Quisinostat is an orally bioavailable potent histone deacetylase inhibitor, specifically selected due to its sustained inhibition of HDAC1 in solid tumor tissues and prolonged period of half-elimination from tissues. Phase 2 clinical trials are ongoing in patients with platinum-resistant ovarian cancer and non-small cell lung cancer (NSCLC). Quisinostat is active in the treatment of patients with relapsed or refractory Sézary syndrome. The most common drug-related adverse events reported in this trial were: nausea, diarrhea, asthenia. Grade 3 adverse events were also reported: hypertension, lethargy and pruritus.

CP-866087 is a mu opioid receptor antagonist, discovered by Pfizer. The compound was able to antagonize the effect of morphine in a rodent tail flick assay and produced a dose-dependent decrease in alcohol intake in alcohol-preferring rats. The compound was investigated in clinical trials for the treatment of obesity, alcoholism and female sexual arousal disorder. In the later study, although improvements were seen with CP-866,087 in the key efficacy endpoints, there was no clinical treatment benefit over placebo.

Ravidasvir (RDV, ASC16) is a second‐generation, pan‐genotypic non‐structural (NS) 5A inhibitor, which inhibits viral replication and assembly. Ravidasvir exhibits high antiviral potency with EC50 0.04–1.14 nM for HCV GT1–GT6. The pharmacokinetics results indicated that steady status achieved quickly after the first dose. Metabolism studies utilizing human clinical samples showed that Ravidasvir was very stable, with only modest (~2%) metabolite formation. Biliary excretion of Ravidasvir appears to be the primary route of elimination of the absorbed dose, while renal excretion of the intact drug appears to be negligible. In clinical trans twelve-week Ravidasvir and ritonavir-boosted Danoprevir in combination with ribavirinfor 12 weeks achieve the sustained virologic response rate of 100% in treatment-naïve non-cirrhotic Asian patients with HCV GT1 infection. Ravidasvir for treatment‐naïve, non‐cirrhotic HCV GT1 patients was safe and well tolerated. There was no death, treatment‐related serious adverse events, and discontinued cases due to adverse events.

Pfizer was developing PF-3882845, an orally available nonsteroidal antagonist of the mineralocorticoid receptor, for the treatment of diabetic nephropathies. PF‐03882845 is a highly potent (IC50 = 6.3‐13.4 nM, 10% fetal bovine serum & IC50 = 0.504–1.11 nM, absence of serum) selective orally bioavailable mineralocorticoid receptor antagonist. It is a non‐steroidal pyrazoline, unlike steroidal compounds eplerenone and spironolactone. It does not significantly activate or inhibit human androgen receptor, estrogen receptor alpha, and glucocorticoid receptor. PF‐03882845 has been shown to modestly inhibit the progesterone receptor (PR) yielding a 45‐fold selectivity over PR in a cell‐based functional assay. PF‐03882845 was previously in development for the treatment of diabetic nephropathy — development for this indication was terminated for strategic reasons. An alternative indication of hypertension also was not pursued for strategic reasons.

Deleobuvir is a drug for the treatment of Hepatitis C, developed by Boehringer Ingelheim. Deleobuvir is a non-nucleoside HCV NS5B polymerase inhibitor that reversibly and noncovalently binds to the thumb pocket 1. It has shown rapid and strong antiviral activity when administered in combination with peginterferon-a2a and ribavirin. In 2014 Boehringer Ingelheim decided to halt further development of deleobuvir because preliminary analysis of phase 3 clinical trials indicated a low efficacy of the drug.

MK-2048, diketo acid derivative, is a second-generation integrase strand transfer inhibitor (INSTI) developed to retain activity against HIV containing mutations associated with resistance to first-generation INSTIs, raltegravir (RAL) and elvitegravir (EVG). MK-2048 implements its inhibitory mechanism by modifying viral integrase-DNA interactions, the important step of the linear HIV-1 cDNA integration into the host genome. It binds to and inactivates the synaptic complex, an intermediate in the concerted integration pathway in vitro thereby preventing target DNA binding and concerted integration. MK-2048 is active against viruses resistant to RAL and EVG. MK-2048 is equally potent against wild-type IN and raltegravir-resistant IN mutant N155H with a low IC50 value of 42 nM for inhibiting concerted integration. It inhibits R263K mutants slightly more effectively than G118R mutants. MK-2048 exposure leads to the selection of G118R as a possible novel resistance mutation.

PF-05089771 is an oral administrated Nav1.7 channel inhibitor. PF-05089771 provided the best opportunity to explore Nav1.7 blockade for the treatment of acute or chronic pain conditions. PF-05089771 has completed Phase II clinical trials of third molar extraction and primary inherited erythromelalgia. The magnitude of efficacy of PF-05089771 in the randomized, placebo-controlled, double-blind clinical study in subjects with painful diabetic peripheral neuropathy was disappointing. Although there was a trend towards a reduction in pain and improvement in sleep rating in patients with painful DPN when compared to placebo treatment, this was not statistically significant.