Rasuvo Offers New "Niche" Options for MTX Auto-Injection

August 15, 2014

A new auto-injectable form of methotrexate offers 10 dosage options. Is this an important advantage for medication management and adherence over the four already available?

Another auto-injectable form of methotrexate waits in the wings: Last month the Food and Drug Administration (FDA) approved Medac's formulation called Rasuvo, the first to be available in so many different dose options (10 of them, ranging from 7.5 mg to 30 mg in 2.5 mg increments).

The first FDA-approved auto-injectable, Otrexup, is marketed by Antares in  only four pre-filled dosage strengths.

Rosuvo's approval has generated some excitement in the courts and among stock analysts, but not so much among rheumatologist observers.

“Admittedly, it’s not a sea-change, but it is an important development because methotrexate is our backbone drug,” said Eric Ruderman, MD, professor of medicine at the Northwestern University Feinberg School of Medicine. “Usually, methotrexate is administered orally, but injectable forms come in to maximize the efficacy.”

Noting the potential absorption issues with oral delivery of methotrexate, he remarked, injectable forms assure that patients receive the full dose.

Pre-filled auto-injectors can simplify medication management and help to assure compliance, observed methotrexate researcher Gary Firestein, MD, who is Dean and Associate Vice Chancellor of Translational Medicine at University of California-San Diego (UCSD) School of Medicine. But that will likely be limited to a niche group of patients, he added-those who can't tolerate oral methotrexate or who can't or won't use existing injectable formulations.

Antares filed a petition to block Medac from releasing Rasuvo, saying that it infringes upon Otrexup’s auto-injectable technology. But this challenge could be an uphill battle, given that the two products use technologies from different companies.

Neither auto-injectable is cheap: Oxtreup currently costs about $500 pre month. Industry analysts anticipate Rasuvo’s cost will be similar.

“The question becomes whether it’s worth it to pay much, much more for the convenience of pre-filled syringes,” said Firestein, who is also Director of UCSD's Clinical and Translational Research Institute. “And will third-party payers be willing to cover for that convenience?”

Additional dosages do give Rasuvo a small advantage over Otrexup, he added, but the overall benefit to rheumatology is probably marginal.