Pacibekitug

Pacibekitug

Monoclonal antibody
Type	Whole antibody
Target	IL6
Clinical data
Other names	C6414H9868N1698O2008S48
Routes of administration	Subcutaneous
Identifiers
CAS Number	2948444-06-0
PubChem CID	472419308
DrugBank	none
ChemSpider	none
UNII	2NHW9AKY9C
KEGG	D13049
Chemical and physical data
Formula	C6414H9868N1698O2008S48
Molar mass	144434.26 g·mol−1

Pacibekitug is an investigational monoclonal antibody developed by Tourmaline Bio, Inc., through a license form Pfizer, targeting interleukin-6 (IL-6) for the treatment of inflammatory conditions. ^{[1] [2] [3] [4]}

It is administered subcutaneously and is designed to reduce systemic inflammation by inhibiting IL-6, a pro-inflammatory cytokine implicated in various diseases, including cardiovascular disease and chronic kidney disease (CKD). ^{[5] [6]}

Pacibekitug is notable for its potential for quarterly dosing, offering a less frequent administration schedule compared to other IL-6 inhibitors. ^[7]

As of May 2025, it is in phase 2 clinical trials, with results demonstrating significant reductions in high-sensitivity C-reactive protein (hsCRP) in CKD patients with elevated inflammation. ^[7]

Medical use

Pacibekitug is being developed to treat inflammatory conditions associated with elevated IL-6 levels, such as cardiovascular disease and CKD. It aims to reduce systemic inflammation, as measured by biomarkers like hsCRP, which is linked to adverse outcomes in these diseases.

As of May 2025, Pacibekitug has not received regulatory approval and is limited to investigational use in clinical trials. ^{[3] [6] [7]}

Mechanism of action

Pacibekitug is a humanized monoclonal antibody that binds to IL-6, preventing its interaction with the IL-6 receptor and subsequent activation of inflammatory pathways. By neutralizing IL-6, it reduces downstream production of acute-phase reactants like hsCRP, which are markers of systemic inflammation.

This mechanism is similar to other IL-6 inhibitors but is optimized for high potency and an extended half-life. ^{[3] [6] [7]}

Clinical Trials

TRANQUILITY Study

The phase 2 TRANQUILITY study evaluated Pacibekitug in patients with stage 3 or 4 CKD and hsCRP levels greater than 2 mg/L, indicating significant inflammation. The open-label, single-arm study enrolled 12 patients who received a single 960 mg subcutaneous dose of Pacibekitug. ^{[3] [6] [7]}

Results, announced on May 7, 2025, showed: ^[8]

• A median hsCRP reduction of 57% at week 12, with 80% of patients achieving hsCRP levels below 2 mg/L.
• Sustained hsCRP reductions through week 24, supporting the potential for quarterly dosing.
• No serious adverse events related to Pacibekitug, with a safety profile consistent with other IL-6 inhibitors.

The study’s findings suggest Pacibekitug’s efficacy in reducing inflammation in CKD patients, a population at high risk for cardiovascular events.Tourmaline Bio plans to initiate a phase 2b study in 2025 to further evaluate dosing regimens and indications, including cardiovascular disease.

Safety and Side Effects

In the TRANQUILITY study, Pacibekitug was well-tolerated, with no serious adverse events reported. ^{[3] [6] [7]}

See also

• ziltivekimab

References

1. "Targeting IL-6 inflammation: A promising frontier in treating thyroid eye disease". Ophthalmology Times. 2024-12-26. Retrieved 2025-05-21.
2. "Pacibekitug - GSRS". gsrs.ncats.nih.gov. Retrieved 2025-05-21.
3. "Tourmaline Bio Announces Positive Phase 2 TRANQUILITY Study Results of Pacibekitug in Patients with Elevated hsCRP and Chronic Kidney Disease". Tourmaline Bio, Inc. 2025-05-07. Retrieved 2025-05-21.
4. "In the crowded cardio space, it's David vs. Goliath for small biotechs | PharmaVoice". www.pharmavoice.com. Retrieved 2025-05-21.
5. "Pacibekitug - Tourmaline Bio - AdisInsight". adisinsight.springer.com. Retrieved 2025-05-21.
6. "Tourmaline's anti-IL-6 antibody pacibekitug cuts inflammation biomarker in kidney disease patients". Fierce Biotech. 2025-05-07. Retrieved 2025-05-21.
7. "Tourmaline Bio's Anti-IL-6 Antibody Pacibekitug Slashes hsCRP Levels in CKD Patients, Sets Stage for Further Trials". BioSpace. 2025-05-07. Retrieved 2025-05-21.
8. "Tourmaline plans CV outcomes study for quarterly dosed IL-6 inhibitor". firstwordpharma.com. Retrieved 2025-05-21.