ImmuneOnco Biopharmaceuticals (Shanghai) (HKG:1541) said there were no undisclosed matters that would warrant an unusual movement in its stock price, according to a Hong Kong filing Friday.

Shares declined over 13% in recent afternoon trade.

The pharma company said it had taken notice of the recent unusual fluctuations in its stock price even though its operations and clinical development remained "normal."

Meanwhile, there were no material adverse changes to the company's financial position, ImmuneOnco Biopharmaceuticals said.