The Needle Issue #15


Welcome to The Needle, a newsletter from Haystack Science to help you navigate the latest translational research, with a roundup of the latest news on preclinical biotech startups from around the world.

This issue, along with the Lasker prize, we celebrate the drug hunters at Vertex Pharmaceuticals/Aurora Biosciences who discovered and developed small-molecule potentiators and correctors of the cystic fibrosis transmembrane conductance regulator (CFTR). These drugs have forever changed the lives of CF patients, but thousands remain for whom these therapies are ineffective, and we talk about some of the ongoing efforts to address the needs of this patient population.

In our survey of the translational literature, Regel Therapeutics, Drug Farm, Defand Therapeutics and Window Therapeutics all disclosed notable advances. In startup news, the trend of universities starting funds to spin out startups continues; Eli Lilly announces an intriguing initiative, offering its preclinical machine learning models to startups in return for use of external data to refine its models. A healthy number of preclinical financings were annouced, but licensing for early preclinical deals continued to be slow. Any financings or collaborations we missed, let us know (info@haystacksci.com).

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On September 11, the Lasker Foundation awarded the 2025 Lasker~DeBakey Clinical Medical Research Award to Michael Welsh, Jesús González and Paul Negulescu for discoveries that led to the development of Trikafta, a triple combination of cystic fibrosis transmembrane conductance regulator (CFTR) potentiators and correctors to treat cystic fibrosis. This award recognizes the contribution of Trikafta to improving the quality of life of ~90% of the 40,000 people living with this condition in the United States, reducing infection-related hospitalizations and lung transplants, among other benefits.

But what about the other 10% of patients who don’t respond to Trikafta, many of whom carry so-called Class I alleles that cannot be rescued by this drug combination? Although a lot of progress has been made, several obstacles lie in the path of effective medicines for people who produce no, or negligible amounts of, CFTR protein.

It should come as no surprise that the main therapeutic strategies for Class I alleles aim to put missing CFTR back into lung cells. Among these strategies, mRNA delivery is the most advanced. VX-522, an RNA therapeutic program from Vertex and Moderna currently in Phase 2, is an inhaled drug that aims to deliver full-length CFTR mRNA to the lung using lipid nanoparticles (LNPs). Two related, competing mRNA delivery programs are at a similar stage of clinical development: ARCT-032 by Arcturus Therapeutics using their LUNAR LNPs; and RCT-2100 by ReCode Therapeutics, which uses a lung-targeted SORT (selective organ-targeting) LNP.

A key feature of RNA-based therapies is that any therapeutic benefit would likely be transient, requiring periodic administration of the medicine to achieve sustained effects. Gene therapy and gene editing have the potential to be a curative, “one and done” procedure. Thus far, however, only gene therapy programs have advanced far enough to be in human testing.

Of these, 4D Molecular Therapeutics’ 4D-710 and Spirovants’ SP-101 use different AAV subtypes designed to optimize delivery to airway basal epithelial cells of a CFTR minigene that lacks the regulatory domain. Both projects are in Phase 1/2 of clinical development.

As the large size (6.2 kb) of the CFTR transgene exceeds the packaging capacity of AAV vectors, Krystal Biotech and Boehringer Ingelheim have launched Phase 1/2 clinical programs using viral vectors with a greater payload capacity: KB407 is a re-dosable herpes simplex virus (HSV)-1 vector with a cargo capacity >30 kb that delivers two copies of the CFTR gene to lung epithelial cells using a nebulizer. BI 3720931 is Boehringer’s inhaled lentiviral vector pseudotyped with Sendai virus F and HN envelope proteins (rSIV.F/HN) engineered to deliver a single copy of the CFTR gene. Further behind in the pipeline, Carbon Biosciences’ CGT-001 is a nebulized non-AAV parvovirus-based vector capable of delivering full-length CFTR gene. Thus far, it has been tested in nonhuman primates and in human bronchial cells in culture.

Companies are also pursuing oligonucleotide therapies to modify disease-causing mutations at the RNA level. SPL84 is an inhaled antisense oligonucleotide (ASO) addressing a splicing defect (cryptic exon; class V mutation) in the ~1,600 CF patients who carry the 3849+10kb C→T mutation. SpliSense has advanced the ASO into phase 2 testing, but it also has in preclinical development an exon-skipping ASO against the class I mutant W1282X. By masking the mutant premature termination codon in exon 23, SP23 induces the splicing machinery to skip exon 23 and stitch together exon 22 and exon 24, forming a partially functional CFTRΔex23 protein.

Gene editing is also beginning to appear on the therapeutic horizon. In July, Prime Medicine announced it had received $25 million in funding to advance prime editors, with a lead program focusing on G542X. Last year, Intellia Therapeutics and ReCode Therapeutics also announced a strategic collaboration to combine the CRISPR pioneer’s Cas9 DNA ‘writing’/insertion technology with Recode’s SORT LNPs. Academic groups have now shown that G542X correction is possible using inhaled LNP- or virus–like particle-delivered adenine base editors. And for RNA editing, at this year’s American Society of Gene & Cell Therapy Wave Life Sciences reported their oligo-based ADAR editors could achieve 21% correction (EC50 = 376nM) of CFTR W1282X nonsense mutations. This is likely a sliver of all the therapeutic activity underway; other programs are targeting mucus itself, which is much thicker than in healthy individuals. If we missed any drug-discovery projects in this space, please let us know!

Despite the plethora of programs, developing genetic therapies against cystic fibrosis patients with class I CFTR mutations faces some stiff translational challenges. For starters, targeted delivery of drugs to lung tissue remains a work in progress. The optimal cell type to be targeted by gene therapy/editing remains an open question, especially as the community continues to identify new cell types in the lung; is it enough to target the more prevalent epithelial cells (alveolar type 2 cells), or will it be necessary to target rarer stem cells (alveolar type 1 cells) to see a long-lasting therapeutic effect? What about the contribution of genetic modifiers and other ion channels known to affect airway dysfunction in CF airway epithelial cells? Also, how to figure out the pharmacokinetics and pharmacodynamics of these disease-modifying therapies in lungs and measure delivery in patients? Specifically, establishing protein expression levels after inhaling a DNA- or RNA-based product would likely require a bronchial biopsy, which is impractical particularly in this fragile patient population.

Last, not unlike most pathologies, new animal and in vitro models with predictive value need to be developed. The use of human bronchial epithelium culture is not as predictive of the efficacy of genetic therapies as it has been for small molecules. At present, the ferret is the gold standard disease model. But it is a time-consuming, challenging animal model, which is only supported by a few groups. All of which slows the path to clinical translation.

Six years after the approval of Trikafta, patient foundations like the CF Foundation, Emily’s Entourage, and the Cystic Fibrosis Trust are devoting increasing resources to translational research to push forward treatments for patients with CFTR Class I mutations who do not respond to potentiators and correctors. The Lasker recognition of the science that led to Trikafta will surely inspire researchers working on those projects to overcome the remaining hurdles.

Papers: Best of the rest

Target biology

Autoimmune disease risk gene ANKRD55 promotes TH17 effector function through metabolic modulation | Journal of Experimental Medicine

WD40 repeat and FYVE domain containing 3 (WDFY3) rare variant confers resistance to neurodegeneration in mouse models of Huntington and other proteinopathies by augmenting selective autophagy | Neuron

Genetic and pharmacological knockdown of fatty acid elongase ELOVL6 induces mutant KRAS degradation in colon, lung and pancreatic cell lines | Nature Chemical Biology

Tubular acyl-coenzyme A (CoA) synthetase medium-chain family member 3 (ACSM3) deficiency impairs medium-chain fatty acid metabolism and aggravates kidney fibrosis in patient biopsies and mouse fibrosis models | PNAS

Fatty acid transport protein-2 inhibition enhances glucose tolerance through enhanced α-cell-mediated GLP-1 secretion in db/db diabetic mice and human islets | JCI

Genetic knockdown of peroxiredoxin 2 prevents hepatocarcinogenesis in mouse model of metabolic liver disease | JCI

ZEB1 promotes chemo-immune resistance in pancreatic cancer models by downregulating chromatin acetylation of CXCL16 in patient-derived organoids, xenografts, and orthotopic mouse models | JCI

Loss-of-function mutations in PLD4 lead to systemic lupus erythematosus through TLR7/9 and STING in an ultra-rare cohort | Nature

Proof-of-concept studies

A potent small-molecule inhibitor specific for NLRP3 effective against both MCC950-sensitive and -resistant inflammation in systemic and localized mouse models | Cell Chemical Biology

A CRISPR-Cas9 A-to-G base editor specific for R179H mutation in alpha actin isotype 2 (ACTA2) used to treat multisystemic smooth muscle dysfunction syndrome (MSMDS) of the vasculature in a GEMM mouse model | Nature Biomedical Engineering

Drug Farm announces discovery of a selective alpha-kinase 1 inhibitor that protects in mice models of ROSAH syndrome | Nature Communications

Delaying pyroptosis with SK56, an artificial intelligence-nominated peptide gasdermin D pore blocker, mitigates inflammatory response in mice | Nature Immunology

Therapeutic antibody binding of endogenous dimeric angiopoietin-2 to restore tetrameric form capable of activating TIE2 receptor, which prevents capillary loss and fibrosis in mouse models of kidney disease | JCI

Regel Therapeutics’ adeno-associated virus serotype 2 mediated delivery of CRISPR activation (Cas9-VP16) epiediting agents in mouse and human models of SCN2A-haploinsufficient neurodevelopmental disorder | Nature

Platforms

Defand Therapeutics’ imaging-based screen for induced-proximity degraders identifies a potent degrader of oncoprotein SKP2 with potent antitumor effects in xenograft non-small cell lung and prostate cancer mouse models | Nature Biotechnology

Window Therapeutics’ antibody–bottlebrush prodrug conjugates enable targeted therapy in subcutaneous and orthotopic mouse models of breast, ovarian and liver cancer | Nature Biotechnology

Broad-spectrum antibiotics unearthed by terabase-scale long-read sequencing of a soil metagenome | Nature Biotechnology

Editing

Engineered Cas9 nickase prime editors with 60-fold lower indel errors | Nature

Small nuclear RNAs capable of enhancing RNA A-to-I base editing with fewer off-targets in a cystic fibrosis human bronchial epithelial cell model | Nature Chemical Biology

Startup news

A new early-stage venture fund annouces close:

T.Rx capital first fund with $77.5 million, with 7 startups seeded and dry powder for five more across biotech, techbio and tech-enabled services.

The trend of universities spinning out funds to galvanize spinout activity continues:

Monash University launches $15 million Monash Ventures Preseed Fund to support spinouts

Rice University launches therapeutics-focused biotech venture creation studio RBL with funding from $25 million Carnite Ventures

Several accelerators and venture studios also made announcements:

Biolabs/Chiesa’s final call (apply by September 30 for Golden Ticket) for offer of 1-year lab membership to US startups focused on pulmonary disease

University of Tokyo Innovation Platform offers Japanese university startups commercialization expertise and non-dilutive ¥10 million ($60K) grants

UK’s Oxford Bioescalator announces Omos Biosciences, a startup focused on early, dysplastic forms of cancers

C-Path’s Translational Therapeutics Accelerator (TRxA) program announces $2.48 million in grants awarded to 7 academic medical centers in US, Holland and Australia

Consultancy Government Bioscience Grants (GBG)’s provides September update on non-dilutive funding programs for startups

Despite all this activity, the value of preclinical startups remains very low:

Endpoints announces its picks for 2025’s “most exciting” startups:

Averna Therapeutics, Candid Therapeutics, Chai Discovery, Dispatch Bio, Jude Bio, Lila Sciences, Orbis Medicines, Sironax, Stylus Medicines, Third Arc and Umoja.

An interesting new business experiment by Lilly, offering its internal machine learning models to train on federated data from biotech startups:

Eli Lilly’s TuneLab offers biotechs access to the pharma’s machine learning models for predicting small-molecule ADMETox and antibody developability

Preclinical financings

Preclinical deals

Stay in touch

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If you’re interested in commercializing your science, get in touch. We can help you figure out the next steps for your startup’s translational research program and connect you with the right investor. Follow us on X, BlueSky and LinkedIn. Please send feedback; we’d love to hear from you (info@haystacksci.com).

Until next week,

Juan Carlos and Andy

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