Interferon-expressing oncolytic adenovirus + chemoradiation inhibited pancreatic cancer growth in a hamster model

Past clinical trials of adjuvant therapy combined with interferon (IFN) alpha, fluorouracil, cisplatin, and radiation improved the 5-year survival rate of pancreatic ductal adenocarcinoma (PDAC). However, these trials also revealed the disadvantages of the systemic toxicity of IFN and insufficient delivery of IFN. To improve efficacy and tolerability, we have developed an oncolytic adenovirus-expressing IFN (IFN-OAd). Here, we evaluated IFN-OAd in combination with chemotherapy (gemcitabine + nab-paclitaxel) + radiation. Combination index (CI) analysis showed that IFN-OAd + chemotherapy + radiation was synergistic (CI <1). Notably, IFN-OAd + chemotherapy + radiation remarkably suppressed tumor growth and induced a higher number of tumor-infiltrating lymphocytes without severe side toxic effects in an immunocompetent and adenovirus replication-permissive hamster PDAC model. This is the first study to report that gemcitabine + nab-paclitaxel, the current first-line chemotherapy for PDAC, did not hamper virus replication in a replication-permissive immunocompetent model. IFN-OAd has the potential to overcome the barriers to clinical application of IFN-based therapy through its tumor-specific expression of IFN, induction of antitumor immunity, and sensitization with chemoradiation. Combining IFN-OAd with gemcitabine + nab-paclitaxel + radiation might be an effective and clinically beneficial treatment for PDAC patients.

Pharmacological Inhibition of PP2A Overcomes Nab-Paclitaxel Resistance by Downregulating MCL1 in Esophageal Squamous Cell Carcinoma (ESCC)

Simple Summary

Paclitaxel-based chemotherapy has been introduced to treat esophageal squamous cell carcinoma. While its initial efficacy has been clinically established, the development of resistance is inevitable. To understand the paclitaxel resistance mechanism, we developed nanoparticle albumin-bound paclitaxel (nab-PTX)-resistant esophageal squamous cell lines from their sensitive counterparts. We found that resistant cells express higher levels of protein phosphatase 2A (PP2A), oxidative phosphorylation, and anti-apoptotic protein MCL1 than their counterparts. Therapeutically, the PP2A inhibitor LB-100 synergistically sensitized resistant esophageal squamous cells to nab-PTX both in vitro and in vivo. Therefore, our data suggest that LB-100 may potentially overcome nab-PTX resistance in a clinical setting.

Abstract

Paclitaxel-based chemotherapy is a treatment option for advanced esophageal squamous cell carcinoma (ESCC). However, the development of chemoresistance leads to treatment failure, and the underlying mechanism remains elusive. We investigated the mechanisms of nanoparticle albumin-bound paclitaxel (nab-PTX) resistance by establishing three nab-PTX resistant ESCC cell lines. Proteomics analysis revealed higher oxidative phosphorylation (OXPHOS) in resistant cell line DR150 than in its parental cell line KYSE150, which is likely caused by stabilized anti-apoptotic protein MCL1. Additionally, we discovered the elevated activity of protein phosphatase 2A (PP2A), the phosphatase that dephosphorylates and stabilizes MCL1, in nab-PTX resistant cell lines. Pharmacological inhibition of PP2A with small molecule compound LB-100 decreased MCL1 protein level, caused more apoptosis in nab-PTX resistant ESCC cell lines than in the parental cells in vitro, and significantly inhibited the tumor growth of nab-PTX resistant xenografts in vivo. Moreover, LB-100 pretreatment partially restored nab-PTX sensitivity in the resistant cell lines and synergistically inhibited the tumor growth of nab-PTX resistant xenografts with nab-PTX. In summary, our study identifies a novel mechanism whereby elevated PP2A activity stabilizes MCL1 protein, increases OXPHOS, and confers nab-PTX resistance, suggesting that targeting PP2A is a potential strategy for reversing nab-PTX resistance in patients with advanced ESCC.

Phase II Study of Nab-paclitaxel Plus Cyclophosphamide Plus Trastuzumab Neoadjuvant Chemotherapy in Early HER-2-positive Breast Cancer

BACKGROUND/AIM

This phase II trial evaluated the efficacy and safety of neoadjuvant nab-paclitaxel plus cyclophosphamide (CPA) plus trastuzumab (AbraC-HER) in patients with early HER2-positive breast cancer.

PATIENTS AND METHODS

This was a single-arm, open-label, single-center prospective phase II study. The primary endpoint was pathological complete response rate (pCR rate). The secondary endpoints were clinical antitumor efficacy and the frequency and severity of adverse events.

RESULTS

Fifty-nine patients were enrolled in this study. pCR (ypT0/is ypN0) was achieved in 29 patients (49%). The overall response rate was 88.1% (52/59) in all patients. Dose reductions because of adverse events occurred in 3 patients (5.1%) and relative dose intensity was 98%. Compared to Abra-HER, AbraC-HER induced fewer adverse effects.

CONCLUSION

Treatment with nab-paclitaxel plus CPA plus trastuzumab was tolerable and effective with a high pCR rate. This AbraC-HER neoadjuvant therapy may be a feasible new treatment option for patients with early HER2-positive breast cancer.

Clinical outcomes of neoadjuvant chemotherapy for patients with breast cancer: Tri-weekly nanoparticle albumin-bound paclitaxel followed by 5-fluorouracil, epirubicin, and cyclophosphamide: a retrospective observational study

Neoadjuvant chemotherapy (NAC) using the combination of anthracycline and taxanes is the standard regimen for patients with primary breast cancer. Among the taxanes, conventional paclitaxel (PTX) and docetaxel have usually been adopted in the neoadjuvant or adjuvant setting. Nanoparticle albumin-bound paclitaxel (nab-PTX) is a solvent-free formulation that can be delivered to cancer cells at higher doses than conventional PTX. This study is a retrospective observational study in a single institution. We evaluated the efficacy and safety of nab-PTX followed by 5-fluorouracil, epirubicin, and cyclophosphamide (FEC) in the neoadjuvant setting. In this study, 50 patients with primary breast cancer received nab-PTX (q3w, 260 mg/m² ± trastuzumab 6 mg/kg) followed by FEC (q3w, 5-fluorouracil 500 mg/m², epirubicin 100 mg/m², and cyclophosphamide 500 mg/m²) prior to surgery. The efficacy was evaluated using the clinical response rate (CRR), pathological complete response (pCR) rate, and Ki67 labeling index. Safety was evaluated using the frequency of treatment-related adverse events and relative dose intensity (RDI). All patients received at least one course of chemotherapy. The CRR and pCR rate were 88.0% and 40.0%, respectively. The mean Ki67 labeling index was significantly decreased from 47.7% to 24.6% after NAC. The safety profiles were comparable with previously reported regimens, and high RDIs were obtained (97.2% for nab-PTX and 95.5% for FEC). This study illustrated the efficacy and tolerability of a neoadjuvant regimen of nab-PTX followed by FEC.

Nanoparticle albumin-bound paclitaxel in elder patients with advanced squamous non-small-cell lung cancer: A retrospective study

PURPOSE

This study aimed to assess the effect of nanoparticle albumin-bound paclitaxel (nab-PTX) chemotherapy regimens in elderly patients (≥70 years old) with advanced squamous non-small-cell lung cancer (NSCLC).

PATIENTS AND METHODS

The clinical records of elderly patients aged ≥70 years with advanced squamous NSCLC were reviewed retrospectively. All of these patients received nab-PTX, with or without combination of chemotherapy in Shandong Cancer Hospital and Institute between 1 July 2012 and 30 June 2017. We analyzed the toxicity profiles, progression-free survival (PFS), overall survival (OS), objective response rate (ORR), and disease control rate (DCR).

RESULTS

Totally, 52 elderly patients with squamous NSCLC were included in the analysis. For all patients, the ORR was 34.6%, the DCR was 80.8%, median PFS was 5.9 months (95% confidence interval [CI]: 4.0-7.8 months), and median OS was 14.3 months (95% CI: 11.0-17.8 months). Combination with chemotherapy significantly prolonged OS (19.3 vs 11.2 months, P = .016), despite a nonsignificant improvement in PFS (7.1 vs 4.2 months, P = .060) vs monotherapy. For patients who received nab-PTX as first-line treatment, the median PFS and OS were 6.7 months and 17.2 months, respectively, and the median OS in combination therapy subgroup was significantly higher than that in monotherapy group (20.3 vs 11.2 months, P = .013). Meanwhile, the median PFS and OS of patients with nab-PTX as second- or later-line treatment were 4.4 months and 13.3 months, respectively, but no survival benefit was achieved by the combination chemotherapy when compared with single-agent chemotherapy. Hematologic toxicities were the most common adverse events (AEs), which include grade 3 or 4 neutropenia (13.7%), thrombocytopenia (4.1%), and anemia (6.8%). The main nonhematologic toxicities were peripheral sensory neuropathy (39.7%), followed by anorexia and nausea/vomiting.

CONCLUSION

In elderly advanced squamous NSCLC patients, the treatment of nab-PTX was effective and well tolerated.

Phase I study of nab-paclitaxel plus carboplatin and concurrent thoracic radiotherapy in patients with locally advanced non-small cell lung cancer

BACKGROUND

The aim of our study was to determine the maximum tolerated dose (MTD) and recommended dose (RD) of nanoparticle albumin-bound paclitaxel (nab-paclitaxel) plus carboplatin in combination with thoracic radiotherapy for patients with locally advanced stage III non-small cell lung cancer (NSCLC).

METHODS

Weekly nab-paclitaxel plus carboplatin was administered intravenously for 6 weeks. Doses of each drug were planned as follows: level 1, 40/2; level 2, 60/2; level 3, 80/2 (nab-paclitaxel [mg/m²]/carboplatin [area under the plasma concentration time curve mg/ml/min]). Concurrent thoracic radiotherapy was administered in 2-Gy fractions 5 times weekly, to a total dose of 60 Gy.

RESULTS

Fourteen patients were enrolled in the present study. Eleven (78%) patients received full cycles (6 cycles) of chemotherapy, and 12 (86%) patients received 60 Gy of thoracic radiotherapy. At level 1, none of 3 patients experienced a dose-limiting toxicity (DLT). At level 2, 2 of 7 patients developed grade 3 diarrhea, grade 3 hyponatremia, grade 3 fatigue, and grade 3 esophagitis. Therefore, 4 patients were started at dose level 3 and none developed a DLT. No pulmonary toxicities, such as interstitial pneumonitis and treatment-related deaths, were observed at either level. Therefore, level 3 was considered the MTD and level 3 was defined as the RD. An objective response was observed in 71.4% of all patients.

CONCLUSIONS

This regimen is feasible and well tolerated for the treatment of patients with unresectable locally advanced NSCLC.