Nonacog alfa: an analysis of safety data from six prospective clinical studies in different patient populations with haemophilia B treated with different therapeutic modalities

Nonacog Alfa for Prophylaxis and Treatment of Bleeding Episodes in Previously Treated Patients with Moderately Severe or Severe Hemophilia B in India

Purpose

Hemophilia B is an X-linked congenital bleeding disorder caused by a deficiency of coagulation factor IX (FIX) clotting activity. This study evaluated safety and efficacy of nonacog alfa, a recombinant human blood coagulation FIX replacement product, in males aged 12-65 years with hemophilia B (FIX activity ≤ 2%) with or without inhibitors in India.

Methods

In this multicenter, open-label, post-approval phase 4 study, participants were treated for up to 8 weeks, with up to a 4-week screening period and a subsequent post-treatment 28-day safety observation period. Intravenous nonacog alfa 40 IU/kg (range 13-78 IU/kg) was administered at intervals of 3-4 days, in accordance with the approved local product document.

Results

A total of 25 participants were enrolled and completed the study. No participants developed FIX inhibitors during the study, experienced treatment-related adverse events (AEs) or serious AEs, or developed a thrombotic event and/or hypersensitivity reaction. No participants experienced bleeding events requiring on-demand treatment with nonacog alfa. Seventeen bleeding episodes (16 spontaneous and 1 traumatic) were reported in 10 participants; all occurred post treatment, with the exception of a minor gum-bleeding event, and were managed without treatment. The mean (SD) annualized total factor consumption (TFC) per patient was 224,582 (75,527) IU; the mean (SD) annualized TFC by weight per patient was 3639 (573) IU/kg.

Conclusion

Nonacog alfa was safe and effective for the prevention of hemorrhagic episodes in Indian males with congenital, severe hemophilia B. No participants developed FIX inhibitors, and no new safety signals were reported.

KGML-xDTD: a knowledge graph-based machine learning framework for drug treatment prediction and mechanism description

BACKGROUND

Computational drug repurposing is a cost- and time-efficient approach that aims to identify new therapeutic targets or diseases (indications) of existing drugs/compounds. It is especially critical for emerging and/or orphan diseases due to its cheaper investment and shorter research cycle compared with traditional wet-lab drug discovery approaches. However, the underlying mechanisms of action (MOAs) between repurposed drugs and their target diseases remain largely unknown, which is still a main obstacle for computational drug repurposing methods to be widely adopted in clinical settings.

RESULTS

In this work, we propose KGML-xDTD: a Knowledge Graph-based Machine Learning framework for explainably predicting Drugs Treating Diseases. It is a 2-module framework that not only predicts the treatment probabilities between drugs/compounds and diseases but also biologically explains them via knowledge graph (KG) path-based, testable MOAs. We leverage knowledge-and-publication-based information to extract biologically meaningful "demonstration paths" as the intermediate guidance in the Graph-based Reinforcement Learning (GRL) path-finding process. Comprehensive experiments and case study analyses show that the proposed framework can achieve state-of-the-art performance in both predictions of drug repurposing and recapitulation of human-curated drug MOA paths.

CONCLUSIONS

KGML-xDTD is the first model framework that can offer KG path explanations for drug repurposing predictions by leveraging the combination of prediction outcomes and existing biological knowledge and publications. We believe it can effectively reduce "black-box" concerns and increase prediction confidence for drug repurposing based on predicted path-based explanations and further accelerate the process of drug discovery for emerging diseases.

First open-label, single-arm, prospective study of real-world use of FIX replacement therapy in a predominantly pediatric hemophilia B population in China

BACKGROUND

Nonacog alfa (recombinant factor IX [FIX]) is approved in China for the control and prevention of bleeding events in patients with hemophilia B. This was the first study to assess prophylaxis and on-demand therapy with recombinant FIX replacement in a real-world setting in China. This study aimed to evaluate the safety and efficacy of nonacog alfa in Chinese patients with hemophilia B.

METHODS

In this open-label, multicenter study (clinicaltrials.gov identifier NCT02336178), patients received on-demand or prophylactic treatment with intravenous nonacog alfa for approximately 6 months or 50 exposure days, whichever occurred first. The primary safety outcome was medically important events (i.e., development of FIX inhibitors, allergic reactions, and thrombotic events). Key secondary efficacy outcomes included the annualized bleeding rate for on-demand treatment and prophylaxis, response to on-demand treatment, the number of infusions per bleeding event, and the number of breakthrough bleeding events within 48 hours of prophylaxis.

RESULTS

Seventy male patients (mean [standard deviation] age 7.8 [7.2] years) were enrolled (on-demand, n = 37; prophylaxis, n = 57 [24 patients were included in both groups]). Thirty-eight (54%) patients had up to 50 FIX exposure days before the study. The only medically important event was a transient low-titer FIX inhibitor (incidence 1.4%, 95% confidence interval, 0-7.7). The mean annualized bleeding rate was 26.3 for on-demand treatment and 6.5 for prophylaxis. A mean (standard deviation) of 1.5 (1.7) nonacog alfa infusions were given per bleeding episode; 78.8% of episodes resolved with 1 infusion. Response was "excellent" or "good" for 88% of the on-demand infusions. Twenty-three bleeding events (n = 11 patients) occurred within 48 hours of 2032 prophylaxis doses (1.13%).

CONCLUSION

In the real-world setting, nonacog alfa is safe and effective for on-demand treatment and for prophylaxis for patients with hemophilia B in China.