Pancreatic cancer has one of the highest mortality rates among cancers, and a combination of nab-paclitaxel with gemcitabine remains the cornerstone of first-line therapy. Nab-paclitaxel with gemcitabine in combination with other therapeutic agents can be new treatment strategies in pancreatic cancer. Seven therapeutic agents (ibrutinib, necuparanib, tarextumab, apatorsen, cisplatin, enzalutamide, and momelotinib) are found.
Table 1 shows the diversity of therapeutic agents under investigation in clinical trials. Considering the diversity in the chemical structures of the therapeutic agents enlisted, molecular biology studies will likely be needed to relate cellular or molecular events with the responses of patients to the triple regimen.
][76][60]. However, a successful triple regimen whose cellular events are known with certainty will bring about a new paradigm for the treatment of pancreatic cancer. Clinical trials of combination therapies that are effective and safe should be complemented by molecular studies to understand the pathways for their biological activities.
The MPACT, a randomized phase III study, reported that NP/G had an OS of 8.5 months, a PFS of 5.5 months, a CR of less than 1%, and an RP of 23% in 431 patients, resulting in greater efficacy than gemcitabine monotherapy. The AE of third grade or higher were as follows: neutropenia (38%), fatigue (17%), and neuropathy (17%). Febrile neutropenia was also present in 3% of the patients [77], whereas in [47][53][56], placebo in combination with the NP/G regimen exceeded the formulation of the main regimen with the additional drug in ORR, OS, and PFS, which means that adding ibrunitib (Bruton’s tyrosine kinase inhibitor), tarextumab (IgG2 antibody against Notch2 and Notch3 receptors), or apatorsen (antisense oligonucleotide targeting heat shock protein 27 messenger RNA) was not more effective than the standard therapy of NP/G. While the formulation with necuparanib (heparin mimetic) was slightly superior to the placebo formulation, there was no significant improvement in OS and PFS, resulting in the same ORR as the NP/G standard therapy.
5-FU | Fluorouracil |
AE | Adverse events |
CNTs | concentrative nucleoside transporters |
CTCAE | Common Terminology Criteria for Adverse Events |
CR | Complete response |
ENTs | Equilibrative nucleoside transporters |
FOLFIRINOX | Chemotherapy regimen containing fluorouracil, folinic acid, irinotecan, and oxaliplatin |
MMRI | Molecular magnetic resonance imaging |
NP/G | Nab-paclitaxel plus gemcitabine |
ORR | Objective response rate |
OS | Overall survival |
PDAC | Pancreatic ductal adenocarcinoma |
PFS | Progression-free survival |
TNBC | Triple-negative breast cancer |
TNM | Tumor/Node/Metastasis staging system from the American Joint Committee on Cancer |
Ref |
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Therapeutic Agent | Structure | Description | |
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[47] | Ibrutinib | Ibrutinib is a Bruton’s tyrosine kinase inhibitor that forms a covalent bond with a cysteine residue (Cys 481). Ibrutinib is used to treat chronic lymphocytic leukemia, mantle cell lymphoma, and Waldenstrom‘s macroglobulinemia, leading to inhibition of BTK activity [48][49]. ClinicalTrials.gov identifier: NCT024366. Phase III RESOLVE study. Ibrutinib plus nab-paclitaxel/gemcitabine did not improve OS or PFS for patients with metastatic PDAC. |
|
[50] | Necuparanib | — | Necuparanib (a heparin mimetic) acts as a multitargeting therapeutic, altering multiple signaling pathways simultaneously by binding and sequestering different proteins [51][52]. ClinicalTrials.gov identifier: NCT01621243. A randomized phase II trial. Necuparanib plus nab-paclitaxel/gemcitabine did not improve OS. |
[53] | Tarextumab | — | Monoclonal antibodies (mAb, anti-Notch2/3, OMP-59R5) are fully human monoclonal antibodies that target the Notch2 and Notch3 receptors. They have been used in trials studying the treatment of solid tumors, stage IV pancreatic cancer, and stage IV small cell lung cancer [54][55]. ClinicalTrials.gov identifier: NCT01647828. A randomized phase II trial. Tarextumab plus nab-paclitaxel/gemcitabine did not improve OS, PFS, or ORR in first-line metastatic PDAC |
[56] | Apatorsen | Apatorsen is a second-generation antisense drug in preclinical experiments that inhibits the production of heat shock protein 27 (Hsp27), a cell survival protein found at elevated levels in many human cancers, including prostate, lung, breast, ovarian, bladder, renal, pancreatic, multiple myeloma, and liver cancer [57][58]. ClinicalTrials.gov identifier: NCT01844817. A randomized, double-blinded, phase II trial. The RAINIER trial. Addition of apatorsen to nab-paclitaxel/gemcitabine regimen did not improve survival or other clinically relevant endpoints in patients with metastatic pancreatic cancer. |
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[59] | Cisplatin | Cisplatin is a platinum-based chemotherapy agent used to treat various sarcomas, carcinomas, lymphomas, and germ cell tumors. Cisplatin exerts its anticancer activities by generating DNA lesions through interactions with purine bases, leading to the activation of various signal transduction pathways leading to apoptosis [60][61][62]. ClinicalTrials.gov identifier: NCT01893801. A nonrandomized phase 1b/2 pilot clinical trial. The addition of cisplatin to nab-paclitaxel/gemcitabine resulted in a high response rate and evolving OS. |
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[63] | Enzalutamide | Enzalutamide is a rationally designed, targeted androgen-receptor inhibitor used to treat castration-resistant prostate cancer. Enzalutamide acts both by inhibiting the translocation of the androgen receptor into the nucleus and by reducing the transcriptional activity of this receptor [64][65]. ClinicalTrials.gov identifier: NCT02138383. A phase I trial. Enzalutamide plus nab-paclitaxel/gemcitabine was safely administered with no unexpected toxicities and resulted in consistent reductions in CA 19–9 (biological marker) levels. |
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[66] | Momelotinib | Momelotinib is a benzamide that acts as an ATP-competitive JAK1/JAK2 inhibitor. Momelotinib has been used in trials studying the treatment of polycythemia vera, primary myelofibrosis, post-polycythemia vera, essential thrombocythemia, and primary myelofibrosis (PMF), among others [67][68]. ClinicalTrials.gov identifier: NCT02101021. Phase 1 dose-escalation study. Momelotinib plus nab-paclitaxel/gemcitabine was safe and well tolerated, with no OS or PFS benefits. |
The molecular effects of paclitaxel, gemcitabine, and cisplatin are well characterized in cancer cells [69][70][71][72][73][74][75