Just be absolutely clear here from the start,; there is absolutely NO suggestion here that this drug helps prevent C19 nor can it ever be accurately described as a 'cure' for C19
( I say that because that appears to be typical of the kind of false claims Trump would say; )
Still, if it helps reduce the number of deaths, this would still be good news.
But the link below does say "...further research was needed on the effectiveness of the drug and the potential for side effect."
And, even more unfortunately, also says
"Tocilizumab currently costs around 800 euros ($870) per injection."
which means this might unfortunately be put well out of the reach of many poor countries.
https://medicalxpress.com/news/2020-04-arthritis-drug-significant-severe-covid-.html