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.