Interstitial cystitis /bladder pain syndrome (IC/BPS) is a chronic bladder condition characterized by inflammation and pain of the bladder lining, often accompanied by symptoms such as urinary frequency, urgency, and pelvic pain. One of the treatment modalities for IC/BPS involves intravesical instillation treatment of hyaluronic acid. Cystistat®, produced by the Irish company "Mylan," is a widely used hyaluronic acid bladder instillation medication internationally. However, the importation of Cystistat® into Taiwan has been affected since the onset of the COVID-19 pandemic in 2019. Consequently, our institution has adopted Hyauro®, a hyaluronic acid product of Taiwan's scivision Biotechnology Co., Ltd. (approved by TFDA( Taiwan FDA)  in 2017), for treatment. From January 2019 to the end of 2023, our institution accumulated approximately one hundred patients who underwent hyaluronic acid therapy. All patients underwent full treatment cycles of both Cystistat® and Hyauro® for six months each, with stable conditions observed during both treatment period

To retrospectively analyze patient medical records and post-treatment questionnaire surveys, aiming to investigate the differences in efficacy between Cystistat® and Hyauro® hyaluronic acid treatments for interstitial cystitis.
Trial Methods:
(1) Number of Subjects:
This study is a retrospective analysis involving a total of 101 participants.
(2) Inclusion and Exclusion Criteria:
Inclusion Criteria:
Patients diagnosed with interstitial cystitis between 2019 and 2023, who underwent full treatment cycles of both Cystistat® and Hyauro® hyaluronic acid treatments for six months each, and remained stable during treatment with Cystistat®.
Exclusion Criteria:
Below 18 years of age
Suspected malignant tumors during treatment
Allergy to hyaluronic acid
Patients who did not complete full treatment cycles of both Cystistat® and Hyauro® hyaluronic acid treatments.
(3) Trial Design and Methods:
Data Collection Methods:
Patient medical records were retrieved using the hospital's medical prescription system between January 1, 2019, and December 31, 2023. Patients diagnosed with interstitial cystitis and treated with both Cystistat® and Hyauro® hyaluronic acid treatments were included in the study if they remained stable during both treatment periods and completed six months of treatment each. Starting from September 1, 2023, researchers approached participants during gynecology outpatient visits, explained the contents of the informed consent form, and invited them to participate in the study. Upon obtaining consent and signed informed consent forms from participants, relevant medical records were accessed.
(4) Evaluation and Statistical Methods:
Analysis included questionnaire surveys assessing improvements in patients' clinical symptoms data (O’Leary–Sant Interstitial Cystitis Symptom Index (ICSI), O’Leary–Sant Interstitial Cystitis Problem Index (ICPI), visual analog scale (VAS) for pain) and, when necessary, pre- and post-treatment urodynamic studies were conducted for analysis.

The average scores of Interstitial Cystitis (IC) Symptom Index were 3.18 and 3.79 for Cystistat® and Hyauro® respectively. Paired t-test analysis revealed no significant difference in the IC Symptom Index scores between the two different medications (t=-0.15; p=0.88). Similarly, paired t-test analysis showed no significant difference in the IC Problem Index scores between the two medications (t=-0.06; p=0.95). Regarding the comparison of IC bladder pain Visual Analog Scale (VAS) scores, the statistical results indicated no significant difference between the two medications (t=0.61; p=0.54). Furthermore, for the Global Response Assessment (GRA) scores, the average scores were 2.00 and 2.25 for Cystistat® and Hyauro® respectively. Paired t-test analysis revealed a significant difference between the two groups (t=-2.84; p=0.005).

The scores of the Interstitial Cystitis Symptom Index (ICSI) and Interstitial Cystitis Problem Index (ICPI), as well as a pain visual analog scale (VAS), were statistically analyzed, showing no significant differences between Cystistat® and Hyauro®. This indicates that the effectiveness of Cystistat ®and Hyauro® ,two brands of hyaluronic acid, is consistent in real-world scenarios. As for the Global Response Assessment (GRA), the variation might be due to the experimental design where patients initially received Cystistat® intravesical  therapy followed by Hyauro ® intravesical therapy. While this design reduces questionnaire errors within the same patient, it's possible that patients who received Hyauro ® intravesical therapy after Cystistat ®had already undergone more multiple cycles of bladder instillation of  hyaluronic acid , potentially resulting in greater improvement. Therefore, GRA may favor Hyauro ®over Cystistat ®.

This is the first real-world comparison of Cystistat ®and Hyauro ®in hyaluronic acid instillation therapy. Essentially, the effects of these two brands of hyaluronic acid are similar with no significant differences

Factors associated with treatment outcomes after intravesical hyaluronic acid therapy in women with refractory interstitial cystitis: A prospective, multicenter studyTsai CP, Yang JM, Liang SJ, Lin YH, Huang WC, Lin TY, Hsu CS, Chuang FC, Hung MJ. J Chin Med Assoc. 2021 Apr 1;84(4):418-422
Changes in sexual function of women with refractory interstitial cystitis/bladder pain syndrome after intravesical therapy with a hyaluronic acid solution. Hung MJ, Su TH, Lin YH, Huang WC, Lin TY, Hsu CS, Chuang FC, Tsai CP, Shen PS, Chen GD. J Sex Med. 2014 Sep;11(9):2256-63.
The effect of intravesical hyaluronic acid therapy on urodynamic and clinical outcomes among women with interstitial cystitis/bladder pain syndrome. Peng YC, Yueh-Hsia Chiu S, Feng M, Liang CC. Taiwan J Obstet Gynecol. 2020 Nov;59(6):922-926