The Third Circuit reversed the trial court opinion for two reasons. First, the Gunvalsons did not prove the existence of a "clear and definite promise" needed to support a promissory estoppel claim; second, the Gunvalsons did not "reasonably rely" on any promise that PTC may have made:
The promises the Gunvalsons assert that PTC and its officers made to them lack the requisite specificity and clarity required to succeed under the theory of promissory estoppel.
. . .
The district court erred in its analysis by failing to recognize the Gunvalsons did not enroll Jacob in the Phase 2a trial because Dr. Finkel, the principal investigator for the Philadelphia area clinical trial, ruled Jacob ineligible based on the medical records Mrs. Gunvalson provided him, and not because the Gunvalsons had been promised PTC 124 via some other means.
. . .
As we explained in open court following oral argument, we are sympathetic to the plight of Jacob and his family. Similarly, we are moved by the Gunvalsons' heroic efforts on behalf of their son and others afficted with this devastating disease. Nevertheless, we are constrained by the law to conclude that the Gunvalsons cannot demonstrate either a clear and definite promise or detrimental reliance, requirements for a promissory estoppel claim. Accordingly, because the Gunvalsons have not shown a reasonable probability of success on the merits, the district court abused its discretion in granting the preliminary junction. We will, therefore, vacate the order granting the preliminary injunction and remand for further proceedings.