UPDATE: Amgen opts to DARP-out after seeing early data from $550M Molecular Partners biobucks collab

After a peek at the earliest data for Molecular Partners’ DARPin therapy, Amgen is saying thanks but no thanks on the $550 million biobucks partnership.

Molecular Partners has disclosed that Amgen is handing back the rights to MP0310, a dual-targeted compound that aims to activate T cells and other immune cells without causing adverse events. For Amgen, the decision to walk away comes after the biotech giant conducted a strategic pipeline review. 

MP0310 is currently being tested in a phase 1 trial that has just begun to reveal clinical findings, Molecular Partners said. The therapy was found to activate the immunostimulatory receptor 4-1BB after an initial dose. The second part of the trial will focus on finding a dose for further study, with completion expected in the second half and the full data set revealed later this year.

Amgen paid $50 million upfront in 2018 for the global rights to MP0310 to test it against some of the pharma’s meds, including its bispecific T-cell engagers. Molecular Partners was in charge of the phase 1 test, and Amgen had an option to advance later-stage development once that was complete. The early-stage trial got underway in October 2019 in patients with solid tumors.

Molecular Partners could have been eligible for $497 million if the deal had met certain milestones.

With the Amgen deal winding down, Molecular Partners plans to continue with clinical research and seek potential partnerships for the program.

DARPin therapies are a new class of protein medicines that are much smaller than monoclonal antibodies and are designed to overcome traditional limitations of that modality.

Molecular Partners has several Big Pharma partnerships, including work with Novartis on a COVID-19 DARPin treatment. The Swiss pharma revealed on Tuesday that the therapy is delayed, as COVID therapeutics can no longer count on hospitalizations or deaths as cases have dropped. Novartis said the FDA will likely want phase 3 data on the treatment before considering an emergency use authorization. The partners will either have to wait for a fall wave of infections or work with regulators for a revamped trial design, according to SVB Leerink analysts. 

"A worst-case scenario of program discontinuation is also on the table, pending Novartis’ assessment of the regulatory requirements and prioritization of ensovibep versus an oral COVID-19 antiviral, which Novartis is also developing," SVB Leerink said.

Despite the double-dose of bad news, SVB Leerink said its appreciation of Molecular Partners' DARPin platform has not been shaken. 

The small biotech's shares tumbled 17% to $13.89 in after-market trading after the news was revealed, compared to a close of $16.90.