Pfenex Moves Forward with Lucentis Biosimilar

The lead-up to OIS@ASRS had been eventful for biotech company PFEnex, as Hubert C. Chin, MD, chief medical officer, reported to the “Paying for Breakthrough Eye Therapies” session. Top-line results of the completed Phase I/II trial of the company’s lead candidate, PF582, a Lucentis biosimilar, showed similar safety and efficacy to the index agent, and PFEnex regained full rights to PF582 from former partner Pfizer.

“Combined with the approaching Phase I/II study results, along with what we believe to be a readiness for manufacturing tech transfer, we are very excited in terms of exploring all strategic options in terms of what to do with PF582 as it returns back to us,” Dr. Chin said. Those options include exploring new partnerships since Pfizer ended its development arrangement with PFEnex to develop PF582, which Dr. Chin announced at OIS@ASRS.

He also provided an overview of the biosimilars market, noting that in branded drugs generics now account for 80% of the market, whereas in biologics, such as Lucentis and Eylea and other high-profile agents like Humira, the FDA did not approve the first biosimilar, Sandoz’s Zarxio (filgrastim), until 2015. Zarxio is a biosimilar to Amgen’s Neupogen for leukemia and other blood disorders.

The challenge with developing biosimilars versus. generics is that the index biologicals are large-molecule agents, whereas branded drugs typically comprise small molecules. It’s akin to building a Ford Explorer out of Legos versus. a 25-piece Lego car, Dr. Chin said.
“Analytical chemistry is advancing to such an extent that we’re able to make sure that we’re actually recreating a faithful copy of the originator,” he explained. “So that’s probably what I want to impart to you – why biosimilars, we believe, are really taking off.”


Chen Hubert

Hubert Chen

Hubert C. Chen is the Chief Medical Officer of Pfenex Inc., a clinical-stage biotechnology company developing biosimilars, therapeutic equivalent peptides and novel vaccines. In his current role, Dr. Chen oversees clinical research, regulatory affairs, and product development.

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Hubert Chen: It’s a pleasure to be here to present to you Pfenex in our biosimilars efforts. I’m Hubert Chen. I’m the Chief Medical Officer, and here is the first slide, which is a corporate overview of Pfenex. We are a biotech company that’s based in San Diego, California. We were initially founded as a platform technology company with expertise in protein production and analysis. However, in about 2009 we decided to repurpose this platform to go into therapeutics production with a focus primarily on the development and commercialization of biosimilars. Now our lead candidate, lead product in the biosimilars portfolio is PF-582, which is a biosimilar candidate to Lucentis. And for this audience I obviously would not be going through the mechanism of action or the intended patient population for PF-582. What I’d like to do, though, is to highlight some of the news that we released earlier today as part of our earnings call, in which we disclosed the top line clinical results from our previously competed phase 1/2 study comparing Lucentis versus PF-582. And we are pleased that we were able to achieve the primary objective of the study, which was to show that the safety and tolerability profiles were comparable. We also looked at efficacy in terms of visual acuity and also some pharmacodynamic parameters. Again, we were very pleased to see that there was consistent pharmacology that was demonstrated between PF-582 and Lucentis. Now as part of the announcement earlier today, we also are in the process of regaining all the rights to PF-582 from our partner. So combined with the encouraging phase 1/2 study results, along with the what we believe to be readiness for manufacturing tech transfer, we are very excited in terms of exploring all strategic options, in terms of what to do with the PF-582 as it returns back to us, including exploring the potential for re-partnering. So really that’s – for the rest of the presentation, though, I want to perhaps share with you Pfenex’s perspectives in terms of why focus on biosimilars, and why we believe that this field really will be taking off in the imminent future. And I think a good way to think about this field is to compare and contrast this to the small molecule generics, in which you can see that the latest statistics show that 80% – and this is increasing – 80% of the prescriptions that are filled in the United States are the generics. In contrast, though, as most of you are aware, the first biosimilar really was not approved by the FDA until 2015, and despite the headlines that are being generated, is still lagging significantly behind. So really the question that we are posing is why is there such a large discrepancy. And of course I think most of us have seen this cartoon in terms of one of the key factors, of course, is the fact that small molecules are relatively easy to manufacture, and this is shown by the cartoon on the left hand side in terms of the atomic structure of aspirin. On the right hand side is your fairly typical biologic, which is a monoclonal antibody, and again, the figure really does impart to you that the complexity involved in terms of recreating a biologic really should be a lot more complicated. However, unless you have spent some time in a chemistry or a biology lab, I think we may understand this intellectually, but in terms of what does this mean, what are the practical implications, sometimes a little bit hard to grasp. So what if we swap in pictures of Lego cars? So here is a 25 piece Lego car. And if we just take a look at this picture, I think most of us feel confident that even without the assembly instructions, we can probably recreate this toy car. What if we now swap in this Ford Explorer that was taken in San Diego, my hometown. So now we probably start to get a little bit challenged in terms of can I really recreate this Lego car. Well, what if – and we’re all in the medical field, or exposed to it – so what if we start to provide some tools so that we can use n X-ray machine from the dentist’s office, we can use a Doppler ultrasound to look at a 3D structure, and we can perhaps even do a laser measuring device so we can actually figure out where to place that Ford decal to the exact millimeter. So really now if we kind of take this analogy back to the biosimilars field, this is exactly what’s happening. The chemistry, the advancements, the technology of analytical chemistry is advancing to such an extent that we’re able to use mass spec, CD and SDS page again to really refine and to make sure that actually are recreating a faithful copy of the originator. So I think that’s probably what I want to impart to you in terms of why the biosimilars we believe is really taking off, and Pfenex is really delighted to be part of this effort. And we look forward to updating you on PF-582 at upcoming events. Thank you very much.