Cosibelimab-ipdl (Unloxcyt)

Cosibelimab-ipdl: KOH-sih-BEL-lih-mab

Unloxcyt: un-LOK-sit

Cutaneous squamous cell carcinoma

Unloxcyt is approved for:

• Patients with squamous cell skin cancer that has grown (locally advanced) or spread to other parts of the body (metastatic), and who cannot receive surgery or radiation to entirely eliminate the cancer.

Limitations of use:

Age: The safety and efficacy of Unloxcyt in patients under 18 years of age have not been established.
Pregnancy/Breastfeeding: Unloxcyt can cause harm to a fetus, and is not recommended for use during pregnancy. Patients who can become pregnant should use effective contraception during treatment and for at least 4 months after the last dose of Unloxcyt. The risks associated with  Unloxcyt during breastfeeding are not known and cannot be ruled out; due to the potential for serious adverse reactions to the breastfed child, women are advised not to breastfeed during treatment and for at least 4 months after the last dose of Unloxcyt.
Complications of stem cell transplant: Serious and life-threatening complications that can lead to death can occur in patients who have received a stem cell transplant from a stem cell donor before or after being treated with Unloxcyt.

Checkpoint blockade

• PD-L1 blockade

• Target: PD-L1

Unloxcyt is an antibody that attaches to a molecule called PD-L1, which is sometimes present on the surface of cancer cells or other cells within a tumor mass. PD-L1 interacts with a molecule called PD-1, which is present on the surface of T cells – the primary immune cells involved in killing cancer cells. In healthy tissues, the interaction between PD-L1 and PD-1 puts on a brake that keeps T cells from creating an immune reaction that gets out of control. However, cancers can hijack this safety mechanism and prevent T cells from doing their job – killing the cancer cells. When PD-L1 interacts with PD-1 on T cells, the T cells become inactive and do not attack the cancer cells. Unloxcyt binds to the PD-L1 molecules on cancer cells and other cells within the tumor mass in such a way that blocks the interaction between PD-1 and PD-L1 and allows the T cells to be active and attack the cancer cells.

There may be other ways by which Unloxcyt helps destroy the cancer, and they are currently under investigation.

Unloxcyt is administered via a tube into a vein (intravenous infusion, or i.v.) over 60 minutes every three weeks, and does not require a hospital stay.

It is important to keep in mind that each patient’s actual outcome is individual and may be different from the results found in the clinical studies. In addition, with immunotherapy, sometimes it takes several months for responses to be observed.

Cutaneous squamous cell carcinoma

In a clinical trial, 109 patients with cutaneous squamous cell carcinoma (CSCC; skin cancer) that had grown (locally advanced) or spread to other parts of the body (metastatic), and who could not receive surgery or radiation to entirely eliminate the cancer, were treated with Unloxcyt.

Note: Rounding percentages after the decimal can cause inconsistencies between the total and the sum of the parts.

The most common side effects of Unloxcyt include fatigue, pain in the muscles and bones, rash, diarrhea, low thyroid function, constipation, nausea, headache, itching, edema (swelling), localized infection, and urinary tract infection.

Unloxcyt can cause the patient’s T cells to attack healthy cells throughout the body. Because of this, Unloxcyt can cause side effects that can become serious or life-threatening, and may lead to death. Some of the serious side effects related to Unloxcyt include inflammation of the lungs, liver, brain, nerves, heart, kidneys (which can lead to kidney failure), or colon (which can result in tears or holes in the intestine). Additionally, problems can arise with hormone glands (including thyroid, pituitary, and adrenal glands, as well as the pancreas). Unloxyt may cause Type 1 diabetes. Skin rash (which could become severe and life-threatening), problems with the heart or eyes, and reactions related to the infusion may also occur.

Patients should report any symptoms to their healthcare provider, who can then initiate actions to limit or reverse the side effects. For a more complete list of possible side effects, see the full prescribing information.

Manufacturer:

Checkpoint Therapeutics, Inc.

Approval

FDA

Links to drug websites

• US: https://unloxcyt.com/

Last updated: October 22, 2025