on concern that this class may be associated with rapidly progressing osteoarthritis or osteonecrosis. Thirty-one patients (of the targeted 70 patients) were randomized, 17 to placebo and 14 to fulranumab, with 15 and 10 patients, respectively, receiving all 3 doses of double-blind treatment. In ANOVA analyses, there was no statistically significant difference between treatment groups for the primary endpoint (LS mean difference [95% CI] vs. placebo, -0.2 [-1.52, 1.10]) or any of the secondary endpoints. Fulranumab was well tolerated, with no patient discontinuing due to an adverse event or experiencing a joint-related serious adverse event over a 26-week follow-up period. No events related to the neurologic or motor systems were reported.

CONCLUSIONS

Efficacy was not demonstrated in the present study with the single dose tested and a limited sample size, leading to lack of statistical power. These findings do not exclude the possibility that fulranumab would provide clinical benefit in a larger study and/or specific populations (phenotypes) in this difficult to treat pain condition.

TRIAL REGISTRATION

NCT01060254 , registered January 29, 2010.

Pentosan polysulfate inhibits atherosclerosis in Watanabe heritable hyperlipidemic rabbits: differential modulation of metalloproteinase-2 and -9

Pentosan polysulfate (PPS), a heparinoid compound essentially devoid of anticoagulant activity, modulates cell growth and decreases inflammation. We investigated the effect of PPS on the progression of established atherosclerosis in Watanabe heritable hyperlipidemic (WHHL) rabbits. After severe atherosclerosis developed on an atherogenic diet, WHHL rabbits were treated with oral PPS or tap water for 1 month. The aortic intima-to-media ratio and macrophage infiltration were reduced, plaque collagen content was increased, and plaque fibrous caps were preserved by PPS treatment. Plasma lipid levels and post-heparin hepatic lipase activity remained unchanged. However, net collagenolytic activity in aortic extracts was decreased, and the levels of matrix metalloproteinase (MMP)-2 and tissue inhibitor of metalloproteinase (TIMP) activity were increased by PPS. Moreover, PPS treatment decreased tumor necrosis factor α (TNFα)-stimulated proinflammatory responses, in particular activation of nuclear factor-κB and p38, and activation of MMPs in macrophages. In conclusion, oral PPS treatment prevents progression of established atherosclerosis in WHHL rabbits. This effect may be partially mediated by increased MMP-2 and TIMP activities in the aortic wall and reduced TNFα-stimulated inflammation and MMP activation in macrophages. Thus, PPS may be a useful agent in inhibiting the progression of atherosclerosis.

Herpes simplex virus vector-mediated gene delivery for the treatment of lower urinary tract pain

Interstitial cystitis (IC)/painful bladder syndrome (PBS) is a painful debilitating chronic visceral pain disorder of unknown etiology that affects an estimated 1 million people in the United States alone. It is characterized by inflammation of the bladder that results in chronic pelvic pain associated with bladder symptoms of urinary frequency and urgency. Regardless of the etiology, IC/PBS involves either increased and/or abnormal activity in afferent nociceptive sensory neurons. Pain-related symptoms in patients with IC/PBS are often very difficult to treat. Both medical and surgical therapies have had limited clinical utility in this debilitating disease and numerous drug treatments, such as heparin, dimethylsulfoxide and amitriptyline, have proven to be palliative at best, and in some IC/PBS patients provide no relief whatsoever. Although opiate narcotics have been employed to help alleviate IC/PBS pain, this strategy is fraught with problems as systemic narcotic administration causes multiple unwanted side effects including mental status change and constipation. Moreover, chronic systemic narcotic use leads to dependency and need for dose escalation due to tolerance; therefore, new therapies are desperately needed to treat refractory IC/PBS. This has led our group to develop a gene therapy strategy that could potentially alleviate chronic pelvic pain using the herpes simplex virus-directed delivery of analgesic proteins to the bladder.

Activity of different phospholipids in attenuating hyperactivity in bladder irritation

OBJECTIVE

To evaluate the effect of liposomes prepared from various natural and synthetic lipids in a rat bladder injury model in the absence or the presence of cholesterol and to elucidate the key structural elements necessary for the efficacy of liposomes required for alleviating bladder hyperactivity.

MATERIALS AND METHODS

The intravesical pressure was recorded using a transurethral catheter in adult female Sprague-Dawley rats anaesthetized with urethane (1.0 g/kg subcutaneously). Continuous cystometrograms (CMGs) were obtained by slowly filling the bladder with solutions of varying compositions after obtaining a baseline CMG with saline. Rat urothelium was injured with protamine sulphate (PS) and irritated by subsequent infusion of KCl (500 mm) for 1 h. Thereafter, liposomes prepared in KCl using several natural and synthetic phospholipids were infused for 2 h. The percentage reduction in bladder contraction frequency (BCF) was used as a comparative variable for judging the activity of different phospholipids.

RESULTS

Exposure of rat bladder to sequential infusion of PS and KCl increased its BCF and empty liposomes of uncharged zwitterionic phospholipids markedly attenuated the PS-induced irritation and decreased the raised BCF. But empty liposomes prepared with either cationic or anionic charged lipids were not able to achieve the same effect. Addition of cholesterol did not significantly increase their efficacy. Optimal efficacy of liposomes was achieved with phosphatidylcholines with longer acyl chains and saturation in only one of the two acyl chains.

CONCLUSIONS

These in vivo studies show that phospholipids attenuate the bladder irritation from KCl after PS-induced bladder injury.

Current management of interstitial cystitis

The management of patients with IC remains a challenge because no single agent has proven universally effective. DMSO and PPS have been evaluated through early placebo-controlled trials, and these two agents are FDA approved treatments for IC. BCG is currently undergoing a large placebo-controlled trial, and hyaluronic acid is receiving similar clinical evaluation. Sacral nerve root stimulation shows promise with early favorable results. As with any treatment algorithm, it is reasonable to begin with conservative treatment using time-dependent milestones, allowing adequate trials of successive therapy while ensuring an appropriate pace for timely symptom resolution.