"Treatment of Ba/F3 or lung cells expressing MDK::ERBB2 with ERBB2 inhibitors (afatinib, poziotinib, tucatinib) blocked phosphorylation of ERBB2 and downstream effectors, and inhibited growth of both cell lines. ERBB2 fusions are rare oncogenic drivers that are candidates for targeted therapy. The subset of recurrent ERBB2 fusions with C-terminal/3' partners may represent an alternative mechanism of fusion oncogenicity."

Our study revealed EGFR-dependent and -independent mechanisms of mobocertinib resistance in patients with advanced EGFR Ex20ins-mutant NSCLC.

A total of 1,418 EGFR E20ins mutations were collected from six studies (FoundationInsights, Geneseeq Technology Inc, mobocertinib phase I/II trial, poziotinib phase II trial, sunvozertinib phase I trial, and Samsung Medical Center) and reorganised according to Human Genome Variation Society (HGVS) nomenclature. To ensure comprehensive coverage in real-world settings, it is essential to standardise the annotations for each variant, for example using the HGVS nomenclature. The accurate classification and analysis of drug responsiveness in EGFR E20ins necessitate consideration of the nomenclature, particularly with respect to the locations where the actual mutations occur.

P2; Trial completion date: Sep 2024 --> Dec 2025 | Trial primary completion date: Sep 2024 --> Dec 2025

P2, N=648, Terminated, Spectrum Pharmaceuticals, Inc | Trial completion date: Dec 2023 --> Apr 2023 | Active, not recruiting --> Terminated; Strategic business decision (unrelated to safety)

Additionally, we confirmed that dacomitinib inhibits chemoresistance in paclitaxel-resistant ovarian cancer HeyA8-MDR cells. Collectively, our research indicated that dacomitinib effectively resensitized paclitaxel in SKOV3-TR cells by inhibiting EGFR signaling and elevating intracellular ROS levels.

We found four compounds:1D6-Foretinib GSK1363089; 15F6-Poziotinib (HM781-36B); 15F9-Dasatinib monohydrate; 15A10-Pexmetinib (ARRY-614); acts as potent inhibitors of necroptosis (Necroptosis Blocking Compounds, NBCs) by blocking the RIPK3 kinase activity. In our study, we explored the role of NBCs in neuroprotection after traumatic brain injury. It's effectiveness in traumatic brain injury animal models and favorable safety profiles make it a potential candidate for the advances of new therapies for necroptosis-associated neuroinflammatory disorders.

Molecular docking indicated strong binding of poziotinib and olmutinib to extrinsic and intrinsic apoptotic pathway markers, with binding energies of -9.4 kcal/mol and -8.5 kcal/mol, respectively, on interacting with STK-11. Combining poziotinib and olmutinib therapies may significantly improve drug tolerance and conquer drug resistance more effectively than using them individually in lung cancer patients, as suggested by this study's mechanisms.

Treatment with the tyrosine kinase inhibitor (TKI) neratinib as a single agent continues to be evaluated in HER2-mutant metastatic disease. Herein, we discuss the under-explored effects of individual HER2 mutant alleles on therapeutic response, a role for HER2 mutation in metastatic propensity, and differences in patient outcomes in ER+ invasive lobular carcinoma (ILC) versus invasive ductal carcinoma (IDC). The preclinical efficacy of additional agents is also discussed, particularly the pan-HER inhibitor poziotinib.

HER2 mutations drive the growth of a subset of breast cancers and are targeted with HER2 tyrosine kinase inhibitors (TKI) such as neratinib...Cells expressing double HER2 mutations exhibited resistance to most HER2 TKIs but retained sensitivity to mobocertinib and poziotinib...Double-mutant cells showed enhanced MEK/ERK signaling, which was blocked by combined inhibition of HER2 and MEK. Together, these findings reveal the driver function of secondary HER2 mutations in resistance to HER2 inhibition and provide a potential treatment strategy to overcome acquired resistance to HER2 TKIs in HER2-mutant breast cancer.

Of these, 35 patients (25 16 mg QD; 10 8 mg BID) had prior HER2 therapy such as trastuzumab, TDM1, and T-DXd...ORRs were 30% with PLT+any systemic therapy; 30% with PLT+docetaxel and 43% with PLT+TKI...Conclusions Poziotinib demonstrated clinically meaningful efficacy in patients who received prior 2+ lines of therapy including HER2 therapy. ZENITH20 study provides a large dataset in the 3rd or later line setting of HER2 exon 20 mutations in NSCLC who have very limited treatment options.

No abstract available

Introduction: HER2 mutation is a newly established actionable target in non-small cell lung cancer (NSCLC) with trastuzumab-deruxtecan (T-DXd) as the only approved targeted therapy for patients as 2nd line therapy...ORRs were 31.3% with platinum+any systemic therapy; 30.8% with platinum+docetaxel; 24.0% with platinum+HER2 antibody-based therapy; 54.5% with platinum+TKI... Poziotinib demonstrated clinically meaningful efficacy in patients who received and progressed on prior 2+ lines of therapy regardless of types and sequence of treatment. ZENITH20 study provides a large dataset in the 3rd or later line setting of HER2 exon 20 mutations NSCLC patients who have very limited treatment options. No new safety signal was detected in this patient population.

P1/2, N=42, Terminated, Spectrum Pharmaceuticals, Inc | N=76 --> 42 | Trial completion date: Mar 2025 --> May 2023 | Active, not recruiting --> Terminated | Trial primary completion date: Jan 2025 --> Feb 2023; Business decision, not related to safety.

P2, N=7, Terminated, Spectrum Pharmaceuticals, Inc | N=20 --> 7 | Trial completion date: Apr 2026 --> Mar 2023 | Active, not recruiting --> Terminated | Trial primary completion date: Oct 2023 --> Mar 2023; Business reasons, not related to safety.

P2; Trial completion date: Mar 2024 --> Sep 2024 | Trial primary completion date: Mar 2024 --> Sep 2024

Poziotinib demonstrated clinically meaningful efficacy with a manageable toxicity profile for treatment-naïve NSCLC patients harboring HER2 exon 20 mutations.

The efficacy of mobocertinib, amivantamab and poziotinib in NSCLC with EGFR exon 20 insertion mutations is promising. However, therapies were assessed in single-arm CTs with low-quality evidence. Comparative studies with more extensive patient follow-up, larger sample size and better design are needed to reliably quantify the effect of these drugs.

In a patient-derived xenograft model of HER2YVMA mutant lung cancer, we observed that HER2 CAR-NK cells showed enhanced antitumor activity in mice treated with the HER2 inhibitor, poziotinib, for two weeks, compared to CAR-NK cells only, poziotinib only, or mice treated upfront with HER2 CAR-NK cells plus poziotinib. Furthermore, we determined that CD70-targeting CAR-T and CAR-NK cells showed promising in vitro activity against the DTPCs of osimertinib-treated EGFR mutant NSCLC. These results demonstrate CAR-based cellular therapy as an effective approach to target DTPCs and identify CD70 as a novel therapeutic target for combatting DTPCs in NSCLC.

In particular, pyrotinib has shown moderate efficacy as well as a manageable safety profile, and it is now being further evaluated as monotherapy or combined with other existing therapies; by contrast, while poziotinib has demonstrated promising preliminary results, the high rates of toxicity has hampered subsequent studies. Most notably, trastuzumab deruxtecan (T-DXd, DS-8201) has led to a significant breakthrough, with the most encouraging efficacy data (response rate of 55 %, median progression-free survival of 8.2 months and median overall survival of 17.8 months) among all the anti-HER2 agents...Several other challenges need to be addressed, such as the intracranial activity of anti-HER2 agents and the optimal sequencing of therapies. Here, we summarise recent therapeutic advances in targeting HER2 alterations in NSCLC and highlight the future perspectives of these patient populations.

P2; Trial completion date: Mar 2023 --> Mar 2024 | Trial primary completion date: Mar 2023 --> Mar 2024

Several molecular TKIs (such as TAK788 and Poziotinib) were recently discovered and demonstrated as effective inhibitors against the most prevalent HER2 or EGFR exon 20 mutations. In vitro and in vivo biological results suggested that compound 56 demonstrated good oral bioavailability, and it was significantly capable of inhibiting the growth of tumor cells with a variety of HER2 exon 20 mutations and EGFR mutants with negligible toxic effects. It was identified that compound 56 might be considered a potential drug candidate for NSCLC target therapy.

P2; Recruiting --> Active, not recruiting | N=80 --> 116

Treatment on mutation identification included chemotherapy (CT) (33.8%), CT-immunotherapy (IO) (18.2%), osimertinib (22.1%), poziotinib (9.1%), mobocertinib (6.5%), mono-IO (3.9%), and amivantamab (1.3%). EXOTIC represents the largest academic real-world evidence data set on EGFR exon 20-mutant NSCLC in Europe. Indirectly compared, treatment with new exon 20-targeting agents is likely to confer survival benefit than CT plus or minus IO.

P2; N=36 --> 0 | Trial completion date: Dec 2024 --> Feb 2023 | Not yet recruiting --> Withdrawn | Trial primary completion date: Dec 2024 --> Feb 2023

P3, N=268, Suspended, Spectrum Pharmaceuticals, Inc | Recruiting --> Suspended

P2, N=603, Active, not recruiting, Spectrum Pharmaceuticals, Inc | Recruiting --> Active, not recruiting

P1/2, N=76, Active, not recruiting, Spectrum Pharmaceuticals, Inc | Recruiting --> Active, not recruiting

Poziotinib demonstrates moderate antitumor activity in previously treated HER2 exon 20 mutant NSCLC patients with a manageable safety profile. In addition, different subgroup mutations show various benefits of poziotinib treatment. Large-scale and multiarm clinical trials are warranted to confirm a suitable population and therapeutic strategies.

We also examined growth inhibitory effect of poziotinib, afatinib, CLN-081, erlotinib, osimertinib, brigatinib and BI4020 using the same Ba/F3 models. These findings indicate that T790M or C797S, depending on the activating mutations, will cause acquired resistance to mobocertinib in NSCLCs with EGFR exon 20 mutations. We also found a novel secondary mutation (F856V) that may confer acquired resistance to mobocertinib.

poziotinib, mobocertinib, or afatinib). In this large, population-based retrospective review of EGFR and HER2 ex20ins NSCLC patients, there was improvement in survival for patients who received any ST vs. those who did not. Overall survival was significantly better among HER2 ex20ins patients who received ex20ins-specific TKIs.

The most promising therapies are ADCs (trastuzumab-deruxtecan) and novel TKIs targeting exon 20 mutations (poziotinib, mobocertinib and pyrotinib); both have resulted in meaningful anti-tumor efficacy in HER2 mutated NSCLC. Given the variety of HER2 targeted drugs, sequencing of these agents and optimizing combination therapies will depend on more mature efficacy data from clinical trials and toxicity profiles. This review highlights the challenges of diagnosing HER2 alterations, summarizes recent progress in novel HER2-targeted agents, and projects next steps in advancing treatment for the thousands of patients with HER2 altered NSCLC.

STX-721 demonstrates EGFR exon 20 mutant selectivity approaching the selectivity of Osimertinib in EGFR T790M mutants, warranting further exploration of this potential best-in-class exon 20 inhibitor in the clinic. Ba/F3: proliferation selectivity vs. EGFR WT Human cells: proliferation selectivity (vs.

Ba/F3 cells harboring EGFR exon 20 insertion and C797S mutations were resistant to mobocertinib, poziotinib, and TAS-6417. Conclusions EGFR C797S mutation and EGFR amplification were identified as resistance mechanisms to mobocertinib in EGFR exon 20 insertion-mutant NSCLC models. Combined treatment of brigatinib plus cetuximab or amivantamab may be an effective therapeutic strategy for EGFR exon 20 insertion/C797S-mutant NSCLC in preclinical models.

In fact, although a few targeted drugs have so far demonstrated antitumour activity for these patients, mainly selective human epidermal receptor-tyrosine kinase inhibitors such as poziotinib and mobocertinib (for both molecular alterations), monoclonal antibodies such as amivantamab (for Ex20ins), and antibody-drug conjugates such as trastuzumab deruxtecan (for HER2 mutants), they are mostly confined for clinical use in pretreated patients. Finally, Ex20ins-targeted or HER2-targeted drugs might be difficult to access in different countries or regions worldwide. In the present review, we provide a concise but comprehensive summary of the challenges that lie ahead as we move towards personalized treatment of Ex20ins-mutant and HER2-mutant advanced NSCLC, also suggesting a treatment algorithm that could be followed for patients with these genetic aberrations.

The most highly recurrent HER2 mutant, L755S, was particularly resistant to neratinib but sensitive to the pan-HER TKI poziotinib, alone or in combination with fulvestrant. Similar therapeutic effects of poziotinib were observed in both an engineered HER2L755S MCF7 model and a patient-derived xenograft harboring a HER2G778_P780dup mutation. Overall, these findings support the need for clinical evaluation of poziotinib for the treatment of HER2 mutant metastatic breast cancer.

Tyrosine kinase inhibitors, antibody drug conjugate in monotherapy and combinations are emerging strategies in many HER2-positive cancers; HER2 therapies are now part of standard of care of HER2-amplified gastric or gastroesophageal junction cancer. Data are pending on several unmet medical needs.

Tyrosine kinase inhibitors, antibody drug conjugate in monotherapy and combinations are emerging strategies in many HER2-positive cancers; HER2 therapies are now part of standard of care of HER2-amplified gastric or gastroesophageal junction cancer. Data are pending on several unmet medical needs.

Interventional studies reported outcomes for TKIs (mobocertinib, poziotinib, osimertinib, afatinib, CLN-081, DZD9008), a monoclonal antibody (amivantamab), and a heat shock protein 90 inhibitor (luminespib). Conventional treatments used in patients with EGFR exon 20 insertion mutation-positive NSCLC have limited efficacy, though chemotherapy appeared to be associated with better response and survival outcomes than non-exon 20 targeting EGFR-TKIs and IO agents. This supports the need to identify EGFR exon 20 insertion mutations as the availability of new targeted treatments may offer additional therapeutic options to these patients.

Our results indicate that allitinib was more effective than afatinib in NSCLC cell lines. KRAS mutations increased aggressive behavior through upregulation of the focal adhesion-PI3K-Akt-mTOR-signaling in NSCLC cells. Significantly, everolimus restored sensibility and improved cytotoxicity of EGFR inhibitors in the KRAS mutant NSCLC cell lines.

Conclusions Poziotinib is highly active in G778, a common HER2 ex20ins alteration, in both treatment-naïve and previously treated patients with NSCLC. The AE profile was typical of a TKI.