Randi Hernandez was science editor at Pharmaceutical Technology from September 2014 to May 2017.

Randi Hernandez

	Celgene is ramping up its cancer drug development pipeline and has chosen another partner in the immune-oncology space. Jounce Therapeutics 

 on July 19, 2016 that it will be Celgene’s newest collaborator to develop and commercialize various immunotherapies targeting “hot” or inflamed tumors affecting B cells, T cells, and macrophages. Celgene already has existing partnerships for the development of CAR-T therapies with bluebirdbio and Juno Therapeutics.

	Through the agreement with Celgene, Jounce will get an upfront payment of $225 million and a $36-million equity investment. It will also would be eligible for milestone payments and royalties on the drugs it develops with Celgene of up to $2.3 billion. Specifically, it would get 60% of the profits from its lead candidate, JTX-2011, and 25% profit from the first additional program. For the subsequent programs (of up to three), Jounce and Celgene would share profits equally. Celgene would retain rights to market the drugs overseas, although Jounce would get royalty payments.

	The first target of interest, JTX-2011, is a monoclonal antibody (mAb) that binds to a protein on the surface of T cells called the inducible T-cell costimulatory (ICOS, or CD278). It is believed that ICOS plays an important role in immune response and cell signaling of helper T cells. The companies plan to test the investigational agent as a standalone therapy and in combination with other therapies, most likely with immune checkpoint inhibitors. The investigational molecule will likely enter Phase I clinical trials by the close of 2016.

	Notably, Celgene is also in a partnership to develop AstraZeneca’s durvalumab (MEDI4736), a mAb directed against programmed cell death ligand 1 (PD-L1) in blood disorders. Durvalumab is currently in clinical trials for the treatment of myelodysplastic syndromes, acute myeloid leukemia, lymphoma, and chronic lymphocytic leukemia. The second 

 that Jounce and Celgene plan to develop is a PD-1 inhibitor (called JTX-4014), which seeks to block PD-1 on the surface of T effector cells.

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The collaboration will focus on the investigational candidate JTX-2011 and up to four other early-stage programs in immune-oncology.

Celgene Partners with Jounce Therapeutics for Immunotherapy Development

	Peptides and proteins generally have low bioavailability when taken by mouth, and this hurdle has generally prevented the oral delivery of many biologic drugs in the past. However, plant cell walls may be ideal transporters to move protein-based drugs through the digestive system without the drugs being exposed to degradation by stomach acids and enzymes, say a group of researchers from the University of Pennsylvania. In a new study, the researchers, led by 

, PhD, professor and interim chair, Department of Biochemistry, say that drugs manufactured in plant cells are not only delivered orally more efficiently, they also allow for the elimination of various purification and cold chain steps that are typically required with proteins manufactured in mammalian, yeast, and bacterial cells.

	Using plant systems as bioreactors has many benefits, the researchers write. “Protein drugs [PDs] made in chloroplasts are stable in lyophilized plant cells when stored at ambient temperatures, maintaining their folding and functional efficacy for several years, thereby eliminating expensive cold chain. In addition, the freeze-drying process increases the concentration of PDs and eliminates bacterial contamination.” Importantly, they write, because plants are not hosts for human pathogens, there is low risk for the transmission of immunogenic components.

	In mouse models, the researchers found that when tags were fused to the protein drugs and fed to the animals orally, the plant cell walls stayed intact, or bioencapsulated, until gut microbes degraded them, releasing the drugs into the gut lumen. After passing through the intestinal epithelium, the drugs were successfully released into the circulatory or immune systems. The authors also noted that plant cells expressing cholera toxin B subunit (CTB) fusion proteins could cross the blood-brain barrier and blood-retinal barrier, and the use of plant cells would perhaps be better than some of the existing methods of drug delivery to the brain (such as direct injection, osmotic shock or ultrasound, or by passive diffusion with lipophilic molecules).

	One of the challenges that has plagued oral delivery of peptide-based biopharmaceuticals is related to dosage-it is difficult to express high enough levels of product that would fit into a capsule, the authors state. They acknowledge that although chloroplasts can exhibit a high level of protein expression for transgenes, it is much for difficult to express eukaryotic human genes within prokaryotic chloroplasts. The authors are working on codon optimization programs to resolve this problem. Nonetheless, the authors believe the oral delivery of biologics could be useful to treat diseases such as diabetes, hemophilia, pulmonary arterial hypertension, ocular disease, Alzheimer’s disease, and Gaucher’s disease.

A new study examines the oral delivery of protein drugs in plant cells and hypothesizes that the cold storage and transportation of biologics could someday be eliminated.

Are Oral Peptide Drugs on the Horizon?

 ahead of a July 13, 2016 meeting that Sandoz’s biosimilar GP2015 has “no clinically meaningful differences” with the US-licensed and EU-licensed versions of Enbrel (etanercept) in terms of safety, purity, and potency. It also stated that a transition from Enbrel to GP2015 during the study “would support the safety of the clinical scenario where non-treatment naïve patients undergo a single transition to GP2015.”

 to FDA an “innovative study design,” one that implies the company may be filing for an interchangeability status for its biosimilar in the future. The design featured multiple switches within the 52-week trial to evaluate the effect of switching between the innovator and biosimilar molecules. In two separate treatment arms, patients switched therapies after week 12, switched back to the original treatment after week 18, and switched a third time back to the alternate treatment regimen after week 24. One arm had patients switching back and forth from Enbrel (with GP2015 in between), and the other had patients switching back and forth from GP2015 with Enbrel in between. The company’s findings were that “switching does not have negative implications for safety, considering also incidences and severity of TEAEs [treatment-emergent adverse events], laboratory values, vital signs, and physical examination findings."

	Sandoz’s biosimilar will go before an FDA advisory committee on July 13, and if it is eventually approved (FDA has a deadline of August 2 to decide, according to Evercore ISI analyst Mark Shoenebaum), it could launch as early as February 2017. The launch would be what is known as an "at risk" launch, however, as it falls before the patent period for Enbrel expires. Although many of the molecule patents have already expired for Enbrel, there are two patents that may constrain biosimilar entry in the United States until at least 2029, according to 

. Patent protection for Enbrel has expired in the European, Canadian, and Australian markets, however.

	The two patents in question (US8,063,182 [‘182] and US8,163,522 [‘522]) were not issued until 2011 and 2012, respectively, and Sandoz tried and failed to challenge the validity of these patents in June 2013. Sandoz claimed that its version of Enbrel did not infringe on the patents in question and they also claimed that these two patents were unenforceable.

	Wednesday's committee of outside experts will discuss whether Sandoz has presented enough evidence to ensure that there are no clinically meaningful differences between Enbrel and GP2015 in Enbrel's five indications. It is likely that the committee will also address the switching component of the findings and assess the potential impact of alternating treatment with GP2015 and Enbrel.

	Amgen reported global sales for Enbrel as US $5.4 billion for 2015, up 14% from 2014. Sales of Enbrel represent a quarter of the company's total sales. Not counting potential biosimilars, competitors for market share currently include Remicade, Humira, and Stelara.

FDA reviewers have found that Sandoz's GP2015, a biosimilar version of Amgen's Enbrel, is highly similar to the original product in terms of purity, safety, and potency.

Sandoz's Biosimilar to Enbrel Gets FDA Support Ahead of Panel

	Drugs that are manufactured at large scale are typically limited to a particular dosage or formulation, and sometimes these parameters do not suit all the needs of the patients who are candidates for treatment with that drug. For patients who are allergic to a component in an FDA-approved medication, for those with swallowing issues, or for those who need a higher or lower dose than what is currently available, compounded forms of an FDA-approved medication are often necessary. FDA 

 new recommendations for the preparation of specialized medications in a set of new guidance documents in July 2016.

	Although compounding has been tapped by large insurers and pharmacy benefit managers as a method to stem drug costs-these stakeholders say compounding could offer an alternative to source drugs that hold a monopoly price in the market-FDA says simply copying the formulation of branded drugs that are already on the market and approved by the agency undermines the drug-approval process. The agency says that exact copies are risky because they have not been evaluated under FDA’s standards for safety, efficacy, and quality. FDA points out that compounders are not required to comply with current good manufacturing practice requirements, and the use of compounding services for “inordinate amounts” of commercially available drugs is inappropriate.

	FDA attests that generic-drug sponsors may be less motivated to manufacture generic versions of drugs if they can be readily copied in bulk without having to submit an abbreviated new drug approval (ANDA) application to FDA. Drugs that are produced in substandard manufacturing conditions, are not adequately labeled, or are produced outside of monograph standards are not as safe as commercially available forms, says the agency. However, drugs that are in short supply or have been discontinued may still be produced by compounding facilities when necessary.

	A drug copy is defined as one that has the same API, excipients, dosage form and strength, and route of administration as a drug that is already on the market. A small change in dosage may sometimes still be considered a copy of an existing drug, as the change may not have a significant clinical impact on the patient. FDA considers oral medications that are within 10% of the strength of the originator as essentially a copy, unless the change has a significant clinical impact. All changes to a drug’s formulation have to be clearly documented and labeled, says FDA. For purposes of having office stock of a compounded drug, physicians must write a statement explaining the formulation change and why stock of a product in that form is necessary.

	The goal of the guidance documents is to dissuade the large-scale manufacturing in compounding labs of versions of FDA-approved drugs and prevent health disasters, such as what occurred in 2012 when the bulk production of a preservative-free methylprednisone acetate at the New England Compounding Center (NECC) spurred a fungal meningitis outbreak. Although compounding represents a small portion of the prescription market (1–3% in the United States), according to the International Academy of Compounding Pharmacists (IACP), it still accounts for $300 billion overall. IACP says that 100% of hospitals have compounding pharmacies.

Considering market competition and “commercial availability” for a drug


	When does reduced access mimic an actual drug shortage? Artificial shortages can occur when sole-source generic companies raise drug prices too high. Turing Pharmaceutical recently raised the cost of pyrimethamine (Daraprim), a 62-year old treatment for toxoplasmosis, by more than 5000%, from $13 to $750 per tablet. Although the drug was technically not considered a drug in shortage, the price of the medication and its narrow distribution channels made it difficult for hospitals to acquire. In response, Imprimis Pharmaceuticals, a compounding pharmacy, said it could make a copy of the drug for approximately $1 a tablet-a strategy that was embraced by a prominent pharmacy benefit manager. Although drug shortages are fair game for the manufacture of replicas, Daraprim was not technically on FDA’s drug shortage list. FDA wrote in the newest guidance that factors such as lower price “are not sufficient to establish that the compounded drug product is not essentially a copy of the commercially available drug product.” Thus, it does not appear that FDA would account for monopolistic conditions and consider permitting the compounding of a drug if the commercially available version were cost prohibitive.

	FDA did make an exception to this rule in 2012 when it allowed compounded versions of Makena (hydroxyprogesterone caproate) to continue to be sold after K-V Pharmaceutical’s version of the drug was deemed too expensive and was made available only through CuraScript (now known as Accredo, which is a CVS company). The agency waived enforcement against compounding pharmacies to support access to the drug in what 

 “a unique situation.” It argued that prior to the approval of Makena, a version of the active ingredient in the drug (a synthetic progestin) had already been available at compounding pharmacies to patients whose physicians requested it.
	
	Sources:
	

The agency says that the routine large-scale compounding of drugs that are exact copies of existing medications undermines the the drug approval process.

New FDA Guidance Documents Seek to Limit Scope of Compounding

	Two recently published studies suggest that pre-exposure to the dengue virus (DENV) could predict a person’s reaction to the Zika virus (ZIKV) because of of the antigenic similarity between the viruses. One study was published on June 23, 2016 in 

Proceedings of the National Academy of Sciences of the United States of America (PNAS)

. Dengue and Zika are both mosquito-borne flaviviruses that are cross-reactive.

, researchers tested the sera and monoclonal antibodies (mAbs) of nine subjects that had previously been exposed to dengue. They showed the dengue sera binds or neutralizes Zika, demonstrating cross-reactivity. For some of the subjects who were immune to the dengue virus, this may mean they had protective immunity from the Zika virus and would not likely experience a negative reaction. However, for some, the prior exposure to dengue may enhance infection with Zika as a result of antibody-dependent enhancement (ADE), as the dengue viral envelope is more than 50% homologous to the Zika envelope protein. The researchers found that although a large number of dengue patient mAbs were able to bind viral epitopes to Zika, only a few were able to cross-neutralize the virus. As a result, they wrote, “Identifying potential targets for broadly cross-neutralizing antibody responses could inform the design of vaccines or antibody-based therapies in the future.”

	Although the findings could have important implications in the future design of a Zika vaccine, the researchers also discovered that pre-existing dengue-induced antibodies could make Zika infection worse. The researchers hypothesized that ADE could occur, and cross-reactive antibodies could join up to form virus-antibody complexes to actually facilitate the infection of cells, causing higher disease loads and higher disease severity. After further investigation, the researchers concluded, “The data presented suggest that ZIKV infection may have the potential to reactivate cross-reactive dengue-induced memory responses in patients with prior DENV exposures.” However, Jens Wrammert, PhD, assistant professor of pediatrics (infectious diseases) at Emory University School of Medicine and Emory Vaccine Center, also warned in an 

, “We find antibody-mediated enhancement of infection with cells in the laboratory, but we have yet to clarify what effects these antibodies have on the outcome of infection in humans.” The researchers also suggested that the appearance of microcephaly or Guillain BarrÃ© syndrome might be related to the the reactivation of pre-existing cross-reactive antibodies acquired through previous infection from dengue.

 also found that antibodies to certain epitopes from dengue that were unable to neutralize Zika instead promoted ADE. They explained that there are four prominent serotypes of dengue, and infection with one of the serotypes increases the severity of disease if another serotype is encountered, largely due to ADE. In other words, infection with one strain does not protect against infection against the other three strains, and antibodies that are present to the first strain may actually make secondary infection more severe. Thus, the 

 authors wrote of the possibility that "pre-existing immunity to DENV might increase ZIKV replication.”

	In vaccine trials for Dengvaxia by Sanofi Pasteur, hospitalization from DENV infection for patients under 9 years of age was more common for vaccinated children than non-vaccinated children, which the authors hypothesized was because the vaccine “primed” the children for secondary infection instead of providing protective immunity. In this context, the authors wrote, a vaccine against ZIKV must account for the potential cross-reactivity between DENV and ZIKV. They also noted that pre-existing immunity might drive greater ZIKV replication and it is possible that “vaccination of DENV-naÃ¯ve subjects against ZIKV might promote ADE of DENV infection and, conversely, that vaccination against DENV might promote ADE of ZIKV.” Lastly, they suggested ADE from prior infection of DENV might aid in the transplacental transfer of ZIKV.

	On June 27, 2016, Emergent BioSolutions 

 it received a task order from the Biomedical Advanced Research and Development Authority (BARDA) valued at nearly $22 million to develop and manufacture three cGMP lots of a Zika vaccine for use in a Phase I clinical trial. An Emergent spokesperson told this publication that the vaccine is not based on yellow fever, and that "Emergent is only working on developing a manufacturing process-BARDA will be handling any animal or clinical studies."

, Emory University, Emergent BioSolutions

Antibodies to dengue may either confer protective immunity to the Zika virus or enhance disease severity in secondary, related infections such as Zika.

Pre-exposure to Dengue Virus May Predict Reaction to Zika Virus

	Although chimeric antigen receptor T-cell therapy (CAR-T) has been nothing short of a medical miracle for the treatment of blood cancers, the applications for use of CAR-T for solid tumors had not been as promising. This is because tumors do not share abnormal cell-surface proteins that appear just on the tumors and not on other, normal cells. Now, researchers from the Perelman School of Medicine at the University of Pennsylvania say they may have found a solution via the engineering of a T cell to produce a novel CAR that recognizes a carbohydrate (specifically, a glycosylation pattern) on the surface of many solid tumors. Making T cells more specific to tumor cells instead of to normal cells will allow treatment without the risks of side effects that are as severe, the researchers hypothesized, and could bring research closer to the identification of a universal CAR to treat all types of cancers.

	Working with researchers from the University of Copenhagen and the University of Chicago, the Penn Researchers developed novel CAR-T cells that express a monoclonal antibody (5E5) that recognizes a common glycosylation pattern on many tumor cells (the Tn glycan on the mucin 1 protein [Tn-MUC1]). This glycosylation pattern is primarily absent on normal cells but present on a variety of cancer cells, including leukemia, ovarian, breast, and pancreatic cancer cells. These “aberrant glycoform epitopes” are valid clinical targets for T cells, the researchers wrote in an article 

, and fairly safe, as the epitopes are minimally expressed on normal tissues. 

	First co-author Avery Posey, an instructor at the Perelman School of Medicine, tells this publication that even though a small portion of normal tissues express the epitope of interest, “confocal immunofluorescence microscopy revealed the antigen only occurred intracellularly in these normal tissues.” Posey states, “This is important because CAR-T cells can only target extracellular epitopes and would not target these normal tissues. We also evaluated whether our 5E5 CAR-T cells could kill normal human primary cells and saw no cytotoxicity, suggesting that this is a very safe cancer target.” Posey adds that there are also other potential epitopes that could serve as valid tumor targets besides the 5E5 epitope, and that the Penn team and one of the co-authors from the University of Copenhagen, Catharina Steentoft, are currently evaluating new CAR-T cells for those targets.

	In the study, there were 40 mice in the leukemia group, and 16 of these animals were treated with the 5E5 CAR (8 animals with a small dose and 8 with a larger dose). There were 22 mice in the pancreatic cancer group, and 6 of these animals were treated with a CAR. All 6 mice (100%) in the pancreatic group survived 113 days after treatment with the 5E5 CAR-T cells compared with 40% and 33% survival of mice treated with non-transduced and CD19 CAR-T cells, respectively. “We did observe better survival and effect in the pancreatic cancer treatment group,” admits Posey, “although the effect we observed in the leukemia group is consistent with results observed by the few other groups that have used this cell line model-and I believe it is a limitation of the animal model.”

	Although the team has not yet evaluated the antitumor effects of 5E5 in an animal model with human ovarian cancer (only 

) and has not published its animal models of breast cancer yet, the researchers say they saw significant antitumor effects against human leukemia, breast, and pancreatic cancer in mice. When asked what disease would likely be the first focus of a clinical trial in human models, Posey responded, "My hope is that we can use this advancement to add treatment options for triple-negative breast cancer and then expand to other cancers."

	Co-senior author Laura Johnson, director, solid tumor immunotherapy laboratory at the Center for Cellular Immunotherapies at the Perelman School of Medicine, commented in a 

, "This is really the first description of a CAR that can target multiple different solid or liquid tumors, without apparent toxicity to normal cells. While it may not be a universal CAR, it is currently the closest thing we have."

 is supported by Novartis, the National Institutes of Health, and the Danish Research Councils, the University of Chicago has already filed a patent on the 5E5 CAR in development. Novartis and Penn are in a strategic alliance to develop CARs.

	Third co-author of the study, Carl June, the Richard W. Vague Professor in Immunotherapy at the Perelman School of Medicine at Penn, is well-known in the immunotherapy world. His work on CARs designed to bind to a protein called CD19 found on the surface of cancerous B cell for the treatment of leukemia was highly lauded in 2013 when it was published. June and Penn 

 that some of the work done to develop the CAR for the groundbreaking research was done by Dario Campana and Chihaya Imai, who worked at St. Jude Children’s Research Hospital. According to a correction 

, the physicians from St. Jude and the facility “provided under material transfer agreements the chimeric antigen receptor (CAR) that was used in this study.”

	June will propose the use of CRISPR for editing CAR-T cells in a meeting with NIH occurring from June 21–22, 2016, marking the first time the use of CRISPR in humans will be appraised. Posey says, “Combining [the 5E5] CAR with the work recently described [to NIH] using CRISPR/Cas9, disruption of PD-1, and the T-cell receptor could augment this therapy to generate a potent, allogeneic ‘off-the-shelf’ product for cancer with the potential to generate antitumor effects in virtually every cancer patient with the most lethal cancers.” Posey cautioned, however, that “safety and efficacy of the first CRISPR clinical trial must be completed and interrogated before we can discuss new approaches with these remarkable gene-editing techniques.”

A research team associated with Dr. Carl June announces it has discovered a way to engineer a patient’s own immune cells to recognize cancer-specific glycoantigens on tumor cells.