What is the medication starting with 'c' used to treat Thrombotic Thrombocytopenic Purpura (TTP)?

Caplacizumab is the Medication Starting with "C" for Treating TTP

Caplacizumab is the medication starting with "C" used to treat Thrombotic Thrombocytopenic Purpura (TTP), specifically approved for acquired TTP (aTTP) in combination with plasma exchange and immunosuppressive therapy. 1

Mechanism and Indication

• Caplacizumab is a humanized anti-von Willebrand Factor (vWF) Nanobody® that targets the A1-domain of vWF, inhibiting the interaction between vWF and platelets, thereby preventing microthrombosis 2
• It is FDA-approved specifically for the treatment of adult patients with acquired TTP (aTTP), and must be used in combination with plasma exchange and immunosuppressive therapy 1
• Unlike other treatments for TTP, caplacizumab offers a direct and rapid therapeutic intervention to stop microthrombosis formation 2

Dosing and Administration

• First day of treatment: 11 mg bolus intravenous injection at least 15 minutes prior to plasma exchange, followed by an 11 mg subcutaneous injection after completion of plasma exchange 1
• Subsequent treatment during daily plasma exchange: 11 mg subcutaneous injection once daily following plasma exchange 1
• After plasma exchange period: 11 mg subcutaneous injection once daily continuing for 30 days following the last daily plasma exchange 1
• Treatment may be extended for a maximum of 28 additional days if signs of persistent underlying disease (such as suppressed ADAMTS13 activity) remain present 1

Clinical Efficacy

• In the pivotal HERCULES trial, caplacizumab demonstrated faster normalization of platelet counts compared to placebo (median time 2.69 days vs 2.88 days) 3
• Patients receiving caplacizumab had a 74% lower rate of composite outcome events (TTP-related death, recurrence of TTP, or thromboembolic events) compared to placebo (12% vs 49%) 3
• The percentage of patients who experienced TTP recurrence at any time during the trial was 67% lower with caplacizumab than with placebo (12% vs 38%) 3
• Patients treated with caplacizumab required less plasma exchange and had shorter hospitalizations than those receiving placebo 3

Safety Considerations

• The most common adverse events associated with caplacizumab are bleeding-related events 4
• In the phase 3 trial, serious bleeding-related adverse events occurred in 11% of patients in the caplacizumab group compared to 1% in the placebo group 4
• Concomitant use of antiplatelet agents or anticoagulants should be avoided due to increased bleeding risk 1
• Caplacizumab should be withheld 7 days prior to elective surgery, dental procedures, or other invasive interventions 1

Special Situations

• In rare cases where patients have anaphylactic reactions to plasma (used in plasma exchange), caplacizumab has been used successfully without concomitant plasma exchange, though this is not the standard approach 5
• Caplacizumab should be discontinued if the patient experiences more than 2 recurrences of aTTP while on the medication 1

Comparison to Traditional TTP Management

• Traditional management of TTP includes plasma exchange and immunosuppression (typically corticosteroids), which remains the backbone of treatment 6
• The addition of caplacizumab to standard therapy provides faster resolution of the acute TTP episode and reduces the risk of TTP-related death and recurrence 3
• While plasma exchange reduced TTP mortality from over 90% to below 20%, the addition of caplacizumab further improves outcomes by targeting the underlying pathophysiology directly 6