DARZALEX FASPRO (daratumumab and hyaluronidase-fihj)

Visit DARZALEX® (daratumumab) for more information about this drug’s original formulation and its intravenous (IV, into the vein) administration. 

What Is Darzalex Faspro?

Darzalex Faspro® is a newer formulation of Darzalex that is administered as an injection under the skin (subcutaneously, SQ). The injection is given by a healthcare professional under the skin of your abdomen, and it takes only a few minutes. Darzalex Faspro has been determined to be equally effective when compared to the original formulation of Darzalex. You must first consult with your doctor if you’re thinking about switching from IV to SQ administration..

What Are Some FDA-Approved Treatment Regimens with Darzalex Faspro SQ? 

• For patients with high-risk (HR) smoldering multiple myeloma (SMM):
  • Darzalex Faspro monotherapy in adults with HR-SMM.
• For patients with newly diagnosed multiple myeloma (NDMM):
  • Darzalex Faspro, Velcade, Revlimid, and dexamethasome [DVRd] in patients with NDMM who are eligible for ASCT, used for induction therapy and consolidation therapy.
  • Darzalex Faspro, Revlimid, and dexamethasome [DRd] in patients with NDMM who are ineligible for ASCT.
  • Darzalex Faspro, Velcade, melphalan, and prednisone [DVMP] in patients with NDMM who are ineligible for ASCT. 
  • Darzalex Faspro, Velcade, thalidomide, and dexamethasone [DVTd] in patients with NDMM who are eligible for ASCT. 
• For patients with relapsed or refractory multiple myeloma (RRMM): 
  • Tecvayli® (teclistamab-cqyv) and Darzalex Faspro [Tec-Dara] in patients with RRMM who have received at least 1 prior line of therapy.
  • Darzalex Faspro, Revlimid, and dexamethasome [DRd] in patients with RRMM who have received at least 1 prior therapy.
  • Darzalex Faspro, Velcade, and dexamethasone [DVd] in patients with RRMM who have received at least 1 prior therapy.
  • Darzalex Faspro, Pomalyst, and dexamethasone [DPd] in patients with RRMM who have received at least 1 prior line of therapy, including Revlimid and a proteasome inhibitor (Velcade, Kyprolis, or Ninlaro).
  • Darzalex Faspro, Kyprolis, and dexamethasone [DKd] in patients with RRMM who have received 1 to 3 prior lines of therapy.
  • Darzalex Faspro monotherapy in patients with RRMM who have received at least 3 prior lines of therapy, including a proteasome inhibitor (Velcade, Kyprolis, or Ninlaro) and an immunomodulatory agent (Revlimid, Pomalyst, or thalidomide), or who are double-refractory to a proteasome inhibitor and an immunomodulatory agent. 

Clinical Trial Experience with Darzalex Faspro

Tec-Dara for patients with relapsed/refractory multiple myeloma (RRMM)

In March 2026, the FDA approved the combination of Tecvayli and Darzalex Faspro [Tec-Dara] for patients with RRMM with at least 1 prior line of therapy. The application for approval was granted priority review by the FDA and was expedited. The FDA approval is based on the efficacy of Tec-Dara evaluated in the MajesTEC-3 clinical trial.

The MajesTEC-3 study added insight into the power of Tec-Dara. The 3-year PFS was over 90% in patients with standard-risk myeloma – a number never seen before – and 80% in patients with high-risk multiple myeloma (HRMM). This study further strengthened the argument for considering Tec-Dara in early relapse of myeloma.

Darzalex Faspro monotherapy for high-risk smoldering multiple myeloma (HR-SMM)

In November 2025, the FDA granted its first-ever approval of a treatment for adult patients with HR-SMM, based on data from the AQUILA clinical trial. This study of 390 patients compared treatment with Darzalex Faspro for 3 years vs. observation (active monitoring) but no treatment. Darzalex Faspro is approved for patients with HR-SMM. It is not approved for other risk categories of SMM. For more information, read the IMF’s publication Understanding MGUS and Smoldering Multiple Myeloma.

How Is Darzalex Faspro Given?

Darzalex Faspro SQ can be given on the same schedule as Darzalex IV, but it is administered as an injection into the abdomen that takes only a few minutes. Patients are monitored for a few hours after the first one or two doses.

The recommended dosage of Darzalex Faspro is 1,800 mg Darzalex plus 30,000 units hyaluronidase per 15 mL (120 mg and 2,000 units/mL) solution in a single-dose vial. Before receiving an injection, patients are given a steroid, acetaminophen, and a histamine-1 receptor antagonist to prevent or minimize possible side effects. Your doctor may also recommend medication after your injection.

Special Precautions with Darzalex Faspro

All treatments for myeloma require close monitoring. As documented in clinical trials with Darzalex or Darzalex Faspro, both drugs have the potential to cause Grade 3 or 4 side effects. A side effect is an unwanted or unexpected effect caused by a drug. In the U.S., the National Cancer Institute (NCI) toxicity is categorized as follows:

• Grade 0 – no symptoms
• Grade 1 – mild symptoms
• Grade 2 – moderate symptoms
• Grade 3 – symptoms requiring treatment
• Grade 4 – symptoms requiring urgent intervention
• Grade 5 – symptoms resulting in death

What Are Some Common Side Effects of Darzalex Faspro?

Hypersensitivity

Hypersensitivity is an undesirable reaction that may occur if a drug overactivates the immune system or the patient has a non-immune activation. Some drug classes, including monoclonal antibodies, are known to cause hypersensitivity reactions. A mild hypersensitivity reaction may be uncomfortable, but a severe reaction may be life-threatening. If you experience a hypersensitivity reaction to Darzalex, your doctor will decide if you should stop receiving it.

Administration-related reaction (ARR)

ARR is a systemic immune/hypersensitivity reactions that occur in response to the subcutaneous injection of the drug. In clinical trials of Darzalex Faspro, the terms "infusion reactions" and "infusion-related reactions" (IRRs) — used for the IV formulation (Darzalex) — were replaced with the term "systemic administration-related reactions" to reflect the subcutaneous route of administration. Clinical trial data documented ARR in 7-11% of patients receiving Darzalex Faspro. Learn more on p. 11 of this IMF publication: Understanding Darzalex and Darzalex Faspro.

Risk of herpes zoster infection

Herpes zoster (“shingles”) is caused by the reactivation of the varicellazoster virus (VZV), the same virus that causes varicella (“chickenpox”). Herpes zoster frequently affects nerves. A small percentage of patients in clinical trials developed shingles.

All patients should receive preventive treatment with antiviral medication within 1 week after starting Darzalex. Patients should continue taking an antiviral medication for 3 months following the last dose of treatment with Darzalex.

Neutropenia, lymphopenia, and thrombocytopenia

Neutropenia is a reduced level of neutrophils, a type of white blood cell necessary to combat bacterial infection. Lymphopenia (also called lymphocytopenia) is low levels of B cells, T cells, and natural killer (NK) cells.

Thrombocytopenia is a low number of platelets (thrombocytes) in the blood. The “normal” level varies from laboratory to laboratory. For example, at Mayo Clinic the “normal” level is ≥150,000 platelets per microliter of circulating blood. If the platelet count is less than 50,000, bleeding problems may occur. Major bleeding is usually associated with a reduction in count to less than 10,000 platelets.

In studies with Darzalex Faspro SQ, blood tests in 40% or more patients identified decreased leukocytes, decreased platelets, and decreased hemoglobin. Your doctor will use the complete blood count (CBC) test to monitor you during treatment. 

If your blood cell counts are low, your doctor will either hold your dose of Darzalex until your counts improve or will provide you with supportive care in the form of transfusions or medications that stimulate the formation of new blood cells.

Embryo-fetal toxicity

Women of reproductive potential and males with female partners of reproductive potential must ask the doctor which effective contraception method to use, and how long to continue using contraception after the last dose of treatment is received. Due to the potential for harm in the breastfed child, lacta ing women should not breastfeed during treatment and for a period of time after treatment ends.

Interference with blood tests

Darzalex and Darzalex Faspro can interfere with red blood cell (RBC) antibody screening. Darzalex and Darzalex Faspro may also interfere with blood compatibility testing, including the matching done prior to blood transfusions. Before starting Darzalex or Darzalex Faspro, your doctor should screen your blood and establish your blood type in case you might need a blood transfusion later. Blood banks must be informed that you have received Darzalex or Darzalex Faspro.

Darzalex is known to interfere with the results of serum protein electrophoresis (SPEP) and immunofixation electrophoresis (IFE) tests used to monitor myeloma. This can lead to inaccurate results when testing for complete response or disease progression. In 2018, the FDA approved a new blood test for evaluating M-protein in patients treated with Darzalex.

Other Possible Side Effects

Side effects that were reported in 20% or more patients in clinical trials include the following:

Fatigue

In the registration trials for Darzalex, 39% of the patients experienced fatigue, all but 2% of which was mild to moderate and did not limit the patients’ ability to care for themselves. Exercise caution when operating machinery, including automobiles. The effects of fatigue may be minimized by maintaining:

• A moderate level of activity.
• A healthy diet and sufficient fluid intake.
• A consistent sleeping schedule with enough rest.
• Regularly scheduled visits with your healthcare team to discuss issues that may contribute to your fatigue.
• A careful review of the side effects of any other products you are taking to ensure that they are not contributing to your fatigue.

For more information, please see the IMF publication Understanding Fatigue in Myeloma.

Nausea

Approximately 25% of the patients in the registration trials for Darzalex IV had mild to moderate nausea. There were no cases of severe nausea. Medications given before and after helped reduce the occurrence and severity of nausea. Ask your doctor prior to your Darzalex IV infusion if you need to fill a prescription of anti-nausea in advance.

Back pain

If you have myeloma-related back pain, read the IMF’s publication Understanding Treatment of Myeloma Bone Disease. 

If you have treatment-related back pain and body aches, this could be due to the release of cytokines in the bloodstream in reaction to Darzalex. Back pain and body aches may also occur if you develop an infection due to low levels of white blood cells (WBC). In the Darzalex registration trials, 25% of patients experienced back pain, with 2% experiencing back pain that limited their ability to care for themselves. Medications given before and after your dose of Darzalex IV may reduce or prevent infusion-related back pain.

Fever

Fever can be a sign of the interaction of Darzalex with the immune system.

To protect yourself, be proactive in the following ways:

• Check your temperature twice a day if you feel warm.
• If you have an oral temperature greater than 100.4°F (38°C), you must get medical care immediately.
• If you are not able to reach your healthcare team, go to an emergency room (ER) or urgent care facility.
• To avoid dehydration, drink a lot of non-alcoholic and non-caffeinated liquids.
• To control the fever, do not take any medication on your own.
• Take medication only as directed by a medical professional familiar with your medical history.

If your fever is a result of an infection, you may be prescribed antibiotics. You may also be given a colony-stimulating factor (CSF) to stimulate the development and growth of white blood cells.

Cough can be managed with medication taken before and after your infusion of Darzalex IV. If you develop a cough as a result of an upper respiratory infection, your doctor will give you medication, if needed.

Typically, you can help relieve your cough by:

• maintaining good hydration
• drinking hot or warm liquids
• taking throat lozenges
• avoiding irritants
• breathing warm steam from a shower or humidifier

Respiratory problems

In the registration trials for Darzalex, 20% of the patients experienced an upper respiratory tract infection. All but 1% were mild to moderate. Upper respiratory tract infections can be a bacterial or viral infection of the nose, throat, sinuses, or larynx. Possible respiratory infections include lung problems such as pneumonia (an infection in one or both lungs). Shortness of breath is also a common side effect. Immediately report your symptoms to your doctor.

If your infection is serious and your white blood cell count is low, the doctor may pause your Darzalex IV until you recover or support you with medications to help with the production of new white blood cells.

Peripheral neuropathy

Peripheral neuropathy (PN) is a serious condition that affects nerves in the hands, feet, lower legs, and/or arms. Myeloma patients may experience PN from the effects of the disease itself or from treatments for myeloma.

Symptoms of PN may include a feeling of:

• numbness 
• tingling
• burning
• pain

Velcade, a drug that is part of many myeloma combination therapies, including regimens with Darzalex or Darzalex Faspro, is known to cause PN. Velcade causes significantly less PN when it is given as an SQ injection under the skin rather than as an IV infusion. In a clinical trial, 6% of patients who received Velcade SQ experienced PN of Grade 3 or 4 vs. 16% of patients who received Velcade IV. If Velcade IV is part of your regimen, be sure to ask your doctor about Velcade SQ.

Diarrhea

Diarrhea is defined as 3 or more loose stools per day. Severe diarrhea is defined as 7 or more loose stools per day. Dizziness, lightheadedness, or fainting may occur due to dehydration caused by either excessive or persistent diarrhea.

Precautions should be taken to prevent dehydration. Ask your doctor how you can maintain an adequate level of hydration. Contact your doctor if you experience dizziness, lightheadedness, or fainting. Your doctor may administer antidiarrheal medication or intravenous fluids on an outpatient basis or may recommend hospitalization if needed.

Constipation

The medical definition of constipation is 3 or fewer bowel movements in 1 week. The stool may become hard, dry, and difficult to pass. You may experience stomach cramps and bloating. Not eating, not drinking enough water, and being less active can make constipation worse.

Ask your doctor for instructions on drinking sufficient fluids and eating high-fiber foods. Try to be active every day, even if you exercise in a chair. Moving your body increases the rhythmic contractions that move food through your intestines.

Darzalex Assistance Program

If you are prescribed Darzalex or Darzalex Faspro, you can sign up for the “DARZALEX withMe” program. Visit darzalex.com or call 1.833.565.9631 Monday–Friday, 8 a.m.–8 p.m. (ET) for help with personalized appointment reminders, access to nurse educators, and referrals to organizations that may provide assistance relevant to the patient’s needs.