Studies on the Biological Ac2vity of HNO

Transcription

1 Studies on the Biological Ac2vity of HNO The Development of an Interac2on between Academia and Industry Partially supported by the CSUPERB ENTREPRENEURIAL JOINT VENTURE MATCHING GRANT PROGRAM with Cardioxyl Pharmaceuticals

2 The Fukuto lab and Cardioxyl Fukuto lab (1989 present): Interested in the chemical biology of small- molecule signaling agents (NO, CO, H 2 S and related/ derived species) in the Department of Pharmacology at UCLA, present in the Chemistry Department at SSU. Cardioxyl (2005 present): Small biopharma startup company (funded by venture capital) developing therapeu2c agents to treat heart failure (more described later).

3 Started with a new, "hot" field of research : Interest in the biology/physiology of nitric oxide (NO) was at its peak. NO was discovered to be involved in numerous physiological func2ons: a. Controls vascular tone. b. Involved in the immune system. c. Present in the CNS. d. Other func2ons. Science, vol 258, 1992 NO biosynthesis discovered to be a result of enzyma2c oxida2on of L- arginine. Three dis2nct enzymes reported and characterized. H 2 N N + H 2 H 2 N NOH H 2 N O NH? NH? NH + NO H 3 N + COO - Arginine H 3 N + COO - N-Hydroxyarginine (NOHA) H 3 N + COO - Citrulline

4 Further work 1990: Began to study the chemistry of NO biosynthesis. Chemical studies indicated that monooxygena2on of arginine led primarily to HNO (not NO) genera2on. Could HNO be the product of the enzyme? V IV III II I -I -III +2e - -2e - +e- -e - +e- -e - +e- -e - +2e- -2e - +2e- -2e - NO 3 - NO 2 NO 2 - NO HNO NH 2 OH NH 3 ONOO - O : Proposed that HNO could be biosynthesized by the enzyme that presumably made NO. Examined the biological ac2vity of HNO and compared it to NO : Studied the chemistry and biological ac2vity of HNO. Established/defined many of the chemical proper2es of HNO (pk a, reduc2on poten2al, thiol reac2vity, etc.) as well as cardiovascular effects. Began collabora2ng extensively with other labs interested in the biological ac2vity of NO/HNO - Dave Wink( NCI), Naz Paolocci/David Kass (JHU) : Paolocci, Kass and Wink find that HNO is a potent inotropic and lusitropic species with ac2vity that is unrelated to NO. Other labs (Toscano, JHU) made HNO donors for possible use as inotropic or lusitropic agents. It is reported that the mechanism of ac2on of HNO is novel, dis2nct from other cardiovascular agents and potent in vivo.

5 Effect of HNO on the Failing Heart HNO Dobutamine (β- agonist) Milrinone (PDE inhibitor) Levosimendan (Ca 2+ sensi2zer) Inotropy In CHF ` Load reduc2on Improved relaxa2on Increase In HR Proarrhythmic effects

6 Reac2ons of HNO with Thiols HNO is electrophilic as evidenced by its reaction with thiols. HNO + RSH RSNHOH etc. HNO + RSH RSH OH.. RS N H H + RS + NH + H 2 O RSSR + NH 2 OH O -H + OH R S NH 2 R S+ NH 2 4-electron oxidation in one step! Doyle et al., JACS, 110, , Wong et al., Biochemistry, 37, , 1998 Bartberger et al., PNAS, 98, , 2001

7 Presumed Mechanism of Ac2on HNO acts as a Ca 2+ cycling enhancer all targets are thiol proteins!

8 HNO and Heart Failure The data indicate: 1. HNO is a potent inotropic agent (increased contrac2ility) 2. HNO is also a lusitropic agent (increased relaxa2on) 3. Sensi2zes cardiac 2ssue to Ca 2+ (muscle contracts at lower Ca 2 + levels) 4. Only moderate arterial dilator with significant venous dila2on. 5. Does not increase metabolic demand. 6. Does not elicit tachycardia (heart rate). This appears to be the perfect drug for heart failure! Academic environment not ideal for drug development

9 HNO and Cardioxyl 1. Cardioxyl founded by Paolocci, Kass and Toscano in Funded by venture capital (14.5 million). 2. Ini2ates Phase I/IIa clinical trials in 2009 with a proprietary HNO- donor. 3. Announces posi2ve results in 2010 at Na2onal mee2ng. 4. Dose ranging studies started in In 2012 Cardioxyl gets second round of funding (28 million) 6. Cardioxyl publishes clinical findings (Circ Heart Fail. 2013;6: ). 7. Clinical trials for second genera2on HNO- donor started in 2014.

10 Results of study Greater SVI (stroke volume index) and CI (cardiac index) The combina2on of effects differen2ates HNO donors from other classes of inotropes or inodilators and provides a strong ra2onale for con2nuing studies to develop donors with op2mized pharmacological and clinical efficacy for the treatment of conges2ve HF.

11 Con2nuing work with Fukuto lab on possible endogenous HNO biosynthesis 1. All pharmacological data point to possible endogenous genera2on of HNO (potency, specific targets, no toxicity, no apparent side- effects, etc.). 2. Previous studies in lab indicate possible amino acid (not arginine) precursor for possible HNO biosynthesis. 3. Chemistry/biochemistry make sense. If HNO is an endogenously generated signaling agent made to help regulate/protect the cardiovascular system, then developing HNO donors as treatments for heart failure becomes significantly easier.

12 What were the key factors in the forma2on of this academic- industry rela2onship? (my perspec2ve) 1. Pharmacology: A great field of study for those wan2ng to develop therapeu2c agents, therapeu2c strategies, do work with clinical relevance, etc. Will learn aspects of drug ac2on, drug metabolism, pharmacokine2cs, integrated physiology, etc. 2. Field of Study: This was a new (hot) field, albeit risky. Linle was known and all mechanism of biological ac2on were new. Allows for the genera2on of intellectual property a key to securing funding, support and successful commercializa2on (CSU system needs to be aware of this and have mechanisms in place to facilitate intellectual property rights). 3. Dissemina2on of the science: Industry will find the science if it's out there to find. 4. Novelty: In this case, biological ac2vity was important but the novel mechanism(s) of ac2on and new small molecule compounds gave this important "patentability". 5. The science: This is always paramount. The science must be strong, credible, reproducible, defendable, etc. This is especially true in the area of drug development.

13 Importance of preclinical data Open 2mes, drug development programs come out of the scien2fic literature. Academic researchers examining therapeu2cally useful pathways, compounds or strategies need to be aware of this and publish with this in mind.

14 Recent study on scien2fic reproducibility Begley and Ellis, Nature, 483, (29 March 2012) "Unques2onably, a significant contributor to failure in oncology trials is the quality of published preclinical data." Knowing that the development of cancer drugs relies heavily on the literature, especially with regards to new targets and biology, they tested the reproducibility of 53 "landmark" studies. Only 6/53 (11%) studies were deemed reproducible enough to drive a drug development program.

15 Perpetua2on of ques2onable science "Some non- reproducible preclinical papers had spawned an en2re field, with hundreds of secondary publica2ons that expanded on elements of the original observa2on, but did not actually seek to confirm or falsify its fundamental basis."

16 Journal rank and credibility?

17 Important points for the CSU 1. Basic research of this type is amenable to a primarily undergraduate ins2tu2on with talented undergraduate students. 2. CSU needs to be aware of the importance of the intellectual property that comes out of research. 3. Dissemina2on of the work is essen2al (publica2on, mee2ng presenta2ons, etc.). If important, it can be found. 4. The quality/reproducibility of the work is paramount. Valuable lesson for young students.