Pfiz­er $PFE re­port­ed out some good news from a late-stage tri­al test­ing its drug tafamidis against a rare con­di­tion that leads to heart fail­ure. The pos­i­tive re­sults of the Phase III study have both Al­ny­lam $AL­NY and Io­n­is $IONS in­vestors squea­mish, as it could be com­pe­ti­tion for patisir­an and in­ot­ersen.

Bren­da Coop­er­stone

The Pfiz­er tri­al, called AT­TR-ACT, test­ed its drug tafamidis in pa­tients with transthyretin car­diomy­opa­thy, an in­her­it­ed con­di­tion in which pro­teins don’t fold in­to their nor­mal shapes cor­rect­ly. The mis­fold­ing makes them build up and cause dam­age to the nerves, heart, and oth­er or­gans. In the tri­al, the drug met its pri­ma­ry end­point, Pfiz­er said, and demon­strat­ed a sta­tis­ti­cal­ly sig­nif­i­cant re­duc­tion in the com­bi­na­tion of all-cause mor­tal­i­ty and fre­quen­cy of car­dio­vas­cu­lar-re­lat­ed hos­pi­tal­iza­tions com­pared to place­bo at 30 months.

Fol­low­ing news on the da­ta, Al­ny­lam stock fell 5%, po­ten­tial­ly on fear of an up­com­ing ri­val as the phar­ma com­pa­ny is al­so pur­su­ing a car­diomy­opa­thy ap­pli­ca­tion for patisir­an. And Io­n­is, which owns a ma­jor­i­ty stake in its spin­out Akcea (which is de­vel­op­ing in­ot­ersen for the same con­di­tion), al­so sank 5%.

Pfiz­er land­ed tafamidis when it ac­quired Fol­dRx in a buy­out back in 2010 as it pushed in­to the rare dis­ease field. Like oth­er phar­ma com­pa­nies, Pfiz­er was lured by the prospect of big re­turns for drugs that meet an ur­gent need in tiny pa­tient pop­u­la­tions.

Pfiz­er test­ed the drug in a rare neu­rode­gen­er­a­tive dis­ease called TTR-FAP, but got re­ject­ed by the FDA in 2012 af­ter try­ing to gain ap­proval with on­ly one tri­al as proof of the drug’s ef­fi­ca­cy. Tafamidis was ap­proved in 40 coun­tries — in­clud­ing the EU in 2011 — how­ev­er. It sells un­der the brand name Vyn­daquel.

In a state­ment ear­li­er this year, Pfiz­er said it’s still work­ing on a way for­ward in the US for tafamidis in TTR-FAP.

“As a leader in TTR amy­loi­do­sis, Pfiz­er Rare Dis­ease con­tin­ues to part­ner with the FDA re­gard­ing a po­ten­tial path to ap­proval for tafamidis for TTR-FAP, as we hope to achieve the ob­jec­tive of pro­vid­ing TTR-FAP pa­tients liv­ing in the Unit­ed States with the same treat­ment op­tion as those pa­tients liv­ing in many oth­er parts of the world.”

For now, tack­ling transthyretin car­diomy­opa­thy gives the drug a new av­enue for rev­enue gen­er­a­tion in the US. Bren­da Coop­er­stone, SVP and chief de­vel­op­ment of­fi­cer in Pfiz­er’s rare dis­ease unit, had this to say about the re­cent Phase III da­ta:

These topline re­sults are im­por­tant for peo­ple with transthyretin car­diomy­opa­thy and bring us one step clos­er to re­al­iz­ing the po­ten­tial for a new treat­ment for those in des­per­ate need. Pfiz­er Rare Dis­ease has been at the fore­front of im­prov­ing the un­der­stand­ing of transthyretin car­diomy­opa­thy, and we thank the pa­tients who par­tic­i­pat­ed in the tri­al and their fam­i­lies, as well as the physi­cians and in­ves­ti­ga­tion­al sites that con­tributed to this im­por­tant study. We look for­ward to shar­ing the de­tailed re­sults of the study with the car­dio­vas­cu­lar com­mu­ni­ty and dis­cussing these da­ta with health au­thor­i­ties to de­ter­mine an ap­pro­pri­ate reg­u­la­to­ry path for­ward.

The FDA’s Oncology Center of Excellence has been a bright spot within the agency in terms of speeding new treatments to patients. That flexibility was on full display this morning as FDA released new draft guidance spelling out exactly how oncology drug developers can fulfill both the accelerated and full approval’s requirements with just a single randomized controlled trial.

While Congress recently passed legislation that will allow FDA to require confirmatory trials to be recruiting and ongoing prior to granting an accelerated approval, the agency is now making clear that the initial trial used to win the AA, if designed appropriately, can also serve as the trial for converting the accelerated approval into a full approval.