CHAPTER-3 Preview: The HAE Readout Everyone's Waiting For

Research evidence excerpt

CHAPTER-3 Preview: The HAE Readout Everyone's Waiting For

 Base case: deucrictibant demonstrates similar efficacy as observed in CHAPTER-1 study

(attack rate reduction ~80%) [probability: 70%, upside: $38]. With other HAE prophy

programs showing translation between Phase 2 and Phase 3 (e.g. Takhzyro), our base case

assumes deucrictibant largely replicates the CHAPTER-1 data and generates an attack rate

reduction ~80%. We see this as a competitive efficacy level versus Takhzyro and an

approvable program. Also important, we assume this effect occurs with no major

safety/tolerability limitations as it will be chronically administered. In this scenario, we

anticipate upside to the ~$38/share level.

 Downside scenario: lower than anticipated attack-rate reductions (70% or lower)

[probability: 20%, downside: $25]. While we assign a lower probability to the downside

scenario, should deucrictibant demonstrate a lower-than-anticipated level of attack rate

reduction, we anticipate shares will come under pressure with downside risk to the

~$25/share level. In this scenario, we see deucrictibant as approvable. Nevertheless, we

could see investor questions arising about the competitiveness in the prophy marketplace.

We do see deucrictibant’s on-demand data as positive and accounts for ~50% of our PHVS

valuation. Thus, this offers some downside protection for PHVS in this prophy scenario.

 Upside scenario: looks better than Takhzyro [probability: 10%, upside: $42]. We assign a

lower probability to the upside scenario simply because we see it as a challenging

mathematical bar to achieve. However, should deucrictibant demonstrate better attack rate

reductions than Takhzyro (e.g. >83%), this would unlock an upside scenario. In this situation,