PF-00446687 is the highly selective, brain-penetrant, melanocortin 4 receptor (MC4R) agonist. PF-00446687 induced partner preferences formation in females prairie voles after a 6-h cohabitation without mating. PF-00446687 had been in phase I clinical trial for the treatment of sexual function disorders.

PF-03893787 is potent and selective histamine H4 receptor (H4R) antagonist. It has comparable binding affinity to the human histamine H3 receptor. PF-03893787 was found to have significant affinity for the hERG channel. Novartis initiates a phase II extension trial in Atopic dermatitis. Studies exploring the utility of PF-3893787 in patients would be reported in due course, being the potential indications of asthma, pruritus, inflammatory skin diseases and pain, among others.

PF-3274167 (Cligosiban) is a potent, selective, brain penetrant oxytocin receptor antagonist. Cligosiban interrupts the expulsion phase of ejaculation by reducing the normal bulbospongiosum burst pattern and reducing the expulsions that accompany bursts. Cligosiban represents a promising compound to test the clinical hypothesis that antagonism of central oxytocin receptors may be of therapeutic benefit in the treatment of premature ejaculation. [11C]PF-3274167 is not a suitable tracer for imaging of OTR in rat brain, probably because of a too low affinity for this receptor in addition to a poor brain penetration. PF-3274167 had been in phase I clinical trial for the treatment of sexual function disorders and urinary incontinence. However, this research has been discontinued.

PF-477736 is a selective, potent and ATP-competitive Chk1 inhibitor. Compound was tested in combination with gembcitabine in phase I clinical trials in patients with advanced solid tumors.

PF-06700841 is an inhibitor of JAK1 and TYK2 kinases. PF-06700841 tosylate salt is potentially a treatment of systemic lupus erythematosus and plaque psoriasis.

PF-06747775 is an irreversible pyrrolopyrimidine inhibitor of epidermal growth factor receptor (EGFR) T790M mutants which provides potent EGFR activity against the four common mutants (exon 19 deletion (Del), L858R, and double mutants T790M/L858R and T790M/Del), selectivity over wild-type EGFR, and desirable ADME properties. The third-generation class of EGFR tyrosine kinase inhibitors PF-06747775 is a clinical candidate drug for treatment of non-small-cell lung cancer (NSCLC) driven by mutant EGFR.

Pfizer was developing PF-03814735, an orally administered, reversible inhibitor of the Aurora A and Aurora B kinases. In intact cells, the inhibitory activity of PF-03814735 on the Aurora1 and Aurora2 kinases reduces levels of phospho-Aurora1 (Thr 232, a sensitive marker of Aurora1 activity, with IC50 ~ 20 nM), phosphohistone H3 (with IC50 50 nM), and phospho-Aurora2 (with IC50 150 nM). PF-03814735 produces a block in cytokinesis, resulting in inhibition of cell proliferation and the formation of polyploid multinucleated cells. A recent research indicates small cell lung cancer (SCLC) and, to a lesser extent, colon cancer lines are very sensitive to PF-03814735. The status of the Myc gene family and retinoblastoma pathway members significantly correlates with the efficacy of PF-03814735. PF-03814735 was under Phase I trials for patients with advanced solid tumors, but later this research was discontinued.

PF-03654764 binds with high affinity to the human H3 receptor and with lower affinity to the rat H3 receptor, in addition to having >1000-fold selectivity versus other human histamine receptor subtypes (H1, H2, and H4). PF-03654764 displayed potent antagonist properties in functional assays measuring cAMP utilizing a reporter gene assay (β-lactamase) in HEK293 cells stably expressing full length human or rat H3 receptors. In human hepatic microsomes, PF-03654764 was metabolically stable and were predicted to have low clearance. It has low potential to inhibit activities of CYP 1A2, 2B6, 2C8, 2C9, 2C19, 2D6, and 3A4. PF-03654764 + fexofenadine failed to provide superior relief of allergic rhinitis-associated nasal symptoms upon exposure to ragweed pollen compared to fexofenadine + pseudoephedrine. Side effects in the PF-03654764-treated groups were clinically significant compared to the controls. PF-03654764 had been in phase II clinical trial for the treatment of allergic rhinitis and in phase I clinical trial for the treatment of Alzheimer's disease. However, these investigations were discontinued.

PF-232798 is a potent oral CCR5 antagonist with a primary and selectivity/safety pharmacology profile similar to maraviroc (MVC). PF-232798 shows increased binding affinity and improved oral absorption compared to maraviroc. In addition, it retains activity against a laboratory generated maraviroc-resistant HIV-1 strain, indicating an alternative drug resistance profile. PF-232798 binds to the same pocket as MVC within the transmembrane region of CCR5, but shows additional interactions at the ECL2 hinge region. PF-232798 is well tolerated in normal volunteers. PF-232798 had been in a phase-II clinical trial for the treatment of HIV infections. However, this development was discontinued.

PF-04418948 is an orally active, potent, and selective EP2 receptor antagonist. It is used as a tool compound to study involvement of EP2 receptor in various pathologies. In combination with EP4 antagonist, PF-04418948 attenuates PGE2-induced airway microvascular leak in model of asthma, and PGE2-induced gut dismotility.