Supersingular isogeny Diffie–Hellman key exchange (SIDH) is a post-quantum cryptographic algorithm used to establish a secret key between two parties over an otherwise insecure communications channel. It is analogous to the Diffie–Hellman key exchange, but is based on walks in a supersingular isogeny graph and is designed to resist cryptanalytic attack by an adversary in possession of a quantum computer (Wikipedia)

SIKE is an isogeny-based key encapsulation suite based on pseudo-random walks in supersingular isogeny graphs, that was submitted to the NIST standardization process on post-quantum cryptography.(SIKE NIST)

SIKE is based on SIDH but it overcomes the use of Ephemeral keys which led to attack for extraction of keys in SIDH if same key is used a number of times.SIKE allows to use same key.