Novel Agent Shows 'Dramatic' Responses in PVNS

PVNS is the result of a clonal neoplastic process related to the translocation of t(1;2) in the COL6A3–CSF1 fusion gene.

"This results in overexpression of CSF1 in synovium, which causes a reactive inflammatory proliferation in the joint by attracting CSF1R-expressing cells, such as monocytes, macrophages, osteoclasts," Dr. Tap explained.

The result is collagen scarring, bone destruction, and repeated joint bleeds. It typically affects the hip or knee, and usually occurs in younger individuals. For the patient, it can manifest as pain, decreased range of motion, stiffness, functional impairment, narcotic use, and disability.

Even though it is characterized by an overgrowth of abnormal cells, PVNS is not considered to be a cancer because it usually does not spread to other parts of the body, Dr. Tap noted.

There is currently no treatment approved by the US Food and Drug Administration (FDA). Although the majority of patients do well with surgical treatment, PVNS generally recurs, necessitating additional surgery or joint replacement. It eventually advances to the point where the condition is no longer operable.

Novel Agent Shows 'Dramatic' Responses in PVNS