The filing of informal response and reply briefs is optional.

https://www.ca4.uscourts.gov/AppellateProcedureGuide/Briefing/APG-informalbriefing.html#pID0ELHA

You are a pro se litigant, therefore informal briefing applies to you.  However, Fed Cir rules says "The filing of informal response and reply briefs is optional."

I think the other party is going to follow Fed Cir local rule 34(a) to proceed directly to oral argument. 

http://www.ca4.uscourts.gov/docs/rules/rule34.pdf

I'd guess your argument is so weak/irrelevant that the other party didn't even bother to respond in writing.