John McHutchison, Assembly Biosciences CEO (Getty Images)

As­sem­bly Bio's he­pati­tis B pro­gram flops as a po­ten­tial cure in PhII, send­ing shares spi­ral­ing

Look­ing for a he­pati­tis B cure, As­sem­bly Bio­sciences $ASMB has struck out in a Phase II.

The South San Fran­cis­co-based com­pa­ny an­nounced Thurs­day af­ter­noon that its lead ex­per­i­men­tal drug ve­bi­corvir, in com­bi­na­tion with nu­cle­o­side ther­a­py, could not keep pa­tients dis­ease-free af­ter stop­ping treat­ments. In to­tal, 39 of the 41 in­di­vid­u­als in the open-la­bel study re­lapsed, as the reg­i­men failed to achieve a mean­ing­ful sus­tained vi­ro­log­ic re­sponse.

In­vestors did not take too kind­ly to the news, ham­mer­ing the biotech’s share prices af­ter the bell. As­sem­bly’s stock dropped as much as 40% on Thurs­day evening but has since lev­eled off to down about 35%.

The He­pati­tis B pa­tients in­volved in As­sem­bly’s Phase II gen­er­al­ly re­quire treat­ments for the rest of their lives. As­sem­bly’s the­o­ry went that if they could show enough of a pro­longed re­sponse af­ter tak­ing pa­tients off the pro­gram, which is sep­a­rate­ly be­ing stud­ied as a chron­ic sup­pres­sive ther­a­py, then it could ef­fec­tive­ly func­tion as a cure.

In or­der to find that out, As­sem­bly treat­ed their pa­tients with the com­bi­na­tion ther­a­py for 12 to 18 months. Fol­low­ing that pe­ri­od, re­searchers stopped the treat­ments and eval­u­at­ed the 41 pa­tients every four weeks to see whether or not the com­bo was ef­fec­tive enough at pre­vent­ing a re­lapse af­ter an ex­tend­ed pe­ri­od of time.

But 33 of the 41 pa­tients saw their he­pati­tis B re­turn af­ter the first four-week eval­u­a­tion. By the 16-week mark, an­oth­er six pa­tients re­lapsed. As­sem­bly had been look­ing for an SVR rate of at least 15% af­ter 24 weeks, but Thurs­day’s re­sults equate to a rate of less than 5%.

Though Thurs­day’s re­sults are in­deed a neg­a­tive, As­sem­bly’s com­bo still has po­ten­tial as a chron­ic ther­a­py, Baird’s Bri­an Sko­r­ney wrote in a note to in­vestors. See­ing that the near-term cure play is now “off the ta­ble,” Sko­r­ney says As­sem­bly can ef­fec­tive­ly piv­ot to­ward that path, but notes the up­side is much more lim­it­ed.

“Al­though the busi­ness op­por­tu­ni­ty for a chron­ic ther­a­py for He­pati­tis B is much less at­trac­tive than a cu­ra­tive reg­i­men, we still see it as a rea­son­able busi­ness,” Sko­r­ney wrote.

Should As­sem­bly take that route, Sko­r­ney pre­dicts the ther­a­py could reach any­where be­tween $500 mil­lion and $1 bil­lion in an­nu­al sales.

As­sem­bly has pre­vi­ous­ly tak­en steps to turn that in­to a re­al­i­ty, ink­ing a $540 mil­lion deal with BeiGene in Ju­ly to take the ve­bi­corvir and nu­cle­o­side com­bo in­to a Phase III for chron­ic sup­pres­sion of He­pati­tis B. The tri­al is ex­pect­ed to be­gin some­time in the first half of next year, and will in­clude a group of pa­tients who have seen on­ly par­tial vi­ral sup­pres­sion af­ter a year or more of nu­cle­o­side monother­a­py.

The com­pa­ny is al­so look­ing in­to whether ve­bi­corvir could still cure he­pati­tis B in a triple ther­a­py con­coc­tion. In Au­gust, As­sem­bly hooked on­to a deal with Ar­bu­tus Bio­phar­ma and plans to launch the first Phase II next year that com­bines ve­bi­corvir, nu­cle­o­side treat­ment and Ar­bu­tus’ RNAi ther­a­peu­tic for the dis­ease. Sko­r­ney notes the com­pa­nies are still in the ear­ly de­vel­op­men­tal stages, how­ev­er.

Big Phar­ma's Twit­ter ex­o­dus; Mer­ck wa­gers $1.35B on buy­out; $3.5M gene ther­a­py; and more

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Paul Perreault, CSL Behring CEO

CSL lands FDA ap­proval for he­mo­phil­ia B gene ther­a­py, sets $3.5M list price

The FDA has approved the world’s first gene therapy for hemophilia B, ushering into the market a treatment that’s historic in both what it promises to do and how much it will cost.

CSL will be marketing the drug, Hemgenix, at a list price of $3.5 million — which sets a new record for the most expensive single-use gene therapy in the US.

In a statement provided to Endpoints News, the Australian company noted that the current costs of treating people with moderate to severe hemophilia B can be significant over a lifetime. By some estimates, healthcare systems could spend more than $20 million per person.

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Image: Shutterstock

MIT re­searchers re­veal DNA "Paste" tech be­hind lat­est gene edit­ing start­up

MIT scientists have developed a tool that they say can insert large gene sequences where they want in the genome.

In a paper published Thursday in Nature Biotechnology, MIT fellows Omar Abudayyeh, Jonathan Gootenberg and colleagues detail a technology they call PASTE, which they say can potentially be used to insert long strands of DNA and treat genetic diseases caused by many different mutations, such as cystic fibrosis and Leber congenital amaurosis, a rare eye disorder that causes blindness.

Elon Musk (GDA via AP Images)

Biggest drug com­pa­nies halt­ed Twit­ter ad buys af­ter Lil­ly in­sulin spoof

Almost all of the drug industry’s biggest advertisers cut their spending on Twitter to zero or near-zero over the last two weeks amid worries about impersonation of their brands by pranksters and the future of the social media company.

Among 18 of the biggest pharmaceutical advertisers in the US market, 12 cut their Twitter ad spending to nothing for the week beginning Nov. 14, according to Pathmatics, which tracks data on prescription drug ad spending as well as general corporate advertising. The list of drugmakers cutting spending to zero includes Merck, AstraZeneca, Eli Lilly, Novartis, Pfizer and others.

J&J's Spra­va­to pulls a PhI­II win against Sero­quel XR in treat­ment-re­sis­tant de­pres­sion

A day before Thanksgiving, J&J’s Janssen has a new cut of Phase III Spravato data to be grateful for.

The pharma giant announced on Wednesday that its nasal spray, also known as esketamine, beat extended-release quetiapine, previously sold by AstraZeneca as Seroquel XR, in treatment-resistant depression (TRD). Of 676 adults, a significantly higher number of patients on Spravato were able to achieve remission and avoid relapse after 32 weeks, according to J&J.

Rob Davis, Merck CEO

Up­dat­ed: No Seagen here: 'Do more' means a small $1.35B pur­chase of Ima­go for Mer­ck

Merck is making an acquisition, the Big Pharma announced before Monday’s opening bell. No, Seagen is not entering the fold, as had been speculated for quarters.

Folding under Merck’s wings will be Pfizer-backed Imago BioSciences. For nearly a year, Merck CEO Rob Davis has been saying the pharma giant needs to “do more” on the business development front after its 2021 $11.5 billion acquisition of Acceleron.

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Isao Teshirogi, Shionogi president and CEO (Kyodo via AP Images)

Sh­ionogi's Covid an­tivi­ral lands first ap­proval in Japan's new emer­gency ap­proval path­way

Japanese regulators on Tuesday signed off on Shionogi’s homegrown antiviral for Covid-19, known as Xocova (ensitrelvir), making it the first approval under Japan’s emergency regulatory approval system.

The emergency approval, following a back-and-forth with regulators since last February, is based on a safety profile with more than 2,000 patients who have accessed the pill, and clinical symptomatic efficacy for five typical Omicron-related symptoms (primary endpoint) and antiviral efficacy (key secondary endpoint) in patients with mild to moderate SARS-CoV-2 infection, regardless of risk factors or vaccination status, and during the Omicron-dominant phase of the pandemic.

Dermavant Sciences' first consumer TV ad for its Vtama psoriasis med shows people ready for a new topical treatment.

Roivant’s Der­ma­vant de­buts first-ever TV com­mer­cial for pso­ri­a­sis cream Vta­ma

Dermavant Sciences has been marketing its first product, psoriasis med Vtama, to dermatologists for months, but on Tuesday it rolled out its first consumer campaign. The debut DTC effort including a streaming TV commercial encourages patients to a “Topical Uprising” in a nod to Vtama being a topical cream.

In the new commercial, a swell of people discards scarves and jacket coverings, gathering in the street to converge on a pharmacy to demand a steroid-free prescription. A moment of levity follows when a pharmacist says, “You know you can just talk to your doctor, right?” The gathered crowds collectively says, “Oh.”

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FDA preps for DMD drug gener­ics as Sarep­ta has yet to fin­ish its con­fir­ma­to­ry tri­al

The FDA typically releases guidance to help generic drug manufacturers develop new copycats of small molecule drugs, oftentimes in preparation for a brand name product’s patents or exclusivity to expire.

This week, FDA released such bioequivalence guidance for any generic drugmakers looking to take on Sarepta’s Duchenne muscular dystrophy (DMD) drug Exondys 51 (eteplirsen), even though the drug’s sponsor has yet to convert the accelerated approval to a full approval, showing clinical benefit.