They will be used to plug a manufacturing gap while the two firms complete their integration and capability upgrade.
In a deal expected to close next week, RLS has bought a 74 per cent stake in GeneMedix at a cost of £14.6m (€22m).
Together the two firms will now run clinical trials, manufacture and commercialise the biosimilar drugs that are currently under development within their joint portfolios.
GeneMedix is developing biosimilar versions of drugs such as the anaemia treatment erythropoietin (EPO), hepatitis B-and C treatment interferon-alfa, and granulocyte colony stimulating factor (G-CSF) - used to treat chemotherapy-induced neutropaenia.
RLS also has a number of biosimilars in development in a range of therapeutic areas, including EPO.
Both firms are hoping to launch their drugs onto the European and eventually the US markets as soon as possible, although due to the non-chemical nature of biosimilar drugs, only a few have so far been approved for these highly regulated markets and the regulatory process is far more cumbersome than it is for regular generic drugs.
The European Medicines Agency (EMEA) has at least been unable to come up with a regulatory framework to bring generic versions to market, which includes submitting clinical trials data, unlike its US counterpart, the Food and Drug Administration (FDA), which is still considering the issue.
For the required clinical trials programmes, and eventual commercialisation, GeneMedix will make some of its own mammalian-cell-based drugs, such as EPO, from its existing Irish facility, although it does not have regulatory-approved microbial cell culture capabilities for the drugs that require this, such as G-CSF.
Meanwhile, RLS is in the process of building a large-scale manufacturing facility in Mumbai that will eventually be able to make both its own mammalian and microbial cell-based biopharmaceuticals, as well as some of GeneMedix's drugs, particularly those that are microbial cell-based.
However, the Mumbai plant is not expected to be commissioned until at least mid next year, and the two firms want to get the EU and US regulatory process for their drugs moving fast to beat a mounting number of competitors who are also trying to push their biosimilar drugs through the approval process, some which are already in the lead.
Only last week Indian generics giant Ranbaxy signed a development and marketing agreement with generic injectables company Zenotech Laboratories to produce its first biosimilar, also a G-CSF, as well as others that it has in development, in a strategic decision to aim for the European biosimilars market.
As part of the agreement, Ranbaxy's biosimilars will be manufactured in Zenotech's FDA/EMEA approvable biologics facility in Hyderabad, where the company has already completed the technical and regulatory requirements for launching G-CSF.
So to move things along while the Mumbai facility is completed, GeneMedix will take on the clinical supply manufacturing of some of RLS' developmental mammalian cell-based biosimilars, while the remainder, as well as those that require a microbial cell culture facility, will be outsourced to contract manufacturers within Europe.
"There will be roughly a 50 per cent split between the in-house manufacturing and the outsourcing of RLS' biosimilars," Julian Attfield, CEO of GeneMedix told Outsourcing-Pharma.com.
"We are a European company so we typically want to work with European contract manufacturers.
No deals have been arranged yet though."
If the Mumbai facility is not ready for commercial production by the time the biosimilars begin receiving regulatory approval, Attfield said that these contract manufacturers would also be used to commercially manufacture the drugs until a time when the Mumbai plant is ready.
"It is important to us that we get these biosimilars onto the European and US market as soon as we can, so we will use the contract manufacturers to speed up the process as long as we need them," said Attfield.
"However, it is cheaper for us to do the manufacturing in-house rather than use a contract manufacturer so as soon as the Mumbai plant is ready for the technology transfer of these drugs, we will do it."