Tagged: Chemotherapy

Could Metformin and Rapamycin Replace Maintenance Chemotherapy?

December 16, 2021

Researchers explored metformin with or without rapamycin as maintenance therapy in patients with metastatic pancreatic adenocarcinoma.

Malignant fluid cytology; Malignant cells of adenocarcinoma may spread to fluid of pleural or peritoneal cavity in cancer from the breast, lung, colon, pancreas, ovary, endometrium or other sites. — Malignant cells of adenocarcinoma

Maintenance chemotherapy has previously been recommended for patients with metastatic pancreatic ductal adenocarcinoma (mPDA)—as PDA is an aggressive cancer at all stages, and treatment options are limited for later-stage mPDA. However, maintenance chemotherapy regimens often lead to toxicity and are not viable long-term options. Therefore, researchers are exploring alternative maintenance therapies for mPDA patients. In preclinical studies, the therapeutic combination of metformin and rapamycin demonstrated a potential synergy of anti-tumor activity in PDA.

“A synergistic effect of the combination of metformin with rapamycin was suggested by preclinical studies demonstrating enhanced inhibition of mTOR in a pancreatic cancer cell line and better growth inhibition of pancreatic cancer cells in a xenograft tumor model with the combination than either agent alone [21].”

Metformin is an antihyperglycemic drug that is frequently prescribed for patients with diabetes to help control blood sugar levels. Rapamycin is an immunosuppressive drug that has historically been prescribed to prevent organ rejection in kidney transplant patients. (Today, rapamycin is also being considered for its potential use in anti-aging and longevity interventions.) In animals, metformin and rapamycin both inhibit the major biological regulator of growth, named the mammalian target of rapamycin (mTOR). mTOR is thought to be a main driver of many (if not all) aging-related diseases, including cancers such as PDA.

“Mechanistic/mammalian target of rapamycin (mTOR) is a serine/threonine protein kinase which acts as a signaling node downstream of several oncogenic pathways including KRAS/MEK/ERK and PI3K/Akt, both of which are thought to be relevant drivers in a majority of PDAs [6–9].”

The Study

Given its promising potential, researchers—from Johns Hopkins University School of Medicine, Virginia Piper Cancer Center at HonorHealth, Translational Genomics Research Institute (TGen), and Shanghai Jiao Tong University School of Medicine—conducted a study exploring metformin, plus or minus rapamycin, in patients with metastatic PDA. Their priority research paper was published by Oncotarget in 2020, and entitled, “An exploratory study of metformin with or without rapamycin as maintenance therapy after induction chemotherapy in patients with metastatic pancreatic adenocarcinoma”.

A total of 22 unselected patients with mPDA were included in this randomized open-label phase 1b study between June 2014 and December 2017. Patients were at least 18 years of age and had previously been treated with chemotherapy for mPDA. At the beginning of the study, patients had either stable mPDA or responding mPDA for at least six months after induction chemotherapy. Half of the patients were randomly assigned to study Arm A, and the other 11 patients were assigned to study Arm B. Of note, the average age of the participants in Arm B was older (52–72; 66) than the participants in Arm A (34-73; 58). Otherwise, baseline characteristics between the study groups were relatively well-balanced.

Participants in study Arm A were assigned to take 850 milligrams of metformin orally, two times per day, for at least 12 months. Participants in study Arm B were assigned to take metformin and four milligrams of rapamycin once per day, for at least 12 months. The researchers conducted PET/CT scans, immunologic and metabolic analyses, statistical analysis, and continuously recorded and monitored for safety, patient tolerance, toxicity, and treatment-related adverse events.

“Treatment was continued until disease progression, intolerance of study treatments, or study closure, which occurred only after all remaining patients received a minimum of 12 months of treatment.”

Results and Conclusion

“In conclusion, the administration of metformin with or without rapamycin in patients with mPDA who achieve a response to chemotherapy is well-tolerated and was associated with better than expected overall survival in this study.”

The researchers observed “remarkably longer than expected” progression free survival and overall survival in this typically poor-prognosis population of patients. In this cohort, a low neutrophil-to-lymphocyte ratio and decreased fluorodeoxyglucose-avidity and/or decreased CA19-9 from baseline predicted improved outcomes among the long-term survivors. Overall, metformin and rapamycin were well-tolerated and their safety profiles were found to be comparable to previous reports. The researchers were forthcoming about limitations of their study—as their cohort was relatively small and the study was not powered to detect differences in clinical activity between the treatment arms.

“To this end, we identified several factors which may be used to select for patients with improved outcomes; however, whether good prognosis patients need any further treatment at all and whether poor prognosis patients will benefit from continued chemotherapy rather than a maintenance approach are not known and additional prospective studies are needed to answer these questions.”

Click here to read the full priority research paper, published by Oncotarget.

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Oncotarget

New Study: Vaccine Enhances Breast Cancer Treatment

October 27, 2021

Researchers conducted a study to examine the efficacy of adding the P10s-PADRE vaccine to chemotherapy treatments for patients with HR+/HER2− breast cancer.

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The most common type of breast cancer in the United States is HR+/HER2− breast cancer. Patients with HR+/HER2− breast cancer often face the threat of distant recurrence—long after the completion of their treatment. Previous studies have found that high levels of tumor infiltrating lymphocytes (TILs) were associated with improved outcomes and recurrence-free survival in patients with HR+/HER2− breast cancer. These studies and many others have prompted researchers to further develop and test cancer vaccines in an effort to elicit anti-tumor immune responses in these patients.

“Therefore, a rational combination therapy that enhances the immune-stimulatory properties of NAC [neoadjuvant chemotherapy], can provide long-term survival benefits for this patient population.”

Researchers from University of Arkansas for Medical Sciences, University of Texas Southwestern, Highlands Oncology Group, and Université Claude Bernard Lyon 1 conducted a new single-arm Phase Ib clinical trial. Early-stage HR+/HER2− breast cancer patients were treated with carbohydrate-mimetic peptides, the P10s-PADRE vaccine, in combination with chemotherapy treatments. Their paper was chosen as the cover of Oncotarget’s Volume 12, Issue 22, and entitled, “P10s-PADRE vaccine combined with neoadjuvant chemotherapy in ER-positive breast cancer patients induces humoral and cellular immune responses.”

“The main objective of our study was to determine an appropriate schedule to be used for adding the P10s-PADRE vaccine to cancer chemotherapy in the neoadjuvant setting considering the ability of the vaccine to elicit adequate antibody response.”

The Study

After meeting the study’s detailed inclusion/exclusion criteria, a total of 25 patients with HR+/HER2− breast cancer were selected to partake in this single-arm Phase Ib clinical trial. Patients were divided into five cohorts (five patients per cohort): A, B, C, D, and E. Each patient was treated with a combination of four therapies over the course of 22-25 weeks, including three doses of the peptide-based P10s-PADRE cancer vaccine, four doses of Cyclophosphamide (chemotherapy), four doses of Doxorubicin (chemotherapy) and four doses of Docetaxel (chemotherapy). Using a cohort-specific treatment schedule for the previously stated combination of therapies, the researchers assessed the feasibility, safety and immunogenicity achieved in each cohort and each patient.

Additionally, patients underwent surgery between weeks 26 and 33 (four to eight weeks after their last chemotherapy treatment). Each cohort also had a cohort-specific blood draw schedule—blood was drawn at eight different times in the 73-week time frame. Blood draws were used to conduct flow cytometry, measure the concentration of cytokines, natural killer (NK) cells and antibodies, and to determine the presence of anti-peptide antibody response and the percentage of TILs. The researchers observed that all five cohorts saw a significant reduction in tumor size.

“The data suggest that subjects enrolled in schedule C generated a more consistent and robust antibody response, therefore schedule C appears as the schedule of choice for future combination therapy.”

Their findings concluded that, in combination with chemotherapy, P10s-PADRE immunization in HR+/HER2− breast cancer patients induced “acceptable” antibody responses in study cohorts C and E. The treatment schedule in cohort C demonstrated the strongest antibody response by affecting the expression levels of NK-cell markers, stimulating the production of cytokines, T-cells and TILs. However, the researchers note that continued analysis of the blood samples collected could show serum antibodies may begin to appear later on in patients enrolled in the other treatment schedules.

Conclusion

“This Phase Ib clinical trial of the P10s-PADRE vaccine shows that immunization in combination with a standard-of-care NAC is feasible and well-tolerated. Combination therapy induces antibody response, stimulates activation of NK cells, and is associated with infiltration of T cells in tumor microenvironment. Randomized phase II trials focusing on treatment schedule C are needed to validate current findings and evaluate clinical efficacy.”

Click here to read the full research paper, published by Oncotarget.

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Oncotarget is a unique platform designed to house scientific studies in a journal format that is available for anyone to read—without a paywall making access more difficult. This means information that has the potential to benefit our societies from the inside out can be shared with friends, neighbors, colleagues, and other researchers, far and wide.

For media inquiries, please contact media@impactjournals.com.

Oncotarget

Trending With Impact: Low-Dose Chemo Inhibits Resistant Breast Cancer

June 18, 2021

In this trending in vitro study, researchers assessed the efficacy of low-dose 6-mercaptopurine and 5-azacitidine to inhibit high resistance triple-negative breast cancer cells.

Photomicrograph of a breast cancer (grade 3 invasive ductal carcinoma) with frequent mitoses (mitotic figures), including a large central atypical mitoses.

The Trending with Impact series highlights Oncotarget publications attracting higher visibility among readers around the world online, in the news, and on social media—beyond normal readership levels. Look for future science news about the latest trending publications here, and at Oncotarget.com.

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Listen to an audio version of this article

Triple-negative breast cancer (TNBC) accounts for 10-15% of all breast cancers. “Triple-negative” in this subtype of breast cancer cell refers to the lack of HER2 protein and estrogen and progesterone receptors. This means that TNBC cannot be treated with hormone inhibition and must be treated with conventional chemotherapy. In addition, many of these breast cancer cells can opportunistically switch between proliferation and quiescence—a difficult phenotype to treat. Patients diagnosed with this highly adaptable cancer frequently relapse and develop resistance to treatments.

In 2021, researchers from The University of Texas MD Anderson Cancer Center conducted a research study in hopes of developing a safe and effective therapeutic combination to treat resistant triple-negative breast cancer. Their paper, published in Oncotarget’s Volume 12, Issue 7, was entitled: “Inhibition of resistant triple-negative breast cancer cells with low-dose 6-mercaptopurine and 5-azacitidine.”

The Study

“Evidence suggests that SUM149-metabolic adaptable (MA) cells are a suitable model of resistant human triple-negative breast cancer (TNBC) cells that can survive bottlenecks in the body, including therapeutic interventions, by opportunistically switching between quiescence and cell proliferation [5, 7, 8].”

In this in vitro study, researchers cultured three highly drug-resistant and metastatic progenitor-like TNBC cell lines with opportunistic switching between quiescence and proliferation. Researchers focused on designing a safe treatment that is effective in both low- and high-risk patients. The researchers note that it was critical to their study that the regimen is proven safe to administer to patients for early use in the minimal residual disease (MRD) stage after surgery, and before clinical metastasis is detected.

“For a potential therapy to be suitable at the MRD stage, it must be safe (an important criterion prior to clinical relapse) and disrupt heterogeneous progenitor-like cancer cells that evolve into clinical metastases.”

Two chemotherapy and immunosuppressive drugs (ribonucleoside analogues) were tested on the cell lines at low doses for the sake of viability in the MRD stage: 6-mercaptopurine (6-MP) and 5-azacitidine (5-AzaC). Both of these drugs have been clinically proven to be well-tolerated and to have drug-sensitizing, quiescence-stabilizing, and apoptosis-inducing effects in cancer cells.

“We chose 5-AzaC because it could complement 6-MP’s effects on the transcriptome and epigenome, and—as indicated by many Phase 1 clinical trials—5-AzaC is well tolerated [11].”

Results & Conclusion

“Our studies suggest that low-dose 6-MP, which is a purine analogue and very effective in maintaining remission in IBD [9], inhibits highly adaptable TNBC cells in our model, presumably by disrupting their transcriptome and epigenome.”

Researchers found that these low-dose therapeutics take several weeks to become effective. Despite the low dose, 6-MP (complimented by 5-AzaC) was capable of inhibiting highly adaptable TNBC cells. The researchers also point out that, based on decades of 6-MP’s use in patients with inflammatory bowel disease (IBD), this drug may be used regularly to modulate the immune system and prevent disease recurrence through its ability to inhibit chronic inflammation associated with advanced cancers.

“We suggest that low dose 6-MP and other drugs that would complement 6-MP’s action, such as 5-AzaC, could be suitable for preventing recurrence and metastasis in high-risk breast cancers. 6-MP could be taken lifelong if it is necessary for maintaining a long-term remission.”

Click here to read the full scientific study, published by Oncotarget.

Oncotarget

Trending with Impact: Nimotuzumab Improves Non-HPV Oropharynx Cancers

January 7, 2021

Researchers perform a subgroup analysis study demonstrating positive results in patients with HPV-negative oropharyngeal cancers due to the addition of nimotuzumab while receiving cisplatin and radiation treatment.

An image depicting the nasopharynx, pharynx, and the oropharynx.

The Trending with Impact series highlights Oncotarget publications attracting higher visibility among readers around the world online, in the news, and on social media—beyond normal readership levels. Look for future science news and articles about the latest trending publications here, and at Oncotarget.com.

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Oral cancer in any part of the oropharynx (the back-third of the tongue, tonsils, soft palate, and back and sides of the throat) is called oropharyngeal cancer. Each year, oral cancer accounts for around 53,000 new patient diagnoses in the United States. However, the highest number of cases of oral cancer in the world are found in India, and this number is increasing.

“As opposed to HPV related oropharyngeal cancer, HPV negative oropharyngeal cancers have worse prognosis.”

Researchers from Tata Memorial Hospital and Tata Memorial Centre in Mumbai, India, previously reported that in a phase three randomized study of an epidermal growth factor receptor inhibitor medication and, called cetuximab, showed a trend towards improvement when used in patients with locally advanced head and neck cancers. Compared with results in other similar studies, they believe their results were likely due to a younger cohort of patients with predominantly HPV negative diseases.

“Taking this into consideration, we decided to perform a subgroup analysis of the HPV negative oropharyngeal cancer cohort, to study the absolute improvement in 2-year outcomes with the addition of nimotuzumab. We compared 2 year progression free survival (PFS), disease free survival (DFS), locoregional control (LRC) and overall survival (OS) between both arms.”

The Study

“HPV negative oropharyngeal cancer has unsatisfactory treatment outcomes and is a candidate for escalation of treatment. We wanted to determine whether the addition of nimotuzumab to cisplatin-radiation could improve outcomes in these poor-risk tumors.”

In this study, the researchers gathered 536 patients undergoing definitive chemoradiation for locally advanced head and neck cancers, with 269 having a primary tumor located in the oropharynx. Of these patients, 187 were p16 protein negative and were divided into two treatment arms: 91 in the cisplatin-radiotherapy (CRT) treatment arm and 97 in the nimotuzumab-cisplatin-radiotherapy (NCRT) treatment arm. Nimotuzumab is an antibody that binds to epidermal growth factor receptor IgG1 and a radiosensitizer.

The cohort consisted of only 21 females, therefore the participants were primarily male, with a median age of 54.5, 90% reported tobacco use, and 80% were in disease stage IV. Patients in the CRT treatment arm were given 30mg/m2 of cisplatin weekly, in addition to radiation therapy. In the NCRT treatment arm, in addition to radiation therapy, patients received 200 mg of nimotuzumab and 30 mg/m2 cisplatin weekly.

Results

Researchers found that the HPV positive/negative interaction test using immunohistochemistry staining taken by each participant was a significant determinant in progression free survival, locoregional control, and overall survival, but not in disease free survival. They suggest this data shows that the addition of nimotuzumab has a differential patient impact on disease free survival with respect to HPV status.

In patients taking nimotuzumab, improvement in locoregional control was largely responsible for their improvement in progression free survival. On average, time to locoregional failure in the CRT treatment arm was 17.3 months, and in the NCRT treatment arm, it was 60.3 months. The team also found that the addition of nimotuzumab led to an 18.6% improvement in 2-year overall survival, jumping from 39.0% to 57.6%.

Figure 4: Restricted mean overall survival plots of both arms. arm = 0 represents the plot of the cisplatin radiotherapy arm while arm = 1 represents the plot of the Nimotuzumab-cisplatin radiotherapy arm. — **Figure 4:** Restricted mean overall survival plots of both arms. arm = 0 represents the plot of the cisplatin radiotherapy arm while arm = 1 represents the plot of the Nimotuzumab-cisplatin radiotherapy arm.

“Locoregional control, progression-free survival and overall survival were improved with the addition of nimotuzumab to cisplatin and radiation.”

Conclusion

“The addition of nimotuzumab to weekly cisplatin-radiation improves outcomes inclusive of OS in HPV negative oropharyngeal cancers.”

“The results of the current study clarify the importance of treatment intensification in HPV negative oropharyngeal cancers.”

Click here to read the full scientific study, published in Oncotarget.

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