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GlobalData’s Investigative News team reviews data generated by an in-house model that combines machine learning and its proprietary algorithm. Likelihood of Approval (LoA) provides the probability of a drug in securing regulatory support; Phase Transition Success Rate (PTSR) indicates the probability of a drug advancing to the next stage of development. The model uses data points from individual drugs, clinical trials, regulatory milestones, company, and financial databases.
Xenon more likely to move forward in epilepsy
Xenon Pharmaceuticals’ XEN-1101 for focal epilepsy saw its PTSR skyrocket 34 points to 44% after positive Phase IIb data. Results were published on a 4 December poster, and the PTSR change took effect 7 December. The completed trial also resulted in a significant boost to the drug’s LoA, which rose 15 points to 19%.
The 325-patient Phase IIb trial (NCT03796962) investigated focal seizure frequency and adverse events as coprimary endpoints. There was a statistically significant, dose-dependent reduction in seizure frequency for all doses. This included a 54.5% seizure reduction for the highest 25mg dose, compared to a 14.9% reduction for placebo (p<0.001). The most common adverse events were dizziness in 24.6% of treated patients and somnolence in 15.6%.
Clinical Trials Arena reported on 10 June that XEN-1101 would likely achieve its Phase II endpoint, but experts were skeptical of its long-term ability to create seizure freedom. XEN-1101 is a potassium channel opener in development for focal onset seizures and major depressive disorder.
Aeglea shares positive Phase III data
Aeglea Biotherapeutics’ hyperargininemia candidate pegzilarginase saw its LoA spring by 15 points to 28% after the unveiling of positive topline data from a Phase III study. The PEACE study (NCT03921541) had its topline data announced on 6 December. GlobalData appraised the asset on 7 December.
PEACE had a statistically significant 80% reduction in the primary endpoint of the mean plasma arginine concentration in participants treated with the asset. Similarly, while 90.5% of subjects who were given pegzilarginase had normal plasma arginine levels, none in the placebo cohort showed the same. The 24-week, double-blinded study had 32 enrolled subjects with hyperargininemia, also known as arginase-1 deficiency (ARG1-D).
Hyperargininemia is an inherited disorder, where patients suffer from a deficiency of the enzyme arginase-1, as well as the build-up of the amino acid arginine. This impairs the urea cycle and can result in neurological impairment. Pegzilarginase functions as an arginine-depleting enzyme.
Neurocrine makes progress in chorea
Neurocrine Biosciences’s valbenazine tosylate for chorea saw its LoA surge ten points to 68% following positive Phase III data. The biotech released positive topline trial data on 7 December, and the LoA score change took effect on 9 December.
The Phase III KINECT-HD trial (NCT04102579) tested valbenazine in 120 patients with chorea associated with the rare neurological disorder Huntington’s Disease. The study met its primary endpoint of improvement in the Unified Huntington’s Disease Rating Scale (UHDRS) Total Maximal Chorea (TMC) Score, which measures chorea in seven body parts. There was a placebo-adjusted mean improvement in the TMC score of 3.2 units after 12 weeks (p<0.0001).
Neurocrine said it plans to file an NDA in 2022 and will present additional data from KINECT-HD at an upcoming medical conference. Chorea is a movement disorder occurring in approximately 90% of patients with Huntington’s Disease. Valbenazine is a selective vesicular monoamine transporter 2 (VMAT2) inhibitor. In the US, it is FDA-approved for tardive dyskinesia under the brand name Ingrezza.
Acadia announces positive topline data
Acadia Pharmaceuticals’ Rett syndrome candidate trofinetide saw its LoA bounce by ten points to 29% after the unveiling of positive topline data from a Phase III study (NCT04181723). The study, also known as LAVENDER, had its data announced on 6 December. GlobalData appraised the asset on 7 December.
LAVENDER saw a statistically significant improvement over placebo in the coprimary endpoint Rett Syndrome Behavior Questionnaire (RSBQ) (p= 0.0175) over 12 weeks. The double-blinded study assessed the efficacy of trofinetide in 187 female subjects. Clinical Trials Arena reported on LAVENDER on 11 November, stating that the RSBQ will likely see an improvement.
Rett syndrome is a genetic neurological disorder, which impairs brain development, resulting in a loss of motor skills and speech predominantly among girls. Trofinetide is a synthetic analogue of a molecule derived from the insulin-like growth factor 1 (IGF-1), which reduces neuroinflammation and supports synaptic function.
Incyte Phase I/II study terminated
Incyte’s INCB-53914 for advanced malignancies saw its PTSR in myelofibrosis tumble 21 points to 12%. The decline followed a Phase I/II trial update from “completed” to “terminated” on ClinicalTrials.gov on 8 December. The PTSR change occurred 10 December. The trial termination also tanked the drug’s LoA by eight points to 4%.
The Phase I/II trial (NCT02587598) was terminated after the combination therapy of INCB-53914 and cytarabine is reported to have tolerability issues, according to results listed on ClinicalTrials.gov. The primary endpoint was number of adverse events, with 97 patients enrolled.
INCB-53914 works by impairing PIM kinases. The idea is that by targeting PIM 1, 2, and 3 kinases, the asset would inhibit cell proliferation and promote cancer cell death.