I don’t quite get Silbersher’s fixation on the 2 patient population vs 500. What is magical about TG = 500?
It's not his fixation...it's at the heart of Amarin's appeal. Marine patents cover trigs 500 and greater. Even though most feel a POSA at the time would expect such people to have a rise in LDL as trigs were lowered, Judge Don't imputed that LDL levels would be impacted in such a population similar to Mori which did not include anyone with trigs that high. Judge Don't even made up a non-existent person with trigs at 500:
At the heart of this case is the following question: at the time the patents were filed, did persons of skill in the art expect that administering pure EPA to patients with triglyceride levels above 500 mg/dL would increase LDL-C? Judge Du found that experts would have not have expected an LDL-C increase. Amarin’s principle argument at trial, which it has returned to on appeal, is the “two patient populations” argument. Amarin argues that Mori studied patients with TG levels below 500 mg/dL, and Mori is therefore inapplicable to the patient population recited in the patents (namely, those above than 500). Moreover, the evidence presented at trial showed that, because of the generally understood mechanism-of-action for reducing triglycerides when the patents were filed, persons of skill understood that patients with severely high triglyceride levels would experience a spike in LDL-C. That, according to Amarin, further underscores a distinction over Mori.
If your question is why he didn't discuss the others errors some here have pointed out...so much the better. Overall he favors the Amarin arguments that he addresses...but it's still a crapshoot.