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Real Time Coverage Morning Session on Precision Oncology: Advancing Precision Medicine Annual Conference, Philadelphia PA November 1 2024

Reporter: Stephen J. Williams, Ph.D.

Notes from Precision Medicine for Rare Diseases 9:00AM – 10:50

Precision Medicine and markers Cure models vs disease models  Dr Ekker from UT MD Anderson

 

  • UT MD Anderson zebrafish disease model program now focusing more on figuring the mechanisms by which a disease model is reverted to normal upon CRISPR screens
  • Traditional drug development process long and expensive
  • 2nd in class only takes 4 years while 3rd in class drugs take only 1.5 years
  • Health-in-a-fish: using a CRE system to go from disease to normal
  • The theory is making a CRE or CURE avatar; taking a diseased zebrafish and reverse engineering the disease genome
  • He used transposon based CRE mutational mutants with protein trap and 3’ exon trap (transposon based mutagenesis)
  • He reverted the diseased gene by CRE
  • He feels that can scale up to using organoids to develop more cure based models

 

FDA Christine Nguyen MD regulatory perspective of framework of drug approval for rare diseases

  • 1 in 10 Amercians have rare diseases; 70% genetic and half are children
  • Due to Orphan Drug Act in 2023 half of novel drugs approved for rare diseases
  • CDER and FDA 550 unique drugs for over 1000 rare diseases
  • Clinical and surrogate validated endpoints are important for traditional approvals
  • For accelerated approval need predictive surrogate endpoint of clinical benefit
  • For accelerated approval needs completion of a confirmatory trials so FDA has new authority under FDORA; FDA can dictate trial milestones
  • Candidate surrogate endpoints: known to predict (validated) for traditional approval but reasonably likely to predict for accelerated approval
  • Does surrogate endpoint associated with a causal pathway?  Also important to understand the magnitude of benefit so surrogate should be quantitative not just qualitative
  • RDEA is a series of 3 public workshops at FY2027 to promote innovation and novel endpoints and guidance

 

Frank Sasinowski FDA regulatory flexibility beyond One Positive Adequate and Well Controlled Trial

  •  As we move to rare diseases we may only have one well controlled study so FDA feels we need new regulatory frameworks and guidelines especially for rare disease clinical trails especially with precision medicine
  • Accelerated approval does not mean your evidence is any less stringent that traditional approval (only difference is endpoint but quality of evidence the same)

 

  • Confirmatory evidence is a primary concern
  • In 2021 FDA coordinated with the two divisions CBER and CDER
  • Sometimes a primary endpoint shows positive benefit but secondary endpoints may not; FDA now feels that results from one well designed AWC gives confirmatory evidence
  • FDA can be flexible by taking in consideration the quantity and quality of confirmatory evidence and the totality of evidence
  • So pharmacology studies, natural history etc.  can be enough
  • For a drug like Lamzede for mannosidosis there were no positive endpoint studies or for ADA SCID disease there was other compelling evidence
  • The FDA does have flexibility when it comes to advanced precision medicines and ultr rare diseases

10:50 Do we Really Need Liquid Biopsy? A Panel Discussion on the Issues Hampering the full Adoption of Liquid Biopsy

  • In Mexico leading cancer is colorectal but only have the FIT test and noone except one organization who issupplying health access
  • Access to precision medicine is a concern:  the communication between the patient, who is pushing this more than healthcare, needs to be coordinated better with all stakeholders in care
  • We also need to educate many physicians even oncologists (like in Virginia) a better understanding of genetics and omics
  • FT3 consortium does testing to therapy (multistakeholder group comprised of patient advocacy groups); focus on amplifying global efforts to increase access; they are trying to make a roadmap to help access in other countries; when it comes to precision medicine it is usually the nurses that are aksing for training because they are usually the first responders for the patient’s questions
  • In rural areas just getting access to liquid biopsy is a concern and maybe satellite sites might be useful because the time to schedule is getting worse (like 3 or more months)
  •  A recent paper showed that liquid biopsy may actually perpetuate health disparities and not ameliorate them
  • BloodPAC: there are barriers to LB access and adoption so consortium felt that there were many areas that need to be addressed: financial, access, disparities, education
  • ctDNA to define variants was the past focus; there is growing realization that there are representatives populations in your R&D studies
  • Submission of data to BloodPac is easier to do for tissue not for liquid biopsy;  there is lack of harmonization across many of these databanks
  • Reimbursement: is a barrier to access for liquid biopsy
  • Illumina: challenge finding clinical utility for payers; FDA approval is not as hard; show improved outcomes for patients; Medicare is starting to approve some tests but the criteria bar keeps changing with payers; 
  • How do we leverage the on-market data to support performance of your diagnostic test or genomic panel

 

This event will be covered by the LPBI Group on Twitter.  Follow on

@Pharma_BI

@StephenJWillia2

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Targeting amyloidopathy

Larry H. Bernstein, MD, FCAP

LPBI

 

Targeting a rare amyloidotic disease through rationally designed polymer conjugates

Inmaculada Conejos–Sánchez, Isabel Cardoso, Maria J. Saraiva, María J.Vicent
Journal of Controlled Release 178 (2014), 95–100
Saraiva et al. discovered in 2006 a RAGE-based peptide sequence capable of preventing transthyretin (TTR) aggregate-induced cytotoxicity, hallmark of initial stages of an inherited rare amyloidosis known as Familial Amyloidotic Polyneuropathy (FAP). To allow clinical progression of this peptidic sequence as FAP treatment, a family of polymer conjugates has been designed, synthesised and fully characterised. This approach fulfills the strategies defined in the Polymer Therapeutics area as an exhaustive physico-chemical characterisation fitting activity output towards a novel molecular target that is described here. RAGE peptide acts extracellularly, therefore, nointracellular drug delivery was necessary. PEG was selected as carrier and polymer–drug linker optimisation was then carried out by means of biodegradable (disulphide) and non-biodegradable (amide) covalent bonds. Conjugate size in solution, stability under invitro and in vivo scenarios and TTR binding affinity through surface plasmon resonance (SPR) was also performed with all synthesised conjugates. In their in vitro evaluation by monitoring the activation of caspase-3 in Schwann cells, peptide derivatives demonstrated retention of peptide activity reducing TTR aggregates (TTRagg) cytotoxicity upon conjugation and a greater plasma stability than the parent free peptide. The results also confirmed that a more stable polymer–peptide linker (amide) is required to secure therapeutic efficiency.

Polymer therapeutics are well established as successful first generation nanomedicines for treatment of infectious diseases and cancer[1]. Polymer–protein, drug and aptamer conjugates are innovative chemical entities capable of improving bioactive compound properties and thus increasing efficacy and decreasing toxicity[2,3]. Design of second generation of conjugates is now focussing on improved polymer structures, polymer–based combination therapy and novel molecular targets with great potential to further progress the clinical importance of these unique technologies [4]. Novel conjugates for the treatment of neuropathological disorders are proposed in this study. Amyloidosis is well known in the form of Alzheimer’s and Parkinson’s disease, but the target disease here is a rarer pathological disorder named familial amyloid polyneuropathy (FAP). FAPs constitute an important group of inherited amyloidosis diseases, and one of the most commonFAPs is caused by a mutated protein called transthyretin (TTR), which forms amyloid deposits, mainly in the peripheral nervous system [5]. The aggregation cascade of this mutated protein, produces a TTR aggregate (TTRagg) able to trigger neurodegeneration through engagement with the receptor-for-advanced-glycation-end-products (RAGE) which is present on peripheral neurons. RAGE signalling has been defined to be involved in many human pathologies such as Alzhehimer’s disease, diabetes and ageing, among others. This receptor is also up-regulated in tissues fromFAP patients [6]. The secreted RAGE form, named soluble RAGE (sRAGE), acts as a decoy to trap ligands and prevent interaction with cell surface receptors. sRAGE was shown to have important inhibitory effects in several cell cultures and transgenic mouse models, in which it prevented or reversed full-length RAGE signalling.

Saraiva et al. [7] discovered a specific peptidic sequence (named RAGE peptide) that is able to suppress TTRagg-induced cytotoxicity in cell culture. A reduced version of that peptide was proved to maintain the activity and the affinity of the initial peptide. The final peptide (compound A) contains 6 amino acids and responds to the sequence (from N to C terminus): YVRVRY. Although this provides an opportunity to design novel therapeutics for FAP treatment, peptide therapeutics themselves display well known challenges for in vivo use, e.g. low stability, poor pharmacokinetics and potential immunogenicity. Moreover the RAGE peptide demonstrates low solubility in plasma limiting its potential for i.v.administration.

……

Herein, novel specific nanoconjugates for the treatment of amyloidosis, and in particular familial amyloidotic polyneuropathy are reported. Apart from the research reported by Prof Arima et al. [22] using a hepatocyte-targeted FAP siRNA complex with lactosylated dendrimer (G3)/α-cyclodextrin(Lac-α-CDE(G3)), no other type of polymer therapeutic has been reported up to now for the treatment of this chronic degenerative family of diseases. Our rational design started from an active biomolecule of peptidic nature (RAGE peptide) that recognises the TTR prefibrillar aggregates responsible to promote cell death in FAPpatients [7]. The clinical progress of this promising inhibitor was masked by the well-known limitations of peptides, such as low solubility, low stability and possible immunogenicity. PEGylation through various linking strategies was successfully accomplished here as a solution for the named drawbacks, using a systematic approach to maintain peptide activity and receptor binding specificity. The data relating toTTR binding affinity, conjugate linker stability and the conjugate size distribution in solution of PEG– RAGE peptide conjugates indicate that the conjugates containing amide linkers have the greatest potential for further development as FAP inhibitors. Moreover, this novel conjugate has promising possibilities as a FAP therapeutic to be used alone in the early stages of the disease or as part of rationally designed combination therapy [23,24]. Preliminary in vivo studies (biodistribution) are shown in the supporting information demonstrating the enhanced plasma stability of the peptide upon conjugation (Fig.5S) , showing nospecific accumulation in any organ and renal excretion. More exhaustive in vivo experiments are currently ongoing with selected conjugates.

 

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