Bill Cosby’s dazzling, decades-long career as a globally respected entertainer has become ruined by a succession of allegations painting him as a serial sexual predator.

On Wednesday, NBC — the network that roared back to television supremacy in the 1980s thanks to Cosby’s warmhearted family sitcom — joined the list of entertainment companies and TV programmes that have abandoned projects or distanced themselves from the 77-year-old comedian and actor amid the cascade of shocking headlines.

NBC scrapped development of an upcoming TV sitcom starring Cosby, one day after Netflix, the video streaming service, backed away from a special that would have saluted Cosby for his long career and comic gifts. Also on Wednesday, cable’s TVLand channel said it would stop airing re-runs of “The Cosby Show,” his iconic, career-making sitcom. Scheduled appearances on “The Queen Latifah Show” and “Late Show with David Letterman” have also been canceled in recent weeks.

Cosby’s growing isolation from an industry that once embraced and profited from him comes amid a series of testimonials from women who said he drugged them and sexually abused them over three and a half decades — an image diametrically opposed to the affable father and humorous grandpa figures that Cosby cultivated.

The allegations, which date from 1969 until 2005, have been remarkably consistent in their details. In each alleged instance, Cosby supposedly lured a young, ambitious woman seeking career counseling, plied her with an unknown substance that disabled her, and then abused her when she was unconscious or unable to resist.

Cosby has rarely spoken in public about the allegations. That includes earlier this month when he simply shook his head when asked repeatedly about them in an interview with NPR. His representatives have denied them repeatedly, and he has never been charged with a crime.

In 2005, a Philadelphia woman, Andrea Constand, filed a civil suit that claimed Cosby had sexually assaulted her and offered her money to keep her allegations from becoming public. More than a dozen women were reportedly prepared to testify in that case, saying Cosby had assaulted them, but the suit was settled out of court.

On Wednesday, Cosby’s camp denied renewed sex-assault allegations by TV host and former supermodel Janice Dickinson, and Cosby attorney Martin Singer, in a new letter, warned journalists who are covering this story: “You proceed at your own peril.”

Cosby’s stand-up comic and TV stardorm of the 1960s marked him not only as an entertainer of the first rank but as an avatar of African-American advancement. His popularity among black and white audiences has bridged generations and virtually every medium: Recordings, television, movies, books and nightclub appearances.

Cosby’s early comedic performances and best-selling albums earned him comparisons to Mark Twain as a humorous storyteller. His best-selling books about family life and fatherhood, as well as his role as Cliff Huxtable, the wise and affable patriarch on “The Cosby Show” in the 1980s, turned him into a genial sage, America’s de facto dad.

Though Netflix’s decision to disassociate itself from Cosby came at the 11th hour — its Cosby comedy special was set to begin streaming on Thanksgiving next week — NBC’s abandonment of its latest Cosby project may have been the deepest blow of all.

The network is the most closely associated with Cosby’s career. It broadcast three hit series with him as the star, including his first, “I Spy,” (1965-68), which was daring for its time in its casting of an African-American actor in a leading role. Cosby played an espionage agent whose cover was as a tennis trainer; he shared top billing with a white counterpart (Robert Culp).

Cosby also starred for NBC in a solo sitcom, “The Bill Cosby Show,” (1969-1971), in which he played a high-school physical education teacher.

But it was the ensemble “The Cosby Show” (1984-92) that proved to be a juggernaut, not just for its star but for its network. The programme helped boost the sitcom format generally, and NBC in particular after its disastrous run in primetime from the late 1970s through the mid-1980s. “Cosby” topped the Nielsen ratings for five of its eight seasons, and sparked NBC’s “Must-See TV” renaissance of the 1990s, an era that included “Seinfeld,” “Friends,” and “ER.”

At one point in the early 1990s, Cosby discussed buying NBC from its then-owner, General Electric Co.

In a conference with reporters this summer, NBC entertainment president Jennife Salke described the network’s unnamed new Cosby vehicle as a “multi-generational family show” in which Cosby would play “the patriarch of the family, dispensing his classic wisdom on relationships and parenthood.”

Though the project was still in its early stages — there was no script and it had not been officially set for production by network executives — further development was apparently impossible in the wake of the latest allegations. The network confirmed that it was stopping development Wednesday but had no further comment

On Tuesday, former “America’s Next Top Model” judge Janice Dickinson became the fifth woman to publicly say that she was sexually assaulted by Cosby. “Stuffing feelings of rape and my unresolved issues from this incident . . . drove me into a life of trying to hurt myself,” the former supermodel told “Entertainment Tonight.” Cosby’s lawyer called Dickinson’s claims “a complete lie.”

The allegations against Cosby have been reported periodically and sporadically since Constand’s suit in 2005. They got renewed buzz this fall, ironically, when a new Cosby biography, “Cosby: His Life and Times,” by former CNN and NBC executive Mark Whitaker, conspicuously failed to mention them.

The story burst back into the mainstream in October when comedian Hannibal Buress called Cosby a rapist in his stand-up act, and a video of his routine went viral.

The tipping point may have been reached last Thursday when former actress Barbara Bowman wrote a first-person account for The Post called “Bill Cosby raped me. Why did it take 30 years for people to believe my story?” The story was widely shared on social media and sparked numerous follow-up stories by the mainstream media.

Cosby’s career as a live performer may be his last haven, albeit a tenuous one. He is scheduled to perform a show in Melbourne, Fla., on Friday. The show, which was booked in 2013, is sold out. Promoters said Wednesday that they intend to proceed with it. Calls to Cosby’s publicist were not returned.

•Adapted from The Washington Post. Photo of Bill Cosby also courtesy of The Post.