Pure guesses: It looks like a hybrid tea, which should be blooming more than once. Can you give more info--what is your climate zone, do you fertilize it, what type of soil is it in, do you water it, are you in an area affected by the extreme heat & drought that much of the country is suffering, is the plant in full sun, etc.

Some HTs will age & die off, unfortunately. SOMETIMES they can be stimulated to send up new canes by pruning, or replanting in a better area with good soil. But I wouldn't recommend any replanting or pruning in August. Maybe you can root cuttings from the cane that has bloomed, although the photo looks like there isn't much plant to take cuttings from.

Sometimes a plant will do poorly because it's in a patch of bad soil or has diseased roots or is attacked by root nematodes.

It's a hard call (& I've had a similar situation) but I think I would wait for moderate fall temps, water heavily, then dig it up with as little root damage as possible & replant in an area of full sun. dig a big hole & amend the soil with a good commercial rose mix & baby the heck out of the plant.

If you're in a hard winter area, other folks here might recommend replanting during winter dormancy--I hope you'll post more info & will get better answers. Best wishes.