The phrase "a significant stage of" is correct and usable in written English.
It can be used when discussing an important phase or milestone in a process, development, or journey.
Example: "Completing the first draft of the manuscript is a significant stage of the writing process."
Alternatives: "an important phase of" or "a crucial step in".
The classic soul-rock fusion of Unknown Mortal Orchestra pulls an enormous audience, however – such a mass of hipsters, hippies, frazzled rockers and families that it feels as if the Kiwi group are on the fringes of a significant stage of their career.
Recent research indicates that apoptotic signaling without full progression to apoptosis is a significant stage of regeneration in salamanders.
Today, odanacatib is the only remaining cathepsin K inhibitor that is still at a significant stage of development in osteoporosis.
The age group represented in this study occupy a significant stage of development in relation to changes in awareness of appearance and as such it is possible the age of the participant could impact upon the outcome of the study.
In the present study, albumin but not C-reactive protein was a significant, stage independent, predictor of survival in patients with primary operable breast cancer.
The creation of FORTRAN, which debuted in 1957, marked a significant stage in the development of computer-programming languages.
In autumn 1999, the magazine heralded "archaeoraptor" as a significant stage in the evolution of birds from dinosaurs.
This proved a significant stage in the development of library provision.
It marked a significant stage in the transformation of natural philosophy into physics and its intended audience was enthusiastic: "Read it!
The dispute represents a significant stage in the creation of a papal monarchy separate from and equal to lay authorities.
In 1984, the Israelis jailed Shehada for two years for his underground political work, releasing him in time to take the Palestinian/Islamic effort a significant stage further at the beginning of the first Intifada, or uprising, towards the end of 1987.
