Plaintiff's motion for summary judgment was premature, since issue had not yet been joined (CPLR 3212 [a]; Costalas v. Amalfitano, 305 AD2d 202, 204). As to the branch of the motion seeking to add a party defendant, leave to amend a pleading should generally be freely granted, but the party seeking amendment has the burden of establishing the merit of the proposal. Leave to amend a complaint should be denied where the claim is palpably insufficient ( Bencivenga Co. v. Phyfe, 210 AD2d 22). Here, plaintiff failed to allege facts indicating the proposed additional party would be bound by an agreement to which it was not a signatory. Conclusory assertions that the proposed additional party was simply an extension of one of the defendants did not sufficiently allege a basis for a departure from the general rule that nonparties to an agreement are not bound thereby ( National Survival Game of N.Y. v. NSG of LI Corp., 169 AD2d 760; see also Brainstorms Internet Mktg. v. USA Networks, 6 AD3d 318).