Ofatumumab Injection

Name: Ofatumumab Injection

Why is this medication prescribed?

Ofatumumab injection is used to treat chronic lymphocytic leukemia (CLL; a type of cancer of the white blood cells) in adults who have not gotten better after treatment with fludarabine (Fludara) and alemtuzumab (Campath). Ofatumumab injection is in a class of medications called monoclonal antibodies. It works by killing cancer cells.

How should this medicine be used?

Ofatumumab injection comes as a solution (liquid) to be added to fluid and injected intravenously (into a vein) by a doctor or nurse in a medical office or hospital. It is usually injected once a week for 8 weeks then once a month for 4 months.

Your doctor may need to interrupt your treatment if you experience certain side effects. Your doctor will give you other medications to prevent or treat certain side effects 30 minutes to 2 hours before you receive each dose of ofatumumab injection. Be sure to tell your doctor how you are feeling during your treatment with ofatumumab injection.

What side effects can this medication cause?

Ofatumumab injection may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • muscle spasms
  • stuffy or runny nose
  • diarrhea
  • headache
  • difficulty sleeping

Some side effects can be serious. If you experience any of these symptoms or those listed in the IMPORTANT WARNING section , call your doctor immediately:

  • difficulty breathing or swallowing
  • heavy sweating
  • swelling of the face, throat, tongue, lips, eyes, hands, feet, ankles, or lower legs
  • hoarseness
  • sudden reddening of the face, neck, or upper chest
  • weakness
  • unusual bleeding or bruising
  • pale skin
  • pinpoint, flat, round, red spots under the skin
  • rash
  • hives
  • fever, chills, cough, sore throat, or other signs of infection
  • pain in arms, back, neck, or jaw
  • chest pain,
  • fast heartbeat
  • fainting

Ofatumumab injection may cause other side effects. Call your doctor if you have any unusual problems while receiving this medication.

If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online (http://www.fda.gov/Safety/MedWatch) or by phone (1-800-332-1088).

Brand names

  • Arzerra®

Clinical pharmacology

Mechanism Of Action

Ofatumumab binds specifically to both the small and large extracellular loops of the CD20 molecule. The CD20 molecule is expressed on normal B lymphocytes (pre–B- to mature B-lymphocyte) and on B-cell CLL. The CD20 molecule is not shed from the cell surface and is not internalized following antibody binding.

The Fab domain of ofatumumab binds to the CD20 molecule and the Fc domain mediates immune effector functions to result in B-cell lysis in vitro. Data suggest that possible mechanisms of cell lysis include complement-dependent cytotoxicity and antibody-dependent, cell-mediated cytotoxicity.

Pharmacodynamics

B-Cell Depletion

In patients with previously untreated CLL, at 6 months after the last dose, the median reductions in CD19-positive B cells were >99% (n = 155) for ARZERRA in combination with chlorambucil and 94% (n = 121) for chlorambucil alone.

In patients with relapsed CLL, the proportion of responders in the ofatumumab in combination with fludarabine and cyclophosphamide (O+FC) arm who showed complete or near complete B cell depletion was 39% (n = 59) and 82% (n = 126) , respectively. The proportion of responders in the fludarabine and cyclophosphamide (FC) arm with complete or near complete B cell depletion was 4% (n = 5) and 23% (n = 28), respectively.

In patients treated with extended treatment for CLL after response to therapy for their recurrent or progressive disease, the median decreases in B-cell counts were 61% (n = 168) after the first infusion and 80% (n = 114) prior to the sixth infusion; in the observation arm, the median changes in B-cell counts at the same time points were increases of 32% (n = 148) and 1,328% (n = 95).

In patients with CLL refractory to fludarabine and alemtuzumab, the median decrease in circulating CD19-positive B cells was 91% (n = 50) with the 8th infusion and 85% (n = 32) with the 12th infusion. The time to recovery of lymphocytes, including CD19-positive B cells, to normal levels has not been determined.

Although the depletion of B-cells in the peripheral blood is a measurable pharmacodynamic effect, it is not directly correlated with the depletion of B cells in solid organs or in malignant deposits. B-cell depletion has not been shown to be directly correlated to clinical response.

Cardiac Electrophysiology:

The effect of multiple doses of ARZERRA on the QTc interval was evaluated in a pooled analysis of 3 open-label studies in patients with CLL (N = 85). Patients received ARZERRA 300 mg on Day 1 followed by either 1,000 mg or 2,000 mg for subsequent doses. No large changes in the mean QTc interval (i.e., >20 milliseconds) were detected in the pooled analysis.

Pharmacokinetics

Ofatumumab is eliminated through both a target-independent route and a B cell-mediated route. Ofatumumab exhibited dose-dependent clearance in the dose range of 100 to 2,000 mg. Due to the depletion of B cells, the clearance of ofatumumab decreased substantially after subsequent infusions compared with the first infusion.

Pharmacokinetic data were obtained after repeated administration (4, 5, 6, 8, or 12 infusions) of 1,000 mg or 2,000 mg doses in 774 patients with CLL (Studies 1, 2, 3, 4 and 5). The geometric mean (% CV) values for clearance, volume of distribution at steady state (Vss), and half-life for ofatumumab in these patients were 9.3 mL/hour (91%), 6.1 L (52%), and 17.6 days (83%). The pharmacokinetic profile was similar across doses in patients with CLL.

Specific Populations

The following population characteristics do not have a clinically meaningful effect on the pharmacokinetics of ofatumumab: body size, gender, age, and renal impairment (evaluated in patients with a calculated creatinine clearance ≥30 mL/min).

No formal studies of ARZERRA in patients with hepatic impairment have been conducted. The effect of a calculated CrCL < 30 mL/min on the pharmacokinetics of ARZERRA has not been evaluated.

Drug Interactions

Coadministration of ARZERRA did not result in clinically relevant effects on the pharmacokinetics of fludarabine, cyclophosphamide, chlorambucil, or its active metabolite, phenylacetic acid mustard.

Clinical Studies

Previously Untreated CLL

The efficacy of ARZERRA was evaluated in a randomized, open-label, parallel-arm study; 447 patients previously untreated for CLL were randomized to receive either ARZERRA as monthly intravenous infusions (Cycle 1: 300 mg on Day 1 and 1,000 mg on Day 8; subsequent cycles: 1,000 mg on Day 1 every 28 days) in combination with chlorambucil (10 mg/m2 orally on Days 1 to 7 every 28 days) or chlorambucil alone (10 mg/m2 orally on Days 1 to 7 every 28 days). Patients received treatment for a minimum of 3 cycles. Treatment was continued for 3 cycles beyond maximal response (2 consecutive response assessments of stable disease, partial response, or complete response) for up to 12 cycles. Approximately 60% of patients received 3 to 6 cycles of ARZERRA and 30% received 7 to 12 cycles.

This trial enrolled patients for whom fludarabine-based therapy was considered to be inappropriate by the investigator for reasons that included advanced age or presence of co-morbidities. In the overall trial population, the median age was 69 years (range: 35 to 92 years) and 69% of patients in both arms were at least 65 years of age. In the overall trial population, 72% of patients had 2 or more co-morbidities and 48% of patients had a creatinine clearance of less than 70 mL/min. Sixty-three percent (63%) of patients were male and 89% were white. Elevated beta-2 microglobulin (β2m) >3,500 mcg/L was present in 72% of patients at baseline.

Efficacy was evaluated by progression-free-survival (PFS) as assessed by a blinded Independent Review Committee (IRC) using the International Workshop for Chronic Lymphocytic Leukemia (IWCLL) updated National Cancer Institute-sponsored Working Group (NCI-WG) guidelines (2008). ARZERRA plus chlorambucil resulted in statistically significant improvement in IRC-assessed median PFS compared with chlorambucil alone (22.4 months versus 13.1 months; hazard ratio: 0.57 [0.45, 0.72]) (Table 9; Figure 1).

Secondary efficacy endpoints, including overall response (OR), complete response (CR), and duration of response, were also assessed by the IRC using the 2008 IWCLL Guidelines (Table 9).

Table 9. IRC-assessed Efficacy Results in Previously Untreated CLL (ITT Populationa)

Primary and Key Secondary Endpoints ARZERRA plus Chlorambucil
(N = 221)
Chlorambucil
(N = 226)
Progression-free survival (PFS)
  Median, months 22.4 13.1
  (95% CI) (19.0, 25.2) (10.6, 13.8)
Hazard ratiob (95% CI) 0.57 (0.45, 0.72)
  Stratified log rank P value P <0.001
Overall response, % 82.4 68.6
  (95% CI) (76.7, 87.1) (62.1, 74.6)
  P value P = 0.001
Complete response, % 12 1
Duration of response   
  Median, months 22.1 13.2
  (95% CI) (19.1, 24.6) (10.8, 16.4)
IRC = Independent Review Committee; ITT = Intention to treat; CI = Confidence interval.
a Intention-to-treat population includes all 447 randomized patients.
b Pike Estimator.

Figure 1. Kaplan-Meier Estimates of IRC-assessed Progression-free Survival

Relapsed CLL

Study 2 (randomized, open-label, parallel-arm, multicenter trial) evaluated the efficacy of ARZERRA in combination with fludarabine and cyclophosphamide compared with fludarabine and cyclophosphamide in 365 patients with relapsed CLL. Baseline disease characteristics and prognostic markers were balanced between treatment arms. Patient median age was 61 years (range: 32 to 90 years), 60% were male and 55% and 28% of patients were Binet stage B and C, respectively. Eighty one percent (81%) of patients received 1-2 prior treatments and 21% of patients had received prior rituximab.

Patients received ARZERRA as intravenous infusions (Cycle 1: 300 mg on Day 1 and 1,000 mg on Day 8; followed by 1,000 mg on Day 1 of subsequent cycles). Approximately 90% of patients received 3-6 cycles of ARZERRA and 66% completed all 6 cycles.

Efficacy was evaluated by progression-free survival (PFS), as assessed by an independent review committee (IRC). PFS was prolonged in the ARZERRA plus fludarabine and cyclophosphamide (O+FC) arm compared to the fludarabine and cyclophosphamide (FC) arm (Table 10) resulting in a 10 months improvement in median PFS (mPFS) (see Figure 2).

Table 10. IRC-assessed Efficacy Results in relapsed CLL (ITT Population)

Primary and Key Secondary Endpoints ARZERRA plus Fludarabine and Cyclophosphamide
(N = 183)
Fludarabine and Cyclophosphamide
(N = 182)
Progression-free survival (PFS)    
  Median, months (95% CI)a
Hazard ratiob (95% CI)
  Stratified log rank P value
28.9 (22.8, 35.9) 18.8 (14.4, 25.8)
0.67 (0.51, 0.88)
P = 0.0032
Overall response, % (95% CI)
  P valuec
Complete response
Complete response with incomplete bone marrow recovery
84 (77, 89) 68 (60, 74)
P = 0.0003
27% 7%
2% 1%
a Confidence intervals were obtained using the Brookmeyer-Crowley method.
b Hazard ratios were obtained using the Pike estimator. A hazard ratio<1 indicates a lower risk with O+FC compared with FC. The hazard ratio and p-value from the stratified log-rank test are adjusted for Binet stage and number of prior therapies.
c Cochran-Mantel-Haenzel test, adjusting for stratification factors: Binet stage and number of prior therapies.

Figure 2. Kaplan-Meier Estimates of IRC-assessed Progression-free Survival

With a median follow-up of approximately 34 months, overall survival results showed a HR of 0.78 [95% CI: 0.56-1.09]. The median overall survival was 56.4 months [95% CI: 44.2, NC] in the O+FC arm and was 45.8 months [95% CI: 37.3, NC] in the FC arm.

Extended Treatment In CLL

The efficacy of ARZERRA as extended treatment in CLL was evaluated in a randomized, parallel arm, openlabel trial. In this trial, 474 patients who were in complete or partial response after at least two lines of prior therapy, were randomized to receive ARZERRA as intravenous infusions (300 mg on Day 1 followed 1 week later by 1,000 mg on Day 8 followed 7 weeks later by 1,000 mg and every 8 weeks thereafter for up to a maximum of 2 years) or observation.

In the overall trial population, the median age was 65 years (range: 33 to 87 years), 68% were male, and 96% were white. Most patients were in partial remission (81%), had two prior treatments (70%), and had received chemoimmunotherapy (80%) as prior therapy. The main efficacy outcome was progression-free survival (PFS) as assessed by the investigator.

At the time of the efficacy analysis, the median follow-up was 19.4 months with the ARZERRA arm and 18.7 months with the observation arm. The event rate (progressed or died) was 33% in the ARZERRA arm and 51% in the observation arm. The investigator-assessed median PFS was 29.4 months in the ARZERRA arm and 15.2 months in the observation arm (hazard ratio: 0.50 with 95% confidence interval [0.38, 0.66]; P <0.0001).

Figure 3. Kaplan-Meier Estimates of Investigator-assessed Progression-free Survival

Refractory CLL

Study 4 was a single-arm, multicenter trial in 154 patients with relapsed or refractory CLL. ARZERRA was administered by intravenous infusion according to the following schedule: 300 mg (Week 0), 2,000 mg weekly for 7 infusions (Weeks 1 through 7), and 2,000 mg every 4 weeks for 4 infusions (Weeks 12 through 24). Patients with CLL refractory to fludarabine and alemtuzumab (n = 59) comprised the efficacy population. Drug refractoriness was defined as failure to achieve at least a partial response to, or disease progression within 6 months of, the last dose of fludarabine or alemtuzumab. The main efficacy outcome was durable objective tumor response rate. Objective tumor responses were determined using the 1996 NCI-WG Guidelines for CLL.

In patients with CLL refractory to fludarabine and alemtuzumab, the median age was 64 years (range: 41 to 86 years), 75% were male, and 95% were white. The median number of prior therapies was 5; 93% received prior alkylating agents, 59% received prior rituximab, and all received prior fludarabine and alemtuzumab. Eighty-eight percent of patients received at least 8 infusions of ARZERRA and 54% received 12 infusions.

The investigator-determined overall response rate in patients with CLL refractory to fludarabine and alemtuzumab was 42% (99% CI: 26, 60) with a median duration of response of 6.5 months (95% CI: 5.8, 8.3). There were no complete responses. Anti-tumor activity was also observed in additional patients in Study 4 and in a multicenter, open-label, dose-escalation study (Study 5) conducted in patients with relapsed or refractory CLL.

What is ofatumumab (arzerra)?

Ofatumumab is a monoclonal antibody that affects the actions of the body's immune system. Monoclonal antibodies are made to target and destroy only certain cells in the body. This may help to protect healthy cells from damage.

Ofatumumab is used in to treat chronic lymphocytic leukemia.

Ofatumumab is usually given after other medications have been tried without successful treatment of symptoms.

Ofatumumab may also be used for other purposes not listed in this medication guide.

What is the most important information i should know about ofatumumab (arzerra)?

Ofatumumab increases the risk of a serious viral infection of the brain that can lead to disability or death. This risk is higher if you have a weak immune system or are receiving certain medicines. Call your doctor right away if you have symptoms such as change in your mental state, problems with speech or walking, or decreased vision. These symptoms may start gradually and get worse quickly.

Before you receive ofatumumab, tell your doctor if you have hepatitis or severe COPD.

To be sure this medication is not causing harmful effects, your blood cells, kidney function, and liver function may need to be tested for several months, even after you stop using ofatumumab. Do not miss any follow-up visits to your doctor.

Call your doctor at once if you develop any symptoms of liver damage, such as nausea, stomach pain, loss of appetite, itching, dark urine, clay-colored stools, or jaundice (yellowing of your skin or eyes).

You should also call your doctor right away if you develop any signs of infection such as fever, chills, body aches, flu symptoms, mouth and throat ulcers, easy bruising or bleeding, or cough with mucus and stabbing chest pain.

Avoid being near people who have colds, the flu, or other contagious illnesses. Contact your doctor at once if you develop signs of infection. Do not receive a "live" vaccine while you are being treated with ofatumumab.

Side effects

The following serious adverse reactions are discussed in greater detail in other sections of the labeling:

  • Infusion Reactions [see WARNINGS AND PRECAUTIONS]
  • Hepatitis B Virus Reactivation [see WARNINGS AND PRECAUTIONS]
  • Hepatitis B Virus Infection [see WARNINGS AND PRECAUTIONS]
  • Progressive Multifocal Leukoencephalopathy [see WARNINGS AND PRECAUTIONS]
  • Tumor Lysis Syndrome [see WARNINGS AND PRECAUTIONS]
  • Cytopenias [see WARNINGS AND PRECAUTIONS]

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared with rates in the clinical trials of another drug and may not reflect the rates observed in practice.

Previously Untreated CLL

The safety of ARZERRA was evaluated in an open-label, parallel-arm, randomized trial (Study 1) in 444 patients with previously untreated CLL. Patients were randomized to receive either ARZERRA as an intravenous infusion every 28 days in combination with chlorambucil (n = 217) or chlorambucil as a single agent (n = 227). In both arms, patients received chlorambucil 10 mg/m2 orally on Days 1 to 7 every 28 days. The infusion schedule for ARZERRA was 300 mg administered on Cycle 1 Day 1, 1,000 mg administered on Cycle 1 Day 8, and 1,000 mg administered on Day 1 of subsequent 28-day cycles. The median number of cycles of ARZERRA completed was 6.

The most common adverse reactions (≥10%) were infusion reactions and neutropenia (Table 4).

The data described in Table 4 include relevant adverse reactions occurring up to 60 days after the last dose of study medication; Table 5 includes relevant hematologic laboratory abnormalities.

Table 4. Adverse Reactions with ≥5% Incidence in Patients Receiving ARZERRA plus Chlorambucil and Also ≥2% More than Patients Receiving Chlorambucil

Adverse Reactions ARZERRA plus Chlorambucil
(N = 217)
Chlorambucil
(N = 227)
All Grades
%
Grade ≥3
%
All Grades
%
Grade ≥3
%
Infusion reactionsa 67 10 0 0
Neutropenia 27 26 18 14
Asthenia 8 <1 5 0
Headache 7 <1 3 0
Leukopenia 6 3 2 <1
Herpes simplexb 6 0 4 <1
Lower respiratory tract infection 5 1 3 <1
Arthralgia 5 <1 3 0
Upper abdominal pain 5 0 3 0
a Includes events which occurred on the day of an infusion or within 24 hours of the end of an infusion and resulted in an interruption or discontinuation of treatment. Infusion reactions may include, but are not limited to, chills, dyspnea, flushing, hypotension, nausea, pain, pruritus, pyrexia, rash, and urticaria.
b Includes oral herpes, herpes, herpes virus infection, genital herpes, and herpes simplex.

Table 5. Post-baseline Hematologic Laboratory Abnormalities Occurring with ≥5% Incidence in Patients Receiving ARZERRA plus Chlorambucil and Also ≥2% More than Patients Receiving Chlorambucil

Investigations ARZERRA plus Chlorambucil
(N = 217)
Chlorambucil
(N = 227)
All Grades
%
Grade ≥3
%
All Grades
%
Grade ≥3
%
Leukopenia 67 23 28 4
Neutropenia 66 29 56 24
Lymphopenia 52 29 20 7

Infusion Reactions

Overall, 67% of patients who received ARZERRA in combination with chlorambucil experienced one or more symptoms of infusion reactions (10% were Grade 3 or greater; none were fatal). Infusion reactions occurred most frequently during Cycle 1 (56% on Day 1 [6% were Grade 3 or greater] and 23% on Day 8 [3% were Grade 3 or greater]) and decreased with subsequent infusions. Infusion reactions led to discontinuation of treatment in 3% of patients. Serious adverse events of infusion reactions occurred in 2% of patients.

Neutropenia

Overall, 3% of patients had neutropenia as a serious adverse event, reported up to 60 days after the last dose. One patient died with neutropenic sepsis and agranulocytosis. Prolonged neutropenia occurred in 6% of patients receiving ARZERRA in combination with chlorambucil compared with 4% of patients receiving chlorambucil. Late-onset neutropenia occurred in 6% of patients receiving ARZERRA in combination with chlorambucil compared with 1% of patients receiving chlorambucil alone.

Relapsed CLL

The safety of ARZERRA in combination with fludarabine and cyclophosphamide compared with fludarabine and cyclophosphamide was evaluated in a randomized, open-label, parallel-arm, multicenter trial (Study 2) in 359 patients with relapsed CLL. Patients were randomized to receive ARZERRA as an intravenous infusion (Cycle 1: 300 mg on Day 1 and 1,000 mg on Day 8; followed by 1,000 mg on Day 1 of subsequent 28-day cycles for a maximum of 6 cycles). Standard fludarabine and cyclophosphamide therapy was administered as a 3-day course starting on the first day of each cycle, with initial dosages of 25 mg/m2 for fludarabine and 250 mg/m2 for cyclophosphamide. Table 6 includes adverse reactions occurring up to 60 days after the last dose of study medication.

The most common adverse reactions (≥10%) were infusion reactions, neutropenia, leukopenia and febrile neutropenia (Table 6).

Table 6. Adverse Reactions with ≥5% Incidence in Patients Receiving ARZERRA plus FC and Also ≥2% More than in Patients in Fludarabine and Cyclophosphamide Arm

Adverse Reactions ARZERRA plus Fludarabine and Cyclophosphamide
(N = 181)
Fludarabine and Cyclophosphamide Arm
(N = 178)
All Grades
%
Grade ≥3
%
All Grades
%
Grade ≥3
%
Infusion reactionsa 60 9 28 3
Neutropenia 55 49 39 36
Leukopenia 15 12 6 3
Febrile neutropenia 10 10 8 8
Bronchitis 6 1 4 <1
a Includes events which occurred on the day of an infusion or within 24 hours of the end of an infusion and resulted in an interruption or discontinuation of treatment. Infusion reactions may include, but are not limited to, chills, dyspnea, flushing, hypotension, nausea, pain, pruritus, pyrexia, rash, and urticaria.

Adverse reactions associated with decreased platelet counts (including but not limited to thrombocytopenia, platelet count decreased and pancytopenia) and decreased hemoglobin (including but not limited to anemia, hemoglobin decreased and pancytopenia) occurred less frequently in the ARZERRA plus fludarabine and cyclophosphamide arm than in the fludarabine and cyclophosphamide arm up to 60 days after the last dose of study treatment: 30% (all grades) and 15% (Grade ≥3) vs 38% (all grades) and 28% (Grade ≥3), respectively for decreased platelet counts; and 23% (all grades) and 10% (Grade ≥ 3) vs 33% (all grades) and 16% (Grade ≥3), respectively for decreased hemoglobin.

Infusion Reactions

On Day 1 of infusion, infusion reactions occurred in 49% (7% were >Grade 3) of patients treated with ARZERRA plus fludarabine and cyclophosphamide, compared to 16% (1% were >Grade 3) of patients treated with fludarabine and cyclophosphamide and decreased with subsequent infusions. Infusion reactions led to discontinuation of treatment in 3% of patients in the ARZERRA plus fludarabine and cyclophosphamide. Serious adverse events of infusion reactions occurred in 2% of patients in the ARZERRA plus fludarabine and cyclophosphamide compared to <1% of patients treated with fludarabine and cyclophosphamide.

Neutropenia

The proportion of patients that had Grade 3 or greater neutropenia reported up to 60 days after the last dose of study medication was higher in patients treated with ARZERRA plus fludarabine and cyclophosphamide (51%) compared to the fludarabine and cyclophosphamide arm (37%). Grade 3 or greater neutropenic sepsis occurred in 2 patients (1%) treated with ARZERRA plus fludarabine and cyclophosphamide vs. 3 patients (2%) in the fludarabine and cyclophosphamide arm. Prolonged neutropenia occurred in 18 patients (10%) treated with ARZERRA plus fludarabine and cyclophosphamide vs. 20 patients (11%) in the fludarabine and cyclophosphamide arm. Late-onset neutropenia occurred in 13 patients (7%) treated with ARZERRA plus fludarabine and cyclophosphamide vs. 5 patients (3%) in the fludarabine and cyclophosphamide arm.

During the period between the first dose and 60 days after last dose there were five (3%) patients who died in the ARZERRA plus fludarabine and cyclophosphamide arm and ten (6%) patients who died in the fludarabine and cyclophosphamide arm.

Extended Treatment In CLL

The safety of ARZERRA was evaluated in an open-label, parallel-arm, randomized trial (Study 3) in 474 patients who had responded to therapy for their recurrent or progressive disease. Patients were randomized to receive ARZERRA as an intravenous infusion every 8 weeks or observation. The infusion schedule for ARZERRA was 300 mg on Day 1 followed 1 week later by 1,000 mg on Day 8 followed 7 weeks later by 1,000 mg and every 8 weeks thereafter for up to a maximum of 2 years. The data described in Table 7 include relevant adverse reactions occurring up to 60 days after the last dose of study medication (last visit for observation arm). The most common adverse reactions (≥10%) were infusion reactions, neutropenia, and upper respiratory tract infection (Table 7).

Table 7. Adverse Reactions with ≥5% Incidence in Patients Receiving ARZERRA and Also ≥2% More than in Patients in Observation Arm

Adverse Reactions ARZERRA
(N = 237)
Observation Arm
(N = 237)
All Grades
%
Grade ≥3
%
All Grades
%
Grade ≥3
%
Infusion reactionsa 46 4 - -
Neutropenia 24 22 9 8
Upper respiratory tract infection 19 1 9 0
Bronchitis 9 <1 7 <1
Pneumonia 8 5 5 3
Influenza 6 0 3 0
Herpes zoster 5 <1 3 <1
Insomnia 5 <1 2 0
Back pain 5 0 3 0
Hypogammaglobulinemia 5 <1 <1 <1
a Includes events which occurred on the day of an infusion or within 24 hours of the end of an infusion and resulted in an interruption or discontinuation of treatment. Infusion reactions may include, but are not limited to, chills, dyspnea, flushing, hypotension, nausea, pain, pruritus, pyrexia, rash, and urticaria.

Infusion Reactions

Infusion reactions occurred in 25% of patients on the day of Infusion 1 (300 mg) and decreased with subsequent infusions (between 2% to 10%).

Infections

A total of 154 patients (65%) treated with ARZERRA compared with 120 patients (51%) in the observation arm experienced bacterial, viral, or fungal infections. The incidence of serious infections, however, was similar for patients treated with ARZERRA (20%) and the observation arm (18%). The proportions of fatal infections in patients treated with ARZERRA and in the observation arm were 2% and 3% respectively.

Neutropenia

The proportion of patients that had Grade 3 or greater neutropenia reported up to 60 days after the last dose of study medication was higher in patients treated with ARZERRA (22%) compared with the observation arm (8%). There were no cases of neutropenic sepsis reported with ARZERRA. Prolonged neutropenia occurred in 13 patients (5%) treated with ARZERRA and in 5 patients (2%) in the observation arm. Late-onset neutropenia occurred in 2 patients (<1%) treated with ARZERRA and 1 patient (<1%) in the observation arm.

During the period between the first dose and 60 days after last dose there were two (1%) patients in the ofatumumab group who died due to adverse events and five (2%) patients in the observation group.

Refractory CLL

The safety of monotherapy with ARZERRA was evaluated in 181 patients with relapsed or refractory CLL in 2 open-label, non-randomized, single-arm studies. In these studies, ARZERRA was administered at 2,000 mg beginning with the second dose for 11 doses (Study 4 [n = 154]) or 3 doses (Study 5 [n = 27]).

The data described in Table 8 and other sections below are derived from 154 patients in Study 4. All patients received 2,000 mg weekly from the second dose onward. Ninety percent (90%) of patients received at least 8 infusions of ARZERRA and 55% received all 12 infusions. The median age was 63 years (range: 41 to 86 years), 72% were male, and 97% were white.

In refractory CLL, the most common adverse reactions (≥10%) were neutropenia, pneumonia, pyrexia, cough, diarrhea, anemia, fatigue, dyspnea, rash, nausea, bronchitis, and upper respiratory tract infections (Table 8). The most common serious adverse reactions were infections (including pneumonia and sepsis), neutropenia, and pyrexia. Infections were the most common adverse reactions leading to drug discontinuation.

Table 8. Incidence of All Adverse Reactions Occurring in ≥5% of Patients and in the Fludarabine- and Alemtuzumab-refractory Subset

Adverse Reaction Total Population
(N = 154)
Fludarabine- and Alemtuzumab-refractory
(N = 59)
All Grades
%
Grade ≥3
%
All Grades
%
Grade ≥3
%
Pneumoniaa 23 14 25 15
Pyrexia 20 3 25 5
Cough 19 0 19 0
Diarrhea 18 0 19 0
Anemia 16 5 17 8
Fatigue 15 0 15 0
Dyspnea 14 2 19 5
Rashb 14 <1 17 2
Bronchitis 11 <1 19 2
Nausea 11 0 12 0
Upper respiratory tract infection 11 0 3 0
Edema peripheral 9 <1 8 2
Back pain 8 1 12 2
Chills 8 0 10 0
Nasopharyngitis 8 0 8 0
Sepsisc 8 8 10 10
Urticaria 8 0 5 0
Insomnia 7 0 10 0
Headache 6 0 7 0
Herpes zoster 6 1 7 2
Hyperhidrosis 5 0 5 0
Hypertension 5 0 8 0
Hypotension 5 0 3 0
Muscle spasms 5 0 3 0
Sinusitis 5 2 3 2
Tachycardia 5 <1 7 2
a Includes pneumonia, lung infection, lobar pneumonia, and bronchopneumonia.
b Includes rash, rash macular, and rash vesicular.
c Includes sepsis, neutropenic sepsis, bacteremia, and septic shock.

Infusion Reactions

Infusion reactions occurred in 44% of patients on the day of the first infusion (300 mg), 29% on the day of the second infusion (2,000 mg), and less frequently during subsequent infusions.

Infections

A total of 108 patients (70%) experienced bacterial, viral, or fungal infections. A total of 45 patients (29%) experienced Grade 3 or greater infections, of which 19 (12%) were fatal. The proportion of fatal infections in the fludarabine- and alemtuzumab-refractory group was 17%.

Neutropenia

Of 108 patients with normal neutrophil counts at baseline, 45 (42%) developed Grade 3 or greater neutropenia. Nineteen (18%) developed Grade 4 neutropenia. Some patients experienced new onset Grade 4 neutropenia >2 weeks in duration.

Immunogenicity

There is a potential for immunogenicity with therapeutic proteins such as ofatumumab. Serum samples from more than 926 patients with CLL were tested during and after treatment for antibodies to ARZERRA. Formation of anti-ofatumumab antibodies was observed in less than 1% of patients with CLL after treatment with ofatumumab.

Immunogenicity assay results are highly dependent on several factors including assay sensitivity and specificity, assay methodology, sample handling, timing of sample collection, concomitant medications, and underlying disease. For these reasons, comparison of incidence of antibodies to ARZERRA with the incidence of antibodies to other products may be misleading.

Postmarketing Experience

The following adverse reactions have been identified during post-approval use of ARZERRA. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Infusion-Related Cardiac Events

Cardiac arrest

Mucocutaneous Reactions

Stevens-Johnson syndrome, porphyria cutanea tarda

Read the entire FDA prescribing information for Arzerra (Ofatumumab Injection)

Read More »
(web3)