Campath (alemtuzumab) Side Effects, Warnings, and Drug Interactions

Campath (alemtuzumab) is an antibody used for the treatment of B-cell chronic lymphocytic leukemia (B-CLL).

Common side effects of Campath include:

• low blood cell counts,
• infusion reactions,
• cytomegalovirus (CMV) and other infections,
• nausea,
• vomiting,
• diarrhea,
• insomnia,
• fever,
• and chills.

Other side effects of Campath include:

• rash,
• itching,
• headache,
• tremor,
• anxiety,
• and shortness of breath.

Campath may interact with other drugs. Campath drug interaction studies have not been conducted. Campath may cross the placental barrier and may be excreted in breast milk. Campath has not been studied in pregnant women or nursing mothers. It should be given to a pregnant or breastfeeding woman only if clearly needed.

Common side effects include:

• Low blood cell counts
• Infusion reactions
• Cytomegalovirus (CMV) and other infections
• Nausea
• Vomiting
• Diarrhea
• Insomnia
• Fever
• Chills

Other side effects include:

• Rash
• Itching
• Headache
• Tremor
• Anxiety
• Shortness of breath

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

• Cytopenias
• Infusion Reactions
• Immunosuppression/Infections

The most common adverse reactions with Campath are:

• infusion reactions (pyrexia, chills, hypotension, urticaria, nausea, rash, tachycardia, dyspnea),
• cytopenias (neutropenia, lymphopenia, thrombocytopenia, anemia),
• infections (CMV viremia, CMV infection, other infections),
• gastrointestinal symptoms (nausea, emesis, abdominal pain),
• and neurological symptoms (insomnia, anxiety).

The most common serious adverse reactions are: 

• cytopenias,
• infusion reactions,
• and immunosuppression/infections.

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 to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
• The data below reflect exposure to Campath in 296 patients with CLL of whom 147 were previously untreated and 149 received at least 2 prior chemotherapy regimens.
• The median duration of exposure was 11.7 weeks for previously untreated patients and 8 weeks for previously treated patients.

Lymphopenia

• Severe lymphopenia and a rapid and sustained decrease in lymphocyte subsets occurred in previously untreated and previously treated patients following administration of Campath.
• In previously untreated patients, the median CD4+ was 0 cells/µL at one month after treatment and 238 cells/µL [25%- 75% interquartile range 115 to 418 cells/µL at 6 months post treatment.

Neutropenia

• In previously untreated patients, the incidence of Grade 3 or 4 neutropenia was 42% with a median time to onset of 31 days and a median duration of 37 days.
• In previously treated patients, the incidence of Grade 3 or 4 neutropenia was 64% with a median duration of 28 days.
• Ten percent of previously untreated patients and 17% of previously treated patients received granulocyte colony-stimulating factors.

Anemia

• In previously untreated patients, the incidence of Grade 3 or 4 anemia was 12% with a median time to onset of 31 days and a median duration of 8 days.
• In previously treated patients, the incidence of Grade 3 or 4 anemia was 38%.
• Seventeen percent of previously untreated patients and 66% of previously treated patients received either erythropoiesis stimulating agents, transfusions or both.

Thrombocytopenia

• In previously untreated patients, the incidence of Grade 3 or 4 thrombocytopenia was 14% with a median time to onset of 9 days and a median duration of 14 days.
• In previously treated patients, the incidence of Grade 3 or 4 thrombocytopenia was 52% with a median duration of 21 days.
• Autoimmune thrombocytopenia was reported in 2% of previously treated patients with one fatality.

Infusion Reactions

• Infusion reactions, which included pyrexia, chills, hypotension, urticaria, and dyspnea, were common.
• Grade 3 and 4 pyrexia and/or chills occurred in approximately 10% of previously untreated patients and in approximately 35% of previously treated patients.
• The occurrence of infusion reactions was greatest during the initial week of treatment and decreased with subsequent doses of Campath.
• All patients were pretreated with antipyretics and antihistamines; additionally, 43% of previously untreated patients received glucocorticoid pre-treatment.

Infections

• In the study of previously untreated patients, patients were tested weekly for CMV using a PCR assay from initiation through completion of therapy, and every 2 weeks for the first 2 months following therapy.
• CMV infection occurred in 16% (23/147) of previously untreated patients; approximately onethird of these infections were serious or life threatening.
• In studies of previously treated patients in which routine CMV surveillance was not required, CMV infection was documented in 6% (9/149) of patients; nearly all of these infections were serious or life-threatening.
• Other infections were reported in approximately 50% of patients across all studies. Grade 3 to 5 sepsis ranged from 3% to 10% across studies and was higher in previously treated patients.
• Grade 3 to 4 febrile neutropenia ranged from 5% to 10% across studies and was higher in previously treated patients.
• Infection-related fatalities occurred in 2% of previously untreated patients and 16% of previously treated patients.
• There were 198 episodes of other infection in 109 previously untreated patients; 16% were bacterial, 7% were fungal, 4% were other viral, and in 73% the organism was not identified.

Cardiac

Cardiac dysrhythmias occurred in approximately 14% of previously untreated patients. The majority were tachycardias and were temporally associated with infusion; dysrhythmias were Grade 3 or 4 in 1% of patients.

Previously Untreated Patients

• Table 1 contains selected adverse reactions observed in 294 patients randomized (1:1) to receive Campath or chlorambucil as first line therapy for B-CLL.
• Campath was administered at a dose of 30 mg intravenously three times weekly for up to 12 weeks.
• The median duration of therapy was 11.7 weeks with a median weekly dose of 82 mg (25-75% interquartile range: 69-90 mg).

Previously Treated Patients

Additional safety information was obtained from 3 single arm studies of 149 previously treated patients with CLL administered 30 mg Campath intravenously three times weekly for 4 to 12 weeks (median cumulative dose 673 mg [range 2-1106 mg]; median duration of therapy 8.0 weeks).

Adverse reactions in these studies not listed in Table 1 that occurred at an incidence rate of >5% were:

• fatigue,
• nausea,
• emesis,
• musculoskeletal pain,
• anorexia,
• dysesthesia,
• mucositis,
• and bronchospasm.

Immunogenicity

As with all therapeutic proteins, there is potential for immunogenicity.

Using an ELISA assay, antihuman antibodies (HAHA) were detected in 11 of 133 (8.3%) previously untreated patients.

In addition, two patients were weakly positive for neutralizing activity.

Limited data suggest that the anti-Campath antibodies did not adversely affect tumor response. Four of 211 (1.9%) previously treated patients were found to have antibodies to Campath following treatment.

The incidence of antibody formation is highly dependent on the sensitivity and specificity of the assay. Additionally, the observed incidence of antibody (including neutralizing antibody) positivity in an assay may be influenced by several factors including:

• assay methodology,
• sample handling,
• timing of sample collection,
• concomitant medications,
• and underlying disease.

For these reasons, comparison of the incidence of antibodies to Campath 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 alemtuzumab. 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.

Fatal Infusion Reactions

Cardiovascular: congestive heart failure, cardiomyopathy, decreased ejection fraction (some patients had been previously treated with cardiotoxic agents).

Gastrointestinal: Acute acalculous cholecystitis

Immune disorders: Goodpasture's syndrome, Graves' disease, aplastic anemia, Guillain Barre syndrome, chronic inflammatory demyelinating polyradiculoneuropathy, serum sickness, fatal transfusion associated graft versus host disease.

Infections: Epstein-Barr virus (EBV) including EBV-associated lymphoproliferative disorder, progressive multifocal leukoencephalopathy (PML), reactivation of latent viruses.

Metabolic: tumor lysis syndrome.

Neurologic: optic neuropathy.

No formal drug interaction studies have been performed with Campath.