As an aside it's worth noting that RSA itself is partially-homomorphic (ciphertext multiplications are preserved in the decrypted plaintext).

The idea of 'homomorphic encryption' was even introduced by another Rivest and Adleman paper, almost immediately after the famous 1977 RSA algorithm ("On Data Banks and Privacy Homomorphisms" by Rivest, Adleman, and Dertouzos 1978).