RAPT Therapeutics (RAPT) Investor Update summary

Strategic partnership and license agreement

• In-licensed RPT904 (JYB1904), a long-acting anti-IgE antibody, from Jemincare for territories outside China, Taiwan, Macau, and Hong Kong, with $35M upfront, up to $672.5M in milestones, and mid-single to low double-digit royalties.

• RPT904 is a half-life-extended omalizumab biobetter, designed for less frequent dosing and improved compliance in food allergy and other allergic disorders.

• The agreement positions the company to address significant unmet needs in food allergy and allergic disorders, leveraging omalizumab's market success.

• $150M financing secured from top-tier investors, extending cash runway into mid-2027, past the phase 2b food allergy data readout.

Clinical development and trial plans

• Phase 2b study in food allergy planned to start in H2 2025, with top-line data expected in H1 2027; parallel PK/PD studies will refine dosing.

• Jemincare is running phase 2 studies in asthma and CSU in China, with data expected in H2 2025 and H1 2026, respectively.

• RPT904's phase 1 data showed a twofold longer half-life (63 vs. 27 days) and deeper IgE suppression compared to omalizumab, supporting Q8- or Q12-week dosing.

• Phase 2b food allergy trial will use a simplified dosing table and include patients currently excluded from omalizumab label.

• Jemincare's Phase 2 and 3 trials in asthma and CSU in China are designed to establish optimal dosing and demonstrate non-inferiority to omalizumab.

Product profile and differentiation

• RPT904 uses YTE mutation for over twofold half-life extension and affinity maturation for about fourfold higher affinity over omalizumab.

• Improved manufacturability, stability, and reduced immunogenicity through targeted molecular modifications.

• RPT904 offers less frequent dosing (Q8W/Q12W) compared to omalizumab (Q2W/Q4W), with potential to treat patients with high weight or IgE levels.

• PK/PD simulations support Q12W dosing for most patients, potentially improving compliance.