[Sorry for the delay.] IIUC from the "In the pipeline" article, drugs with silicon are too similar to their equivalent with carbon, and more difficult to make:

[Sorry for the delay.] IIUC from the "In the pipeline" article, drugs with silicon are too similar to their equivalent with carbon, and more difficult to make: "so why bother?" Are they using the silicon to avoid the usual rules of substitutions in benzene cycles? Is it possible to do the same trick with carbon? > that molecule almost certainly fails the ClogP not greater than five lipinski rule (it's too greasy) Is it possible to fix it adding some -NH2 (or -COOH ?) group in the second aromatic cycle? [I understand it's a nice science fair project but the article oversell it.]