I would like to inform you that any bit in the OTP region can be programmed from 1 to 0 only once. There is no erase operation option for OTP region and hence, bits which are already programmed to 0 cannot be erased to 1. Subsequent OTP programming can be performed only on the un-programmed bits (that is, 1 data).
The OTP lock bits ensure that no further programming is possible to that particular OTP region.
Hope this answers your query.