▁by ▁prevent ing ▁assembly ▁of ▁IL - 4 ▁re ceptor ▁alpha ▁( IL - 4 R α ) ▁with ▁either ▁IL - 2 R γ ▁or ▁IL - 1 3 R α . ▁U pre g ulation ▁of ▁Th 2 ▁cy tok ines , ▁including ▁IL - 4 ▁and ▁IL - 1 3 , ▁is ▁thought ▁to ▁be ▁critical ▁for ▁the ▁all erg ic ▁infl amm ation ▁associated ▁with ▁at op ic ▁dise ases ▁such ▁as ▁ast h ma ▁and ▁e cz ema . ▁The ▁targets ▁of ▁pit rak in ra ▁action ▁are ▁infl am mat ory ▁cells ▁( d end rit ic ▁cells , ▁Th 2 ▁cells , ▁B ▁cells ) ▁and ▁struct ural ▁cells ▁( sm ooth ▁mus cle , ▁end oth el ium , ▁ep ith el ium ) ▁that ▁express ▁IL - 4 R α . ▁The ▁drug ▁has ▁been ▁applied ▁both ▁as ▁a ▁sub cut aneous ▁injection ▁and ▁as ▁an ▁in hal ation , ▁but ▁the ▁latter ▁form ulation ▁proved ▁to ▁be ▁more ▁effective . ▁ ▁Mechan ism ▁of ▁action ▁Ast h ma ▁results ▁from ▁a ▁d ys reg ulated , ▁hyper respons ive ▁imm une ▁response ▁in ▁the ▁air ways . ▁Some ▁imm une ▁cells ▁in ▁all erg ic ▁ast h mat ics ▁respond ▁ag gress ively ▁to ▁foreign ▁all erg ens ▁with ▁the ▁release ▁of ▁IL - 4 ▁and ▁ 1 3 , ▁two ▁key ▁medi ators ▁that ▁initi ate ▁a ▁cycle ▁of ▁infl amm ation ▁in ▁the ▁lung . ▁Pit rak in ra ▁is ▁an