Drugs that lack single-agent activity: are they worth pursuing in combination?

Characteristics and outcomes of new molecular oncology drug approvals, in combination or monotherapy

IMPORTANCE

Understanding the factors that are associated with new molecular entity (NME) cancer drug approvals as a single agent and in combination, and European Society for Medical Oncology (ESMO) scores, can aid in identifying suitable factors to consider in trial designs for future drugs. In addition, the association between the various outcomes can aid in determining benefit when surrogate outcomes are used in approval consideration.

OBJECTIVE

This study aims to (1) use the measures used in evaluating clinical trials by ESMO scores to determine the differences in the characteristics of 2013-2022 Food and Drug Administration (FDA) oncology NME drug approvals for those approved for use in combination or as a monotherapy, and (2) analyze the association between survival outcomes and the response rate for monotherapy NME drugs and/or drugs approved in combination.

DESIGN

Cross-sectional analysis.

SETTING

US FDA Oncology Drug Approvals (2013-2022) PARTICIPANTS: US FDA Oncology Drug Approvals (2013-2022) EXPOSURES: Trial-level characteristics (tumor types, basis of approval, randomized or not, phase) and associations between overall survival (OS), progression-free survival (PFS), or overall response rate (ORR) and whether NME drugs were approved as monotherapy or in combination .

RESULTS

Drugs approved for use as a monotherapy are less likely to be approved using a randomized study (p < 0.001) and more likely to be approved via the accelerated pathway (p = 0.012) and be open-label (p < 0.001). Drugs approved for use as a combination or monotherapy significantly differed on their approval basis (p = 0.002), phase of trial at the time of approval (p = 0.02), and ESMO scores (p = 0.02). There was low correlation between response rate and either PFS or OS metrics. However, nearly all of the drugs with large improvements in OS (> 5months) were drugs with robust ORR.

CONCLUSIONS AND RELEVANCE

Drugs approved as monotherapy with a low response rate are likely to have marginal benefit in OS and PFS.

Cardiovascular/anti-inflammatory drugs repurposed for treating or preventing cancer: A systematic review and meta-analysis of randomized trials

BACKGROUND

Due to encouraging pre-clinical data and supportive observational studies, there has been growing interest in applying cardiovascular drugs (including aspirin, angiotensin-converting enzyme [ACE] inhibitors, statins, and metformin) approved to treat diseases such as hypertension, hyperlipidemia, and diabetes mellitus to the field of oncology. Moreover, given growing costs with cancer care, these medications have offered a potentially more affordable avenue to treat or prevent recurrence of cancer. We sought to investigate the anti-cancer effects of drugs repurposed from cardiology or anti-inflammatories to treat cancer. We specifically evaluated the following drug classes: HMG-CoA reductase inhibitors (statins), cyclo-oxygenase inhibitors, aspirin, metformin, and both angiotensin receptor blockers (ARBs) and angiotensin-converting enzyme inhibitors. We also included non-steroidal anti-inflammatory drugs (NSAIDs) because they exert a similar mechanism to aspirin by blocking prostaglandins and reducing inflammation that is thought to promote the development of cancer.

METHODS

We performed a systematic literature review using PubMed and Web of Science with search terms including "aspirin," "NSAID," "statin" (including specific statin drug names), "metformin," "ACE inhibitors," and "ARBs" (including specific anti-hypertensive drug names) in combination with "cancer." Searches were limited to human studies published between 2000 and 2023.

MAIN OUTCOMES AND MEASURES

The number and percentage of studies reported positive results and pooled estimates of overall survival, progression-free survival, response, and disease-free survival.

RESULTS

We reviewed 3094 titles and included 67 randomized clinical trials. The most common drugs that were tested were metformin (n = 21; 30.9%), celecoxib (n = 20; 29.4%), and simvastatin (n = 8; 11.8%). There was only one study that tested cardiac glycosides and none that studied ACE inhibitors. The most common tumor types were non-small-cell lung cancer (n = 19; 27.9%); breast (n = 8; 20.6%), colorectal (n = 7; 10.3%), and hepatocellular (n = 6; 8.8%). Most studies were conducted in a phase II trial (n = 38; 55.9%). Most studies were tested in metastatic cancers (n = 49; 72.1%) and in the first-line setting (n = 36; 521.9%). Four studies (5.9%) were stopped early because of difficulty with accrual. The majority of studies did not demonstrate an improvement in either progression-free survival (86.1% of studies testing progression-free survival) or in overall survival (94.3% of studies testing overall survival). Progression-free survival was improved in five studies (7.4%), and overall survival was improved in three studies (4.4%). Overall survival was significantly worse in two studies (3.8% of studies testing overall survival), and progression-free survival was worse in one study (2.8% of studies testing progression-free survival).

CONCLUSIONS AND RELEVANCE

Despite promising pre-clinical and population-based data, cardiovascular drugs and anti-inflammatory medications have overall not demonstrated benefit in the treatment or preventing recurrence of cancer. These findings may help guide future potential clinical trials involving these medications when applied in oncology.

Repositioning canakinumab for non-small cell lung cancer-important lessons for drug repurposing in oncology

Canakinumab is an anti-interleukin-1β monoclonal antibody approved for use in a range of immune-related disorders. During the clinical investigation (CANTOS trial) for prevention of cardiovascular complications, therapy was linked to a reduction in both the occurrence and mortality of lung cancer. This unexpected observation fuelled the rapid initiation of four large clinical trials to evaluate potential anticancer efficacy (in combination with chemotherapy and/or immunotherapy), before fully validating these observations in a dedicated study. The first two trials (CANOPY-1 and 2) have now been reported and have both have failed to meet their primary efficacy endpoints. In this article, we explore the scientific and clinical rationale behind the development of canakinumab in oncology, the repurposing approach utilised and implications this may have for the wider drug repurposing field in the development of new cancer medicines.

Independent Drug Action in Combination Therapy: Implications for Precision Oncology

Combination therapies are superior to monotherapy for many cancers. This advantage was historically ascribed to the ability of combinations to address tumor heterogeneity, but synergistic interaction is now a common explanation as well as a design criterion for new combinations. We review evidence that independent drug action, described in 1961, explains the efficacy of many practice-changing combination therapies: it provides populations of patients with heterogeneous drug sensitivities multiple chances of benefit from at least one drug. Understanding response heterogeneity could reveal predictive or pharmacodynamic biomarkers for more precise use of existing drugs and realize the benefits of additivity or synergy.

Implementing targeted therapies in the treatment of glioblastoma: Previous shortcomings, future promises, and a multimodal strategy recommendation

The introduction of targeted therapies to the field of oncology has prolonged the survival of several tumor types. Despite extensive research and numerous trials, similar outcomes have unfortunately not been realized for glioblastoma. For more than 15 years, the standard treatment of glioblastoma has been unchanged. This review walks through the elements that have challenged the success of previous trials and highlight some future promises. Concurrently, this review describes how institutions, through a multimodal and comprehensive strategy with 4 essential components, may increase the probability of finding a meaningful role for targeted therapies in the treatment of glioblastoma. These components are (1) prudent trial designs, (2) considered drug and target selection, (3) harnessed real-world clinical and molecular evidence, and (4) incorporation of translational research.

Can Any Drug Be Repurposed for Cancer Treatment? A Systematic Assessment of the Scientific Literature

Drug repurposing is a complementary pathway for introducing new drugs against cancer. Broad systematic assessments of ongoing repurposing efforts in oncology are lacking, but may be helpful to critically appraise current and future efforts. Hence, we conducted a systematic PubMed search encompassing 100 frequently prescribed and 100 randomly selected drugs, and assessed the published preclinical anti-cancer effects. Furthermore, we evaluated all the identified original articles for methodological quality. We found reports indicating anti-cancer effects for 138/200 drugs, especially among frequently prescribed drugs (81/100). Most were reports suggesting single-agent activity of the drugs (61%). Basic information, such as the cell line used or control treatments utilized, were reported consistently, while more detailed information (e.g., excluded data) was mostly missing. The majority (56%) of in vivo studies reported randomizing animals, while only few articles stated that the experiments were conducted in a blinded fashion. In conclusion, we found promising reports of anti-cancer effects for the majority of the assessed drugs, but speculate that many of them are false-positive findings. Reward systems should be adjusted to encourage the widespread usage of high reporting quality and bias-reducing methodologies, aiming to decrease the rate of false-positive results, and thereby increasing the trust in the findings.

Pharmacology-based ranking of anti-cancer drugs to guide clinical development of cancer immunotherapy combinations

The success of antibodies targeting Programmed cell death protein 1 (PD-1) and its ligand L1 (PD-L1) in cancer treatment and the need for improving response rates has led to an increased demand for the development of combination therapies with anti-PD-1/PD-L1 blockers as a backbone. As more and more drugs with translational potential are identified, the number of clinical trials evaluating combinations has increased considerably and the demand to prioritize combinations having potential for success over the ones that are unlikely to be successful is rising. This review aims to address the unmet need to prioritize cancer immunotherapy combinations through comprehensive search of potential drugs and ranking them based on their mechanism of action, clinical efficacy and safety. As lung cancer is one of the most frequently studied cancer types, combinations that showed potential for the treatment of lung cancer were prioritized. A literature search was performed to identify drugs with potential in combination with PD-1/PD-L1 blockers and the drugs were ranked based on their mechanism of action and known clinical efficacy. Nineteen drugs or drug classes were identified from an internal list of lead molecules and were scored for their clinical potential. Efficacy and safety data from pivotal studies was summarized for the selected drugs. Further, overlap of mechanisms of action and adverse events was visualized using a heat map illustration to help screen drugs for combinations. The quantitative scoring methodology provided in this review could serve as a template for preliminary ranking of novel combinations.

Thinking Differently about Cancer Treatment Regimens

Most experimental cancer drugs ultimately fail during the course of clinical development, contributing to the high cost of the few that are granted regulatory approval. Moreover, approved drugs often deliver only modest clinical benefit to patients with advanced disease due to the development of resistance. Here, we discuss opportunities we consider promising to overcome drug resistance associated with interactions between signaling pathways and the presence of multiple coexisting cell states within tumors with distinct vulnerabilities. We highlight how understanding drug-resistance mechanisms can enable innovative treatment regimens that deliver longer-lasting benefit to patients.

Evaluation of the contribution of randomised cancer clinical trials evaluating agents without documented single-agent activity

BACKGROUND

With the development of targeted agents, the approach to combination cancer therapy has evolved to focus on identifying ways in which pathway inhibition by one agent may enhance the activity of other agents. In theory, this implies that under this new paradigm, agents are no longer required to show single-agent activity, as the pathway inhibited by the targeted agent may only have a therapeutic effect when given with other agents. This raises the question of the extent to which anticancer agents without single-agent activity can contribute to effective combination regimens.

PATIENTS AND METHODS

We reviewed outcomes of randomised phase 2 combination trials sponsored by the National Cancer Institute Cancer Therapy Evaluation Program that were activated in 2008 to 2017 and noted the single-agent activity of the experimental agents.

RESULTS

Fifty-three trials were identified, and 50 had available results: 7 (14%), 15 (30%) and 28 (56%) had experimental agents with single-agent activity classified as active, inactive and indeterminate, respectively. Thirteen per cent (95% CI=1.7% to 40.5%) of trials evaluating inactive agents and 11.6% (95% CI=3.9% to 25.1%) of trials evaluating agents without known single-agent activity (pooled inactive and indeterminate) were positive, compared with 42.9% (95% CI=9.9% to 81.6%) for agents with single-agent activity.

CONCLUSIONS

Incorporating agents without documented single-agent activity into treatment regimens is unlikely to produce meaningful improvements in activity unless there is compelling biological rationale. This finding has important implications for the prioritisation of anticancer agents for combination testing, and for the allocation of clinical trial resources.

Emerging immunotherapies in multiple myeloma

Despite considerable advances in treatment approaches in the past two decades, multiple myeloma remains an incurable disease. Treatments for myeloma continue to evolve with many emerging immunotherapies. The first immunotherapy used to treat hematologic cancers, including multiple myeloma, was an allogeneic stem cell transplant. In the mid-2000s, immunomodulatory drugs thalidomide, lenalidomide, and subsequently pomalidomide were proven to be effective in multiple myeloma and substantially improved survival. The next wave of immunotherapies for multiple myeloma included the monoclonal antibodies daratumumab and elotuzumab, which were approved by the Food and Drug Administration in 2015. Subsequently, a variety of immunotherapies have been developed for multiple myeloma, including chimeric antigen receptor T cells, bispecific antibodies, antibody drug conjugates, and checkpoint inhibitors. Many of these emerging treatments target the B cell maturation antigen, which is expressed on plasma cells, although several other novel receptors are also being studied. This review summarizes the evidence of these various immunotherapies, their mechanism of action, and data from clinical trials regarding the treatments' safety and efficacy.

Benefit, burden, and impact for a cohort of post-approval cancer combination trials

BACKGROUND

After approval, drug developers often pursue trials aimed at extending the uses of a new drug by combining it with other drugs. Little is known about the risk and benefits associated with such research.

METHODS

To establish a historic benchmark of risk and benefit, we searched Medline and Embase for clinical trials testing anti-cancer drugs in combination within 5 years of approval by the Food and Drug Administration of 12 anti-cancer "index" drugs first licensed 2005-2007 inclusive. Risk was assessed based on grade 3 or above drug-related adverse events; benefit was assessed based on efficacy outcomes and advancement of combinations into clinical practice guidelines or approval by the Food and Drug Administration.

RESULTS

We captured 323 published post-approval trials exploring combinations, including 266 unique combination-indication pairings and enrolling 29,835 patients. The pooled risk ratios for treatment-related grade 3-4 severe adverse events and deaths attributed to the study drugs for trials randomized between a combination arm and a comparator were 1.54 (1.33-1.79) and 1.51 (1.16-1.97), respectively. The pooled hazard ratios for overall survival and progression-free survival were 0.99 (0.92-1.05) and 0.85 (0.79-0.93), respectively. None of the combination-indication pairings launched after initial drug approval received approval by the Food and Drug Administration, and 13 pairings (4.9%) were recommended by the National Comprehensive Cancer Network within 5 years of the first trial within that pairing. The proportion of patients in our sample who participated in trials leading to an approval by the Food and Drug Administration or a National Comprehensive Cancer Network guideline recommendation was 12.7% with 5 years of follow-up, and 22.3% among pairings for which there were 8 years of follow-up.

CONCLUSION

Patients were just as likely to benefit in the treatment arm as the control arm in terms of overall survival, but they were more likely to experience a treatment-related severe adverse event in post-approval trials of combination therapy.

Combining epigenetic drugs with other therapies for solid tumours - past lessons and future promise

Epigenetic dysregulation has long been recognized as a key factor contributing to tumorigenesis and tumour maintenance that can influence all of the recognized hallmarks of cancer. Despite regulatory approvals for the treatment of certain haematological malignancies, the efficacy of the first generation of epigenetic drugs (epi-drugs) in patients with solid tumours has been disappointing; however, successes have now been achieved in selected solid tumour subtypes, thanks to the development of novel compounds and a better understanding of cancer biology that have enabled precision medicine approaches. Several lines of evidence support that, beyond their potential as monotherapies, epigenetic drugs could have important roles in synergy with other anticancer therapies or in reversing acquired therapy resistance. Herein, we review the mechanisms by which epi-drugs can modulate the sensitivity of cancer cells to other forms of anticancer therapy, including chemotherapy, radiation therapy, hormone therapy, molecularly targeted therapy and immunotherapy. We provide a critical appraisal of the preclinical rationale, completed clinical studies and ongoing clinical trials relating to combination therapies incorporating epi-drugs. Finally, we propose and discuss rational clinical trial designs and drug development strategies, considering key factors including patient selection, tumour biomarker evaluation, drug scheduling and response assessment and study end points, with the aim of optimizing the development of such combinations.

Novel therapies for malignant pleural mesothelioma

Malignant pleural mesothelioma is a rare cancer that is typically associated with exposure to asbestos. Patients with malignant pleural mesothelioma have poor outcomes with suboptimal therapeutic options and currently no treatment is curative. The standard frontline treatment, cisplatin plus pemetrexed chemotherapy, has only short and insufficient efficacy, and no validated treatment beyond first-line therapy is available. New therapeutic strategies are therefore needed. The addition of bevacizumab (an anti-VEGF antibody) combined with cisplatin plus pemetrexed has shown some promise. However, immunotherapy, especially immune checkpoint inhibitors, has generated a lot of excitement because of data suggesting the potential value of immune checkpoint inhibitors for patients who have failed chemotherapy. In this Review, we describe immune checkpoint inhibitors, other immunotherapies, targeted therapies, or combinations of novel drugs being investigated in malignant pleural mesothelioma, as well as the issues surrounding the selection of the best candidates for these treatments.

Report of the 14th International Conference on Malignant Lymphoma (ICML) Closed Workshop on Future Design of Clinical Trials in Lymphomas

The 14th ICML held in Lugano in June 2017 was preceded by a closed workshop (organized in collaboration with the American Association for Cancer Research and the European School of Oncology) where experts in preclinical and clinical research in lymphomas met to discuss the current drug development landscape focusing on critical open questions that need to be addressed in the future to permit a more efficient drug development paradigm in lymphoma. Topics discussed included both preclinical models that can be used to test new drugs and drug combinations, as well as the optimal design of clinical trials and the endpoints that should be used to facilitate accelerated progress. This report represents a summary of the workshop. Clin Cancer Res; 24(13); 2993-8. ©2018 AACR.

Management of relapsed and refractory multiple myeloma: novel agents, antibodies, immunotherapies and beyond

Despite enormous advances, management of multiple myeloma (MM) remains challenging. Multiple factors impact the decision to treat or which regimen to use at MM relapse/progression. Recent major randomized controlled trials (RCTs) showed widely varying progression-free survivals (PFS), ranging from a median of 4 months (MM-003) to 23.6 months (ASPIRE). Based on these RCTs, next-generation proteasome inhibitors (carfilzomib and ixazomib), next-generation immunomodulatory agent (pomalidomide), and monoclonal antibodies (elotuzumab and daratumumab) were approved for relapsed and refractory MM. Daratumumab, targeting CD38, has multiple mechanisms of action including modulation of the immunosuppressive bone marrow micro-environment. In addition to the remarkable single agent activity in refractory MM, daratumumab produced deep responses and superior PFS in MM when combined with lenalidomide/dexamethasone, or bortezomib/dexamethasone. Other anti-CD38 antibodies, such as isatuximab and MOR202, are undergoing assessment. Elotuzumab, targeting SLAMF7, yielded superior response rates and PFS when combined with lenalidomide/dexamethasone. New combinations of these next generation novel agents and/or antibodies are undergoing clinical trials. Venetoclax, an oral BH3 mimetic inhibiting BCL2, showed single agent activity in MM with t(11;14), and is being studied in combination with bortezomib/dexamethasone. Selinexor, an Exportin-1 inhibitor, yielded promising results in quad- or penta-refractory MM including patients resistant to daratumumab. Pembrolizumab, an anti-PD1 check-point inhibitor, is being tested in combination with lenalidomide/dexamethasone or pomalidomide/dexamethasone. Chimeric antigen receptor-T cells targeting B-cell maturation antigen have yielded deep responses in RRMM. Finally, salvage autologous stem cell transplantation (ASCT) remains an important treatment in MM relapsing/progressing after a first ASCT. Herein, the clinical trial data of these agents are summarized, cautious interpretation of RCTs highlighted, and algorithm for salvage treatment of relapse/refractory MM proposed.