It is normally a sign of bad news but Genmab says that it is delighted that Merck KGaA has returned the rights to a new lymphoma drug to the Denmark-based drugmaker.

Genmab has regained all rights to the HuMax-CD4 (zanolimumab) antibody from the Darmstadt-headquartered firm which is in Phase III trials for the treatment of cutaneous T-cell lymphoma and in Phase II for non-cutaneous T-cell lymphoma. Interestingly, such a move tends to be accompanied by disappointing data but this is not the case here and Merck was highly complementary about the compound and its potential.

A spokeswoman for the German firm told PharmaTimes World News that the decision to return the rights, which it licensed in August 2005, is strictly a strategic one, “driven by internal project prioritisation” and the move is “in no way a reflection of the efficacy of HuMax-CD4". Indeed the announcement came as Genmab highlighted final data from two Phase II studies in early and late-stage mycosis fungoides (MF), a form of CTCL, reported in the journal Blood. In the high dose levels of 560mg and 980mg, 13 MF patients had objective responses lasting between 8 and 91 weeks, with median response duration of 81 weeks, almost double the increase compared to previously-reported data.

Genmab will continue the ongoing studies with HuMax-CD4, and said it would also expand development into earlier stage patients in combination with psoralens with ultraviolet A (PUVA), as well as with existing therapies for CTCL. Also, the firm said it plans to develop its Unibody antibody technology to target the CD4 receptor for potential HIV applications.

Plans for sales force

Lisa Drakeman, Genmab’s chief executive, said that the company was delighted to regain the rights as HuMax-CD4 “is a nice fit” with the rest of its pipeline “and may provide us with an additional commercial opportunity to move the company forward into the sales and marketing arena”. She added that “if we ultimately build a sales force” for HuMax-CD20 (ofatumumab), the fully human monoclonal antibody partnered with GlaxoSmithKline which is about to go into late-stage trials as a treatment for rheumatoid arthritis, “we would be in a position for this same sales force to market HuMax-CD4".

When asked by PharmaTimes World News whether ‘when’ rather than ‘if’ should be the operative word in terms of building a sales force, Ms Drakeman said that “I can’t guarantee it but we certainly think it makes a lot of sense”. The GSK deal gives Genmab the option to co-promote ofatumumab and Genmab feels that in the USA, a field force for Humax-CD4 of 20-30 people would be sufficient to contact the specialty dermatalogists who are the people who primarily treat CTCL patients.

Getting back the rights from Merck has involved no further payment and under the August 2005 deal, Genmab has already received $70 million from its ex-partner. Furthermore Merck will continue to pay development costs for Humax-CD4 until the end of 2007 and is not entitled to any share of the profits if the compound makes it to the market. Genmab is also well-equipped to fund trials after that, Ms Drakeman noted, as the studies do not involve huge numbers of patients, but the biggest cost will be manufacturing product to meet supply. This is being undertaken at present by DSM. By Kevin Grogan