Hi Rohith -
Sounds like a tough case. My understanding from previous conversations was that Pharming is planning a pediatric leniolisib trial for the US "early" this year. I'm not sure how far along they are (or aren't) in the execution of the study, but it may be worth reaching out to see what information they have. Joe Harper (firstname.lastname@example.org) has been a point of contact for NICER in the past and may have information related to the anticipated trial/compassionate use options.
From my end, sirolimus seems reasonable as a starting point. Koneti Rao (email@example.com) would likely have additional insights on how well patients similar to yours have done with sirolimus vs HSCT.
Please keep us updated as to how the patient fares.