Updated Complete & Utter M&A Guesses Purely for Entertainment Purposes:

$Merck & Co(MRK.US)$ x $Immunovant(IMVT.US)$
$Eli Lilly and Co(LLY.US)$ x $Cytokinetics(CYTK.US)$ (and soon)
$Regeneron Pharmaceuticals(REGN.US)$ x $Apellis Pharmaceuticals(APLS.US)$ (panache & brash)
$Gilead Sciences(GILD.US)$ x % $Madrigal Pharmaceuticals(MDGL.US)$ (liver king)
$Bristol-Myers Squibb(BMY.US)$ x $Iovance Biotherapeutics(IOVA.US)$ (cell Tx boost needed)
$Eli Lilly and Co(LLY.US)$ x $Merus(MRUS.US)$ (partner no more)
$Eli Lilly and Co(LLY.US)$ x $Blueprint Medicines(BPMC.US)$ (just buying all of them)
$Pfizer(PFE.US)$ x $Viking Therapeutics(VKTX.US)$ (acquihigher)
$ROCHE HOLDING AG(RHHBY.US)$ x $Affimed NV(AFMD.US)$ (phoenix)
$AstraZeneca(AZN.US)$ x $Mereo BioPharma(MREO.US)$ (rare)