Merck & Co has announced its updated pipeline following the merger with Schering-Plough which includes more than 20 candidates in Phase III or under regulatory review, and over 20 others in Phase II.

The New Jersey-based major has completed a “comprehensive prioritisation process” based on a series of criteria, including “potential for impact on human health, molecular characteristics, stage of development, probability of success and commercial potential”. Merck claimed that the pipeline is particularly strong in areas in which both companies have “long-established research programmes”, such as cardiovascular and infectious diseases and the company has eight investigational drugs in each of these two categories.

Highlights of the pipeline include vorapaxar, S-P’s novel oral thrombin receptor antagonist, or TRA, for blood clots, which analysts believe will be a blockbuster. Another potentially huge earner is boceprevir, another S-P drug, for hepatitis C, which could be filed with regulators before the end of the year.

Merck also made special mention of MK-4305, its novel orexin antagonist being evaluated for insomnia, and an immunotherapy tablet for ragweed allergies, known as SCH 39641. Both have just moved into Phase III, though one candidate that has not made the grade, for “strategic reasons”, is esmirtazapine, an S-P drug for hot flushes and insomnia.

The company added that the complementary nature of the two pipelines “is underscored by the fact that only two programmes, hepatitis C and cancer, needed to prioritise a lead molecule for continued development”. The ‘winners’ were both Merck drugs – vaniprevir, a second-generation hepatitis C protease inhibitor candidate and dalotuzumab, an IGF-1R inhibitor – and both are currently in Phase II trials.

The rest of the pipeline is composed of “small molecules, vaccines and biologics targeting a broad range of unmet medical needs”, including atherosclerosis, diabetes and schizophrenia. Peter Kim, president of Merck Research Laboratories, said he believes the pipeline is the best in the industry and analysts agree it has the potential to soften the blows the company has suffered – and will continue to suffer over the next couple of years – from patent expiries on key products,