AstraZeneca's phase 3 TIGIT surprise

Although AstraZeneca had already disclosed in February that it would move its anti-TIGIT/PD-1 bispecific antibody rilvegostomig into phase 3 this year, no details had been provided on its development strategy plans. The surprise came this Wednesday when the phase 3 study was posted on clinicaltrials.gov. Rilvegostomig will be evaluated in combination with chemotherapy as adjuvant therapy in patients with biliary tract cancer (BTC). The Artemide-Biliary01 trial, set to start in December, intends to enrol 750 BTC patients (intrahepatic or extrahepatic) and the primary endpoint will determine the recurrence-free survival versus chemotherapy alone. Targeting a small indication in a setting without approved checkpoint inhibitors leads to speculation that Astra might be looking for a relatively easy approval pathway for this asset. TIGIT evaluation in BTC is extremely limited, and Merck & Co.'s Keyvibe-005 basket trial for the fixed-dosed combination of vibostolimab and Keytruda seems to be the only company-sponsored trial with a specific focus on these patients.  Other ongoing trials evaluating TIGIT in biliary tract cancerAssetTrial nameTrial detailsSponsorVibostolimab/ Keytruda FDC(Merck & Co)Keyvibe-005Randomised phase 2 basket trial vs Keytruda in selected solid tumoursMonotherapy & multiple combinationsIncludes unresectable biliary adenocarcinoma (gallbladder or biliary tree [intrahepatic or extrahepatic] cholangiocarcinoma)Industry-ledMerck & CoDomvanalimab(Gilead & Arcus)SCCC-20Y22Phase 2 basket trial in combination with zimberelimab in advanced hepatobiliary cancersIncludes intrahepatic and extrahepatic cholangiocarcinoma and gallbladder cancersInvestigator-ledUniversity of Texas Southwestern Medical CenterOciperlimab(BeiGene)ZSAB-TOPPhase 2 combination with tislelizumab and gemcitabine/cisplatin for 1st-line unresectable BTCInvestigator-ledShanghai Zhongshan HospitalSource: OncologyPipeline.