Hm.

Unfortunately a second hand (third hand, for me) statement from Mr. Mcaffrey is not inherently trustworthy.

From what I can find:

• A quick browse of the clinical trial database for binimetinib against triple negative breast cancer or solid tumors does not show any other toxicity-related suspensions/terminations related to that drug.
• It is also an already approved drug (Mektovi), presumably having had an acceptable safety profile for its approved indication (melanoma).
• Zen3694 presumably has a good (so far) safety profile in its TNBC indication with the combination drugs it is doing its own trials in.
• Zen also has 3 other ongoing trials in patients with solid tumors, including a phase 2 in combination with talazoparib.

I can't really preclude the problem from being a combination of the drugs, or it could be a Zen-related problem in this specific patient population. Who knows? I would prefer to hear a public statement from one of the doctors.