Merck & Co. will acquire Idenix Pharmaceuticals for about $3.85 billion cash, the companies said today, in a transaction that boosts the buyer’s hepatitis C virus (HCV) pipeline—and could set off yet another wave of portfolio-reshaping megadeals this deal-filled year.
Idenix brings to Merck three clinical-phase HCV drugs that the buyer is evaluating for potential inclusion in future combination therapies—IDX21437 and IDX21459, both nucleotide prodrugs, and samatasvir, a NS5A inhibitor.
“Idenix’ investigational hepatitis C candidates complement our promising therapies in development and will help advance our work to develop a highly effective, once-daily, all oral, ribavirin-free, pan-genotypic regimen that has a duration of treatment as short as possible for millions of patients in need around the world,” Roger Perlmutter, M.D., Ph.D., president, Merck Research Laboratories, said in a statement.
Merck’s lead hep C candidate is a pivotal-phase combination of two company-developed compounds—MK-5172, an HCV NS3/4A protease inhibitor; and MK-8742, an investigational HCV NS5A replication complex inhibitor. In April, Merck launched a series of Phase III clinical trials designed to evaluate the combination’s effectiveness with and without ribavirin in various genotypes, and across a broad range of patient populations with chronic HCV.
Earlier that month, Merck reported promising interim results from the Phase II c-WORTHY trial for the MK-5172/MK-8742 combination—which has received FDA’s Breakthrough Therapy designation. Treatment-naive patients with HCV genotype 1 infection who had cirrhosis achieved a 97% sustained viral response rate after both 12 and 18 weeks of treatment.
The same 97% rate was seen after 18 weeks of treatment in patients with chronic HCV Genotype 1 infection who also had a prior null response to pegylated interferon and ribavirin; and after 12 weeks of treatment in treatment-naïve, non-cirrhotic patients with HCV/HIV co-infection and who were also treated with ribavirin.
Merck presented the interim data at the 49th Annual Meeting of the European Association for the Study of the Liver, also called The International Liver Congress™ 2014 in London.
Also in April, Idenix disclosed it had begun enrollment for the healthy volunteer portion of a phase I clinical trial of IDX21459 in Europe, and reported positive seven-day proof-of-concept data from a Phase I/II clinical trial for IDX21437 in treatment-naïve genotype 1, 2 and 3 HCV-infected patients in the highest dose group (300 mg) for seven days. Based on these findings, Idenix chose the 300 mg dose of IDX21437 for a phase II combination study of IDX21437 with samatasvir that Idenix said at the time would get under way in mid-2014.
Through a collaboration with Johnson & Johnson’s Janssen Pharmaceuticals unit, Idenix is also evaluating samatasvir, simeprevir and TMC647055/r in a phase II clinical program. One of the trial’s programs, HELIX-1, reported safety and sustained virologic response rate (SVR4) findings at a medical meeting, while another, HELIX-2, is expected to report SVR4 data in the second half of this year. During the program, Idenix reported, samatasvir-containing regimens were found to be safe and well tolerated after they were administered to more than 140 patients for 12-week treatment durations.
However, last year Idenix’ effort to develop another nucleotide prodrug hit a snag last year when the FDA requested additional preclinical data for its then-lead compound in the category, IDX20963, effectively delaying the onset of Phase I human trials.
Worse, Idenix during 2013 scuttled two of its other experimental drugs, the nucleotide polymerase inhibitors IDX184 and IDX19368, following FDA clinical holds because of the compounds’ similarities to BMS-986094, a Bristol-Myers Squibb (BMS)-developed compound.
BMS halted development of BMS-986094 in 2012 after a patient in a Phase IIb study experienced heart failure after receiving the highest daily dose, 200 mg, in combination with BMS’ daclatasvir, another hepatitis C drug candidate. BMS took a $1.8 billion non-cash impairment charge in connection with the failure of BMS-986094, whose development it took over when it acquired Inhibitex for $2.5 billion early in 2012.
Merck agreed to offer, through a subsidiary, a tender offer for all outstanding Idenix shares at $24.50 per share—an eye-popping premium of more than triple Idenix’ closing stock price of $7.23 on Friday.
Idenix carries out its clinical development operations and drug discovery operations in Cambridge, MA, where the company is headquartered, and maintains European laboratories in Montpellier, France.