Organisers of the NN Mission Marathon have pushed back the event to April 18 due to COVID-19 restrictions, with a new location also being sought for the race.
The elite-only race was announced in February by Dutch athletics management group Global Sports Communication, the NN Running Team and the Hamburg Marathon.
The event was scheduled to take place on April 11.
The event was expected to see around 100, mainly European, elite athletes compete on a looped 10.5 kilometre city centre route in Hamburg.
Organisers said the event was designed to provide a much-needed opportunity for athlete runners to qualify for the Tokyo 2020 Olympic Games.
Frank Thaleiser, managing director of Marathon Hamburg Veranstaltungs, said organisers were optimistic of finding a new venue for the event.
"Of course we were quite disappointed at first, but we can understand the decision given the current situation.
"We are now putting all our efforts into the realisation of the event at a different location and are optimistic that we will find a solution.
"We owe this not least to the more than 70 athletes who have trained to the point in recent weeks and want to keep their hopes alive for an Olympic ticket."
Kenya’s Eliud Kipchoge is among the star names expected to take part in the NN Mission Marathon.
The men’s world record holder is hoping to use the event to hone his preparations for Tokyo 2020, where he will hope to secure a second successive Olympic title.
"Over the past months we have learned that we need to be flexible and stay positive," Kipchoge said.
"With this in mind, I thank everybody involved from the organisation, to sponsors, to my fellow runners, to keep working hard with positive minds to find a good alternative for us as athletes.
"This race is really important, it is a hugely positive thing for the fans to see that life continues during this pandemic."