Mecasermin rinfabate (INN, USAN) (brand name Iplex), also known as rhIGF-1/rhIGFBP-3, is a drug consisting of recombinant human insulin-like growth factor 1 (IGF-1) and recombinant human insulin-like growth factor binding protein-3 (IGFBP-3) which is used for the treatment of amyotrophic lateral sclerosis (Lou Gehrig's disease).

On March 11, 2009 the FDA announced that mecasermin rinfabate would be made available to Americans with amyotrophic lateral sclerosis (ALS), more commonly known as Lou Gehrig's disease, as a part of a clinical trial.

[4][5] Iplex was investigated in a Phase II clinical study at the University of Rochester School of Medicine, with funding provided by the Muscular Dystrophy Association and the National Institutes of Health.

This Phase II program studied the safety and tolerability of once-daily, subcutaneous injection of Iplex in patients with MMD.

Data is being collected from a Phase II open-label clinical study directed by Morris Schambelan, M.D., a professor of medicine at University of California San Francisco.

This disease, affecting an estimated 14,000 to 16,000 premature infants each year, causes the lack of development of the small blood vessels in the back of the eye leading to blindness in the majority of cases.

With voluntary muscle action progressively affected, patients in the later stages of the disease may become totally paralyzed.