Jasper Therapeutics Reports Positive Data from BEACON Study of Briquilimab in Chronic Spontaneous Urticaria Rapid onset of deep and durable clinical responses observed across multiple dosing cohorts with a favorable safe

Jasper Therapeutics Reports Positive Data from

BEACON Study of Briquilimab in Chronic Spontaneous Urticaria

Rapid onset of deep and durable clinical

responses observed across multiple dosing cohorts with a favorable safety profile

Mean change in UAS7 from baseline

of -26.6 observed in the 240mg single dose cohort at 8 weeks, multiple dosing regimens 120mg demonstrated UAS7 change of more than

100% (N=3) Complete Responses (UAS7

= 0) observed in the 240mg single dose cohort at 8 weeks and 66% maintained Well Controlled disease at 12 weeks

Serum tryptase reductions below the

lower limit of quantification observed at multiple dose levels

Data supports commencement of CSU

registrational program expected to commence second half of 2025

Company to host conference call and

webinar today at 8:00 a.m. EDT

REDWOOD CITY, Calif., January 8, 2025 (GLOBE

NEWSWIRE) - Jasper Therapeutics, Inc. (Nasdaq: JSPR) (Jasper), a clinical stage biotechnology company focused on development

of briquilimab, a novel antibody therapy targeting c-Kit (CD117) to address mast cell driven diseases such as chronic spontaneous urticaria

(CSU), chronic inducible urticaria (CIndU) and asthma, today reported positive preliminary data from Jasper's ongoing BEACON Phase

1b/2a study of subcutaneous briquilimab in adult participants with CSU. Substantial reductions in UAS7 were reported, with a mean change

from baseline at 8 weeks of -26.6 in the 240mg single-dose cohort and multiple dosing regimens at or above 120mg demonstrating UAS7 changes

of more than -25 points. Clinical responses were observed as early as 1-week post-first dose, and Complete Responses (UAS7 = 0) were achieved

by patients at each therapeutic dose level (80mg, 120mg, 180mg and 240mg), most notably, all patients in the 240mg single-dose cohort

(N=3) maintained Complete Responses through the 8-week time-point. Durability of response was generally dose dependent and reductions

in serum tryptase to levels below the lower limit of quantification were observed at multiple dose levels. Briquilimab was well tolerated

in the study with a favorable safety profile.

"I am excited to see the preliminary clinical

data which demonstrated that treatment with briquilimab led to rapid and durable symptom control in patients with CSU, especially given

the omalizumab-experienced population enrolled in the BEACON study," said Thomas B. Casale, M.D., Professor of Medicine and Pediatrics,

University of South Florida Morsani College of Medicine. "I am also very encouraged by the safety and tolerability profile observed

thus far in both the BEACON and SPOTLIGHT studies. I believe these data support advancing briquilimab into a registrational program following

the completion of BEACON, and I look forward to participating in additional studies of briquilimab in chronic urticaria."

"We are very pleased to present the positive

preliminary data from the BEACON study, which demonstrates the potential of briquilimab as a leading therapeutic for CSU patients,"

said Edwin Tucker, Chief Medical Officer of Jasper. "The profound reduction in UAS7 from baseline in multiple cohorts, the dose

dependent durability of response and the significant and prolonged drops in mean serum tryptase from baseline demonstrate the potential

for deep and durable efficacy of briquilimab in CSU. Combined with the favorable safety profile enabled by our optimal biologic dosing

approach, we believe briquilimab has demonstrated the potential to be a leading therapeutic option for patients with CSU. On behalf of

the entire Jasper team, I'd like to thank the investigators and the patients who are participating in the study, along with their

families and caregivers."

BEACON Study Design and Data Summary:

The BEACON study is a randomized, double-blind,

and placebo-controlled Phase 1b/2a trial evaluating multiple ascending doses of subcutaneous briquilimab as a treatment for adult patients

with moderate to severe CSU despite high dose antihistamines and treatment with, or who cannot tolerate, omalizumab. The primary endpoints

are safety and tolerability of briquilimab and secondary endpoints are focused on clinical activity and PK/PD, including measurement of

serum tryptase and mast cells in skin. Primary measurements used to assess clinical activity were the sum of the Hives Severity Score

and the daily Itch Severity Score (ISS), as measured via the Urticaria Activity Score over 7 days (UAS7) on a 0 to 42-point scale.

The preliminary data, as of December 31, 2024,

includes the results from 49 participants (N=3 at 10mg, N=3 at 40mg, N=6 at 80mg, N=8 at 120mg, N=14 at 180mg, N=3 at 240mg, and N=12

placebo) who completed at least 12 weeks of follow-up following initial dosing with investigational product. Participants had high disease

burden as assessed by UAS7 score with mean baseline score of 27.9 in the 120mg dose group, 25.9 in the 180mg dose group, 26.6 in the 240mg

dose group, and 28.6 in the placebo group.

Substantial reductions in UAS7 score were reported

with multiple dosing regimens at or above 120mg demonstrating mean change from baseline of greater than -25 points at 12 weeks, as well

as a mean change from baseline at 8 weeks of -26.6 points in the 240mg single-dose cohort. Complete responses (UAS7 = 0) were achieved

by patients treated at each therapeutic dose level (80mg, 120mg, 180mg and 240mg), and all patients in the 240mg single-dose cohort (N=3)

maintained Complete Responses through the 8-week time-point. In general, clinical responses following first dose at the 120mg and 180mg

dose levels showed durability out to 4-6 weeks, while clinical responses at the 240mg level showed durability out to 8-12 weeks. These

data demonstrate that treatment with briquilimab leads to rapid onset of durable and dose-dependent symptom control in patients with CSU.

Single-Dose Clinical Activity Assessments

Q8W Dose Clinical Activity Assessments Summary

Q12W Dose Clinical Activity Assessments Summary

Mean baseline serum tryptase for participants

in the enrolled in the study was within the normal range in all cohorts. Substantial reductions in tryptase were observed as early as

the week 1 assessment and were correlated with the onset of clinical responses. Tryptase levels below the lower limit of quantification

were reported for 86% (6 of 7) of participants in the 180mg Q8W cohort at week 2, and for 100% (3 of 3) of participants in 240mg single

dose cohort at week 1.

Briquilimab was well tolerated in the study, with

no dose limiting toxicities observed. Safety observations potentially related to c-Kit blockade were infrequent and generally limited

to low grade events, none of which resulted in discontinuations or dose delays and the majority of which resolved during repeat

dosing. Predictable decreases in neutrophil counts were observed upon dosing, with counts generally recovering prior to subsequent dose

and no association to fever or infection. A single Grade 3 neutropenia event was reported in a participant with prior history of idiopathic

neutropenia and thrombocytopenia.

Patients enrolled in the study will continue to

be dosed and assessed for safety/tolerability and clinical activity, and Jasper has commenced an open-label extension study in chronic

urticarias that will roll over patients from the BEACON to a 180mg Q8W dose upon completion of their initial follow up period. Consistent

with the Company's clinical development plan, Jasper submitted for regulatory review of two additional BEACON cohorts, 240mg Q8W

(N=8) and 180mg Q8W following a 240mg induction dose (N=8).

Jasper expects to begin a registrational program

in CSU with a Phase 2b study expected to commence in the second half of 2025. Final selection of doses for the Phase 2b study will be

further informed by additional data at 180mg Q8W from the open-label extension study, as well as by further data from BEACON cohorts evaluating

a 360mg single dose, a 240mg Q8W dose and a 180mg Q8W dose following a 240mg loading dose. Data from these additional cohorts are expected

to be presented by mid-2025.

"We are very happy to report preliminary

data from the BEACON study," said Ronald Martell, President and Chief Executive Officer of Jasper. "The favorable safety profile,

rapid onset of durable responses, the pharmacokinetic profile, and the depth and durability of tryptase reductions observed, all support

advancing a 240mg dosing regimen into the Phase 2b portion of a CSU registrational program that we plan to commence in the second half

of 2025. With positive data in both SPOTLIGHT and BEACON studies and preliminary data on the ETESIAN study in asthma expected in the second

half of 2025, we continue to rapidly advance our briquilimab franchise in mast cell driven diseases."

Conference Call / Webinar

Jasper will host a conference call and webinar

today at 8:00 a.m. EDT, including remarks from Dr. Thomas B. Casale, M.D., the lead US investigator for the BEACON study. A live question

and answer session with management will follow the formal presentations. A link to the webinar, including presentation slides, can be

The presentation slides and a link to the live

and archived webcast will also be available on the Events & News - Events page of Jasper's Investor Relations website.

Jasper is a clinical-stage biotechnology company

focused on developing briquilimab as a therapeutic for chronic mast cell diseases. Briquilimab is a targeted aglycosylated monoclonal

antibody that blocks stem cell factor from binding to the cell-surface receptor c-Kit, also known as CD117, thereby inhibiting signaling