Upcoming events – FDA decision for Adamas in Parkinson’s dyskinesia and growth data for Versartis

Welcome to your weekly digest of approaching regulatory and clinical readouts. Adamas Pharmaceuticals could not be blamed for being confident of the approval prospects of ADS-5102, its therapy for levodopa-induced dyskinesia in Parkinson’s disease; the FDA is due to decide by August 24.

Meanwhile, Versartis hopes to be first to market with a long-acting recombinant human growth hormone. Phase III data in children, due next month, will provide an indication of whether it can achieve this aim.

Lifting the LID

If it is approved by the FDA this month, Adamas’s ADS-5102 will become the first medicine for treating levodopa-induced dyskinesia in Parkinson’s disease. The glutamate antagonist has posted decent results in three late-stage trials, and the FDA has not requested an advisory panel – probably a positive sign.

Last September the extended-release formulation of amantadine hit the primary endpoint of its second phase III trial, Ease Lid 3, showing a significant reduction on the unified dyskinesia rating scale versus placebo. After 12 weeks of treatment patients taking ADS-5102 had their UDysRS score reduced by 46% versus 16% for placebo.

ADS-5102 increased on-time without troublesome dyskinesia by a placebo-adjusted 1.9 hours per day, and off-time was decreased by 1.1 hours per day; both improvements were significant.

In the first phase III trial, Ease Lid, the project again hit its primary endpoint with high statistical significance, showing a 23% reduction versus placebo on the UDysRS at 12 weeks (Rare success allows Adamas to jump ahead of Osmotica, December 24, 2015).

On balance the clinical data look good. But if approval is forthcoming Adamas might still have difficulty with payers. Mizuho analysts expect reimbursement to be “somewhat challenging” in the first year despite the lack of alternative therapies for what is an unpleasant side-effect of Parkinson’s therapy. ADS-5102 has US orphan drug status, so maximising orphan pricing while keeping payers on side could be tricky.

According to EvaluatePharma’s sellside consensus, 2022 worldwide sales are forecast to reach $280m. In May, Adamas signed a royalty-monetisation deal with Healthcare Royalty Partners, getting $35m up front plus an additional $65m if ADS-5102 is approved. Mizuho says Adamas will owe $200m in combined principal and interest expense payments, which it will repay by 2024.

Hoping for growth

Versartis's phase III Velocity study compares twice-monthly somavaratan with daily growth hormone treatment, with a primary endpoint of height velocity at one year. The trial is designed to show non-inferiority with a margin of 2cm; topline data are due in late September.

This is a fairly low bar to clear, according to Morgan Stanley analysts, who believe that somavaratan will need to do better to be deemed a commercial success. The project will also have to show a safety profile “at least on par” with daily growth hormone treatments, which have been used for years.

If successful, Versartis could file somavaratan for paediatric growth hormone deficiency this year. The company is also developing the project in adults, where it expects to start a phase III trial, Vital, by the end of the year. Meanwhile, patients are still being recruited into a long-term safety study in children, Vista, and a paediatric phase III Japanese trial that should complete enrolment in the second half.

Top five growth hormone products in 2022
Global sales ($m)
Product Company Status 2016 2022e
Norditropin SimpleXx Novo Nordisk Marketed 1,303 1,210
Genotropin Pfizer Marketed 579 423
Somavaratan Versartis Phase III - 410
Saizen Merck KGaA Marketed 298 276
Humatrope Lilly Marketed 305 222
Source: EvaluatePharma.

The paediatric indication is forecast to be the bigger of the two, with EvaluatePharma sellside consensus predicting that $310m of its $410m in 2022 sales will come here.

This would make it the third-biggest growth hormone product that year. But first, it needs to prevail in the upcoming study.

Company Project Study  Trial ID
Adamas ADS-5102  Ease Lid 3 NCT02274766
Adamas ADS-5102  Ease Lid NCT02136914
Versartis Somavaratan Velocity NCT02339090
Versartis Somavaratan Phase III Japanese trial NCT03145831
Versartis Somavaratan Vista NCT02068521

To contact the writers of this story email Elizabeth Cairns or Madeleine Armstrong in London at [email protected] or follow @LizVantage or @ByMadeleineA on Twitter

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