Abstract: The invention claims a process for making an insulin-oligomer conjugate IN-105. IN-105 precursor having formula G-A-V-R-[B-Chain]-R-D-A-D-D-R-[A-Chain] is cloned and expressed in Pichia. The biosynthetic precursor is then conjugated with an activated oligomer. The IN-105 precursor-oligomer conjugate is then treated with protease and purified to afford active insulin-oligomer conjugate of formula insulin-OC—CH2—CH2—(OCH2CH2)3—OCH3.