The Bill Cosby backlash continued this week with the comedian's upcoming appearance on Late Show With David Letterman canceled amid a resurgence of claims that he drugged and raped over a dozen women.

Though the rape allegations first came to light nearly a decade ago when a number of women filed a lawsuit against Cosby, they were pushed back into the public eye last month when comedian Hannibal Buress brought them up again in front of an audience in Philadelphia. Earlier this week, Cosby's social media team unwittingly launched a viral onslaught of Cosby rape-related tweets when they prompted the Twitterverse to make memes of the comedian. And on Thursday, one of Cosby's accusers published an essay on the Washington Post's website rehashing claims that Cosby had repeatedly drugged and raped her when she was an aspiring actress in the 1980s, and calling for a re-examination of all assault accusations against him:

For Cosby to commit these assaults against multiple victims over several years, there had to be a network of willfully blind wallflowers at best, or people willing to aid him in committing these sexual crimes at worst. As I told the Daily Mail, when I was a teenager, his assistants transported me to hotels and events to meet him. When I blacked out at Cosby’s home, there were several staffers with us. My agent, who introduced me to Cosby, had me take a pregnancy test when I returned from my last trip with him. Talent agents, hotel staff, personal assistants and others who knowingly made arrangements for Cosby’s criminal acts or overlooked them should be held equally accountable.

Cosby was set to appear on Letterman's show on Wednesday, but it was confirmed last night that that appearance has been canceled. Neither the show nor Cosby's representatives will confirm whether Cosby pulled out or was asked not to appear. Last month, Cosby was supposed to make an appearance on Queen Latifah's talk show, but that was canceled as well; his representation told TMZ that the comedian chose not to appear, though sources told the website the show canceled on him over the rape allegations.

And this morning, Cosby spoke with Scott Simon, the host of NPR's Weekend Edition, who asked him if he could address the allegations head-on. Cosby stayed silent. Per Raw Story:

SCOTT SIMON: “This question gives me no pleasure Mr. Cosby, but there have been serious allegations raised about you in recent days.”

BILL COSBY: [SILENCE]

SIMON: “You’re shaking your head no. I’m in the news business. I have to ask the question. Do you have any response to those charges?”

COSBY: [SILENCE]

SIMON: “Shaking your head no. There are people who love you who might like to hear from you about this. I want to give you the chance.”

COSBY: [SILENCE]

Regis Philbin will appear on Letterman in Cosby's stead.