| Document And Entity Information | Jan. 21, 2025 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Jan. 21, 2025 |
| Entity Registrant Name | Kyverna Therapeutics, Inc. |
| Entity Central Index Key | 0001994702 |
| Entity Emerging Growth Company | true |
| Entity File Number | 001-41947 |
| Entity Incorporation, State or Country Code | DE |
| Entity Tax Identification Number | 83-1365441 |
| Entity Address, Address Line One | 5980 Horton St., STE 550 |
| Entity Address, City or Town | Emeryville |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 94608 |
| City Area Code | (510) |
| Local Phone Number | 925-2492 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Ex Transition Period | false |
| Title of 12(b) Security | Common Stock, par value $0.00001 per share |
| Trading Symbol | KYTX |
| Security Exchange Name | NASDAQ |
