Ivozall: Uses, Dosage & Side Effects

What Is Ivozall and What Is It Used For?

Ivozall contains the active substance clofarabine, a second-generation purine nucleoside analogue that was specifically designed to overcome the limitations of older nucleoside analogues such as fludarabine and cladribine. Clofarabine is a synthetic deoxyadenosine analogue in which a fluorine atom has been substituted at the 2-position of the purine ring and a chlorine atom at the 2'-position of the arabinose sugar moiety. These structural modifications give clofarabine enhanced metabolic stability, greater resistance to phosphorolytic cleavage by purine nucleoside phosphorylase, and improved oral bioavailability compared to its parent compounds, although the intravenous formulation is the approved route of administration.

Acute lymphoblastic leukemia (ALL) is the most common cancer in children, accounting for approximately 25–30% of all childhood malignancies worldwide. While first-line treatment achieves remission in approximately 85–90% of pediatric patients, a significant proportion of children (approximately 15–20%) will experience relapse. The prognosis for relapsed ALL is considerably worse than for newly diagnosed disease, and each subsequent relapse carries a progressively lower chance of achieving durable remission. For patients who have failed two or more prior treatment regimens, therapeutic options become extremely limited, and the overall survival rate without further intervention is very poor.

Clofarabine exerts its antileukemic effects through a unique triple mechanism of action that distinguishes it from other nucleoside analogues. First, after entering the leukemic cell and being converted to its active triphosphate metabolite (clofarabine 5'-triphosphate) by deoxycytidine kinase, it competitively inhibits DNA polymerase alpha, the enzyme responsible for initiating DNA replication. This prevents the cancer cell from copying its genetic material and dividing. Second, clofarabine 5'-triphosphate potently inhibits ribonucleotide reductase, an enzyme essential for the de novo synthesis of deoxyribonucleotides (the building blocks of DNA). By depleting the intracellular pool of natural deoxyribonucleotides, clofarabine creates an environment in which cells cannot produce the raw materials needed for DNA synthesis, further compounding the inhibition of cell division.

Third, and perhaps most critically, clofarabine 5'-triphosphate is directly incorporated into the growing DNA chain during attempted replication. Because of its structural modifications, it acts as a chain terminator, halting further extension of the DNA strand and creating irreparable breaks in the genetic code. This DNA damage activates the intrinsic apoptotic pathway by disrupting mitochondrial membrane integrity, leading to the release of pro-apoptotic factors such as cytochrome c and apoptosis-inducing factor. The convergence of these three mechanisms results in a potent and relatively selective cytotoxic effect against rapidly dividing leukemic cells.

The clinical development of clofarabine for pediatric ALL was based on a pivotal single-arm, open-label phase II study that enrolled 61 pediatric patients aged 1 to 20 years with relapsed or refractory ALL who had received at least two prior treatment regimens. In this heavily pretreated population, clofarabine monotherapy achieved an overall remission rate of approximately 30% (20% complete remission and 10% complete remission without full platelet recovery). While these remission rates may appear modest compared to first-line therapy outcomes, they represent a clinically meaningful achievement in a patient population with extremely limited treatment options and a very poor prognosis. Importantly, a substantial proportion of responding patients were able to proceed to hematopoietic stem cell transplantation (HSCT), which remains the best chance for long-term cure in this setting.

Clofarabine was first approved by the U.S. Food and Drug Administration (FDA) in December 2004 under the brand name Clolar for the treatment of pediatric patients aged 1 to 21 years with relapsed or refractory ALL after at least two prior regimens. The European Medicines Agency (EMA) subsequently approved clofarabine under the brand name Evoltra in 2006, and Ivozall is an authorized generic formulation available in European markets. The drug has also been investigated in adult acute leukemias, where it is used off-label in various combination regimens, particularly for older adults with acute myeloid leukemia (AML) who cannot tolerate intensive chemotherapy.

What Should You Know Before Taking Ivozall?

Contraindications

Ivozall is contraindicated in the following situations. You must not receive Ivozall if you have a known hypersensitivity (allergy) to clofarabine or to any of the excipients in the formulation. Severe allergic reactions can be life-threatening and require immediate medical attention. The product must not be given to patients who have severe renal impairment (creatinine clearance less than 30 mL/min) because clofarabine is primarily eliminated through the kidneys, and impaired renal function significantly increases the risk of drug accumulation and toxicity.

Ivozall is also contraindicated in patients with severe hepatic impairment. Since clofarabine undergoes partial hepatic metabolism and can itself cause hepatotoxicity, pre-existing severe liver dysfunction substantially increases the risk of life-threatening liver damage, including veno-occlusive disease (VOD), also known as sinusoidal obstruction syndrome (SOS). Women who are breastfeeding must not receive Ivozall, as it is not known whether clofarabine or its metabolites are excreted in human breast milk, and the potential for serious adverse effects in the nursing infant makes breastfeeding during treatment incompatible with the drug's use.

Warnings and Precautions

Before and during treatment with Ivozall, patients must be carefully monitored for a range of potentially serious complications. The following warnings and precautions are essential for the safe use of this medication:

• Bone marrow suppression: Clofarabine causes profound and prolonged myelosuppression (suppression of bone marrow function) in virtually all patients. This results in severe neutropenia (low white blood cells), anemia (low red blood cells), and thrombocytopenia (low platelets), which increases the risk of serious infections, bleeding, and need for blood transfusions. Complete blood counts must be monitored regularly during treatment, and patients should be observed closely for signs of infection, hemorrhage, and anemia.
• Tumor lysis syndrome (TLS): The rapid destruction of leukemic cells by clofarabine can lead to tumor lysis syndrome, a metabolic emergency characterized by hyperuricemia, hyperkalemia, hyperphosphatemia, and hypocalcemia. TLS can cause acute kidney injury, cardiac arrhythmias, seizures, and death. Prophylactic measures including intravenous hydration and allopurinol or rasburicase should be initiated before treatment. Electrolytes and renal function must be monitored frequently during the first treatment cycle.
• Systemic inflammatory response syndrome (SIRS) and capillary leak syndrome: Clofarabine can trigger SIRS, characterized by fever, tachycardia, tachypnea, and hypotension, as well as capillary leak syndrome with rapid-onset peripheral edema, pulmonary edema, and hypotension. These conditions can be life-threatening and may require intensive care support. Prophylactic corticosteroids (such as hydrocortisone 100 mg/m² on days 1 through 3) are recommended to reduce the incidence of SIRS.
• Hepatotoxicity: Clofarabine can cause significant liver damage, including elevated transaminases, hyperbilirubinemia, and in severe cases, veno-occlusive disease (VOD/SOS). The risk of hepatotoxicity is increased in patients who have previously undergone hematopoietic stem cell transplantation and in those receiving concurrent hepatotoxic medications. Liver function tests should be monitored before each treatment cycle and during therapy.
• Nephrotoxicity: Renal toxicity including elevated creatinine and renal failure can occur. Patients should receive adequate intravenous hydration throughout treatment to maintain renal perfusion. Concomitant use of other nephrotoxic medications should be avoided when possible. Renal function should be monitored before and during treatment.
• Cardiac toxicity: Cases of pericardial effusion and left ventricular systolic dysfunction have been reported with clofarabine use. Patients with pre-existing cardiac conditions should be monitored carefully. Cardiac function should be assessed before initiating treatment and periodically during therapy.
• Infections: Due to the profound immunosuppression caused by clofarabine, patients are at high risk for serious and potentially fatal infections, including bacterial, fungal, and viral infections. Prophylactic antimicrobial therapy should be considered, and any signs of infection must be treated promptly and aggressively.

Pregnancy and Breastfeeding

Ivozall should not be used during pregnancy unless absolutely necessary and only if the potential benefit to the mother outweighs the potential risk to the fetus. Clofarabine has been shown to be teratogenic and embryotoxic in animal studies. Women of childbearing potential must use effective contraception during treatment and for at least 6 months after the last dose. Male patients should also use effective contraception during treatment and for at least 3 months after the last dose, as clofarabine may cause genotoxic damage to sperm.

Breastfeeding is contraindicated during treatment with Ivozall and for at least 2 weeks after the last dose. It is not known whether clofarabine is excreted in human breast milk, but given the drug's mechanism of action and potential for serious adverse effects, the risk to the nursing infant is considered too great to permit breastfeeding during therapy.

Fertility

Clofarabine may impair fertility in both males and females. Animal studies have shown adverse effects on male and female reproductive organs. Patients who wish to have children in the future should discuss fertility preservation options (such as sperm banking or oocyte cryopreservation) with their oncologist before starting treatment. The long-term effects of clofarabine on fertility in humans have not been fully characterized.

How Does Ivozall Interact with Other Drugs?

Clofarabine has not been the subject of formal drug-drug interaction studies in humans. However, based on its pharmacological properties, metabolic pathway, and clinical experience, several important potential interactions and precautions have been identified. Because clofarabine is primarily eliminated through the kidneys (approximately 49–60% excreted unchanged in urine) and can itself cause nephrotoxicity, concomitant use of other nephrotoxic agents may increase the risk of acute kidney injury. Similarly, because clofarabine has been associated with hepatotoxicity, concurrent use of hepatotoxic drugs may compound the risk of liver damage.

Clofarabine is not significantly metabolized by cytochrome P450 (CYP) enzymes. In vitro studies have shown that clofarabine does not inhibit or induce the major CYP enzymes (CYP1A2, CYP2A6, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP2E1, and CYP3A4/5) at clinically relevant concentrations. Therefore, pharmacokinetic interactions mediated through CYP enzyme inhibition or induction are not expected. However, as clofarabine is a substrate for renal organic cation and anion transporters, drugs that affect renal tubular secretion could theoretically alter its clearance.

Major Interactions

The most clinically significant interactions with clofarabine involve agents that share overlapping toxicity profiles. Nephrotoxic agents such as aminoglycosides (gentamicin, tobramycin, amikacin), amphotericin B (both conventional and liposomal formulations), cisplatin, and high-dose methotrexate can significantly increase the risk of acute kidney injury when given concurrently with or shortly after clofarabine. Because many of these agents are commonly used in the supportive care or treatment of patients with acute leukemia, careful planning of treatment schedules is essential. When nephrotoxic antibiotics are required for the treatment of infections during clofarabine therapy, renal function should be monitored daily and alternative antibiotics with less nephrotoxic potential should be preferred when available.

Hepatotoxic drugs present a similar concern. Clofarabine alone can cause clinically significant liver injury, and concurrent exposure to other hepatotoxic agents can compound this risk. This is particularly relevant for patients who may be receiving azole antifungals (voriconazole, posaconazole) for prophylaxis or treatment of invasive fungal infections, as well as those who may have recently received high-dose methotrexate or other hepatotoxic chemotherapy agents. Liver function should be monitored before each treatment cycle and at regular intervals during therapy.

Minor Interactions

Because clofarabine is not significantly metabolized by CYP enzymes, traditional drug-drug interactions involving enzyme inhibition or induction are not a major concern. Mild interactions may occur with drugs that affect renal tubular secretion, potentially altering clofarabine clearance, but these interactions have not been well characterized in clinical studies. Probenecid, for example, which inhibits organic anion transporters in the kidney, could theoretically decrease clofarabine clearance, but clinical data to support this interaction are lacking.

Standard supportive care medications including antiemetics (ondansetron, granisetron), corticosteroids (dexamethasone, hydrocortisone), proton pump inhibitors, and acetaminophen (at standard therapeutic doses) are generally considered safe to use with clofarabine. Patients should be advised to inform their treatment team about all medications they are taking, including over-the-counter drugs, herbal supplements, and vitamins.

What Is the Correct Dosage of Ivozall?

Ivozall should always be administered under the supervision of a physician experienced in the use of antineoplastic agents in a hospital or specialized treatment center with appropriate supportive care facilities. The dose is individualized based on the patient's body surface area (BSA), which is calculated from the patient's height and weight.

Pediatric Patients (Ages 1–21 Years)

Before each treatment cycle, patients must meet specific criteria to ensure it is safe to proceed. These typically include adequate recovery of blood counts (absolute neutrophil count and platelet count), adequate renal function (creatinine clearance or serum creatinine within acceptable limits), adequate hepatic function (bilirubin and transaminases within acceptable limits), and absence of active uncontrolled infection. The treating physician will determine the appropriate timing for each subsequent cycle based on the individual patient's clinical status and recovery.

Continuous intravenous hydration with 0.9% sodium chloride (normal saline) at a rate appropriate for the patient's size is recommended throughout the 5 days of treatment to maintain adequate urine output and reduce the risk of tumor lysis syndrome and nephrotoxicity. Prophylactic allopurinol (or rasburicase in patients at high risk of tumor lysis syndrome) should be started before the first dose and continued throughout the treatment cycle.

Adults (Off-Label Use)

Ivozall is not approved for use in adults. However, clofarabine has been extensively studied in adult acute leukemias and is used off-label in various clinical settings. In adult acute myeloid leukemia (AML), clofarabine has been used both as monotherapy and in combination with other agents, particularly cytarabine. Common adult dosing regimens include clofarabine 40 mg/m²/day for 5 days as monotherapy, or clofarabine 20–30 mg/m²/day for 5 days in combination regimens. Adult dosing is generally lower than the pediatric dose due to differences in tolerability. Any use in adults should be under the guidance of a hematologist/oncologist experienced in treating acute leukemias.

Dose Modifications for Toxicity

Dose reductions or treatment delays may be necessary based on the severity of adverse effects. A 25% dose reduction (to 39 mg/m²/day) is recommended for patients who experience certain grade 3 or 4 toxicities. Treatment should be delayed until the patient has recovered from the previous cycle's toxicity. Specific dose modification guidelines include:

• Hematologic toxicity: Treatment should be delayed until the absolute neutrophil count (ANC) recovers to at least 0.75 × 10&sup9;/L. If recovery takes longer than 6 weeks, dose reduction or treatment discontinuation should be considered.
• Renal toxicity: If serum creatinine rises to greater than 2 times the upper limit of normal, treatment should be withheld until renal function recovers. A dose reduction should be considered for subsequent cycles.
• Hepatic toxicity: If bilirubin rises to greater than 3 times the upper limit of normal or transaminases rise to greater than 5 times the upper limit of normal, treatment should be withheld until liver function recovers. Discontinuation should be considered for veno-occlusive disease.
• SIRS or capillary leak syndrome: Treatment should be discontinued immediately if signs of SIRS or capillary leak develop. The patient should receive aggressive supportive care. Treatment may be resumed at a reduced dose after full recovery, with careful monitoring.

Missed Dose

Because Ivozall is administered in a hospital setting under physician supervision, missed doses are uncommon. If a dose within a 5-day cycle is delayed or missed due to toxicity, the treating physician will determine whether to make up the missed dose or proceed to the next scheduled dose based on the patient's clinical condition. Doses should not be doubled to compensate for a missed administration.

Overdose

There is no known specific antidote for clofarabine overdose. In the event of overdose, treatment should be discontinued immediately, and aggressive supportive care should be provided. Anticipated complications of overdose include severe bone marrow suppression, hepatic failure, renal failure, and gastrointestinal toxicity. The patient should receive intensive monitoring including complete blood counts, liver function tests, renal function tests, and electrolytes. Supportive measures including blood product transfusions, antimicrobial therapy, and fluid management should be employed as needed. Given the drug's elimination half-life of approximately 5.2 hours, close monitoring should continue for at least several days after the overdose.

What Are the Side Effects of Ivozall?

As an antineoplastic agent, Ivozall has a significant side effect profile that reflects its mechanism of action against rapidly dividing cells. The adverse effects of clofarabine affect multiple organ systems and range from common, expected consequences of myelosuppression to rare but potentially life-threatening complications. It is important for patients and caregivers to be aware of these side effects so that they can be reported to the treatment team promptly. The frequency classifications below are based on clinical trial data and post-marketing surveillance.

The side effects listed here are categorized by frequency according to the internationally recognized classification system used in regulatory medicine: Very common (>1/10, affecting more than 1 in 10 patients), Common (1/10 to 1/100, affecting between 1 in 10 and 1 in 100 patients), Uncommon (1/100 to 1/1,000), and Rare (<1/1,000).

The bone marrow suppressive effects of clofarabine are expected and are a direct consequence of its mechanism of action. Virtually all patients will experience some degree of neutropenia, anemia, and thrombocytopenia during treatment. The nadir (lowest point) of blood counts typically occurs between days 7 and 14 after the start of a treatment cycle, with recovery generally occurring within 2 to 4 weeks, although prolonged cytopenias can occur, particularly in heavily pretreated patients.

Gastrointestinal effects including nausea, vomiting, and diarrhea are very common and are generally manageable with standard antiemetic therapy (5-HT3 receptor antagonists such as ondansetron or granisetron) and supportive care. Mucositis (inflammation and ulceration of the mucosal lining of the mouth and gastrointestinal tract) can occur and may be severe, requiring parenteral nutrition and pain management in some cases.

Hepatic toxicity is a significant concern with clofarabine therapy. Most patients experience some degree of liver enzyme elevation during treatment. In severe cases, veno-occlusive disease (VOD), also known as sinusoidal obstruction syndrome (SOS), can develop. VOD is characterized by hepatomegaly, right upper quadrant pain, jaundice, ascites, and weight gain, and can be fatal. The risk of VOD is increased in patients who have previously undergone hematopoietic stem cell transplantation.

How Should You Store Ivozall?

Proper storage of Ivozall is essential to maintain the stability and efficacy of the medication. Because Ivozall is an antineoplastic agent that is handled and administered in hospital settings, storage and preparation are typically managed by trained pharmacy personnel following strict protocols for the handling of cytotoxic drugs.

Unopened vials of Ivozall should be stored in a refrigerator at 2–8°C (36–46°F). The vials should be kept in the original carton to protect the solution from light, as clofarabine is sensitive to photodegradation. The vials must not be frozen, as freezing may alter the physical and chemical stability of the concentrate. Unopened vials stored under these conditions are stable until the expiration date printed on the packaging.

Once diluted for administration (typically in 0.9% sodium chloride solution or 5% dextrose solution), the infusion solution is chemically and physically stable for up to 24 hours when stored at room temperature (up to 25°C) or for up to 72 hours when stored in a refrigerator (2–8°C). However, from a microbiological standpoint, the diluted solution should be used immediately unless it was prepared under validated aseptic conditions. Any unused portion of the diluted solution should be discarded in accordance with local requirements for the disposal of cytotoxic waste.

As with all medications, Ivozall should be kept out of the reach and sight of children. Do not use the medication after the expiration date stated on the vial label and outer carton. The expiration date refers to the last day of that month. Do not use the medication if the solution appears discolored, cloudy, or contains visible particles.

What Does Ivozall Contain?

Ivozall is supplied as a sterile, preservative-free, clear to practically colorless or slightly yellow concentrate for solution for infusion. Each mL of the concentrate contains 1 mg of clofarabine. The concentrate is available in single-use glass vials containing 20 mL of solution (equivalent to 20 mg of clofarabine per vial).

The complete composition of Ivozall is as follows:

• Active substance: Clofarabine 1 mg per mL. Clofarabine is a synthetic purine nucleoside analogue with the chemical name 2-chloro-9-(2-deoxy-2-fluoro-β-D-arabinofuranosyl)-9H-purin-6-amine. Its molecular formula is C₁₀H₁₁ClFN₅O₃ with a molecular weight of 303.68 g/mol.
• Excipients: Sodium chloride (for tonicity adjustment) and water for injections. Hydrochloric acid and/or sodium hydroxide may be added for pH adjustment. The solution has a pH of approximately 4.5 to 7.5.

Before administration, Ivozall concentrate must be diluted with 0.9% sodium chloride solution (normal saline) or 5% dextrose solution. The concentrate should be filtered through a sterile 0.2 micron syringe filter before being added to the infusion bag. The final diluted solution should be inspected visually for particulate matter and discoloration before administration. The total volume of the diluted infusion solution is typically adjusted to allow for administration over approximately 2 hours.

Ivozall does not contain any preservatives, latex, or animal-derived excipients. The sodium content of the concentrate is approximately 5.85 mg of sodium per mL, which should be taken into consideration for patients on a sodium-restricted diet or receiving large volumes of sodium chloride diluent during treatment. As a cytotoxic medication, any unused product or waste material must be disposed of in accordance with local requirements for hazardous pharmaceutical waste.