Merck KGaA is looking to strengthen its position in the human growth hormone arena and has signed a pact with the USA’s Ambrx to develop products for that market that will require less frequent dosing.

Under the terms of the deal, the German firm’s biopharmaceutical unit Merck Serono will receive worldwide commercialisation rights for ARX201, Ambrx’ most advanced product candidate and the initial focus of the collaboration. The latter firm will receive an undisclosed payment and be eligible to get clinical, regulatory and commercial milestones, as well as royalties on net sales of any products that come out of the alliance. In addition, Ambrx retains an option to co-promote those products in the US market which would see the firms share commercialisation expenses as well as profits.

In February this year, Ambrx started a Phase I/II clinical trial of ARX201 in patients with growth hormone deficiency following single-dose escalation and repeated dosing. The compound has been modified using the firm’s ReCODE technology and Ambrx now believes that ARX201 “may have improved pharmacological performance over existing growth hormone products, including the potential for less frequent dosing”. Current therapies have a once-daily dosing regimen.

Francois Feig, in charge of Merck Serono’s endocrinology and cardio-metabolic care division, said ARX201 “has the potential to establish a new standard of care in growth hormone therapy” as “less frequent administration would represent a significant advance for patients in terms of improved convenience and quality of life”. It would also provide a welcome addition to the firm’s Saizen (somatropin), which had sales of $209 million last year and in January, Merck Serono launched a device, called easypod, for the once-daily administration of Saizen to improve patients' ease of daily use, reliability and convenience.