OP above is Army SM, and we've discussed ab it over DM already. I'll leave details there, but to give basic run down of current Army policy and situation I share the general info here.
Current regulation status:
40-501 2016 Dec update = Non-deployable status = automatic finding of Unfit at PEB.
40-502 2018 update = biologic therapy, chronic immune suppression are not compatible with deployed environment because of inability to treat opportunistic infection in deployed setting.
40-501 Jun 2019 = Conditions requiring IV therapy, chronic lab tests, or treatments requiring repeated supervision of a physician do not meet the standard.
Conditions controlled on oral medications and stable, meet the standard.
Also currently MOD 14 and soon to be released MOD 15 for CENTCOM don't allow immune suppression or biologic. Current Army policy allows MEB for not meeting COCOM/GCC deployment standards (which can be more strict than 40-501).
Separate from that:
SM's are still able to have 365 days before reaching MRDP (Medical retention Decision Point). If a physician wishes to start MEB prior to 365 MRDP they must support why the SM will not be able to recover or have their situation change in the remaining time period.
Patients on Biologics CAN transition back to orals, and remain in service if they choose. Decision to stop biologic and transition to orals needs to be made by SM and their provider understanding the risks of lose of control and the outcome of symptoms return worse.
In this case SM has only 4 months on the duty limiting medication. The above listed diagnosis, while certainly debilitating/distracting its not life threatening, so SM and Provider can have a reasonable discussion about cessation and transition to orals without risk to life/limb/eyesight. Some biologics once withdrawn cannot be reused. Any SM looking at this option need to have long discussion and make informed decisions about their diagnosis and future treatment.
If SM wishes to reach 20, should discuss P3 being changes to T3 until 365 days on Biologics and around the 9-10m mark discuss a trial of orals.