# An Update on Clinically Advanced PROTAC Degraders and Their Synthesis

**Authors:** Ranjan Kumar Acharyya, Yugandhar Kothapalli, Suresh Yarlagadda, Chayan K. De, Srinivasa Rao Allu, Joyeeta Roy, Rohan Kalyan Rej

PMC · DOI: 10.3390/molecules31010033 · Molecules · 2025-12-22

## TL;DR

This review discusses the progress of PROTACs, a new type of drug that can degrade harmful proteins, and their potential for clinical approval.

## Contribution

The paper provides an updated synthesis and clinical development overview of PROTAC degraders.

## Key findings

- PROTACs offer advantages like increased specificity and catalytic activity over traditional inhibitors.
- Several PROTAC molecules have advanced to clinical trials, showing significant progress in target protein degradation.
- The review details the design and synthesis methods of clinically advanced PROTAC degraders.

## Abstract

Proteolysis-targeting chimeras (PROTACs) have emerged as a revolutionary therapeutic modality that enables degradation of therapeutically relevant proteins through the protein disposal machinery, the ubiquitin-proteasome system (UPS). Unlike traditional small-molecule inhibitors, PROTACs harness bifunctional molecules to induce targeted protein degradation, offering advantages such as increased specificity, catalytic activity, and the potential to address previously undruggable targets. Since their conception 20 years ago, PROTACs have made significant strides in target protein degradation (TPD), and today, PROTACs are on the verge of their first clinical approval. This review presents a detailed overview of PROTAC targets, clinical development progress, and the design and detailed synthesis of degrader molecules that have advanced to clinical trials.

## Full-text entities

- **Genes:** IKZF3 (IKAROS family zinc finger 3) [NCBI Gene 22806] {aka AIO, AIOLOS, IMD84, ZNFN1A3}, IKZF1 (IKAROS family zinc finger 1) [NCBI Gene 10320] {aka CVID13, Hs.54452, IK1, IKAROS, LYF1, LyF-1}, Kras (Kras proto-oncogene, GTPase) [NCBI Gene 16653] {aka K-Ras, K-Ras 2, K-ras, Ki-ras, Kras-2, Kras2}, IRAK4 (interleukin 1 receptor associated kinase 4) [NCBI Gene 51135] {aka IMD67, IPD1, IRAK-4, NY-REN-64, REN64}, BRD7 (bromodomain containing 7) [NCBI Gene 29117] {aka BP75, CELTIX1, NAG4, SMARCI1}, Cd19 (CD19 antigen) [NCBI Gene 12478], DNAH8 (dynein axonemal heavy chain 8) [NCBI Gene 1769] {aka ATPase, SPGF46, hdhc9}, Trp53 (transformation related protein 53) [NCBI Gene 22059] {aka Tp53, bbl, bfy, bhy, p44, p53}, TSPAN2 (tetraspanin 2) [NCBI Gene 10100] {aka NET3, TSN2, TSPAN-2}, Bcl2 (B cell leukemia/lymphoma 2) [NCBI Gene 12043] {aka Bcl-2, C430015F12Rik, D630044D05Rik, D830018M01Rik}, Bpifa5 (BPI fold containing family A, member 5) [NCBI Gene 67135] {aka 2310021H06Rik, 2310074B19Rik, Pluncl, Splunc5, Tpl}, MAPK1 (mitogen-activated protein kinase 1) [NCBI Gene 5594] {aka ERK, ERK-2, ERK2, ERT1, MAPK2, NS13}, BRD9 (bromodomain containing 9) [NCBI Gene 65980] {aka LAVS3040, PRO9856, SMARCI2}, BCL6 (BCL6 transcription repressor) [NCBI Gene 604] {aka BCL5, BCL6A, LAZ3, ZBTB27, ZNF51}, SLC38A5 (solute carrier family 38 member 5) [NCBI Gene 92745] {aka JM24, SN2, SNAT5, pp7194}, MTOR (mechanistic target of rapamycin kinase) [NCBI Gene 2475] {aka FRAP, FRAP1, FRAP2, RAFT1, RAPT1, SKS}, BCL2L1 (BCL2 like 1) [NCBI Gene 598] {aka BCL-XL/S, BCL2L, BCLX, Bcl-X, PPP1R52}, VHL (von Hippel-Lindau tumor suppressor) [NCBI Gene 7428] {aka HRCA1, RCA1, VHL1, pVHL}, BCL2 (BCL2 apoptosis regulator) [NCBI Gene 596] {aka Bcl-2, PPP1R50}, GDF15 (growth differentiation factor 15) [NCBI Gene 9518] {aka GDF-15, HG, MIC-1, MIC1, NAG-1, PDF}, Esr1 (estrogen receptor 1 (alpha)) [NCBI Gene 13982] {aka ER, ER-alpha, ERa, ERalpha, ESR, Estr}, SALL4 (spalt like transcription factor 4) [NCBI Gene 57167] {aka DRRS, HSAL4, IVIC, ZNF797}, CRBN (cereblon) [NCBI Gene 51185] {aka MRT2, MRT2A}, CSNK1A1 (casein kinase 1 alpha 1) [NCBI Gene 1452] {aka CK1, CK1a, CKIa, HEL-S-77p, HLCDGP1, PRO2975}, GSPT1 (G1 to S phase transition 1) [NCBI Gene 2935] {aka 551G9.2, ETF3A, GST1, eRF3a}, Bcl2l1 (BCL2-like 1) [NCBI Gene 12048] {aka Bcl(X)L, Bcl-XL, Bcl2l, BclX, bcl-x, bcl2-L-1}, Vhl (von Hippel-Lindau tumor suppressor) [NCBI Gene 22346] {aka Vhlh, pVHL}, ESR1 (estrogen receptor 1) [NCBI Gene 2099] {aka ER, ESR, ESRA, ESTRR, Era, NR3A1}, Btk (Bruton agammaglobulinemia tyrosine kinase) [NCBI Gene 12229] {aka xid}, BANF1 (barrier to autointegration nuclear assembly factor 1) [NCBI Gene 8815] {aka BAF, BCRP1, D14S1460, NGPS}, PIK3CB (phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit beta) [NCBI Gene 5291] {aka P110BETA, PI3K, PI3KBETA, PIK3C1}, SSX2B (SSX family member 2B) [NCBI Gene 727837] {aka CT5.2, CT5.2b, HOM-MEL-40, SSX}, SMARCA4 (SWI/SNF related BAF chromatin remodeling complex subunit ATPase 4) [NCBI Gene 6597] {aka BAF190, BAF190A, BRG1, CSS4, MRD16, OTSC12}, MYD88 (MYD88 innate immune signal transduction adaptor) [NCBI Gene 4615] {aka IMD68, MYD88D, WM1}, BTK (Bruton tyrosine kinase) [NCBI Gene 695] {aka AGMX1, AT, ATK, BPK, IGHD3, IMD1}, Irak4 (interleukin-1 receptor-associated kinase 4) [NCBI Gene 266632] {aka 8430405M07Rik, 9330209D03Rik, IRAK-4, NY-REN-64}, KLK3 (kallikrein related peptidase 3) [NCBI Gene 354] {aka APS, KLK2A1, PSA, hK3}, ACIN1 (apoptotic chromatin condensation inducer 1) [NCBI Gene 22985] {aka ACINUS, ACN, fSAP152}, Ezh2 (enhancer of zeste 2 polycomb repressive complex 2 subunit) [NCBI Gene 14056] {aka Enx-1, Enx1h, KMT6, mKIAA4065}, Braf (B-Raf proto-oncogene, serine/threonine kinase) [NCBI Gene 109880] {aka 9930012E13Rik, B-raf, Braf-2, Braf2, C230098H17, D6Ertd631e}, Brd9 (bromodomain containing 9) [NCBI Gene 105246], NMI (N-myc and STAT interactor) [NCBI Gene 9111], AR (androgen receptor) [NCBI Gene 367] {aka AIS, AR8, DHTR, HPCX3, HUMARA, HYSP1}, Ms4a1 (membrane-spanning 4-domains, subfamily A, member 1) [NCBI Gene 12482] {aka Cd20, Ly-44, Ms4a2}, SMARCB1 (SWI/SNF related BAF chromatin remodeling complex subunit B1) [NCBI Gene 6598] {aka BAF47, CSS3, INI-1, INI1, MRD15, PPP1R144}, Bcl6 (B cell leukemia/lymphoma 6) [NCBI Gene 12053] {aka Bcl5}, STAT3 (signal transducer and activator of transcription 3) [NCBI Gene 6774] {aka ADMIO, ADMIO1, APRF, HIES}, STAT4 (signal transducer and activator of transcription 4) [NCBI Gene 6775] {aka DPMC, SLEB11}, EREG (epiregulin) [NCBI Gene 2069] {aka EPR, ER, Ep}, AKT1 (AKT serine/threonine kinase 1) [NCBI Gene 207] {aka AKT, PKB, PKB-ALPHA, PRKBA, RAC, RAC-ALPHA}, Iap1-3 (intracisternal A particle, Eya1 linked) [NCBI Gene 15601] {aka IAP}, MDM2 (MDM2 proto-oncogene) [NCBI Gene 4193] {aka ACTFS, HDMX, LSKB, hdm2}, PHLDA3 (pleckstrin homology like domain family A member 3) [NCBI Gene 23612] {aka TIH1}, Mdm2 (MDM2 proto-oncogene) [NCBI Gene 17246] {aka 1700007J15Rik, Mdm-2}, SS18 (SS18 subunit of BAF chromatin remodeling complex) [NCBI Gene 6760] {aka SMARCL1, SSXT, SYT}, CDKN1A (cyclin dependent kinase inhibitor 1A) [NCBI Gene 1026] {aka CAP20, CDKN1, CIP1, MDA-6, P21, SDI1}, BRAF (B-Raf proto-oncogene, serine/threonine kinase) [NCBI Gene 673] {aka B-RAF1, B-raf, BRAF-1, BRAF1, NS7, RAFB1}, TP53 (tumor protein p53) [NCBI Gene 7157] {aka BCC7, BMFS5, LFS1, P53, TRP53}, Fdxr (ferredoxin reductase) [NCBI Gene 14149] {aka AR}, STAT1 (signal transducer and activator of transcription 1) [NCBI Gene 6772] {aka CANDF7, IMD31A, IMD31B, IMD31C, ISGF-3, STAT91}
- **Diseases:** Crohn's disease (MESH:D003424), thrombocytopenia (MESH:D013921), acute lymphoblastic leukemia (MESH:D054198), atrial fibrillation (MESH:D001281), MZL (MESH:D018442), toxicities (MESH:D064420), anemia (MESH:D000740), FL (MESH:D008224), rheumatoid arthritis (MESH:D001172), NK-cell lymphoma (MESH:D016399), hypertension (MESH:D006973), deaths (MESH:D003643), neutropenia (MESH:D009503), rPFS (MESH:D011475), leukemia (MESH:D007938), colorectal cancer (MESH:D015179), Synovial sarcoma (MESH:D013584), atherosclerosis (MESH:D050197), MCL (MESH:D020522), DLBCL (MESH:D016403), QTc prolongation (MESH:D008133), WM (MESH:D008258), DLTs (MESH:D045745), renal cell carcinoma (MESH:D002292), contusion (MESH:D003288), petechiae (MESH:D011693), lymphoma (MESH:D008223), nausea, vomiting (MESH:D020250), B-cell malignancies (MESH:D016393), Breast cancer (MESH:D001943), chronic pain (MESH:D059350), post-myeloproliferative neoplasm (MESH:D017169), inflammatory bowel disease (MESH:D015212), non-Hodgkin lymphoma (MESH:D008228), PTCL (MESH:D016411), Tumors (MESH:D009369), metastatic (MESH:D000092182), injury to (MESH:D014947), inflammatory conditions (MESH:D007249), Prostate cancer (MESH:D011471), melanoma (MESH:D008545), adenoid cystic carcinoma (MESH:D003528), CTCL (MESH:D016410), small cell lung cancer (MESH:D055752), CLL (MESH:D015451), Parkinson's (MESH:D010300), pancreatic adenocarcinoma (MESH:D010190), LBD (MESH:D020192), AML (MESH:D015470), Merkel cell carcinoma (MESH:D015266), fibromyxoid sarcoma (MESH:D012509), hematologic malignancies (MESH:D019337), NSCLC (MESH:D002289), rash (MESH:D005076), autoimmune and inflammatory diseases (MESH:D001327), gastric cancer (MESH:D013274), CRPC (MESH:D064129), fatigue (MESH:D005221), hairy cell leukemia (MESH:D007943), Hodgkin's lymphoma (MESH:D006689)
- **Chemicals:** toluene (MESH:D014050), 2-iodopropane (MESH:C005952), Trichloroethyl chloroformate (MESH:C012586), phosphotyrosine (MESH:D019000), DIBAL-H (MESH:C035719), 4-fluoro-thalidomide (MESH:C513750), Urea (MESH:D014508), tafasitamab (MESH:C000613469), MgSO4 (MESH:D008278), rituximab (MESH:D000069283), Isopropyl acetate (MESH:C069372), mesyl chloride (MESH:C030209), ammonium bicarbonate (MESH:C027043), CAN (MESH:C004653), chlorine (MESH:D002713), TFA (MESH:D014269), amine (MESH:D000588), NaOCl (MESH:D012973), 2-Me-THF (MESH:C587233), sodium cyanoborohydride (MESH:C009282), Pd(OAc)2 (MESH:C516071), DMA (MESH:C013959), tert-butanol (MESH:D020002), diphenyl disulfide (MESH:C053871), acetyl chloride (MESH:C081124), 3-chloro-2-fluoro benzaldehyde (-), BCl3 (MESH:C092267), sotorasib (MESH:C000706028), NaHCO3 (MESH:D017693), 1,4-dioxane (MESH:C025223), ethyl acetate (MESH:C007650), AIBN (MESH:C004526), H2O2 (MESH:D006861), K2CO3 (MESH:C037593), benzyl bromide (MESH:C038682), DMP (MESH:C513869), pyrrolidine (MESH:C032519), prednisolone (MESH:D011239), nitrile (MESH:D009570), sodium hydride (MESH:C524957), MRTX1133 (MESH:C000723088), PDC (MESH:C061685), pyridine (MESH:C023666), phenylboronic acid (MESH:C010686), potassium tert-butoxide (MESH:C077664), POCl3 (MESH:C013196), imine (MESH:D007097), sodium acetate (MESH:D019346), 1-Ethyl-3-(3-dimethylaminopropyl)carbodiimide (MESH:D005022), DT-2216 (MESH:C000717534), nemtabrutinib (MESH:C000721068), alcohol (MESH:D000438), DABCO (MESH:C007306), DHT (MESH:D013196), H2 (MESH:D006859), ether (MESH:D004986), docetaxel (MESH:D000077143), mesylate (MESH:D008698), DMSO (MESH:D004121), chlorosulfonic acid (MESH:C013880)
- **Species:** Homo sapiens (human, species) [taxon 9606], Mus musculus (house mouse, species) [taxon 10090]
- **Mutations:** C381S/R/Y, G12D, C381, T878A/S, A428D, M750V, T474I/F, V600K, G12C, W742C, C to -10, L702H, H875Y, T878A, D539A, S889G, Y545N, V416L, Serine/Threonine, F877L, C to -15, Y537S, C481S, Cys481, D891H, V600, L528W, D538G

## Full text

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## Figures

34 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12786869/full.md

## References

154 references — full list in the complete paper: https://tomesphere.com/paper/PMC12786869/full.md

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Source: https://tomesphere.com/paper/PMC12786869