Comparing the outcome of doublet therapy (gemcitabine and cisplatin) with triplet therapy (gemcitabine, cisplatin and nab paclitaxel) in locally advanced or metastatic gall bladder carcinoma patients: An open-label randomized control trial.

TPS497 Background: There are various studies evaluating the role of dual agent chemotherapy like gemcitabine and cisplatin in locally advanced or metastatic gall bladder cancer (1). This has been the standard of treatment up till now. Also there has been a single arm phase II trial of gemcitabine, cisplatin and nab-paclitaxel (triplet therapy) by Shroff et al (2) reporting an impressive data with RR (response rate) of 45 %, median PFS (progression free survival) of 11.8 months (5% CI; 6.0-15.6) and median OS (overall survival) was 19.2 months. This data was promising when compared to historical data of dual agents like gemcitabine and cisplatin. So it would be informative to conduct an RCT comparing doublet chemotherapy in locally advanced or metastatic GBC with triplet regimen chemotherapy. Methods: It is an open label randomized control study conducted in Indraprastha Apollo hospital New Delhi, India in newly diagnosed locally advanced or metastatic gall bladder cancer patients proven histologically and on imaging. The sample size calculated using the appropriate formula is, 27 in each arm that is total of 54 patients, but 60 patients will be enrolled in the study keeping in view 10% drop out rate. For simple randomization, we will use online computer generated random number table and then patients will be assigned in two groups, arms A and B. Arm A receiving two drugs gemcitabine 1,000mg/m2 i.v and cisplatin 25mg/m2 i.v on Day 1 and Day 8 of 21-day cycle and arm B receiving three drugs gemcitabine, 1,000 mg/m2, cisplatin, 25 mg/m2, and nab-paclitaxel, 125 mg/m2, on days 1 and 8 of 21-day cycle. Primary end point was response rates based on radiological response as per RECIST or PRECIST. Secondary end points were to determine median progression free survival and median overall survival and to evaluate the toxicities according to NCI-CTC v 4.0.Then response [on basis of RECIST or PRECIST criteria] will be seen after 3 and 6 cycles of chemotherapy are completed and at follow up of every 6 months for 2 years period for assessment of primary and secondary end points of the study. Statistical analysis for correlation between clinical and laboratory features and treatment outcomes will be done using the SPSS software. Till now we have enrolled 1 patient in each arm. CTRI/2021/09/036362. References: Valle J, Wasan H, Palmer DH, et al. Cisplatin plus gemcitabine versus gemcitabine for biliary tract cancer. N Engl J Med 2010;362:1273-81. Shroff RT, Javle MM, Xiao L, et al. Gemcitabine,Cisplatin, and nab-Paclitaxel for the Treatment of Advanced Biliary Tract Cancers: A Phase 2 Clinical Trial JAMA Oncol 2019. Clinical trial information: CTRI/2021/09/036362.