Inotuzumab Ozogamicin (Besponsa)
Anti-CD22 antibody-drug conjugate for relapsed or refractory B-cell precursor ALL.
What is Inotuzumab Ozogamicin?
What it targets
CD22, a protein found on the surface of B-lineage leukemia cells — the antibody half of the conjugate delivers a cytotoxic payload directly into CD22-positive cells.
Who it may help
Adults and children with relapsed or refractory B-cell precursor acute lymphoblastic leukemia (B-ALL) that has returned or not responded to prior treatment.
Why testing matters
CD22 expression on leukemia cells and baseline liver function must be confirmed before starting, given the drug's risk of liver toxicity.
Which cancers can Inotuzumab Ozogamicin treat?
Inotuzumab ozogamicin is approved for CD22-positive B-cell precursor ALL in relapsed or refractory settings. Use in other contexts requires specialist guidance.
| Relapsed or refractory B-cell precursor ALL | Approved for CD22-positive disease in adults and paediatric patients aged 1 year and older in the USA; adults in Europe. |
| Philadelphia chromosome-positive (Ph+) B-ALL | In Europe, Ph-positive patients must have failed at least one tyrosine kinase inhibitor before Besponsa is considered. |
| Bridge to stem cell transplant | Used in selected patients to achieve remission before haematopoietic stem cell transplant (HSCT) when prior therapy has failed. |
| Other ALL settings (investigational) | Earlier-line use, paediatric strategies, and combination regimens are being studied in clinical trials under specialist guidance. |
Who may be considered for Inotuzumab Ozogamicin?
Patient selection is made by a leukemia specialist after reviewing disease biology, prior treatments, organ function, and transplant plan.
- Confirmed relapsed or refractory B-cell precursor ALL diagnosis.
- CD22-positive leukemia cells confirmed by flow cytometry or immunophenotyping.
- Prior treatment that has stopped working or did not produce an adequate response.
- Acceptable liver function — hepatic veno-occlusive disease risk must be assessed before starting.
- Adequate blood counts and no uncontrolled active infection at the time of treatment.
- Treatment plan that may include stem cell transplant after remission — eligibility reviewed before starting.
- Performance status and overall health deemed acceptable by the treating hemato-oncologist.
- Philadelphia chromosome status and prior TKI history reviewed, especially under EMA labelling.
How does Inotuzumab Ozogamicin work?
- Step 1: CD22 targeting
- Step 2: Internalisation into the leukemia cell
- Step 3: Release of cytotoxic payload
- Step 4: DNA damage and cell death
Tests needed before and during treatment
A full assessment is required before starting inotuzumab ozogamicin to confirm eligibility, establish baseline organ function, and assess transplant suitability.
| Bone marrow biopsy and immunophenotyping | Confirms ALL diagnosis, CD22 expression, and leukemia burden before treatment. |
| CD22 testing by flow cytometry | Required to confirm CD22-positive disease — the key eligibility criterion. |
| Cytogenetic and molecular testing | Includes Philadelphia chromosome / BCR-ABL1 testing and other relevant markers. |
| Complete blood count (CBC) | Baseline and ongoing monitoring during all cycles for cytopenias. |
| Liver function tests and bilirubin | Critical before starting — VOD risk must be assessed and monitored throughout treatment. |
| Kidney function, electrolytes | Baseline metabolic panel for dosing and safety assessment. |
| Infection screening | Active infection must be assessed before each cycle; hepatitis and other screening as indicated. |
| Transplant eligibility review | Performed before treatment if stem cell transplant is being considered after remission. |
| Pregnancy test | Required for females of reproductive potential before starting treatment. |
How is Inotuzumab Ozogamicin given?
Inotuzumab ozogamicin is given by intravenous infusion in a specialist leukemia centre experienced in managing acute leukemia and serious complications.
| Standard dose — Cycle 1 | 1.8 mg/m² per cycle: 0.8 mg/m² on Day 1, 0.5 mg/m² on Days 8 and 15; 21-day cycle. |
| Standard dose — Cycles 2 onward | 1.5 mg/m² per cycle: 0.5 mg/m² on Days 1, 8, and 15; 21-day cycle for patients achieving remission. |
| Pre-medication | Patients receive a corticosteroid, antipyretic, and antihistamine before each infusion to reduce infusion-related reactions. |
| Infusion duration | Each infusion is given over approximately 1 hour in an infusion centre or hospital setting. |
| Number of cycles | Typically 2 to 6 cycles depending on response, tolerance, and transplant plan; decided by the treating team. |
| Transplant timing | If stem cell transplant is planned, the number of cycles before transplant is carefully limited to reduce VOD risk. |
| Missed or delayed doses | Any dose delay is managed by the treating team based on blood counts, liver tests, and infection status. |
| Monitoring during treatment | CBC and liver function tests before each dose; bone marrow response assessed during and after cycles. |
Possible benefits of Inotuzumab Ozogamicin
In the INO-VATE ALL trial — the pivotal study for Besponsa — inotuzumab ozogamicin demonstrated meaningful outcomes compared to standard chemotherapy in relapsed or refractory B-ALL.
| Higher complete remission rates | Substantially more patients achieved complete remission compared to standard salvage chemotherapy in the INO-VATE ALL trial. |
| Improved measurable residual disease negativity | A higher proportion of patients achieved MRD-negative remission — a marker of deeper disease clearance — compared to standard therapy. |
| Bridge to stem cell transplant | More patients were able to proceed to haematopoietic stem cell transplant following inotuzumab ozogamicin versus standard chemotherapy in clinical studies. |
| Progression-free survival improvement | The INO-VATE ALL trial demonstrated significantly longer progression-free survival in favour of inotuzumab ozogamicin over salvage chemotherapy. |
| Overall survival benefit | An overall survival benefit was observed in the primary analysis in favour of inotuzumab ozogamicin over standard chemotherapy. |
| Targeted mechanism | Delivers cytotoxic payload directly to CD22-positive leukemia cells, offering an option in patients who have failed multiple lines of therapy. |
Individual responses vary. These represent published clinical trial data. Benefit depends on disease biology, prior therapy, CD22 expression, and overall health.
Side effects of Inotuzumab Ozogamicin
As an intravenous ADC given in relapsed leukemia, inotuzumab ozogamicin has significant side effects requiring close monitoring. Some are related to the leukemia itself; others are drug-specific.
| Low platelets (thrombocytopenia) | Very common; monitored before each dose. May require dose modification, transfusion support, or delay. |
| Low neutrophils (neutropenia) | Very common; increases infection risk. Growth factors and antibiotics used as needed. |
| Anaemia | Common; managed with transfusions and monitoring of haemoglobin levels. |
| Fever (febrile neutropenia) | Common; may indicate serious infection and requires urgent assessment and antibiotic treatment. |
| Infection | Common; bacterial, fungal, and viral infections occur. Prophylaxis and close monitoring are standard. |
| Nausea and vomiting | Common; managed with antiemetic pre-medication and supportive care. |
| Fatigue | Common; often related to anaemia and the intensity of leukemia treatment. |
| Increased liver enzymes (ALT, AST) | Common; liver tests monitored before each cycle. Elevated enzymes may require dose delay or modification. |
| Increased bilirubin | Common; an early sign of liver stress that requires careful monitoring for VOD. |
| Headache | Reported; generally manageable with supportive care. |
| Bleeding | Can occur due to low platelets; patients should report any unusual bruising or bleeding. |
| Hepatic veno-occlusive disease (VOD) | Serious, potentially fatal; highest risk in patients proceeding to stem cell transplant. Requires urgent specialist management. |
Contact your doctor immediately if you develop:
- Fever, chills, or signs of infection — may indicate serious or life-threatening infection.
- Yellow eyes or skin, dark urine, or right-sided abdominal pain — possible signs of liver VOD.
- Rapid unexplained weight gain or abdominal swelling — a key warning sign of sinusoidal obstruction syndrome.
- Unusual or severe bleeding, blood in urine or stools, or heavy bruising.
- Shortness of breath, chest pain, or extreme fatigue — may indicate anaemia or cardiac events.
- Confusion, reduced consciousness, or inability to stand — may indicate severe infection or metabolic crisis.
Safety precautions and drug interactions
Tell your hemato-oncologist and pharmacist about all medicines, supplements, and herbal products before starting inotuzumab ozogamicin.
- Tell your doctor about any past or current liver disease — including prior hepatitis, cirrhosis, or elevated liver enzymes.
- Disclose any prior stem cell transplant and whether a future transplant is planned — this directly affects VOD risk and cycle decisions.
- Report all QT-prolonging medicines — inotuzumab ozogamicin can prolong the QT interval and should be used carefully with other QT-affecting drugs.
- Avoid pregnancy during treatment and for at least 8 months after the last dose — the drug can cause serious harm to an unborn baby.
- Do not breastfeed during treatment and for at least 2 months after the last dose.
- Report all active infections before each cycle — treatment may need to be delayed if infection is present or uncontrolled.
- Disclose all medications including anticoagulants, antifungals, and antibiotics — drug interactions can affect toxicity and efficacy.
- Avoid live vaccines during treatment — the immune system is suppressed and live vaccines may be unsafe.
Inotuzumab Ozogamicin combination treatments
Inotuzumab ozogamicin may be used as part of a broader leukemia treatment plan. The sequence and combination depend on disease biology, prior treatments, and transplant plans.
| Inotuzumab + TKI (Ph+ ALL) | In Philadelphia chromosome-positive B-ALL, inotuzumab ozogamicin may be combined or sequenced with tyrosine kinase inhibitors such as ponatinib or dasatinib under specialist guidance. |
| Bridge to stem cell transplant | Remission achieved with inotuzumab ozogamicin may allow eligible patients to proceed to allogeneic haematopoietic stem cell transplant — the combination of ADC followed by HSCT requires careful VOD risk management. |
| CNS prophylaxis or treatment | CNS-directed therapy may be added or continued alongside inotuzumab ozogamicin when CNS involvement is present or at risk. |
| Supportive care | Antibiotics, antifungals, antivirals, transfusions, and growth factors are routinely used alongside treatment to manage cytopenias and infections. |
| Switching to next-line options | If inotuzumab ozogamicin fails, blinatumomab, CAR-T cell therapy, or clinical trial options may be considered depending on disease characteristics and patient fitness. |
If Inotuzumab Ozogamicin stops working
If the leukemia does not respond or progresses after inotuzumab ozogamicin, the treating team will reassess disease biology and identify the most appropriate next step.
| Loss or reduction of CD22 expression | CD22 downregulation or loss on leukemia cells after ADC therapy can reduce drug effectiveness; repeat flow cytometry helps guide next-line decisions. |
| MDR resistance mechanisms | Multi-drug resistance through drug efflux pumps and altered drug metabolism may contribute to reduced activity after repeat exposure. |
| CAR-T cell therapy | In eligible patients with CD19-positive disease, CD19-directed CAR-T cell therapy (such as tisagenlecleucel) may be considered as next-line if available. |
| Blinatumomab | CD3/CD19 bispecific T-cell engager; may be considered after ADC failure in CD19-positive B-ALL with appropriate performance status. |
| Stem cell transplant | If remission can be achieved by another means after inotuzumab ozogamicin failure, allogeneic HSCT may be reconsidered with careful risk assessment. |
| Clinical trials | Trials evaluating novel agents, combinations, or next-generation ADCs are available at specialist centres in India, China, and internationally. |
Cost of Inotuzumab Ozogamicin by country
Inotuzumab ozogamicin (Besponsa) is a branded ADC with no generic available. Cost varies significantly by country, hospital, number of cycles, import status, and insurance coverage.
| India | No local manufacturing; typically requires import through specialist oncology hospitals. Cost per cycle is substantial and varies by hospital. Patient assistance or compassionate use channels may be available. CancerFax can help explore current access routes. |
| USA | Branded Besponsa available through hospital pharmacies. Pfizer patient assistance programmes exist for eligible uninsured or underinsured patients. Insurance coverage varies by plan and indication. |
| UK / Europe | NHS England has approved Besponsa for relapsed or refractory B-ALL under specific conditions. Cost in self-pay European markets is high; national insurance schemes may provide coverage through managed access. |
| China | NMPA approval reported for relapsed or refractory precursor B-cell ALL. Access through approved cancer hospitals; local pricing and insurance coverage should be confirmed with the treating centre. |
| Other countries | Availability varies by country and hospital. Patients in Southeast Asia, the Middle East, and other regions may require import or referral to a centre with access. CancerFax can assist with cost and pathway guidance. |
Availability of Inotuzumab Ozogamicin globally
Besponsa is approved by the FDA and EMA. China NMPA approval has been reported. Availability varies by hospital, supply route, and national insurance system.
USA
FDA-approved for relapsed or refractory CD22-positive B-cell precursor ALL in adults and paediatric patients aged 1 year and older. Available through specialist hospital pharmacies. Pfizer patient assistance available for eligible patients.
UK / Europe
EMA-approved for adults with relapsed or refractory CD22-positive B-cell precursor ALL. NHS England covers Besponsa for eligible patients. Self-pay cost is high; national insurance access varies by country.
China
China NMPA approval reported for adults with relapsed or refractory precursor B-cell ALL. Access through approved cancer hospitals. Coverage under national insurance should be confirmed with the treating centre at time of treatment.
India
No local registration as of mid-2026; typically accessed via import through specialist oncology hospitals. Patients should confirm availability and import status with the treating centre before planning treatment.
Other countries
Availability varies. Patients in Southeast Asia, the Middle East, and other regions should confirm access with specialist leukemia centres. CancerFax can assist with access navigation and hospital referral.
Inotuzumab Ozogamicin in current clinical trials
Research into inotuzumab ozogamicin continues across several areas, including earlier-line use, paediatric strategies, and novel combinations.
| Earlier-line ALL treatment | Trials studying inotuzumab ozogamicin in newly diagnosed or first-relapse ALL to determine whether earlier use improves outcomes compared to standard chemotherapy. |
| Paediatric and young adult leukemia | Studies evaluating dosing, safety, and efficacy in children and young adults, including paediatric formulation and combination regimens. |
| Combination with blinatumomab | Early-phase trials exploring sequential or combination use of inotuzumab ozogamicin and blinatumomab to deepen remission and reduce transplant need. |
| Combination with TKIs in Ph+ ALL | Studies of inotuzumab ozogamicin combined with next-generation TKIs (ponatinib, asciminib) in Philadelphia chromosome-positive B-ALL. |
| MRD-directed strategies | Trials using measurable residual disease status to guide the number of cycles and transplant decisions, aiming to personalise treatment duration. |
| Transplant-free regimens | Research exploring whether patients achieving deep MRD-negative remission may be able to avoid transplant and its associated risks including VOD. |
Your treatment journey with Inotuzumab Ozogamicin
Diagnosis of relapsed or refractory B-ALL
CD22 testing and leukemia profiling
Baseline assessment and transplant review
Treatment planning and consent
Inotuzumab ozogamicin infusion cycles
Bone marrow response assessment
Transplant or next-line decision
Questions to ask your oncologist about Inotuzumab Ozogamicin
- Has my leukemia been confirmed as CD22-positive?
- What is the risk of liver disease (VOD) in my specific case?
- Am I being treated with the goal of achieving transplant?
- How many cycles are planned and when will you assess my response?
- What blood tests and symptoms should make me call urgently?
- What are my alternatives if this drug does not work or I cannot tolerate it?
- Is the drug available at this hospital, or do I need referral to another centre?
- What is the expected total cost and what financial support is available?
How CancerFax supports Inotuzumab Ozogamicin patients
CancerFax helps leukemia patients and families navigate access to inotuzumab ozogamicin and connects them with experienced hemato-oncologists in India, China, and internationally.
| Medical report review | Upload your bone marrow report, CD22 flow cytometry result, molecular testing, or liver function tests — our team reviews them and explains the implications for inotuzumab ozogamicin eligibility. |
| Specialist connection | We connect patients with haematologists and leukemia specialists experienced in B-ALL, ADC therapy, and stem cell transplant across India, UAE, Singapore, South Korea, China, and other centres. |
| Second opinion | If you are uncertain about the treatment plan, VOD risk, or transplant decision, CancerFax arranges a second opinion from a specialist leukemia centre with experience in inotuzumab ozogamicin. |
| Access and cost guidance | We help patients in India and other countries understand current access routes, import options, patient assistance programmes, and cost implications for Besponsa. |
| China treatment access | For patients considering advanced leukemia treatment in China — including ADC therapy, CAR-T, or clinical trials — CancerFax manages coordination with Chinese oncology centres. |
| Clinical trial exploration | We identify relevant leukemia trials in India, China, and internationally for patients whose disease has progressed or who need options beyond standard therapy. |
Frequently asked questions about Inotuzumab Ozogamicin
Common questions from patients and caregivers about Besponsa and B-ALL treatment
Inotuzumab ozogamicin (Besponsa) is an antibody-drug conjugate — it combines a targeted antibody that seeks out CD22 on leukemia cells with a powerful cytotoxic payload called calicheamicin. Unlike standard chemotherapy, which affects all dividing cells, this drug delivers its toxic component specifically to CD22-positive B-cell leukemia cells, potentially reducing harm to healthy tissue. It is given by intravenous infusion in cycles, not taken as a daily oral tablet.
Yes. CD22 expression on leukemia cells is the key requirement for inotuzumab ozogamicin to work. Your oncologist will confirm CD22 status using flow cytometry or immunophenotyping of a bone marrow or blood sample before recommending this drug. The drug has no benefit in CD22-negative disease. In most cases of B-cell precursor ALL, CD22 is expressed on leukemia cells, but testing is still required to confirm eligibility.
The most serious risk is hepatic veno-occlusive disease (VOD), also called sinusoidal obstruction syndrome — a potentially life-threatening liver condition. This risk is highest in patients who go on to receive a stem cell transplant after treatment. Symptoms include rapid weight gain, fluid buildup in the abdomen, and yellowing of the eyes or skin. Your oncologist will monitor liver function closely during and after treatment and will discuss transplant timing carefully to manage this risk.
For many patients, inotuzumab ozogamicin is used as a bridge to hematopoietic stem cell transplant — achieving remission so a transplant becomes possible. However, transplant eligibility depends on the depth of remission achieved, your overall fitness, donor availability, and liver function. Not every patient proceeds to transplant, and the decision is made by your leukemia team based on your individual situation. The drug carries specific risks that are higher when followed by transplant, which your oncologist will explain before treatment.
Treatment is given in cycles of 21 days. Each cycle involves infusions on Days 1, 8, and 15. Most patients receive 2 to 6 cycles depending on response, tolerance, and whether transplant is planned. The total duration is determined by your oncologist after assessing bone marrow response, liver function, and overall tolerability. Your team will perform bone marrow assessments during treatment to evaluate response and guide decisions about continuing or stopping.
Inotuzumab ozogamicin (Besponsa) is FDA-approved and EMA-approved. China NMPA approval has been reported for adults with relapsed or refractory precursor B-cell ALL. Availability in India may be limited and typically requires import through specialist oncology hospitals or compassionate use channels. CancerFax can help you explore current access options in India, China, and other countries, and connect you with leukemia centres that have experience with this drug.
If the leukemia does not respond or progresses after treatment, your oncologist will reassess the disease with bone marrow testing and molecular profiling. Next-line options may include blinatumomab, CAR-T cell therapy (where available), clinical trials, or stem cell transplant if remission can be achieved by other means. A second opinion at a specialist leukemia centre can help identify the most appropriate next step, including advanced options in India, China, or internationally.