Here is the design of a clinical trial:

Official Title: A Phase III Randomized Clinical Trial to Study the Radiosensitizing Effect of Nelfinavir in Locally Advanced Carcinoma of Uterine Cervix.

Included conditions:
- Carcinoma Cervix,Stage III

Study Armgroups:
- {'label': 'Nelfinavir Arm', 'type': 'EXPERIMENTAL', 'description': 'If patient is randomized to nelfinavir arm then nelfinavir will be given orally with food at the dose of 1250 mg bid 5-7 days prior to start of chemoradiation.\n\nThen Pelvic EBRT (45-50 Gy/23-25 #/5weeks) + Weekly cisplatin 40mg/m2 \\& ICRT 7Gy X4 # will be given.', 'interventionNames': ['Drug: Nelfinavir', 'Drug: Cisplatin', 'Radiation: Pelvic EBRT and Brachytherapy']}
- {'label': 'Standard Arm', 'type': 'OTHER', 'description': 'If patient is randomized to standard arm (Cisplatin +Pelvic EBRT and Brachytherapy).\n\nIn this patient will receive Pelvic EBRT (45-50 Gy/23-25 #/5weeks) + Weekly cisplatin 40mg/m2 \\& ICRT 7Gy X4 #', 'interventionNames': ['Drug: Cisplatin', 'Radiation: Pelvic EBRT and Brachytherapy']}

Interventions:
- {'type': 'DRUG', 'name': 'Nelfinavir', 'description': 'Nelfinavir (HIV protease inhibitor) targets proteasome and inhibits AKT phosphorylation and plays an important role in radiosensitization of tumour cells.Nelfinavir will be given to the patient orally with food, because the bioavailability increases under the influence of food.', 'armGroupLabels': ['Nelfinavir Arm']}
- {'type': 'DRUG', 'name': 'Cisplatin', 'description': 'Cisplatin will be administered on a weekly basis with a dose of 40 mg/m2 by IV infusion over a period of 1 hour 2-4 hours prior to start of EBRT. Patient will be premedicated with I.V Ondansetron to prevent emesis. Pre chemotherapy and post chemotherapy, patient will be administered IV fluids for effective renal clearance of cisplatin.', 'armGroupLabels': ['Nelfinavir Arm', 'Standard Arm']}
- {'type': 'RADIATION', 'name': 'Pelvic EBRT and Brachytherapy', 'description': 'Pelvic EBRT will delivered by standard 4 field technique using 6MV/15 MV photon beams. Prior to delivery of radiation, patients will be simulated by CT simulator for planning the beam arrangements. Total dose of pelvic EBRT will be 45- 50Gy/23-25 #/5 weeks. The prescribed dose will be specified according to ICRU 50 guidelines. All patients will be treated with 3D conformal external radiation with target delineation and multileaf collimator leaf shaping.', 'armGroupLabels': ['Nelfinavir Arm', 'Standard Arm'], 'otherNames': ['Radiation Therapy']}

Primary Outcomes:
- {'measure': 'Improvement in 3 year disease free survival', 'description': 'Improvement in 3 year disease free survival by the addition of Nelfinavir to patients with advanced carcinoma of cervix and receiving standard chemoradiation (Cisplatin and Radiotherapy).', 'timeFrame': '3 years'}

Please estimate the sample size based on the assumption: 
The trial uses a group sequential design with 1:1 randomization. Safety analysis is scheduled at 50% recruitment, with safety assessed based on specific toxicity criteria. The significance level for toxicity is set at p < 0.01. An interim analysis for futility is planned at 32 events (or 190 patients), and the final analysis at 192 events. The study assumes a two-sided type I error of 0.05 and a type II error of 0.20.
Statistical considerations and sample size calculation
        The studyâs primary endpoint is 3-year DFS which will be defined as time in months from date of randomization to date of any recurrence/relapse/death due to any cause. This is a superiority trial design that intends to demonstrate a 3-year improvement in DFS from 65%6 9 39 to 75%. Using a group sequential design, considering a HR of 0.66, 1:1 randomisation is planned. A safety analysis report is scheduled at 50% recruitment. Safety will be assessed in terms of the following: diarrhoea>grade 3, which does not settle with optimal use of antidiarrheal medication for more than 3âdays or any>grade 4 haematological toxicity. The test regimen will be deemed to be associated with higher toxicity if the incidence of the above toxicities is different with a p value of <0.01. An interim analysis is planned for futility at 32 events (or 190) patients, and the final analysis is planned at 192 events. With two-sided type, I error of 0.05 and type II error of 0.20, a total sample size of 348 patients is planned. The details of statistical assumption are provided in online supplemental appendix A.
        
          10.1136/bmjopen-2021-055765.supp1
          Supplementary data