Teva's SCOTUS appeal is here. But how much can the outcome really affect Copaxone's market share?

Teva ($TEVA) pushed hard for a Supreme Court appeal after a federal court last summer upturned its patents on cash cow Copaxone. Today, SCOTUS is due to hear oral arguments for the case. But when it comes to Teva's market share, other factors may have just as big an impact as the court's decision.

One reason: Even if Teva does come away with the Supreme Court's favor, the legal battle won't end there. SCOTUS isn't discussing Copaxone specifically; rather, Teva is arguing that the appeals court that nixed its patent should have deferred to the district court--which upheld it--on issues of fact.

As Wolf Greenfield IP attorney Charlie Steenburg told FiercePharmaMarketing, the court's recent track record and its decision to hear the appeal in the first place "would suggest that Teva probably has a decent shot." But if the Israeli pharma wins, the case will likely be remanded back to the appeals court--and that court could very well uphold its earlier decision to invalidate that key Copaxone patent.

More importantly, the way ISI Group analyst Umer Raffat sees it, is the timing for generic launches from teams of Mylan ($MYL) and India's Natco Pharma, and Novartis' ($NVS) Sandoz and Momenta Pharmaceuticals ($MNTA), both of which have ANDAs pending with the FDA.

While the companies face paying damages if Teva's IP shield is ultimately upheld, that may not be enough to deter them. And if one copy rolls out, there's a good chance the other will, too, Raffat says. "They all want to be there together at market formation, assuming approvals come at the same time," he told FiercePharmaMarketing.

But that doesn't necessarily mean the generic rivals will be successful in poaching Copaxone's market share, especially considering the hurdles in establishing bioequivalency. The drug isn't just a simple chemical or biologic, but rather a polymer mixture that Uffat likened to a handful of currency of different sizes and colors.

And whereas someone tracking the effects of a generic diabetes drug, for example, could examine a patient's blood sugar control daily to see if the newcomer controls it as well as the original, in multiple sclerosis, relapses are the most defining clinical episode--and those can occur as infrequently as every several months or once a year, depending on the patient.

Beyond the bioequivalency hurdles, the fact that Teva has already begun switching patients over to a new, patent-protected, long-lasting version of the drug also puts up a potential barrier for copycats looking to grab a slice of the pie, Raffat said.

"When these patients are stable, they don't want to screw around with switching--especially when you're telling a patient who went from taking injections every other day to start taking it every day," he said. "It's not ideal. Who wants to do that?"

Despite the fact that Teva has that bit of built-in market share protection, the Petah Tikva-based drugmaker would of course like to snag a Supreme Court victory. If its case does go back to appeals court, no matter which way the final ruling looks upon remand, it'll have additional time to change patients over to the new dose before the old one ultimately loses patent coverage. And that's something it's done with astonishing speed since the new drug rolled out early this year.

"The fact that they've switched over about 60%--it's an uphill task now for generics makers," Raffat said. -- Carly Helfand (email | twitter)