Drug could aid standard care for aTTP

Results of a phase 2 trial suggest an investigational agent may improve upon standard care for acquired thrombotic thrombocytopenic purpura (aTTP).

The agent, caplacizumab, is an anti-von Willebrand factor, humanized, single-variable-domain immunoglobulin that works by inhibiting the interaction between ultralarge von Willebrand factor multimers and platelets.

In the phase 2 TITAN trial, caplacizumab plus standard care induced a faster resolution of aTTP episodes when compared to placebo plus standard care. However, caplacizumab was also associated with a higher risk of bleeding.

Flora Peyvandi, MD, PhD, of the University of Milan in Italy, and her colleagues reported these results in The New England Journal of Medicine. The study was supported by Ablynx, the company developing caplacizumab.

“Caplacizumab has the potential to become an important new component in the standard of care for patients with acquired TTP,” Dr Peyvandi said. “The results from the phase 2 TITAN study showed that caplacizumab acts quickly to control the critical acute phase of the disease and protects patients until immunosuppressive treatments take effect.”

TITAN was a single-blinded, randomized, placebo-controlled study conducted at 56 centers around the world. The trial included 75 aTTP patients who were randomized to caplacizumab (n=36) or placebo (n=39), with all patients receiving the current standard of care (daily plasma exchange and immunosuppressive therapy).

Patients in the caplacizumab arm immediately received an intravenous bolus dose of caplacizumab at 10 mg and then a 10 mg subcutaneous dose of the drug daily until 30 days had elapsed after the final plasma exchange. Patients in the control arm received placebo at the same time points.

Response, recurrence, and relapse

The study’s primary endpoint was time to response (platelet count normalization). Patients in the caplacizumab arm had a 39% reduction in the median time to response compared to patients in the placebo arm (P=0.005).

Among the 69 patients who had not undergone a plasma-exchange session before enrollment, the median time to response was 3.0 days in the caplacizumab arm and 4.9 days in the placebo arm.

Among the 6 patients who did undergo a plasma-exchange session before enrollment, the median time to a response was 2.4 days in the caplacizumab arm and 4.3 days in the placebo arm.

The rate of confirmed response was 86.1% (n=31) in the caplacizumab arm and 71.8% (n=28) in the placebo arm.

One of the study’s secondary endpoints was exacerbation, which was defined as recurrent thrombocytopenia within 30 days of the end of daily plasma exchange that required reinitiation of daily exchange.

There were fewer exacerbations in the caplacizumab arm than the placebo arm—3 (8.3%) and 11 (28.2%), respectively.

Another secondary endpoint was relapse, which was defined as a TTP event occurring more than 30 days after the end of daily plasma exchange.

There were more relapses in the caplacizumab arm than the placebo arm—8 (22.2%) and 0, respectively. The investigators noted that 7 of the 8 patients had ADAMTS13 activity that remained below 10%, which suggests unresolved autoimmune activity.

Adverse events

There were 541 adverse events (AEs) in 34 of the 35 evaluable patients receiving caplacizumab (97%) and 522 AEs in all 37 evaluable patients receiving placebo (100%). TTP exacerbations and relapses were not included as AEs.

The rate of AEs thought to be related to the study drug was 17% in the caplacizumab arm and 11% in the placebo arm. The rate of AEs that were possibly related was 54% and 8%, respectively. And the rate of serious AEs was 37% and 32%, respectively.

The rate of bleeding-related AEs was 54% in the caplacizumab arm and 38% in the placebo arm. Of the 101 bleeding-related AEs, 84 (83%) were reported as mild, 14 (14%) as moderate, and 3 (3%) as severe.

There were no deaths in the caplacizumab arm and 2 in the placebo arm. One death was due to severe, refractory TTP, and the other was due to cerebral hemorrhage.

Caplacizumab development

The results of this trial will serve as the basis for filing for conditional approval of caplacizumab in Europe in the first half of 2017, according to Ablynx. The company is planning to file in the US in 2018.

Ablynx has started a phase 3 trial of caplacizumab known as the HERCULES study. In this double-blind, placebo-controlled study, investigators are evaluating the safety and efficacy of caplacizumab, in conjunction with the standard of care, in patients with aTTP.

The study is expected to enroll 92 patients at clinical sites across 17 countries. Recruitment is expected to be complete by the end of 2017.

Results of a phase 2 trial suggest an investigational agent may improve upon standard care for acquired thrombotic thrombocytopenic purpura (aTTP).

The agent, caplacizumab, is an anti-von Willebrand factor, humanized, single-variable-domain immunoglobulin that works by inhibiting the interaction between ultralarge von Willebrand factor multimers and platelets.

In the phase 2 TITAN trial, caplacizumab plus standard care induced a faster resolution of aTTP episodes when compared to placebo plus standard care. However, caplacizumab was also associated with a higher risk of bleeding.

Flora Peyvandi, MD, PhD, of the University of Milan in Italy, and her colleagues reported these results in The New England Journal of Medicine. The study was supported by Ablynx, the company developing caplacizumab.

“Caplacizumab has the potential to become an important new component in the standard of care for patients with acquired TTP,” Dr Peyvandi said. “The results from the phase 2 TITAN study showed that caplacizumab acts quickly to control the critical acute phase of the disease and protects patients until immunosuppressive treatments take effect.”

TITAN was a single-blinded, randomized, placebo-controlled study conducted at 56 centers around the world. The trial included 75 aTTP patients who were randomized to caplacizumab (n=36) or placebo (n=39), with all patients receiving the current standard of care (daily plasma exchange and immunosuppressive therapy).

Patients in the caplacizumab arm immediately received an intravenous bolus dose of caplacizumab at 10 mg and then a 10 mg subcutaneous dose of the drug daily until 30 days had elapsed after the final plasma exchange. Patients in the control arm received placebo at the same time points.

Response, recurrence, and relapse

The study’s primary endpoint was time to response (platelet count normalization). Patients in the caplacizumab arm had a 39% reduction in the median time to response compared to patients in the placebo arm (P=0.005).

Among the 69 patients who had not undergone a plasma-exchange session before enrollment, the median time to response was 3.0 days in the caplacizumab arm and 4.9 days in the placebo arm.

Among the 6 patients who did undergo a plasma-exchange session before enrollment, the median time to a response was 2.4 days in the caplacizumab arm and 4.3 days in the placebo arm.

The rate of confirmed response was 86.1% (n=31) in the caplacizumab arm and 71.8% (n=28) in the placebo arm.

One of the study’s secondary endpoints was exacerbation, which was defined as recurrent thrombocytopenia within 30 days of the end of daily plasma exchange that required reinitiation of daily exchange.

There were fewer exacerbations in the caplacizumab arm than the placebo arm—3 (8.3%) and 11 (28.2%), respectively.

Another secondary endpoint was relapse, which was defined as a TTP event occurring more than 30 days after the end of daily plasma exchange.

There were more relapses in the caplacizumab arm than the placebo arm—8 (22.2%) and 0, respectively. The investigators noted that 7 of the 8 patients had ADAMTS13 activity that remained below 10%, which suggests unresolved autoimmune activity.

Adverse events

There were 541 adverse events (AEs) in 34 of the 35 evaluable patients receiving caplacizumab (97%) and 522 AEs in all 37 evaluable patients receiving placebo (100%). TTP exacerbations and relapses were not included as AEs.

The rate of AEs thought to be related to the study drug was 17% in the caplacizumab arm and 11% in the placebo arm. The rate of AEs that were possibly related was 54% and 8%, respectively. And the rate of serious AEs was 37% and 32%, respectively.

The rate of bleeding-related AEs was 54% in the caplacizumab arm and 38% in the placebo arm. Of the 101 bleeding-related AEs, 84 (83%) were reported as mild, 14 (14%) as moderate, and 3 (3%) as severe.

There were no deaths in the caplacizumab arm and 2 in the placebo arm. One death was due to severe, refractory TTP, and the other was due to cerebral hemorrhage.

Caplacizumab development

The results of this trial will serve as the basis for filing for conditional approval of caplacizumab in Europe in the first half of 2017, according to Ablynx. The company is planning to file in the US in 2018.

Ablynx has started a phase 3 trial of caplacizumab known as the HERCULES study. In this double-blind, placebo-controlled study, investigators are evaluating the safety and efficacy of caplacizumab, in conjunction with the standard of care, in patients with aTTP.

The study is expected to enroll 92 patients at clinical sites across 17 countries. Recruitment is expected to be complete by the end of 2017.

Results of a phase 2 trial suggest an investigational agent may improve upon standard care for acquired thrombotic thrombocytopenic purpura (aTTP).

The agent, caplacizumab, is an anti-von Willebrand factor, humanized, single-variable-domain immunoglobulin that works by inhibiting the interaction between ultralarge von Willebrand factor multimers and platelets.

In the phase 2 TITAN trial, caplacizumab plus standard care induced a faster resolution of aTTP episodes when compared to placebo plus standard care. However, caplacizumab was also associated with a higher risk of bleeding.

Flora Peyvandi, MD, PhD, of the University of Milan in Italy, and her colleagues reported these results in The New England Journal of Medicine. The study was supported by Ablynx, the company developing caplacizumab.

“Caplacizumab has the potential to become an important new component in the standard of care for patients with acquired TTP,” Dr Peyvandi said. “The results from the phase 2 TITAN study showed that caplacizumab acts quickly to control the critical acute phase of the disease and protects patients until immunosuppressive treatments take effect.”

TITAN was a single-blinded, randomized, placebo-controlled study conducted at 56 centers around the world. The trial included 75 aTTP patients who were randomized to caplacizumab (n=36) or placebo (n=39), with all patients receiving the current standard of care (daily plasma exchange and immunosuppressive therapy).

Patients in the caplacizumab arm immediately received an intravenous bolus dose of caplacizumab at 10 mg and then a 10 mg subcutaneous dose of the drug daily until 30 days had elapsed after the final plasma exchange. Patients in the control arm received placebo at the same time points.

Response, recurrence, and relapse

The study’s primary endpoint was time to response (platelet count normalization). Patients in the caplacizumab arm had a 39% reduction in the median time to response compared to patients in the placebo arm (P=0.005).

Among the 69 patients who had not undergone a plasma-exchange session before enrollment, the median time to response was 3.0 days in the caplacizumab arm and 4.9 days in the placebo arm.

Among the 6 patients who did undergo a plasma-exchange session before enrollment, the median time to a response was 2.4 days in the caplacizumab arm and 4.3 days in the placebo arm.

The rate of confirmed response was 86.1% (n=31) in the caplacizumab arm and 71.8% (n=28) in the placebo arm.

One of the study’s secondary endpoints was exacerbation, which was defined as recurrent thrombocytopenia within 30 days of the end of daily plasma exchange that required reinitiation of daily exchange.

There were fewer exacerbations in the caplacizumab arm than the placebo arm—3 (8.3%) and 11 (28.2%), respectively.

Another secondary endpoint was relapse, which was defined as a TTP event occurring more than 30 days after the end of daily plasma exchange.

There were more relapses in the caplacizumab arm than the placebo arm—8 (22.2%) and 0, respectively. The investigators noted that 7 of the 8 patients had ADAMTS13 activity that remained below 10%, which suggests unresolved autoimmune activity.

Adverse events

There were 541 adverse events (AEs) in 34 of the 35 evaluable patients receiving caplacizumab (97%) and 522 AEs in all 37 evaluable patients receiving placebo (100%). TTP exacerbations and relapses were not included as AEs.

The rate of AEs thought to be related to the study drug was 17% in the caplacizumab arm and 11% in the placebo arm. The rate of AEs that were possibly related was 54% and 8%, respectively. And the rate of serious AEs was 37% and 32%, respectively.

The rate of bleeding-related AEs was 54% in the caplacizumab arm and 38% in the placebo arm. Of the 101 bleeding-related AEs, 84 (83%) were reported as mild, 14 (14%) as moderate, and 3 (3%) as severe.

There were no deaths in the caplacizumab arm and 2 in the placebo arm. One death was due to severe, refractory TTP, and the other was due to cerebral hemorrhage.

Caplacizumab development

The results of this trial will serve as the basis for filing for conditional approval of caplacizumab in Europe in the first half of 2017, according to Ablynx. The company is planning to file in the US in 2018.

Ablynx has started a phase 3 trial of caplacizumab known as the HERCULES study. In this double-blind, placebo-controlled study, investigators are evaluating the safety and efficacy of caplacizumab, in conjunction with the standard of care, in patients with aTTP.

The study is expected to enroll 92 patients at clinical sites across 17 countries. Recruitment is expected to be complete by the end of 2017.