Immune Checkpoint Inhibitor Therapy and Cardiovascular Adverse Events

SUMMARY: Immune checkpoint inhibitors (ICIs) have dramatically transformed the management and prognosis of various malignancies. By enhancing the immune systems ability to identify and destroy cancer cells, ICIs have provided significant improvements in treatment outcomes across a range of tumor types. However, the introduction of these therapies has also been accompanied by a spectrum of immune-related Adverse Events (irAEs), including those affecting the cardiovascular system. These CardioVascular Adverse Events (CVAEs) present a serious concern due to their potential impact on patient health and treatment outcomes.

The cardiovascular manifestations associated with ICIs encompass a range of conditions such as myocarditis, pericarditis, acute coronary syndrome, heart failure, arrhythmias, conduction abnormalities, and cardiac arrest. Although the incidence of these events is relatively low (less than 1% of patients), their severity can be profound. Myocarditis, in particular, is a critical concern due to its association with a high mortality rate, which can be as high as 60%. This underscores the need for vigilant monitoring and management strategies to mitigate these risks.

The objective of the systematic review and meta-analysis was to elucidate the incidence and outcomes of CVAEs associated with ICIs and to assess the effectiveness of various management strategies for myocarditis. This analysis sought to update the clinical understanding of these adverse effects and provide recommendations based on the most recent data.

The researchers review process involved searching several databases, including PubMed, Embase, and the Cochrane Central Register of Controlled Trials, up to April 4, 2023, and with the gathered data, two separate analyses were performed:
1. Phase 1 to 4 Trials Analysis: Focused on trials involving adults with malignant neoplasms treated with FDA- or EMA-approved ICIs. This analysis aimed to gather data on the incidence of CVAEs associated with these therapies.
2. Case Reports and Retrospective Studies Analysis: Concentrated on clinical manifestations and treatment outcomes for patients who developed CVAEs due to ICIs.

Data were meticulously extracted by two independent investigators, with stringent criteria applied to ensure the relevance and quality of the studies included. For instance, studies with dose escalation, small sample sizes, or non-English publications were excluded. The Primary outcome measure was the incidence of CVAEs.

Incidence of Cardiovascular Adverse Events
The meta-analysis of clinical trials included data from 83,315 participants across 589 trials. The therapies investigated included several ICIs such as Pembrolizumab (KEYTRUDA&reg:), Nivolumab (OPDIVO®), Cemiplimab (LIBTAYO®), Atezolizumab (TECENTRIQ®), Durvalumab (IMFINZI®), Avelumab (BAVENCIO®), and Ipilimumab (YERVOY®). The overall incidence of CVAEs in patients treated with anti-PD-1 or anti-PD-L1 therapies was found to be 0.8%. Notably, Cemiplimab was associated with a higher risk of high-grade cardiovascular adverse events compared to other ICIs (2.91% for Cemiplimab versus 0.69% overall).

The incidence of myocarditis specifically was reported as 0.24% for any grade and 0.2% for high-grade myocarditis. While dual ICI therapy was linked to a higher incidence of myocarditis compared to other regimens, the overall incidence of CVAEs did not significantly differ between dual ICI therapy, ICI plus chemotherapy, or ICI plus Tyrosine Kinase Inhibitors.

Management and Outcomes of Myocarditis

In the analysis of myocarditis cases, which included 223 patients (64.5% men), the majority had received PD-1 or PD-L1 inhibitors. A substantial proportion of these patients had cardiovascular risk factors: 41.1% had hypertension, 16.3% had diabetes, and 46.5% had other risk factors. Among 220 evaluable patients, the mortality rate for myocarditis was alarmingly high at 37.7%.

Management strategies for myocarditis varied, with treatments including high-dose Corticosteroids, Methylprednisolone, IV immunoglobulin, Plasma exchange, Mycophenolate mofetil, Infliximab, and Antithymocyte globulin. Outcomes of these treatments showed mixed results. For instance, high-dose Corticosteroids were associated with a 63.5% improvement rate but also a 26% cardiac mortality rate. Abatacept showed promise with an improvement rate of 91.7% among those who received it. Prospective data suggested that systematic screening for respiratory muscle involvement, active ventilation, prompt use of Abatacept, and the addition of Ruxolitinib might reduce mortality rates. However, the review emphasized that the current management strategies are largely empirical, and there is no definitive evidence on the most effective approach.

Recommendations and Conclusions
The review highlighted a critical need for standardized diagnostic and therapeutic approaches due to the variability in management strategies and the lack of prospective clinical trials. The findings underscore the importance of early recognition, cessation of ICI therapy, and prompt initiation of corticosteroid therapy for optimal management of myocarditis. The review also suggests that further research, including prospective clinical trials and the establishment of international registries, is necessary to enhance the understanding and management of ICI-induced CVAEs.

In summary, while cardiovascular adverse events related to ICIs are rare, their potential severity, particularly myocarditis, warrants heightened awareness and proactive management by clinicians. Early identification and intervention are crucial to improving patient outcomes and reducing mortality associated with these adverse effects.

Immune Checkpoint Inhibitor–Induced Cardiotoxicity. A Systematic Review and Meta-Analysis. Nielsen DL, Juhl CB, Nielsen OH, et al. JAMA Oncol. 2024;doi:10.1001/jamaoncol.2024.3065.

Lung Cancer Risk with Vaping and Cigarette Smoking

SUMMARY: According to the American Cancer Society, tobacco use is responsible for nearly 1 in 5 deaths in the United States and accounts for at least 30% of all cancer deaths. Smokeless tobacco products are a major source of cancer causing nitrosamines, and increase the risk of developing cancer of the oropharynx, esophagus, and pancreas. Cigarette smoke contains more than 7,000 chemicals, many of which are toxic and some linked to cancer.

The use of e-cigarettes (electronic cigarettes) often referred to as “vaping” was introduced to the U.S. market in 2007 after e-cigarettes were first developed in China. When a smoker inhales through the mouth piece of an e-cigarette, the air flow triggers a sensor that switches on a small lithium battery powered heater, which in turn vaporizes liquid nicotine along with PolyEthylene Glycol (PEG) present in a small cartridge. The PEG vapor looks like smoke. The potent liquid form of nicotine extracted from tobacco is tinctured with fragrant flavors such as chocolate, cherry and bubble gum, coloring substances, as well as other chemicals and these e-liquids are powerful neurotoxins. With the rapid growth of the e-cigarette industry and the evidence of potential dangers and risk to public health, particularly children, experts from the world’s leading lung organizations were compelled to release a POSITION statement on e-cigarettes, specifically focusing on their potential adverse effects on human health, and calling on government organizations to ban or restrict the use of e-cigarettes, until their impact on health is better understood. With epidemiological data demonstrating that nicotine use is a gateway to the use of cocaine and marijuana and subsequent lifelong addiction, the Forum of International Respiratory Societies (FIRS), an organization composed of the world’s leading international respiratory societies including American Thoracic Society (ATS) and the American College of Chest Physicians (ACCP) made several important recommendations (not included here).

The health risks associated with vaping might be compounded by the presence of harmful substances in e-cigarette aerosols, such as diacetyl, diethylene glycol, aldehydes, cadmium, benzene, and heavy metals like nickel, tin, and lead. These components are known to be toxic and carcinogenic, raising concerns about their contribution to lung cancer risk.

Recent concerns have emerged about the potential health risks associated with vaping, particularly in relation to lung cancer. Although nicotine exposure from electronic delivery systems (vaping) has been linked to elevated risks of lung conditions, the impact on lung cancer risk has remained relatively unexplored. To address this gap, the researchers in this publication conducted a comprehensive case-control study at The Ohio State University in Columbus, Ohio, examining the association between vaping, cigarette smoking, and lung cancer risk. The researchers in this study analyzed medical records from the James Cancer Hospital and Solove Research Institute, encompassing data from 4,975 patients diagnosed with pathologically confirmed lung cancer between 2013 and 2021. This patient cohort was meticulously matched to 27,294 control individuals without cancer on a 5:1 ratio based on age, gender, race, and year of ascertainment. The researchers utilized descriptive statistics and performed logistic regression analyses to evaluate the associations between vaping, smoking, and lung cancer risk. This analysis aimed to determine how these factors individually and synergistically contributed to the likelihood of developing lung cancer.

The results of this analysis demonstrated that the demographic profile of the lung cancer cases showed a predominance of males (55%), with a majority being White (88%). The mean age at diagnosis was 62 years. There was a significantly higher risk of lung cancer among individuals who both vaped and smoked compared to those who only smoked. Specifically, the adjusted Odds Ratio (OR) for those who reported both vaping and smoking was 21.1 (95% CI = 17.1, 26.1), while for smoking alone, it was 6.3 (95% CI = 5.8, 6.8). Further stratification by gender and histologic cell type demonstrated that the risk associated with combined vaping and smoking was consistently over 3X higher compared to smoking alone (P<0.001). This elevated risk persisted even after adjusting for comorbidities, Chronic Obstructive Pulmonary Disease (COPD), and cardiovascular disease.

The researchers added that these findings underscore a markedly higher risk of lung cancer associated with the combination of vaping and smoking compared to smoking alone. This synergistic effect is reminiscent of the risks associated with known carcinogens such as radon or asbestos. The results suggest that the addition of vaping to smoking significantly accelerates the risk of developing lung cancer.

The limitations of this study are that this analysis did not include a vaping-only group, as nearly 97% of those who vaped also reported smoking. Additionally, there was no detailed temporal data on the duration and frequency of vaping versus smoking. However, the consistent significant increase in lung cancer risk observed with combined vaping and smoking indicates a potentially substantial interaction effect.

In conclusion, this case-control study provides compelling evidence suggesting that vaping combined with smoking may significantly elevate lung cancer risk. While these preliminary findings highlight the potential dangers of e-cigarettes, further research is necessary to confirm these results and explore the long-term implications of vaping on lung cancer risk. Physicians should reconsider harm-reduction messages related to vaping, as it may NOT be safer than smoking. Further studies are needed to quantify the exact risks associated with vaping and smoking, as well as to understand the long-term effects.

Vaping, smoking and lung cancer: A case-control study. Bittoni MA, Carbone D, Harris R. Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract 2213.

Cardiovascular Adverse Events Associated with Bispecific T-cell Engager Therapy

SUMMARY: Bispecific T-cell engager (BTE) therapies are a novel class of targeted immunotherapies with activity against hematologic malignancies. These bispecific antibodies have 2 binding domains, one targeting and binding to CD3 on the T-cell receptor, whereas the other is a modifiable domain designed to bind to specific tumor-associated antigens, which can be CD19, CD20, B-Cell Maturation Antigen (BCMA) or GPRC5D. Blinatumomab (BLINCYTO®) targets the CD19 on B-cells and is approved for the treatment of advanced Acute Lymphoblastic Leukemia (ALL); Mosunetuzumab (LUNSUMIO®), Glofitamab (COLUMVI®), and Epcoritamab (EPKINLY®), target CD20 on B cells and have also been approved for the treatment of Non-Hodgkin lymphoma; Teclistamab (TECVAYLI®), targets BCMA expressed on myeloma cells and is approved for use in relapsed/refractory multiple myeloma; Talquetamab (TALVEY®) targets GPRC5D expressed on myeloma cells and is approved for use in relapsed/refractory multiple myeloma.

Adverse events of BTEs include Cytokine Release Syndrome (CRS), hematological toxicities, and neurotoxicity. Serious CardioVascular Adverse Events (CVAEs) have been reported with certain BTEs. However, this has not been clearly defined. Given that CVAEs have not been observed in a previous pharmacovigilance analysis focused on CAR-T therapy, it appears that the pathophysiology of CVAEs associated with novel T-cell modulatory therapies (BTEs) may be different.

The present study was conducted to examine the CardioVascular Adverse Events (CVAEs) associated with Bispecific T-cell Engager therapies (BTEs). The five BTE products considered for analysis were Blinatumomab, Teclistamab, Mosunetuzumab, Glofitamab, and Epcoritamab. Leveraging the vast repository of the US Food and Drug Administration’s Adverse Events Reporting System (FAERS), researchers embarked on a meticulous analysis, investigating the frequency and association of CVAE reporting with BTE, the prognostic implications of CVAEs in patients receiving BTEs, as well as the extent these adverse events overlap with CRS, spanning from October 2014 to March 2023. The primary objective was to delineate the frequency and fatality rates of CVAEs associated with BTEs, encompassing a spectrum of conditions including bleeding, hypotension or shock, thromboembolic disease, heart failure, and conduction abnormalities, myocarditis, pericarditis, sudden death, and vasculitis.

Utilizing multivariable logistic regression models, adjusted for age, sex, and disease status, the researchers calculated adjusted Reporting Odds Ratios (RORs). These RORs served as a metric to gauge the likelihood of reporting a given adverse event with BTEs compared to reporting the same event with all other drugs in the FAERS database.

Their study examined 3,668 cases of reported adverse events, 73.9% of which involved Blinatumomab and 11.2% involved Teclistamab as the primary suspected drug. Mosunetuzumab, Glofitamab and Epcoritamab accounted for a smaller proportion of events. (7.4%, 5.2% and 2.3%, respectively). The median age of patients was 52.0 years, with individuals from 52 countries represented in this analysis, with 43.2% of cases coming from the U.S. The indication for BTE therapy was leukemia/lymphoma in 88.7% of cases, multiple myeloma in 11.2% of cases, and both in 0.1% of cases.

The results of the study unveiled several significant findings:
1) Of the 3668 BTE-related cases reported to FAERS, 20.4% involved CVAEs.
2) BTEs were associated with disproportionately higher rates of fatal CVAEs, an association mainly driven by Teclistamab. Teclistamab was also associated with a disproportionate risk of myocarditis and shock, whereas Blinatumomab was associated with a disproportionate risk of Disseminated Intravascular Coagulation and hypotension.
3) Majority of these fatal CVAEs (96.7%) occurred in individuals without previously documented cardiovascular comorbidities.
4) CVAEs were more likely to be fatal compared with non-CVAEs (31.1% versus 17.4%).
5) CVAEs were not necessarily a consequence of Cytokine Release Syndrome (CRS), as approximately 85% of CVAE reports did not involve concurrent CRS.
6) In general, CVAEs tended to occur sooner following BTE therapy compared with non-CVAEs (median time to onset 6 days versus17 days; p<0.001).
7) No significant associations with CVAEs were observed with the other three BTE products (Glofitamab, Mosunetuzumab, and Epcoritamab).
8) Compared with CVAEs, neurotoxicity and CRS commonly associated with BTEs were associated with lower mortality. The elevated risk of death following CVAEs was especially noted for myocarditis, heart failure, bleeding, and DIC, with which mortality rates were 2-3 times higher than other AEs.

The researchers concluded that in this first postmarketing pharmacovigilance analysis of BTEs, CVAEs were involved in approximately 1 in 5 Adverse Event reports, and carried a significantly high mortality rate. The researchers cautioned that clinicians must be cognizant of the potential of CVAEs when treating patients with BTEs, and consider either stopping or switching therapies when CVAEs are suspected.

Cardiovascular toxicities associated with bispecific T-cell engager therapy. Sayed A, Munir M, Ghazi SM, et al. J Immunother Cancer. 2024 Feb 21;12(2):e008518. doi: 10.1136/jitc-2023-008518.

FDA Approves ENHERTU® for Unresectable or Metastatic HER2-Positive Solid Tumors

SUMMARY: The FDA on April 5, 2024, granted accelerated approval to ENHERTU® (fam-Trastuzumab Deruxtecan-nxki) for adult patients with unresectable or metastatic HER2-positive (IHC3+) solid tumors who have received prior systemic treatment, and have no satisfactory alternative treatment options. This tumor agnostic indication was approved based on Objective Response Rate and Duration of Response.

The HER or erbB family of receptors consist of HER1, HER2, HER3 and HER4. HER2 is a Tyrosine Kinase Receptor growth-promoting protein and is involved in normal cell growth. It is expressed on the surface of various tissue cells throughout the body. In some cancers, HER2 expression is amplified or the cells have activating mutations. HER2 gene amplification can result in HER2 protein overexpression which is often associated with aggressive disease and poor prognosis. Approximately 15-20% of invasive breast cancers as well as advanced Gastric and GastroEsophageal (GE) junction cancers overexpress or have amplification of the HER2 oncogene. These patients often receive first line treatment with a combination of chemotherapy plus anti-HER2 antibody. Additionally, HER2 directed therapies have been used to treat lung and colorectal cancers. HER2 is an emerging biomarker in other solid tumor types including biliary tract, bladder, cervical, endometrial, ovarian and pancreatic cancers with HER2 positive expression rates varying from 1-28%. There are currently no approved HER2 directed therapies for these cancers following progression on standard of care therapies. There is an unmet need for effective therapies for these HER2 expressing tumor types.

ENHERTU® (Trastuzumab Deruxtecan) is an Antibody-Drug Conjugate (ADC) composed of a humanized monoclonal antibody specifically targeting HER2, with the amino acid sequence similar to Trastuzumab, a cleavable tetrapeptide-based linker, and a potent cytotoxic Topoisomerase I inhibitor as the cytotoxic drug (payload). ENHERTU® has a favorable pharmacokinetic profile and the tetrapeptide-based linker is stable in the plasma and is selectively cleaved by cathepsins that are up-regulated in tumor cells. Unlike KADCYLA® (ado-Trastuzumab emtansine), another ADC targeting HER2, ENHERTU® has a higher drug-to-antibody ratio (8 versus 4), released payload easily crosses the cell membrane with resulting potent cytotoxic effect on neighboring tumor cells regardless of target expression, and the released cytotoxic agent (payload) has a short half-life, thus minimizing systemic exposure.

The FDA approval was based on the efficacy of ENHERTU® in 192 adult patients with previously treated unresectable or metastatic HER2-positive (IHC 3+) solid tumors who were enrolled in one of three multicenter trials: DESTINY-PanTumor02 (NCT04482309), DESTINY-Lung01 (NCT03505710), and DESTINY-CRC02 (NCT04744831). All three trials excluded patients with a history of Interstitial Lung Disease /pneumonitis requiring treatment with steroids or Interstitial Lung Disease /pneumonitis at screening and clinically significant cardiac disease. Patients were also excluded for active brain metastases or ECOG performance status more than 1. Treatment was administered until disease progression or unacceptable toxicity. The major efficacy outcome measure in all three trials was confirmed Objective Response Rate (ORR), and an additional efficacy outcome was Duration of Response (DOR). All outcomes were assessed by Independent Central Review based on RECIST criteria.

DESTINY-PanTumor02 is a global, multicenter, multi-cohort, open-label, ongoing Phase II trial evaluating the efficacy and safety of ENHERTU® 5.4 mg/kg IV for the treatment of previously treated HER2 expressing tumors, including biliary tract, bladder, cervical, endometrial, ovarian, pancreatic cancer or other tumors. DESTINY-PanTumor02 enrolled 267 patients (N=267) at multiple sites in Asia, Europe and North America. Patients had received a median of two prior cancer therapies. In this study, the ORR was 51.4% and median DOR was 19.4 months.

DESTINY-Lung01 is a global, open-label, two-cohort, Phase II trial evaluating the efficacy and safety of ENHERTU® 6.4 mg/kg IV and 5.4 mg/kg IV in patients with HER2 mutant (cohort 2, N=91) or HER2 overexpressing (cohort 1 and 1a, N=90) (defined as IHC 3+ or IHC 2+) unresectable or metastatic non-squamous Non-Small Cell Lung Cancer (NSCLC), who had progressed after one or more systemic therapies. In this study, the ORR was 52.9% and the median DOR was 6.9 months.

DESTINY-CRC02 is a global, randomized, two arm, parallel, multicenter Phase II trial evaluating the efficacy and safety of two doses, 5.4 mg/kg IV or 6.4 mg/kg IV of ENHERTU® in patients with locally advanced, unresectable or metastatic HER2 positive colorectal cancer of BRAF wild-type, or RAS wild-type and RAS mutant tumor types, previously treated with standard therapy. The trial was conducted in two stages. In the first stage, patients (N=80) were randomized 1:1 to receive either 5.4 mg/kg IV or 6.4 mg/kg IV of ENHERTU®. In the second stage, additional patients (N=42) were enrolled in the 5.4 mg/kg IV arm. In DESTINY-CRC02, ORR was 46.9%, and DOR was 5.5 months.

The most common adverse reactions were cytopenias, nausea, vomiting, fatigue, liver function abnormalities and upper respiratory tract infection. The recommended dose of ENHERTU® for this indication is 5.4 mg/kg IV every 3 weeks until disease progression or unacceptable toxicity.

The forementioned trials validate HER2 as an actionable biomarker across a broad range of tumor types, and ENHERTU® has the potential to benefit patients with HER2 expressing advanced disease, who may face a poor prognosis and currently have limited treatment options.

https://www.fda.gov/drugs/resources-information-approved-drugs/fda-grants-accelerated-approval-fam-trastuzumab-deruxtecan-nxki-unresectable-or-metastatic-her2.

April 2024: Current Tumor-Agnostic Therapies

The FDA on April 5, 2024, granted accelerated approval to Fam-trastuzumab deruxtecan-nxki (ENHERTU®) for adult patients with unresectable or metastatic HER2-positive (IHC3+) solid tumors who have received prior systemic treatment and have no satisfactory alternative treatment options.

This is the 6th Tumor-Agnostic therapeutic target for which an agent has received regulatory agency approval.

A current summary of the Tumor-Agnostic therapeutic targets, and agents approved, is provided below. Please review the drug Prescribing Information for the respective therapeutic agents, as NOT all products are approved for First Line therapy.

MMRd/MSI-H: Pembrolizumab (KEYTRUDA®) and Dostarlimab (JEMPERLI®)
TMB-H: Pembrolizumab (KEYTRUDA®)
NTRK fusions: Larotrectinib (VITRAKVI) and Entrectinib (ROZLYTREK®)
BRAF V600E: Dabrafenib (TAFINLAR®) plus Trametinib (MEKINIST®)
RET Fusions: Selpercatinib (RETEVMO®)
HER2 Overexpression: Fam-trastuzumab deruxtecan (ENHERTU®)

The National Cancer Institute describes Tumor-Agnostic therapy as a type of targeted treatment that uses drugs or other substances to treat cancer based on the cancer’s genetic and molecular features, without regard to the cancer type or where the cancer started in the body. Tissue-Agnostic therapy uses the same drug to treat all cancer types that have the genetic mutation or biomarker, that is targeted by the drug.

Metformin May Reduce the Risk of Cancers, Especially GI Malignancies

SUMMARY: The American Cancer Society estimates that in 2024, 2,001,140 new cancer cases will be diagnosed, and 611,720 cancer deaths are projected to occur in the United States. The Center for Disease Control and Prevention recommends healthy eating habits, limiting alcohol consumption and skin protection for cancer prevention, screening tests for breast, cervical, colorectal and lung cancer for early detection, as well as HPV and Hepatitis B vaccination to lower the risk of cervical and liver cancer respectively.

Metformin is one of the most commonly prescribed agents for Type 2 diabetes worldwide. Metformin is a synthetic guanidine derived compound. Numerous epidemiological studies have shown that Type 2 diabetes patients receiving Metformin had a decreased risk of the occurrence of various types of cancers, compared to those taking other antidiabetic agents. Numerous meta-analyses have also confirmed that Metformin reduces cancer incidence by 30-50%. These findings in addition to the safety and cost-effectiveness of Metformin have generated a lot of interest in the research community. Metformin exhibited promising anticancer effects in preclinical studies by inducing cell cycle arrest at different stages of cell division depending on the cancer type, promoting cell death, suppressing cancer cell migration, invasion and metastasis, as well as deregulating cancer metabolism. Further Metformin enhanced sensitivity to radiotherapy, chemotherapy, and immunotherapy.

There has been renewed interest in the anticancer mechanisms of Metformin and it has been reported to mimic significant metabolic effects of caloric restriction at both cellular and systemic levels. It has been postulated that Metformin induces a direct effect on cancer cells, independent of blood glucose and insulin levels, and indirect effect thru systemic metabolic changes depending on blood glucose and insulin levels. The primary site at which Metformin exerts its anticancer activity is the mitochondria. Metformin inhibits mitochondrial complex I and triggers energy depletion, which activates AMPK (Adenosine Monophosphate-activated Protein Kinase ) and inhibits mTOR, limiting cancer growth. Additionally, metformin also exerts anticancer effects that are independent of AMPK but rather dependent on Rag GTPases or REDD1.

To date, there has been no comprehensive review of the literature assessing the relationship between Metformin and cancer risk. The researchers therefore conducted a comprehensive systematic review of literature and meta-analysis, to investigate the association between Metformin or any of its analogs use, and cancer risk, and specific cancer type when possible. From an initial pool of more than 6,000 articles, identified in PubMed/MEDLINE, Embase, Cochrane Library, Web of Science, and Scopus from inception through March 7, 2023, 166 studies with cancer incidence information were included in the meta-analysis. Majority of these studies took place in populations with Type 2 diabetes. This analysis was then stratified by cancer type and study type. The authors decided not to provide a summary analysis for specific cancer types because of the heterogeneity between studies due to different study designs, as this analysis included many case-control studies, some prospective cohort studies and some retrospective cohort studies.

This analysis showed a reduced risk for overall cancer in case-control studies (RR=0.55) and in prospective cohort studies (RR = 0.65). Metformin use was associated with reduced risk of gastrointestinal cancer (RR = 0.79), urologic cancer (RR = 0.88) and hematologic malignancies (RR = 0.87). The most striking association was observed for gastrointestinal cancer risk, which showed a risk reduction of 21%.

It was concluded that Metformin may be associated with a decreased risk of many cancer types, and there appears a striking association between Metformin and reduced risk for gastrointestinal cancers. The researchers added that additional studies in populations without diabetes are needed to better understand the utility of Metformin in cancer prevention.

Association of metformin use and cancer incidence: a systematic review and meta-analysis. O’Connor L, Bailey-Whyte M, Bhattacharya M, et al. JNCI:Journal of the National Cancer Institute, djae021, https://doi.org/10.1093/jnci/djae021. 30 January 2024.

Late Breaking Abstract: ASH – 2023: Pomalidomide Reduces Epistaxis and Improves Quality of Life in Hereditary Hemorrhagic Telangiectasia

SUMMARY: Hereditary Hemorrhagic Telangiectasia (HHT) is an Autosomal Dominant inherited disorder caused by mutations in regulators of angiogenesis. Also known as Osler-Weber-Rendu syndrome, HHT is the second most common inherited bleeding disorder after Von Willebrand Disease, with an estimated prevalence of 1 in 5000. HHT presents with a triad of recurrent epistaxis with iron deficiency anemia, mucocutaneous telangiectasias, and visceral arteriovenous malformations (AVMs) and in more severe cases, patients may experience life-threatening hemorrhage, stroke, or high-output heart failure, requiring hospitalizations, with a negative impact on Quality of Life (QOL). HHT is caused by disruptions in angiogenesis signaling, resulting in impaired vascular development. Three genes in the Transforming Growth Factor-beta (TGF-β) signaling pathway have been implicated and they include Endoglin (ENG), activin A receptor ligand type I (ACVRL1 or ALK-1), and SMAD family member 4 (MADH4 or SMAD4).

Small non-randomized studies suggested that systemic antiangiogenic agent Bevacizumab or immunomodulatory drugs with antiangiogenic properties such as Thalidomide, Lenalidomide, and Pomalidomide may be effective in treating HHT. There are presently no FDA approved therapies for HHT.

PATH-HHT is a randomized, placebo-controlled, multicenter clinical trial, conducted in the US to determine the safety and efficacy of Pomalidomide, for bleeding in HHT. In this study, 144 patients (N=144) diagnosed with HHT were randomly assigned in a 2:1 ratio to receive either Pomalidomide 4 mg orally daily or a matching placebo, for a duration of six months. Pomalidomide, instead of another immunomodulatory drug, was chosen due to its favorable safety profile. Eligibility criteria included a confirmed HHT diagnosis per Curaçao Diagnostic Criteria, documented anemia, and an Epistaxis Severity Score (ESS) of 3 or more over the prior 3 months. Epistaxis Severity Score (ESS) was developed to self- describe epistaxis severity from 0-10, with 10 representing the most severe epistaxis. Mild is ESS of 1-4, moderate is ESS of 4-7 and Severe is ESS of 7-10. The mean age was 59 years and 48% were female. Among the 134 patients who agreed to genetic testing, ENG mutations were detected in 37%, ACVRL1 in 51%, and SMAD4 in 1%. Patients had a mean ESS of 5 at baseline, and mean daily epistaxis duration of 16 minutes. In the preceding 6 months, 84% of patients had required iron infusions and 19% required blood transfusions. More than a third of the patients also had GI bleeding, and 40% had pulmonary AVMs. The Primary endpoint of the study was the change in Epistaxis Severity Score (ESS), from baseline to the end of the six-month treatment period. Secondary endpoints included changes in the average daily self-reported duration of epistaxis from the 4 weeks preceding the baseline visit to weeks 20-24 of treatment, the amount of parenteral iron infused or blood transfused, and change in Quality-of-Life (QOL) measurements, including an HHT-specific QOL score.

The results of this study showed that treatment with Pomalidomide led to a significant reduction in epistaxis severity compared to placebo. The mean ESS decreased by -1.84 in the Pomalidomide group versus -0.89 in the placebo group at 24 weeks (P=0.003). This benefit was seen as early as week 12. Additionally, patients treated with Pomalidomide reported greater improvements in Quality of Life (QOL) related to HHT. The HHT-specific QOL score (ranges from 0-16 with higher scores indicating more limitations) also decreased more in the Pomalidomide group versus the placebo group at 24 weeks (P=0.015). Adverse events were more common in the Pomalidomide group and included mild to moderate neutropenia (45% versus 10%), constipation/diarrhea (60% versus 37%), and rash (36% versus 10%).

It was concluded from this largest HHT study that treatment with Pomalidomide demonstrated a significant and highly clinically relevant reduction in epistaxis, as well as an improvement in the HHT-specific QOL score. Pomalidomide holds promise as a therapeutic option for patients with HHT, addressing an unmet medical need, in managing this challenging genetic disorder. Additional studies may identify biomarkers predicting responses to Pomalidomide.

PATH-HHT, a Double-Blind, Randomized, Placebo-Controlled Trial in Hereditary Hemorrhagic Telangiectasia Demonstrates That Pomalidomide Reduces Epistaxis and Improves Quality of Life. Al-Samkari H, Kasthuri RS, Iyer V, et al. Blood (2023) 142 (Supplement 2): LBA-3. https://doi.org/10.1182/blood-2023-191983.

ROZLYTREK® (Entrectinib)

The FDA on October 20, 2023, granted accelerated approval to ROZLYTREK® for pediatric patients older than 1 month with solid tumors that have a Neurotrophic Tyrosine Receptor Kinase (NTRK) gene fusion without a known acquired resistance mutation, are metastatic or where surgical resection is likely to result in severe morbidity, and have progressed following treatment or have no satisfactory standard therapy. In August 2019, FDA granted accelerated approval to ROZLYTREK® for pediatric patients 12 years of age and older for this indication. ROZLYTREK® is a product of Genentech Inc.

TEMODAR® (Temozolomide)

The FDA on September 14, 2023, approved updated labeling for TEMODAR® under Project Renewal, an Oncology Center of Excellence (OCE) initiative aimed at updating labeling information for older oncology drugs to ensure information is clinically meaningful and scientifically up-to-date. This is the second drug to receive a labeling update under this pilot program. The first drug that received approval under Project Renewal was XELODA® (Capecitabine). TEMODAR® is a product of Merck & Co., Inc..