Just days af­ter Bris­tol-My­ers Squibb man­aged to sur­prise the an­a­lyst brigade with a Phase III flop for its PD-1 check­point Op­di­vo com­bined with chemo in lung can­cer, Mer­ck’s dom­i­nant team is back with an­oth­er sol­id hit for a par­tic­u­lar­ly tough-to-treat sub­group of breast can­cer pa­tients.

Mer­ck’s Phase III KEYNOTE-522 tri­al con­nect­ed on one of two pri­ma­ry end­points, with their Keytru­da/chemo com­bo elim­i­nat­ing all signs of triple-neg­a­tive breast can­cer — what’s called a patho­log­i­cal com­plete re­sponse — at a sig­nif­i­cant­ly high­er rate than chemo alone, re­gard­less of PD-L1 lev­els in the neo-ad­ju­vant set­ting.

That’s an­oth­er first for Mer­ck, which has been steadi­ly rack­ing up new Phase III suc­cess­es for the mar­quee PD-1. In­ves­ti­ga­tors are con­tin­u­ing the tri­al as they wait to see how Keytru­da/chemo did on event-free sur­vival.

As usu­al, we’ll have to wait for a sci­en­tif­ic con­fer­ence to see the hard num­bers. But it’s im­por­tant to note that Mer­ck’s string of suc­cess­es with Keytru­da is al­so a psy­cho­log­i­cal vic­to­ry that can’t be un­der­es­ti­mat­ed. When Bris­tol-My­ers re­leased its lat­est batch of da­ta on Op­di­vo, the com­pa­ny al­so claimed a suc­cess on Part 1a of the Check­mate -227 tri­al, which met the co-pri­ma­ry end­point of OS, “demon­strat­ing a sta­tis­ti­cal­ly sig­nif­i­cant ben­e­fit for Op­di­vo plus low-dose Yer­voy (ip­il­i­mum­ab) ver­sus chemother­a­py in pa­tients whose tu­mors ex­press PD-L1 ≥1%.”

An­a­lysts weren’t hav­ing it, though, skep­ti­cal that the drug would beat Keytru­da af­ter see­ing the Keynote-189 da­ta. At this stage of the PD-1 bat­tle, Bris­tol-My­ers is as­sumed to come in be­hind Mer­ck.

The string of suc­cess­es has an­a­lysts com­pet­ing in peak sales fore­casts for Keytru­da. Mizuho’s Mara Gold­stein re­cent­ly not­ed:

News of the fail­ure of BMY’s Check­mate-227 Part 2, OP­DI­VO + chemother­a­py in front­line NSCLC to demon­strate an OS ben­e­fit vs. chemother­a­py alone, fur­ther so­lid­i­fies KEYTRU­DA’s dom­i­nance in this mul­ti-bil­lion dol­lar mar­ket op­por­tu­ni­ty, in our view, and is sup­port­ive of our in­vest­ment the­sis. We es­ti­mate that KEYTRU­DA sales will sur­pass $20 bil­lion by 2024, and that KEYTRU­DA will re­main the dom­i­nant check­point in­hibitor in the mar­ket.

Gold­stein added this morn­ing that every­thing is still look­ing rosy for Mer­ck as the com­pa­ny looks to add to its lead in triple neg­a­tive breast can­cer. Plus, the Eu­ro­peans are help­ing with an­oth­er pos­i­tive opin­ion for Mer­ck.

In ad­di­tion to TNBC, MRK al­so an­nounced a pos­i­tive CHMP opin­ion for KEYTRU­DA+IN­LY­TA in 1L RCC based on piv­otal Phase III KEYNOTE-426 da­ta – im­proved OS, PFS, and ORR vs SU­TENT. We think this lends sup­port to our view that KEYTRU­DA should pull far­ther ahead of com­peti­tors as the lead­ing check­point in­hibitor, and is sup­port­ive of our in­vest­ment the­sis.

So­cial im­age: Shut­ter­stock

Gilead recently decided to pull two indications for its cancer drug Zydelig — in relapsed follicular B-cell non-Hodgkin lymphoma (FL) and relapsed small lymphocytic leukemia (SLL) — after failing to complete the confirmatory trials required as part of the accelerated approvals from 2014.

“As the treatment landscape for FL and SLL has evolved, enrollment into the confirmatory study has been an ongoing challenge,” Gilead said in a statement, noting it formally notified the FDA of its decision to voluntarily withdraw these indications.