AR-13503 is an active metabolite of Netarsudil

SAR407899 is a potent, ATP-competitive Rho kinase inhibitor. It antihypertensive action in animals. Sanofi is developing SAR 407899 for the treatment of microvascular angina (Syndrome X). It was previously being developed in clinical trials for the treatment of diabetic neuropathies, diabetic nephropathies, erectile dysfunction, pulmonary hypertension, hypertension and kidney disorders, but development was discontinued for those indications.

AT13148, being developed by Astex Pharmaceuticals and its collaborators, is an orally active small molecule inhibitor of Rho activated kinases (ROCK) 1 and 2 and of protein kinase (PK) A and is currently in phase 1 clinical studies under Cancer Research UK’s Clinical Development Program (CDP). AT13148 is currently being tested in a phase 1 clinical trial in patients with advanced solid tumors.

Staurosporine is an alkaloid isolated from the culture broth of Streptomyces staurosporesa. It exerts antimicrobial, hypotensive, and cytotoxic activity. The main biological activity of staurosporine is the inhibition of protein kinases through the prevention of ATP binding to the kinase. This is achieved through the stronger affinity of staurosporine to the ATP-binding site on the kinase. Staurosporine is a prototypical ATP-competitive kinase inhibitor in that it binds to many kinases with high affinity, though with little selectivity. It is a potent, cell permeable protein kinase C inhibitor with an IC50 of 0.7 nM. At higher concentration (1-20 nM), staurosporine also inhibits other kinases such as PKA, PKG, CAMKII and Myosin light chain kinase (MLCK). At 50-100 nM, it is a functional neurotrophin agonist, promoting neurite outgrowth in neuroblastoma, pheochromocytoma and brain primary neuronal cultures. At 0.2- 1 uM, staurosporine induces cell apoptosis. Staurosporine is also a potent GSK-3β inhibitor with a reported IC50 value of 15 nM. In research, staurosporine is used to induce apoptosis. It has been found that one way in which staurosporine induces apoptosis is by activating caspase-3. Staurosporine was discovered to have biological activities ranging from anti-fungal to anti-hypertensive. The interest in these activities resulted in a large investigative effort in chemistry and biology and the discovery of the potential for anti-cancer treatment. Staurosporine induces apoptosis by multiple pathways and that the inhibition of more than one kinase is responsible for its potent activity. Because the mechanism of action of staurosporine is distinct from traditional anticancer drugs, this may warrant further preclinical evaluations of the antitumor potential of new staurosporine derivatives either alone or in combination with death ligands or conventional chemotherapeutic drugs.

RKI 1447 is a potent and selective ROCK inhibitor. It displays anti-invasive and antitumor activities in breast cancer cells. RKI-1447 can inhibit the proliferation, migration and invasion abilities of ovarian cancer cells. RKI 1447 exhibits cytotoxic and cytostatic effects on VHL-deficient clear cell renal cell carcinoma (CC-RCC), making them candidate novel therapeutics for CC-RCC. RKI-1447 significantly inhibited mammary tumor growth in animal models.

Y-27632, originally synthesized by Mitsubishi Tanabe Pharma Corporation, is a selective and a strong ROCK inhibitor, which activates the ROCK signal cascade. It was found, that the inhibition of ROCK was beneficial for the prevention of systemic lupus erythematosus, which possibly by suppressing NF-κB activation. Y-27632 can promote both the ex vivo and in vitro proliferation of limbal epithelial cell proliferation. The in vivo enhanced epithelial wound healing further implies that the Y-27632 may act as a new strategy for treating limbal stem cell deficiency. Preliminary human cases confirmed that ROCK inhibitor eye drops were considered effective for treatment of corneal edema associated with cataract surgery.

Y-33075 is potent and selective ROCK (Rho-associated coiled-coil-forming protein kinase) inhibitor, developed by Yoshitomi Pharmaceutical Industries for encephalomyelitis treatment. In rabbits and in monkeys, Y-33075 lowers IOP in a dose-dependent fashion. An increase in regenerating axons of RGCs in 100 mM Y-33075-treated eyes is observed compared with saline-treated eyes. Y-33075 dose-dependently increases the number of RGCs with regenerating axons. Both Y-33075 induces a concentration-dependent relaxation in rabbit ciliary arteries precontracted with a high-potassium (high-K) solution. The amplitude of relaxation induced by Y-33075 is not affected by either 100 μM N (G)-nitro-L: -arginine methyl ester (L: -NAME) or 10 μM indomethacin. In Ca2 -free solution, Y-27632 and Y-39983 significantly inhibit the transient contraction of ciliary arteries induced by 10 μM histamine. However, neither Y-27632 nor Y-39983 affects the elevation of [Ca2 ](i) induced by high-K solution and histamine.

Ripasudil (K-115) is a selective Rho-associated coiled coil-containing protein kinase (ROCK) inhibitor. This compound, which was originally discovered by D. Western Therapeutics Institute, Inc., reduces intraocular pressure (IOP) by directly acting on the trabecular meshwork, thereby increasing conventional outflow through the Schlemm's canal. As a result of this mechanism of action, ripasudil may offer additive effects in the treatment of glaucoma and ocular hypertension when used in combination with agents such as prostaglandin analogues (which increase uveoscleral outflow) and β blockers (which reduce aqueous production). GLANATEC® (Ripasudil hydrochloride hydrate) ophthalmic solution 0.4% is launched in Japan for the treatment of glaucoma and ocular hypertension.