KEYNOTE-975 study design: a Phase III study of definitive chemoradiotherapy plus pembrolizumab in patients with esophageal carcinoma

Despite curative-intent treatment, most patients with locally advanced esophageal cancer will experience disease recurrence or locoregional progression, highlighting the need for new therapies. Current guidelines recommend definitive chemoradiotherapy in patients ineligible for surgical resection, but survival outcomes are poor. Pembrolizumab is well tolerated and provides promising antitumor activity in patients with previously treated, advanced, unresectable esophageal/esophagogastric junction cancer. Combining pembrolizumab with chemoradiotherapy may further improve outcomes in the first-line setting. Here, we describe the design and rationale for the double-blind, Phase III, placebo-co…

A phase III trial-in-progress comparing tislelizumab plus chemotherapy with placebo plus chemotherapy as first-line therapy in patients with locally advanced unresectable or metastatic gastric or gastroesophageal junction (G/GEJ) adenocarcinoma.

TPS2655 Background: In patients (pts) with locally advanced or metastatic G/GEJ cancer, fluoropyrimidine- and platinum (plt)-based combination chemotherapy is first-line standard of care. Despite improvement in chemotherapy regimens, outcomes are poor and survival remains low. Tislelizumab, an investigational anti-PD-1 antibody, was engineered to minimize binding of FcγR on macrophages in order to abrogate antibody-dependent phagocytosis, a mechanism of T-cell clearance and potential resistance to anti-PD-1 therapy. Previous reports suggested tislelizumab, as a single agent and in combination with chemotherapy, was generally well tolerated and had antitumor activity in pts with advanced so…

P-26 RATIONALE 305: Tislelizumab plus chemotherapy versus placebo plus chemotherapy as first-line therapy in patients with gastric or gastroesophageal junction adenocarcinoma

Abstract CT282: KEYNOTE-975: A randomized, double-blind, placebo-controlled phase 3 trial of pembrolizumab vs placebo in participants with esophageal carcinoma receiving concurrent definitive chemoradiotherapy

Abstract Background: For patients with unresectable esophageal cancer (EC), definitive chemoradiotherapy (dCRT) is a standard treatment option. Platinum plus fluoropyrimidine-based regimens are comparable in dCRT and are considered standard options; however, overall survival (OS) is still poor, indicating a need for more effective therapies. The programmed cell death 1 inhibitor pembrolizumab showed promising response as third- and second-line monotherapy in patients with advanced, unresectable EC in the KEYNOTE-180 and KEYNOTE-181 studies, respectively. In the phase 3 KEYNOTE-181 trial, pembrolizumab extended OS vs chemotherapy in patients with a PD-L1 combined positive score (CPS) ≥10. KE…

Tislelizumab plus chemotherapy versus placebo plus chemotherapy as first-line therapy in patients with locally advanced unresectable or metastatic gastric or gastroesophageal junction (G/GEJ) adenocarcinoma.

TPS458 Background: First-line standard of care in patients with locally advanced or metastatic G/GEJ adenocarcinoma is fluoropyrimidine- and platinum (plat)-based combination chemotherapy. Despite improved chemotherapy regimens, outcomes remain poor and survival is low. Tislelizumab, an investigational humanized IgG4 monoclonal antibody with high affinity and binding specificity for PD-1, was engineered to minimize binding of FcγR on macrophages in order to abrogate antibody-dependent phagocytosis, a mechanism of T-cell clearance and potential resistance to anti-PD-1 therapy. Previous reports from early phase studies suggested tislelizumab, as a single agent and combined with chemotherapy,…