Ordspono: Uses, Dosage & Side Effects

What Is Ordspono and What Is It Used For?

Ordspono contains the active substance odronextamab, a hinge-stabilized, humanized IgG4-based bispecific antibody. In the nomenclature of modern cancer immunotherapy it belongs to a class known as T-cell engagers, a type of antineoplastic medicine that harnesses the body's own immune system to destroy malignant cells. Rather than killing cancer cells directly – as traditional cytotoxic chemotherapy does – bispecific antibodies act as a molecular bridge between the cancer and the immune system.

At the molecular level, odronextamab has two different binding arms. One arm recognizes and attaches to the CD20 protein, a surface marker that is highly expressed on most mature B cells, including the malignant B cells that make up B-cell non-Hodgkin lymphomas such as FL and DLBCL. The other arm binds to the CD3 protein, which is part of the T-cell receptor complex found on all T lymphocytes. When odronextamab simultaneously binds CD20 on a lymphoma cell and CD3 on a neighboring T cell, it forms an immunological synapse that brings the two cells into close contact. The T cell becomes activated, releases cytotoxic granules containing perforin and granzymes, and destroys the CD20-positive B cell. This mechanism is independent of the T-cell receptor specificity and does not require the presentation of tumor antigens on major histocompatibility complex (MHC) class I molecules, allowing T cells to kill cancer cells even when the tumor has developed mechanisms to evade conventional immune recognition.

Ordspono is authorized by the European Medicines Agency (EMA) and is also being evaluated or approved in other major regulatory jurisdictions for the following indications, based on the ELM-1 and ELM-2 clinical development program:

• Relapsed or refractory follicular lymphoma (FL): Ordspono is indicated as monotherapy for adults who have received at least two prior lines of systemic therapy. Follicular lymphoma is the most common indolent (slow-growing) B-cell non-Hodgkin lymphoma. Although FL is generally responsive to first-line therapy, most patients eventually relapse, and outcomes progressively worsen with each subsequent line of treatment. The pivotal ELM-2 study demonstrated high response rates in heavily pretreated FL patients, including those refractory to anti-CD20 antibody therapy such as rituximab.
• Relapsed or refractory diffuse large B-cell lymphoma (DLBCL): Ordspono is indicated as monotherapy for adults with DLBCL who have received at least two prior lines of systemic therapy. DLBCL is the most common aggressive B-cell non-Hodgkin lymphoma. Patients whose disease does not respond to or relapses after first-line immunochemotherapy (R-CHOP and similar regimens) and who are ineligible for or have failed autologous stem cell transplantation or CAR-T cell therapy have historically had very poor outcomes. Ordspono provides a new treatment option in this setting.

Both FL and DLBCL are malignancies of B lymphocytes, white blood cells that form part of the adaptive immune system. In follicular lymphoma, the malignant cells typically arise from germinal-center B cells and grow slowly, often over many years. In DLBCL, the malignant cells are large, rapidly dividing B cells that form diffuse tumor masses, and without effective treatment the disease progresses quickly. Both lymphoma subtypes consistently express CD20, making them ideal targets for CD20-directed therapies, including monoclonal antibodies (such as rituximab and obinutuzumab), antibody-drug conjugates, CAR-T cell therapies, and bispecific antibodies like Ordspono.

The clinical value of Ordspono lies in its off-the-shelf availability. Unlike CAR-T cell therapies, which require the collection of a patient's T cells, weeks of manufacturing, and lymphodepleting chemotherapy before administration, Ordspono can be administered relatively quickly from a readily available supply. This is particularly important in patients with rapidly progressing disease who cannot afford long delays between prior treatment failure and next-line therapy. Treatment is administered under specialist supervision in hematology/oncology units with experience in managing immune-mediated toxicities.

What Should You Know Before Receiving Ordspono?

Contraindications

Ordspono has a limited list of formal contraindications, but extreme caution and specialist judgment are required before initiating therapy. The main absolute and strong relative contraindications include:

• Hypersensitivity: Do not receive Ordspono if you have a known severe hypersensitivity to the active substance (odronextamab) or to any of the other ingredients listed in the product information, including histidine, sucrose, or polysorbate 80.
• Active severe or uncontrolled infection: Initiating Ordspono in the setting of an uncontrolled bacterial, viral, or fungal infection substantially increases the risk of sepsis and life-threatening complications, and treatment should be deferred until the infection has been adequately treated.
• Active central nervous system (CNS) lymphoma: Patients with active CNS involvement of lymphoma were generally excluded from pivotal clinical trials. Ordspono is not recommended in this setting due to the increased risk of neurological toxicities and limited efficacy data.

Warnings and Precautions

Before and during treatment with Ordspono, inform your medical team if any of the following apply to you:

• Infections and hepatitis B status: Ordspono depletes normal B cells and can cause prolonged hypogammaglobulinemia, increasing the risk of bacterial, viral, and opportunistic infections. Baseline screening for chronic infections – including hepatitis B virus (HBV), hepatitis C virus, HIV, and tuberculosis – is performed before starting treatment. Patients with previous HBV exposure may require antiviral prophylaxis and close monitoring for viral reactivation, which can be severe and even fatal.
• Tumor lysis syndrome (TLS): Patients with high tumor burden are at increased risk for rapid cancer cell destruction leading to metabolic disturbances such as high potassium, high phosphate, high uric acid, low calcium, and acute kidney injury. Risk mitigation includes hydration, uric-acid lowering agents (allopurinol or rasburicase), and careful laboratory monitoring.
• Cytopenias: Ordspono commonly causes low blood counts, including neutropenia, anemia, and thrombocytopenia. These may be prolonged in some patients. Regular blood tests guide dose timing and supportive care (growth factors, transfusions, antimicrobial prophylaxis).
• Infusion-related reactions: Beyond true CRS, generic infusion reactions may occur, including fever, rigors, shortness of breath, nausea, headache, and hypotension. Pre-medication with paracetamol, antihistamines, and corticosteroids is standard.
• Hypogammaglobulinemia: Low immunoglobulin levels (particularly IgG) are common due to normal B-cell depletion and may persist for months. Some patients may require intravenous or subcutaneous immunoglobulin replacement.
• Progressive multifocal leukoencephalopathy (PML): This rare but potentially fatal brain infection caused by reactivation of the JC virus has been reported in patients receiving B-cell-depleting therapies. Any new neurological symptoms should prompt urgent evaluation.
• Vaccinations: Live attenuated vaccines must not be given during treatment and for a period after discontinuation due to immunosuppression. Where possible, required vaccinations should be completed prior to starting Ordspono.
• Cardiac and pulmonary conditions: CRS can destabilize pre-existing cardiac or pulmonary disease. Patients with significant comorbidities require careful baseline assessment and monitoring.
• Liver and kidney function: Although Ordspono is not metabolized via standard hepatic or renal pathways, pre-existing organ impairment may influence complication risk and the management of concomitant medications.

Your care team will perform ongoing clinical assessments, including vital signs, neurological examinations, laboratory tests, and symptom monitoring at each visit throughout therapy.

Pregnancy and Breastfeeding

Ordspono is not recommended during pregnancy. As an IgG4-based antibody, odronextamab can cross the placenta, particularly during the second and third trimesters, and may cause B-cell depletion in the fetus, with potential immunological consequences for the newborn. Animal reproductive toxicity data are limited, but the targeted mechanism of action and known effects of B-cell depletion raise concern for fetal harm. If pregnancy occurs during treatment, the patient should be counseled about the potential risks, and the newborn should be monitored for B-cell depletion and infections.

Women of reproductive potential must use highly effective contraception during treatment and for at least 4 months after the last dose of Ordspono. Before starting therapy, pregnancy status should be confirmed with a test. If you become pregnant during treatment, inform your medical team immediately.

It is not known whether odronextamab passes into human breast milk. As IgG antibodies are known to be present in milk during the first days after birth and given the potential for serious adverse reactions in the breastfed infant, breastfeeding is not recommended during treatment with Ordspono and for a period after discontinuation.

Fertility data specific to odronextamab are limited. Patients planning a family should discuss fertility preservation options with their oncology team prior to initiating therapy where feasible.

Driving and Operating Machinery

Ordspono may substantially affect your ability to drive or operate machinery. During cycle 1 and in the immediate period after each dose, you may experience fatigue, dizziness, confusion, tremor, or other neurological symptoms that make driving dangerous. Do not drive or operate heavy machinery for at least 48 hours after each dose in cycle 1 and for longer if you experience any neurological or cognitive symptoms. Your treating physician will give specific advice tailored to your situation.

Important Information About Ingredients

Ordspono contains polysorbate 80 as an excipient. Polysorbates can cause rare allergic reactions in some individuals. Inform your doctor if you have any known allergies to polysorbate or polyethylene glycol. Ordspono also contains less than 1 mmol sodium (23 mg) per dose, meaning it is essentially "sodium-free" and compatible with sodium-restricted diets.

How Does Ordspono Interact with Other Drugs?

Formal, dedicated pharmacokinetic drug-drug interaction studies with odronextamab have not been performed. However, several interaction considerations are clinically important due to the biology of bispecific antibodies and the effects of cytokine release. As a large IgG-based molecule, odronextamab is not metabolized by cytochrome P450 (CYP) enzymes and is not a substrate, inhibitor, or inducer of CYP enzymes or transporters. The antibody is cleared via typical IgG catabolic pathways.

However, during CRS, elevated levels of interleukin-6 (IL-6) and other pro-inflammatory cytokines can transiently suppress the activity of several CYP enzymes, particularly CYP3A4. This can temporarily increase blood concentrations of medicines metabolized by CYP3A4, especially those with a narrow therapeutic index. Close monitoring of drug levels and clinical response is recommended, particularly during cycle 1.

Major Interactions

Minor Interactions

Inform your medical team about all medications you are taking, including prescription and non-prescription drugs, herbal products, and supplements. During Ordspono therapy, any new medication should be reviewed by your oncology team to evaluate potential interactions, particularly in the context of cycle-1 CRS risk. Alcohol and cannabis are not known to have direct pharmacological interactions with odronextamab, but both can worsen symptoms such as fatigue, dizziness, and cognitive impairment that may already occur during treatment.

What Is the Correct Dosage of Ordspono?

Ordspono must only be prescribed by physicians experienced in the diagnosis and treatment of hematologic malignancies and is administered in a healthcare setting equipped to manage cytokine release syndrome, severe infusion reactions, and neurological toxicities. The 2 mg vial described on this page is primarily used during the step-up dosing phase of cycle 1; higher-strength vials provided by the manufacturer are used for full-dose administrations from cycle 2 onward. The total dose for each infusion is calculated by your healthcare team.

Step-Up Dosing (Cycle 1)

Full-Dose Treatment

Dose Modifications

Your medical team may modify your treatment in the following situations:

• Cytokine release syndrome (CRS): Management is based on CRS severity using the ASTCT grading system. Mild cases (Grade 1) are managed symptomatically; moderate cases (Grade 2) typically require tocilizumab and corticosteroids; severe or life-threatening cases (Grade 3-4) require intensive care, high-dose corticosteroids, and treatment discontinuation may be necessary for recurrent or refractory events.
• Neurological toxicity (ICANS): Requires prompt neurological assessment (CANS score, brain imaging if indicated), corticosteroids, and in severe cases permanent discontinuation of Ordspono.
• Infections: Treatment is withheld for Grade 3 or higher infections until resolution. Serious or opportunistic infections may require permanent discontinuation.
• Cytopenias: Prolonged or severe neutropenia, thrombocytopenia, or anemia may require treatment delay, growth factor support, or dose modification.
• Tumor lysis syndrome (TLS): High-risk patients require pre-infusion hydration, uric-acid lowering therapy, and close electrolyte monitoring. Treatment of established TLS follows standard hematology protocols.
• Missed doses: If a scheduled dose is missed, the next dose should be administered as soon as possible, and the schedule re-established as per the product information. Depending on the length of interruption, a re-initiation of the step-up dosing scheme may be required to re-mitigate CRS risk.
• Overdose: There is no specific antidote for odronextamab overdose. In the event of a suspected overdose, patients should be observed for signs and symptoms of adverse reactions, particularly CRS and ICANS, and treated symptomatically and supportively.

Children and Adolescents

Ordspono is not authorized for use in patients under 18 years of age. The safety and efficacy of odronextamab in children and adolescents with follicular lymphoma or DLBCL have not been established. Use in this population should only occur within clinical trials.

Elderly Patients

No specific dose adjustment is required for older adults based on age alone. However, elderly patients may be more susceptible to CRS, infections, cytopenias, and complications from comorbidities. Careful pre-treatment assessment of cardiopulmonary reserve, renal function, performance status, and concomitant medications is particularly important. Monitoring during cycle 1 should be performed with heightened vigilance.

Renal and Hepatic Impairment

As an IgG antibody, odronextamab is not excreted via the kidneys or metabolized by the liver in a conventional sense, and no dose adjustment is required for mild-to-moderate renal or hepatic impairment based on available data. Experience in severe renal impairment, end-stage renal disease, severe hepatic impairment, or pre-transplant patients is very limited, and close clinical and laboratory monitoring is required in these settings.

How Ordspono Is Given

Ordspono is supplied as a concentrate for solution for infusion that is prepared in the hospital pharmacy by trained personnel and administered only by healthcare professionals. The concentrate is diluted with sodium chloride 0.9% solution for injection to the prescribed volume and administered as an intravenous infusion using an infusion pump with an in-line, sterile, non-pyrogenic, low-protein-binding filter. The infusion must not be administered as an IV push or bolus.

During cycle 1, you will typically be observed in an inpatient or closely monitored outpatient setting for a defined number of hours or overnight after specified doses, allowing early detection and management of CRS or ICANS. Subsequent cycles may be given in a day-case or outpatient unit, provided your treatment is well tolerated.

What Are the Side Effects of Ordspono?

Like all medicines, Ordspono can cause side effects, although not everyone experiences them. The adverse reaction profile reflects the mechanism of action (T-cell activation and B-cell depletion) and the clinical characteristics of the patient population (heavily pretreated B-cell lymphomas). Some adverse reactions are characteristic of T-cell engagers and require specific monitoring and management strategies.

Cytokine Release Syndrome (CRS)

CRS is the most characteristic and clinically significant adverse reaction associated with Ordspono. It is a systemic inflammatory response caused by widespread T-cell activation and release of cytokines such as IL-6, IFN-γ, and TNF-α. CRS occurs most frequently during cycle 1, typically within hours after infusion, and becomes progressively less frequent and less severe with subsequent doses. Symptoms include fever, low blood pressure, rapid heartbeat, low oxygen levels, shortness of breath, chills, nausea, headache, confusion, and, in severe cases, organ dysfunction. Step-up dosing, pre-medications, and inpatient monitoring are specifically designed to mitigate CRS, and tocilizumab with corticosteroids is the cornerstone of treatment for moderate-to-severe events.

Infusion-Related Reactions (Non-CRS)

In addition to CRS, generic infusion-related reactions may occur, with symptoms such as fever, chills, rash, flushing, and hypotension. These reactions are typically mild to moderate and respond to slowing or interrupting the infusion and administering supportive medications.

Side Effects by Frequency

If you experience any side effects, including those not listed here, tell your doctor, nurse, or pharmacist. You can also report suspected side effects to your national pharmacovigilance authority (such as the EMA via the EudraVigilance system, the FDA MedWatch program in the United States, or the MHRA Yellow Card Scheme in the United Kingdom) to contribute to ongoing safety surveillance.

How Should Ordspono Be Stored?

Ordspono is provided to hospitals and clinics as a refrigerated liquid concentrate in single-use glass vials. It is stored, prepared, and administered exclusively by trained healthcare professionals. The following storage conditions apply:

• Unopened vials: Store in a refrigerator at 2°C to 8°C (36°F to 46°F).
• Do not freeze: Freezing damages the antibody and renders the product unusable.
• Light protection: Keep the vial in the original outer carton until time of use to protect from light.
• Do not shake: Vigorous shaking can cause aggregation of the antibody and is not permitted.
• Prepared infusion solution: Following dilution, the diluted solution should be used immediately. If not used immediately, storage conditions and time limits described in the Summary of Product Characteristics (SmPC) must be observed. Use the product before the expiry date printed on the vial and carton.
• Visual inspection: Before administration, the solution should be visually inspected for particulates and discoloration. Do not use if the solution is cloudy, discolored, or contains visible particles.
• Disposal: Any unused product or waste material must be disposed of in accordance with local requirements for cytotoxic and biologic medicines. Do not discard in household waste or wastewater.

As Ordspono is an in-hospital medicinal product, patients and caregivers do not need to store it at home. If you have any questions about storage or stability of your treatment, your pharmacist or oncology nurse can provide specific guidance.

What Does Ordspono Contain?

Active Substance

The active substance is odronextamab, a humanized, hinge-stabilized IgG4-based bispecific antibody. Odronextamab is produced by recombinant DNA technology in mammalian Chinese hamster ovary (CHO) cells. Each vial contains a precise labeled amount of odronextamab in a buffered aqueous solution, and higher-strength vials are available for full-dose administration. The 2 mg strength referenced on this page contains 2 mg of odronextamab per vial, which is used primarily during the step-up dosing phase of cycle 1 to allow accurate preparation of small priming doses.

Inactive Ingredients (Excipients)

• Histidine (buffer)
• Histidine hydrochloride monohydrate (buffer)
• Sucrose (stabilizer)
• Polysorbate 80 (surfactant, E433)
• Water for injections

Appearance

The concentrate is a clear to slightly opalescent, colorless to pale yellow solution, essentially free from visible particles. After dilution in sodium chloride 0.9% solution for injection, the final infusion solution appears clear to slightly opalescent and colorless.

Pack Size

Ordspono is supplied in single-use vials. Different vial strengths are provided to support the step-up dosing regimen and full-dose administration, including a 2 mg vial used in the early steps of cycle 1. Dispensing is exclusively to hospital and specialist clinic pharmacies.

Manufacturer and Marketing Authorization Holder

Ordspono is marketed by Regeneron Ireland DAC, with manufacturing operations at designated facilities that meet Good Manufacturing Practice (GMP) standards. The marketing authorization was granted by the European Commission based on the recommendation of the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency.