Liveblogging First-Time Disclosures of Drug Structures from #ACSNOLA
Apr04

Liveblogging First-Time Disclosures of Drug Structures from #ACSNOLA

Bookmark this page now, folks. On Wednesday, April 10, I will be here, liveblogging the public debut of five drug candidates' structures. The "First Time Disclosures" Session at the ACS National Meeting in New Orleans runs from 2PM-4:55PM Central time. I am not able to conjure up a permalink to the session program, so here's a screengrab instead. 1:20PM I'm in hall R02, where the session's set to begin in about 40 minutes. Found a seat with a power outlet nearby, so I'm good to go! 2:29PM BMS-906024 Company: Bristol-Myers Squibb Meant to treat: cancers including breast, lung, colon, and leukemia Mode of action: pan-Notch inhibitor Medicinal chemistry tidbit: The BMS team used an oxidative enolate heterocoupling en route to the candidate-- a procedure from Phil Baran's lab at Scripps Research Institute. JACS 130, 11546 Status in the pipeline: Phase I Relevant documents: WO 2012/129353 3:02PM LGX818 Company: Novartis Institutes for Biomedical Research and Genomics Institute of the Novartis Research Foundation Meant to treat: melanoma with a specific mutation in B-RAF kinase: V600E Mode of action: selective mutant B-RAF kinase inhibitor Status in the pipeline: Phase Ib/II Relevant documents: WO 2011/023773 ; WO 2011/025927 3:47PM AZD5423 Company: AstraZeneca Meant to treat: respiratory diseases, in particular chronic obstructive pulmonary disease Mode of action: non-steroidal glucocorticoid receptor modulators Medicinal chemistry tidbit: This compound originated in part from a collaboration with Bayer Pharma. Status in the pipeline: Phase II Relevant documents: WO 2011/061527 ; WO 2010/008341 ; WO 2009/142568 4:17PM Birinapant (formerly known as TL32711) Company: TetraLogic Pharmaceuticals Meant to treat: cancer Mode of action: blocks the inhibitor of apoptosis proteins to reinstate cancer cell death Status in the pipeline: Phase II Relevant documents: US 8,283,372 5:00PM MGL-3196 (previously VIA-3196) Company: Madrigal Pharmaceuticals, acquired from VIA Pharmaceuticals, licensed from Roche Meant to treat: high cholesterol/high triglycerides Mode of action: mimics thyroid hormone, targeted to thyroid hormone receptor beta in the liver Medicinal chemistry tidbit: this molecule was discovered at Roche's now-shuttered Nutley site. Status in the pipeline: completed Phase I trials Relevant documents: WO 2007/009913 ; WO 2009/037172 And that's it, folks! Watch the April 22nd issue of C&EN for more on this...

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BMS-AstraZeneca Dapagliflozin Diabetes Drug Falls Short; Pfizer’s Answer on the Horizon?
Jul29

BMS-AstraZeneca Dapagliflozin Diabetes Drug Falls Short; Pfizer’s Answer on the Horizon?

As reported by Nature News and Forbes’ The Medicine Show  on July 20, dapagliflozin, a BMS-developed diabetes drug marketed with partner AstraZeneca, was given a “thumbs-down” by an FDA review panel on July 19. After the 9-6 final vote, panel members commented favorably on the drug’s new mechanism, but evidently felt that the safety profile could not be overlooked: the FDA committee meeting statement mentions increased risk of breast and bladder cancer, increased genital infections, and perhaps most seriously, potential for drug-induced liver injury (DILI). Dapagliflozin has been one of the rising stars of the new class of Sodium-Glucose cotransporter 2 (SGLT2) inhibitors for diabetes treatment, whose development roster includes Johnson & Johnson, Astellas, Boehringer Ingelheim, Roche, GSK, and Lexicon (Note: see Nat. Rev. Drug Disc. 2010, 551 for a full recap).  The excitement behind these drugs comes from a relatively new idea for diabetes treatment: inhibition of the SGLT2 enzyme stops the kidney from reabsorbing sugar, leading to excretion of the excess glucose in the urine, which in turn lowers blood sugar. Dapagliflozin, like most SGLT2 inhibitors, is a glucose molecule with a large aromatic group attached to the carbon atom in the spot chemists call the anomeric position. Such so-called C-glycosides are thought to have improved staying power in the bloodstream relative to O-glycosides (where the linkage point is at an oxygen atom, a more common scenario in sugars), since they are less susceptible to enzymatic breakdown. So, how do you improve these compounds? A paper Pfizer published last March (J. Med. Chem. 2011, 2952) may offer some hope.  Pfizer noted that some of the C-glycoside SGLT2 inhibitors gave a positive micronucleus test, indicating their potential to damage chromosomes. To work around this liability, their chemists  designed an analog of dapagliflozin where a second hydroxymethyl (CH2-OH) group is “tied” underneath the ring, forming a bicyclic compound that advantageously rigidifies the compound, increasing potency, while at the same time blocking a potential site of reactive metabolite formation (which might contribute to further DILI). The improved compound shows high potency for SGLT2 (~920 pm), a negative micronucleus test, and is now in Phase II  trials. Want to hear more? The lead author of Pfizer's paper, Dr. Vincent Mascitti, will speak about the study as part of the Organic Division program at the ACS National Meeting in Denver - Sunday, August 28, 8:00 AM-8:30AM, Four Seasons...

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Strong Panel Backing For AstraZeneca Blood Thinner Brilinta
Jul28

Strong Panel Backing For AstraZeneca Blood Thinner Brilinta

The blood-thinning drug club is one step closer to getting a new member. Today, an FDA advisory panel gave a thumbs-up recommendation to Brilinta (ticagrelor), an experimental blood thinner from AstraZeneca. The vote was 7-1 in favor of approval, an enthusiastic endorsement that increases the chances that FDA will decide to approve the drug. The FDA is supposed to make its call on Brilinta by Sept. 16. Brilinta is in the same drug class as Plavix (clopidogrel), a blood thinner that's the second best-selling drug in the world, and a drug that is going off-patent next year. Also in this class of drugs: Effient (prasugrel). Brilinta's got the same molecular target as Plavix and Effient- P2Y12, a G-protein-coupled receptor on platelets that responds to the nucleotide adenosine diphosphate. But unlike the other two drugs, Brilinta targets P2Y12 reversibly. That reversibility could come in very handy in the clinic, as is implied in the opening sentences of this paper describing the clinical trial PLATO, which compared Plavix and Brilinta. Variation in and irreversibility of platelet inhibition with clopidogrel has led to controversy about its optimum dose and timing of administration in patients with acute coronary syndromes. We compared ticagrelor, a more potent reversible P2Y12 inhibitor with clopidogrel in such patients. And it seems that the vote at the FDA panel is a vote of confidence for that mechanism. The most uncertain moments in the meeting had to do with unexpected clinical trial results in U.S. patients. Here's how Ed Silverman at Pharmalot described it. The key clinical trial compared Brilinta to Plavix in 18,624 patients in 43 countries who were being treated for a blocked artery or heart attack. The results showed the med reduced heart attacks, strokes and cardiovascular death 16 percent compared with Plavix after a year’s treatment. And all of the patients were given aspirin. But about 9 percent - who were from the US - saw no benefit. The FDA explained the difference by suggesting the dosage of aspirin given US patients was higher, but there was no clear understanding, as the panel grappled with differing patient treatment methods beyond aspirin dosing. It's still not clear what happened in that subset of patients. I'll be watching this space to see whether more clinical trials pop up. And a blast-from-the-past bonus: check out C&EN's own coverage of the medicinal chemistry story behind Brilinta, from back in 2003. (It was called AZD6140 back...

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