TOKYO, July 13 (Reuters) - Japanese government bond prices fell across the board on Monday as Tokyo equities rose on a positive analysis of a potential COVID-19 drug, denting the appeal of safe-haven debt.

Benchmark 10-year JGB futures fell 0.15 point to 152.07, with a trading volume of 11,838 lots, while the 10-year JGB yield added 1 basis point to 0.025%.

The 20-year JGB yield jumped 3 basis points to 0.425%.

The 30-year JGB yield and the 40-year JGB yield spiked 4 basis points each to 0.600% and 0.635%, respectively.

At the shorter end of the market, the two-year JGB yield inched up half a basis point to minus 0.140%, while the five-year yield added 1 basis point to minus 0.105%.

On the Tokyo stock exchange, the benchmark Nikkei average rose to a one-month closing high on improved risk appetite as an analysis of Gilead Sciences Inc's antiviral remdesivir showed reduced risk of death in severely ill COVID-19 patients. (Reporting by Tokyo Markets Team; Editing by Subhranshu Sahu)