How to setup slave addressing with a HT16K33 in Proteus?
I came to conclusion that the HT16K33 chip need some time to initialize and setup the addressing. Otherwise, the PIC send the data over the I2C bus too early and the HT16K33 is not ready. Adding a small delay before sending the data solve the problem (a ACK is send) : 

void main() {
   delay_ms(10);

   I2C1_Init(100000);
   I2C1_Start();
   I2C1_Wr(0xE2);
}


Maybe there is a better way to achieve this.