Exicure Presents Positive Topline Phase 2 Data for Burixafor in Multiple Myeloma at 2025 ASH Annual Meeting

Exicure (Nasdaq: XCUR) reported positive topline Phase 2 results for burixafor (GPC-100) combined with propranolol and G-CSF for hematopoietic progenitor cell mobilization in multiple myeloma.

Rhea-AI Summary

Exicure (Nasdaq: XCUR) reported positive topline Phase 2 results for burixafor (GPC-100) combined with propranolol and G-CSF for hematopoietic progenitor cell mobilization in multiple myeloma.

In the open-label, multicenter trial (NCT05561751), 17 of 19 participants (89.5%) collected ≥2×10⁶ CD34+ cells/kg within two leukapheresis sessions; two required an additional session. Median time to neutrophil engraftment was 13 days and platelet engraftment 17.5 days. Peak peripheral CD34+ levels occurred within one hour after dosing. Among 16 participants with prior daratumumab, 14 (87.5%) met the primary endpoint. Burixafor with propranolol and G-CSF was well tolerated with no burixafor-related adverse events >Grade 2.

Positive

• Primary endpoint: 17 of 19 participants (89.5%) achieved ≥2×10⁶ CD34+ cells/kg
• Rapid mobilization: peak CD34+ levels observed within one hour
• Engraftment: median neutrophil engraftment 13 days, platelet engraftment 17.5 days
• Prior daratumumab subgroup: 14 of 16 (87.5%) achieved the primary endpoint
• Safety: no burixafor-related adverse events above Grade 2

Negative

• Small trial size: total of 19 participants
• Two participants required an additional leukapheresis session to reach target

Argus Dec 9 session

+36.77% close to close Open Argus

Details

News Market Reaction – XCUR

In the Dec 9 session, XCUR gained 36.77%, reflecting a significant positive market reaction.

Data tracked by StockTitan Argus on the day of publication.

Market Context

The stock surged +36.8% in the session following this news. A strong positive reaction aligns with t...

Analysis

The stock surged +36.8% in the session following this news. A strong positive reaction aligns with the de‑risking nature of these Phase 2 results, where 89.5% of patients met the collection endpoint and no burixafor‑related adverse events exceeded Grade 2. Historically, clinical‑trial headlines produced mixed but generally moderate moves around 3.25%. Sustainability would depend on how investors balance this efficacy and safety against the company’s previously disclosed liquidity constraints.

Key Figures

Primary endpoint success: 17 of 19 patients (89.5%) Collection threshold: ≥2 × 10⁶ CD34+ cells/kg Neutrophil engraftment: 13 days (median) +5 more

Primary endpoint success

17 of 19 patients (89.5%)

Phase 2 trial achieving ≥2 × 10⁶ CD34+ cells/kg within two sessions

Collection threshold

≥2 × 10⁶ CD34+ cells/kg

Primary endpoint target for hematopoietic progenitor cell collection

Neutrophil engraftment

13 days (median)

Time to neutrophil engraftment among transplanted participants

Platelet engraftment

17.5 days (median)

Time to platelet engraftment among transplanted participants

Prior daratumumab exposure

16 of 19 patients (84.2%)

Participants with history of daratumumab, which is linked to reduced mobilization

Endpoint success with daratumumab

14 of 16 patients (87.5%)

Prior daratumumab‑treated participants achieving the primary endpoint

Endpoint success with dara+lenalidomide

12 of 14 patients (85.7%)

Participants treated with both daratumumab and lenalidomide achieving endpoint

Adverse event severity

No events > Grade 2

Burixafor‑related safety profile in Phase 2 trial

Historical Context

5 past events · Latest: Nov 07

5 events

1. Nov 07

   Earnings update

   24h Move

   -2.3%

   Q3 2025 results highlighted low cash and need for substantial new financing.

2. Nov 03

   Clinical data preview

   24h Move

   -4.3%

   Announced upcoming ASH oral presentation of completed Phase 2 burixafor data.

3. Oct 06

   Program progress

   24h Move

   +2.4%

   Highlighted burixafor Phase 2 success in initial patients and expansion plans.

4. Aug 08

   Earnings update

   24h Move

   +1.7%

   Q2 2025 results showed higher losses and urgent need for additional financing.

5. Aug 04

   Listing compliance

   24h Move

   -2.6%

   Regained compliance with Nasdaq filing requirements after resolving delays.

24h Move is the share-price change in the day after each event; other market factors may also have contributed.

Key Terms

granulocyte colony-stimulating factor (G-CSF), hematopoietic progenitor cells (HPCs), autologous hematopoietic cell transplantation (AHCT), CXCR4, +4 more

8 terms

granulocyte colony-stimulating factor (G-CSF) medical

"in combination with propranolol and granulocyte colony-stimulating factor (G-CSF)"

A naturally occurring protein that tells the bone marrow to make and release granulocytes — primarily neutrophils, the white blood cells that fight infection — functioning like a fertilizer for the body’s infection‑fighting factory. As a drug, synthetic G‑CSF is used to prevent or treat low white blood cell counts from chemotherapy and to move stem cells for transplantation, so its clinical effectiveness, regulatory approvals, supply and pricing directly affect drug revenues, biosimilar competition, and investor risk and opportunity.

hematopoietic progenitor cells (HPCs) medical

"for the mobilization of hematopoietic progenitor cells (HPCs) in patients"

Hematopoietic progenitor cells (HPCs) are early-stage cells in the bone marrow that act like seedlings capable of maturing into the various types of blood cells—red cells, white cells, and platelets—but with less flexibility than primitive stem cells. Investors care because these cells are the raw material for therapies and transplants that treat blood disorders and enable gene-editing or cell-based products; their availability, quality, and regulatory status can directly affect clinical success and company value.

autologous hematopoietic cell transplantation (AHCT) medical

"multiple myeloma undergoing autologous hematopoietic cell transplantation (AHCT)"

A medical procedure that collects a patient’s own blood-forming stem cells, gives high-dose chemotherapy or other intense treatment to wipe out diseased cells, then returns those saved cells to rebuild the blood and immune system — like restoring a backed-up operating system after a major reset. Investors track AHCT because its use influences demand for supportive drugs, cell‑processing services, medical devices and hospital capacity, and outcomes, costs and reimbursement determine commercial opportunity and adoption.

CXCR4 medical

"blocks CXCL12 binding to CXCR4 receptors on HPCs, rapidly mobilizing"

CXCR4 is a protein on the surface of many cells that acts like a lock for a specific chemical signal, guiding cells where to go and how to behave. It matters to investors because drugs that block or mimic this receptor can change immune responses, stop cancer cells from spreading, help mobilize stem cells for transplants, or affect viral entry; thus CXCR4-targeted therapies can drive clinical value, regulatory milestones, and licensing or partnership opportunities.

CXCL12 medical

"Burixafor is an investigational small molecule that blocks CXCL12 binding"

CXCL12 (also called SDF-1) is a naturally occurring signaling protein that guides cells in the body, especially immune and stem cells, to move, grow or survive. Investors should watch mentions of CXCL12 because drugs or diagnostics that target this signal can change how diseases like cancer, heart disease and inflammatory disorders are treated; think of it as a GPS for cells, so altering the signal can redirect disease processes and create commercial or regulatory value.

β2-adrenergic receptor (β2AR) medical

"propranolol enhanced burixafor-induced mobilization by inhibiting the β2-adrenergic receptor (β2AR)"

The β2-adrenergic receptor is a protein on the surface of many cells that acts like a lock that natural hormones (and drugs) can fit into to trigger changes such as widening airways, altering heart and muscle activity, or shifting metabolism. For investors it matters because this receptor is a common drug target; whether a medicine safely and effectively hits that lock can determine clinical trial success, regulatory approval, market size, and revenue potential.

leukapheresis medical

"within two leukapheresis sessions. Two required another session"

Leukapheresis is a medical procedure that separates and removes white blood cells from a person’s blood, like running blood through a specialized filter to pull out a specific ingredient. It matters to investors because those collected cells are often the raw material for advanced therapies and clinical trials, so the availability, cost, production speed, and regulation of leukapheresis can directly affect a biotech company’s ability to manufacture treatments and generate revenue.

engraftment medical

"median time to neutrophil engraftment was 13 days, and the median time to platelet engraftment"

Engraftment is when transplanted cells or tissue successfully take root in a patient and begin to grow and perform the functions they were intended to do, such as producing blood cells or attacking diseased cells. For investors, engraftment is a key clinical milestone — like a seed sprouting in a garden — because its timing and durability signal whether a therapy is working, affect patient safety, and drive regulatory approvals and commercial prospects.

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REDWOOD CITY, Calif., Dec. 08, 2025 (GLOBE NEWSWIRE) -- Exicure, Inc. (Nasdaq: XCUR), a clinical-stage biotechnology company developing therapeutics for hematologic diseases, today announced positive results from its completed Phase 2 trial evaluating burixafor (GPC-100) in combination with propranolol and granulocyte colony-stimulating factor (G-CSF) for the mobilization of hematopoietic progenitor cells (HPCs) in patients with multiple myeloma undergoing autologous hematopoietic cell transplantation (AHCT). The data, which showed that approximately 90% of study participants achieved the primary endpoint, were presented today in an oral session at the 67th American Society of Hematology (ASH) Annual Meeting in Orlando, Florida.

Burixafor is an investigational small molecule that blocks CXCL12 binding to CXCR4 receptors on HPCs, rapidly mobilizing these cells from the bone marrow into the peripheral blood. In preclinical studies, propranolol enhanced burixafor-induced mobilization by inhibiting the β2-adrenergic receptor (β2AR).

In the open-label, multicenter Phase 2 trial (NCT05561751), 17 of 19 participants (89.5%) achieved the primary endpoint of collecting ≥2 × 10⁶ CD34+ cells/kg within two leukapheresis sessions. Two required another session to achieve 2x10⁶ CD34+ cells/kg. Among participants who proceeded to transplant, the median time to neutrophil engraftment was 13 days, and the median time to platelet engraftment was 17.5 days. Burixafor has a differentiated and rapid mobilization kinetics, with peak peripheral levels of CD34+ cells observed within one hour of administration. This distinguishes it from other CXCR4 inhibitors and allows for same day burixafor administration and apheresis.

Notably, 16 of 19 participants (84.2%) had prior exposure to daratumumab, a therapy associated with reduced mobilization, yet 14 of those 16 participants (87.5%) achieved the primary endpoint, including 12 of 14 participants (85.7%) who had received both daratumumab and lenalidomide. Longer intervals between the last dose of daratumumab and leukapheresis were associated with higher CD34+ cell yields.

Burixafor administered in combination with propranolol and G-CSF was well tolerated and demonstrated an excellent safety profile. There were no burixafor-related adverse events higher than Grade 2.

“In this Phase 2 study, the combination of burixafor, G-CSF and propranolol showed an excellent safety profile and supported reliable mobilization of hematopoietic progenitor cells, allowing all participants who elected to proceed with transplant to undergo AHCT and successfully engraft,” said Jack Khouri, M.D., Associate Professor of Medicine at the Cleveland Clinic Lerner College of Medicine, Case Western Reserve University and the study’s lead investigator. “We’re encouraged by these results, particularly given the high proportion of participants previously treated with daratumumab, an agent which may reduce stem cell yield. The ability to achieve peak circulating HPC levels rapidly after burixafor administration for immediate leukapheresis also has the potential to meaningfully improve the patient experience by reducing the burden of the mobilization process.”

Oral Presentation Details
Abstract Number: 1050
Title: An open-label, multi-center Phase 2 study to assess the safety and efficacy of burixafor (GPC-100) and propranolol with G-CSF for the mobilization of hematopoietic progenitor cells in patients with multiple myeloma
Presenter: Dr. Jack Khouri, Associate Professor of Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University
Session: 711. Cell Collection and Manufacturing of HSPCs, CAR-T Cells, and Other Cellular Therapy Products: Refining CAR-T Cells and Engineered HSPCs; New Approaches to HSPC mobilization
Date and Time: December 8, 2025, 5:45-6:00pm EST
Location: Hyatt - Regency Ballroom R

About Burixafor (GPC-100)
Burixafor (GPC-100) is a highly selective small molecule antagonist of CXCR4, a chemokine receptor that plays a central role in retaining hematopoietic stem cells in the bone marrow niche. By blocking CXCR4, burixafor may enhance the mobilization of these cells into the peripheral blood for collection and use in autologous stem cell transplant (ASCT) procedures. Originally developed by GPCR Therapeutics, Inc., burixafor became part of Exicure’s pipeline following the company’s acquisition in January 2025. In addition to multiple myeloma, burixafor is also being considered in other diseases where improved stem cell mobilization could help enable more efficient and effective treatment approaches, such as sickle cell disease, rare diseases requiring autologous transplant, and cell and gene therapy settings. A chemosensitization trial in AML is also being planned, leveraging burixafor’s mechanism of mobilizing malignant cells from protective bone marrow niches into the peripheral blood, where they may be more effectively targeted by chemotherapy.

About Exicure
Exicure, Inc. (Nasdaq: XCUR) is a clinical-stage biotechnology company developing therapies to address key challenges in hematologic diseases. The company’s lead program, burixafor (GPC-100), is being evaluated for its ability to improve stem cell mobilization in multiple myeloma, sickle cell disease, and in support of cell and gene therapy. It is also being studied as a potential chemosensitizing agent in acute myeloid leukemia (AML). For more information, visit www.exicuretx.com.

Media Contact:
Sarah Ellinwood, PhD
Kendall Investor Relations
sellinwood@kendallir.com

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What were Exicure's topline Phase 2 results for burixafor (XCUR) presented on December 8, 2025?

The Phase 2 trial reported 17 of 19 participants (89.5%) collected ≥2×10⁶ CD34+ cells/kg within two leukapheresis sessions.

How fast did burixafor (XCUR) mobilize CD34+ cells in the Phase 2 study?

Peak peripheral CD34+ cell levels were observed within one hour after burixafor administration.

What were engraftment times after burixafor mobilization in the XCUR Phase 2 trial?

Median time to neutrophil engraftment was 13 days and median time to platelet engraftment was 17.5 days.

How did prior daratumumab exposure affect burixafor mobilization in the XCUR study?

Among 16 participants with prior daratumumab, 14 (87.5%) achieved the primary endpoint of ≥2×10⁶ CD34+ cells/kg.

Were there safety concerns reported for burixafor in the Phase 2 study (XCUR)?

Burixafor with propranolol and G-CSF was reported as well tolerated with no burixafor-related adverse events above Grade 2.

How many participants in Exicure's Phase 2 trial needed more than two leukapheresis sessions (XCUR)?

Two participants required an additional leukapheresis session to reach the 2×10⁶ CD34+ cells/kg target.