Bankruptcy Rule 7015 provides that amendments to claims shall be governed by Rule 15 of the Federal Rules of Civil Procedure, Fed. R. Bankr.P. 7015, which commits the decision to grant or deny leave to amend to the trial court's sound discretion. See generally Coventry v. United States Steel Corp., 856 F.2d 514, 518 (3d Cir.1988).