Treatment Beyond Progression After Anti-PD-1 Blockade in Hepatocellular Carcinoma

Immune checkpoint inhibitors (ICI) can induce atypical tumor responses including pseudoprogression in a subset of patients who may benefit from treatment beyond progression. While ICIs have emerged as frontline treatments for hepatocellular carcinoma (HCC) and are associated with clinical benefit in a minority of patients, it is unclear whether treatment beyond progression has utility in this disease type. In a multicenter cohort analysis, treatment beyond progression was associated with no new safety signals, objective responses in 5.8% of patients, and disease control in 44% of patients. Progression-free survival and overall survival were comparable between patients treated beyond progression and patients treated with subsequent therapies, demonstrating that treatment beyond progression was not detrimental to survival outcomes. Rather, treatment beyond progression may benefit select patients with HCC and could represent a viable strategy for maximizing treatment benefit in these patients.

SIGNIFICANCE

Treatment beyond progression with ICIs in patients with HCC is safe and may benefit a subset of patients due to later-onset tumor responses or disease stability. These findings may guide the design of trials testing ICIs in HCC and the use of treatment beyond progression in routine practice.

Osteolectin increases bone elongation and body length by promoting growth plate chondrocyte proliferation

Osteolectin is a recently identified osteogenic growth factor that binds to Integrin α11 (encoded by Itga11), promoting Wnt pathway activation and osteogenic differentiation by bone marrow stromal cells. While Osteolectin and Itga11 are not required for the formation of the skeleton during fetal development, they are required for the maintenance of adult bone mass. Genome-wide association studies in humans reported a single-nucleotide variant (rs182722517) 16 kb downstream of Osteolectin associated with reduced height and plasma Osteolectin levels. In this study, we tested whether Osteolectin promotes bone elongation and found that Osteolectin-deficient mice have shorter bones than those of sex-matched littermate controls. Integrin α11 deficiency in limb mesenchymal progenitors or chondrocytes reduced growth plate chondrocyte proliferation and bone elongation. Recombinant Osteolectin injections increased femur length in juvenile mice. Human bone marrow stromal cells edited to contain the rs182722517 variant produced less Osteolectin and underwent less osteogenic differentiation than that of control cells. These studies identify Osteolectin/Integrin α11 as a regulator of bone elongation and body length in mice and humans.