Mer­sana Ther­a­peu­tics’ rocky road in de­vel­op­ing its lead drug has cul­mi­nat­ed in the aban­don­ment of the ex­per­i­men­tal can­cer treat­ment, days af­ter its high-pro­file part­ner Take­da de­cid­ed to walk away from their deal.

Back in 2016, Take­da and its unit Mil­len­ni­um ex­pand­ed a pri­or part­ner­ship with Mer­sana by se­cur­ing the the ex-US com­mer­cial rights to the Cam­bridge, Mass­a­chu­setts-based com­pa­ny’s then-lead pre­clin­i­cal an­ti­body drug con­ju­gate — XMT-1522 — for $60 mil­lion up­front and a host of oth­er mile­stone pay­ments, which in tan­dem with their ex­ist­ing agree­ment added up to a $1 bil­lion-plus deal.

Take­da backed Mer­sana $MRSN on the promise of its next-gen an­ti­body-drug con­ju­gates (AD­Cs), or armed an­ti­bod­ies.

This po­tent class of drugs brings to­geth­er two in­gre­di­ents by chem­i­cal­ly link­ing an­ti­bod­ies to a bi­o­log­i­cal­ly ac­tive drug or cy­to­tox­ic com­pound. This com­bines the tar­get­ing ca­pa­bil­i­ties of an­ti­bod­ies — al­low­ing sen­si­tive dis­crim­i­na­tion be­tween healthy and can­cer tis­sues — with the cell-killing abil­i­ty of chemother­a­pies. While ex­ist­ing AD­Cs can be lim­it­ed to just a few ther­a­pies, Mer­sana’s tech plat­form is de­signed to pro­duce drugs that can link up with 12 to 15, in the­o­ry vast­ly en­hanc­ing the ther­a­peu­tic po­ten­tial of their crop of AD­Cs for dis­eases pre­vi­ous­ly out of reach.

An­na Pro­topa­pas

It was this ad­di­tion­al fire­pow­er that at­tract­ed Take­da to Mer­sana, which is run by for­mer Mil­len­ni­um chief An­na Pro­topa­pas. Mer­sana went pub­lic in 2017, but a year lat­er trou­ble was afoot. Last Ju­ly, Mer­sana re­port­ed a pa­tient death in a Phase I tri­al test­ing XMT-1522 in pa­tients with breast, gas­tric, and non-small cell lung can­cers whose tu­mors ex­press HER2. The com­pa­ny ac­knowl­edged the death could be re­lat­ed to the ex­per­i­men­tal drug, and the FDA slapped a par­tial clin­i­cal hold on the tri­al. Mer­sana’s oth­er can­cer drug-in-de­vel­op­ment, XMT-1536, was un­af­fect­ed.

By Sep­tem­ber, the com­pa­ny and the FDA agreed to a re­vamped de­vel­op­ment pro­gram for XMT-1522, and the agency lift­ed its hold. How­ev­er, it looks like Take­da man­age­ment de­cid­ed that the pro­gram, and in­deed Mer­sana’s tech, was too risky to con­tin­ue their col­lab­o­ra­tion. In an SEC fil­ing, Mer­sana said that the Japan­ese drug­mak­er’s Mil­len­ni­um unit had elect­ed to ter­mi­nate the part­ner­ship on Jan­u­ary 2.

In its press re­lease on Fri­day, Mer­sana said it had aban­doned the de­vel­op­ment of XMT-1522 al­to­geth­er to fo­cus on its oth­er ex­per­i­men­tal drug, XMT-1536. The com­pa­ny’s shares were down about 15% in ear­ly trad­ing.

“We have made the dif­fi­cult de­ci­sion to ter­mi­nate the fur­ther de­vel­op­ment of XMT-1522 de­spite a fa­vor­able emerg­ing pro­file of ef­fi­ca­cy and tol­er­a­bil­i­ty due to the com­pet­i­tive en­vi­ron­ment for HER2-tar­get­ed ther­a­pies,” Mer­sana chief Pro­topa­pas said in a state­ment.

Leerink and Cowen an­a­lysts sug­gest­ed Mer­sana’s de­ci­sion was per­ti­nent, con­sid­er­ing the com­pet­i­tive land­scape for HER2-tar­get­ing ther­a­pies. Sev­er­al such ther­a­pies have al­ready been sanc­tioned ap­proval, and oth­ers are in de­vel­op­ment, in­clud­ing Dai­ichi Sankyo’s DS-8201 that car­ries 7-8 pay­loads, not­ed Cowen’s Boris Peak­er.

“Many in­vestors al­ready had very low ex­pec­ta­tions for XMT-1522…es­pe­cial­ly fol­low­ing the brief par­tial clin­i­cal hold placed on XMT-1522 that has con­tributed to the stock trad­ing near his­toric lows. The de­ci­sion to fo­cus re­sources on ad­vanc­ing XMT-1536 could al­so have a pos­i­tive im­pact on the com­pa­ny’s cash run­way,” Leerink an­a­lysts wrote in a note.

The com­pa­ny al­so pro­vid­ed en­cour­ag­ing ini­tial da­ta on XMT-1536 — a NaPi2b- tar­get­ing ADC — from an on­go­ing dose es­ca­la­tion study.

“Ul­ti­mate­ly…it will be im­por­tant for XMT-1536 to demon­strate dura­bil­i­ty of re­spons­es achieved giv­en Roche’s past NaPi2b dis­ap­point­ments,” they added.

Mer­sana con­tact­ed End­points News to as­sert that the Take­da part­ner­ship was ter­mi­nat­ed by mu­tu­al con­sent, echo­ing its press re­lease post­ed on Fri­day. 

The European Medicines Agency’s Committee for Medicinal Products for Human Use (CHMP) recommended nine drugs for approval this week while also giving thumbs up for six expanded indications, including Novo Nordisk’s approved obesity medication Wegovy for younger people. Wegovy is already approved as an obesity treatment in the EU for adults, and the new indication would allow prescriptions for adolescents aged 12 and older.

RNA biotech GreenLight Biosciences has been handed an offer for potential acquisition.

GreenLight said in a release that it has received a non-binding “indication of interest” from Fall Line Endurance Fund to acquire GreenLight’s capital stock for $0.60 per share in cash. The release said any potential agreement between the two parties would depend on certain conditions.

Through a special committee, the biotech will evaluate the offer but added there’s no certainty a deal will go forward. GreenLight will also not make any more announcements until a deal comes through or “otherwise determines” a statement is necessary.

A public T cell biotech’s chief executive has decided to leave the company.

TScan Therapeutics said Friday morning that CEO David Southwell stepped down earlier this week, leaving both his chief executive and board member roles. Filling in is Gavin MacBeath, the company’s CSO and COO. He became the acting CEO on Tuesday, and will continue to remain CSO and COO, TScan’s announcement read.

The German life science group Sartorius will be picking up French contract manufacturer Polyplus for the price of €2.4 billion, or $2.6 billion.

On Friday, Sartorius announced the acquisition through its French subgroup, Sartorius Stedim Biotech, which will be acquiring Polyplus from private investors ARCHIMED and WP GG Holdings IV. Polyplus has 270 employees and produces materials and components that go into making viral vectors that are used in cell and gene therapies. This includes DNA/RNA reagents as well as plasmid DNA. Polyplus has locations in France, Belgium, China and the US.