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It can pay to be a copycat — for a time.

Consider Marinus Pharmaceuticals (MRNS), a little-known biotech that delivered the second-best stock performance in the sector last year. Why did Marinus enjoy an eightfold jump in its stock price in 2017? Because speculative investors viewed the company as a cheaper clone of high-flying Sage Therapeutics (SAGE).

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Both companies’ drugs aim to treat forms of depression and epilepsy. Both are analogs of a hormone that activates GABA neurotransmitter receptors in the brain. The therapeutic effect: Controlling seizures or improving mood or anxiety, without long-term side effects.

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  • “Both [drugs] are analogs of a hormone that activates GABA neurotransmitter receptors in the brain.”
    One is indeed a synthetic analog (ganaxolone), the other is the endogenous neurosteroid allopregnanolone conjugated with Ligand’s captisol product for IV administration – known as ‘brexanolone’.
    “The therapeutic effect: Controlling seizures or improving mood or anxiety, without long-term side effects.”
    That may be the desired outcome for both drugs but it is grossly misleading to imply that the administration of allopregnanolone does not cause ‘long-term side effects’. The reason why ganaxolone and other synthetic analogs of allo were developed in the first place is to overcome the well known side-effects of long-term allo administration.
    Mr. Fontanini writes that Marinus’ PhII study in PPD will “address many open questions about its efficacy and bioavailability”. However, the study uses the IV version of the drug, yielding no insights into bioavailability whatsoever.
    Mr. Fontanini further asserts: “When Marinus does complete its ganaxolone postpartum study, investors will be able to compare the data to Sage’s very similar Phase 2 study.”
    The studies are by no stretch of the imagination “very similar”. One was a rather straightforward, small cohort study exploring two dose regimens, the other explores multiple regimens as well as an IV-to-oral switch. Overall, Mr. Fontanini appears to be strikingly ignorant about these clinical trials.
    An investor is cited as saying:
    “If you have a trial larger than Sage’s, and your whole investment thesis is that you’re a baby Sage, then your data should be at least in the same ballpark.”
    Are Marinus, with their long-standing orphan pediatric programs which go unmentioned in this article, the ones portraying themselves as a ‘baby Sage’ or would that be a projection of investor expectations?
    STAT – I expected better from you.

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