In 1 Cor 11:26, we read the following:
For as often as you eat this bread and drink the cup, you proclaim the Lord's death until he comes. (NRSV)
The term "until he comes" is αχρι ου coupled with ἔλθῃ, the 3rd person subjunctive aorist of ερχομαι. As many have noted (e.g., Eric Svendsen; C.K. Barrett; Joachim Jeremias), whenever αχρι is coupled with ου (without being followed by the particle αν) and is followed by a verb in the subjunctive, it means that once the "until" is reached, the main clause ceases. Instances of such in the LXX, Greek NT, and the pseudepigrapha which prove the validity of this conclusion include:
Behold, I waited for your words; I gave ear to your reasons, whilst ye searched out (ἄχρι οὗ ἐτάσητε) what to say. (Job 32:11)
And they shall fall by the edge of the sword, and shall be led away captive into all nations: and Jerusalem shall be trodden down of the Gentiles, until the times of the Gentiles be fulfilled (ἄχρι οὗ πληρωθῶσιν καιροὶ ἐθνῶν). (Luke 21:24)
For I would not, brethren, that ye should be ignorant of this mystery, lest ye should be wise in your own conceits; that blindness in part is happened to Israel, until the fulness of the Gentiles be come in (ἄχρι οὗ τὸ πλήρωμα τῶν ἐθνῶν εἰσέλθη). (Rom 11:25)
For I would not, brethren, that ye should be ignorant of this mystery, lest ye should be wise in your own conceits; that blindness in part is happened to Israel, until the fulness of the Gentiles be come in (ἄχρι οὗ τὸ πλήρωμα τῶν ἐθνῶν εἰσέλθη). (Rom 11:25)
For he must reign, till he hath put (ἄχρι οὗ θῇ) all enemies under his feet . . . And when all things shall be subdued unto him, then shall the Son also himself be subject unto him that put all things under him, that God may be all in all. (1 Cor 15:25, 28)
Wherefore then serveth the law? It was added because of transgressions, till the seed should come (ἄχρις οὗ ἔλθῃ τὸ σπέρμα) to whom the promise was made; and it was ordained by angels in the hand of a mediator. (Gal 3:19)
"(If) a worm (escaped), I took (it) and returned (it) to the same place, saying, 'Remain in the place in which were appointed, until which time it should be commanded (ἄχρις οὗ ἐπισταλθη) by the one who orders you.'" (Testament of Job 20:9)
With respect to 1 Cor 11:26 and Paul’s theology of the Eucharist, we are to celebrate the Eucharist until Christ's parousia (coming in glory), and such will result in a cessation of the celebration of the Lord's supper. Instead, we will then celebrate the long-promised “Messianic Banquet,” something that is also promised in modern revelation, not just ancient (e.g., D&C 58:11; 65:3; cf. 27:5).