C Malignancies, Memorial Sloan Kettering Cancer Center, New York, New York, USA; bDivision of Hematology Oncology, Knight Cancer Institute, cDepartment of Public Health and Preventive Medicine, and dCenter for Health Care Ethics, Oregon Health Science University, Portland, Oregon, USADisclosures of potential conflicts of interest may be found at the end of this article.aDebates surrounding the appropriateness of expanded access programs and right-to-try laws center on the question of under what TAPI-2MedChemExpress TAPI-2 circumstances should cancer patients be able to receive drugs or combinations that have not fully completed the stages of drug development (not completed testing in phase I, II, or III).The commonality here is that the agent in question has not been approved for any use in the U.S. A path to the drug thus requires special logistics. However, the fundamental question raised by expanded access is a broader one. Given that many cancer drugs are approved for one indication but, once approved, can be used alone or in combination for many others, the core question of expanded access is: Under what circumstances should providers and patients be able to attempt drugs or combinations for indications for which we still lack formal clinical trials? At the outset, let us stipulate that we consider this question only as it pertains to off-protocol use of these drugs (i.e., use outside of clinical trials) and for patients who have exhausted all proventherapies.Whenclinicaltrialsareanoption,weencourage theirenrollment, and the ethics ofsuch trials has been extensively discussed. But, outside of trials, few articles have tackled the offprotocol use ofdrugsfor unapproved uses, although authors have recognized that this is a key challenge in clinical medicine [1] and such use is common. It must also be remembered that off-label use often pertains to cancer drugs with annual costs in excess of 100,000[2];thus financial implications ofthis usearelarge.As an example, one of us recently faced the question of whether, for a patient with relapsed refractory multiple myeloma, it was permissible to treat with daratumumab, a monoclonal antibody approved as single agent, in combination with pomalidomide–a combination that has demonstrated relative safety in phase I trials but lacks phase II or phase III efficacy results (i.e., no proof that the combination is better than either agent alone). Thesekinds ofquestions arefrequentlyencountered in clinical oncology, although reliable statistics are absent. For patients with relatively good performance status who are interested in pursuing more treatment but who have exhausted recommended options, many oncologists attempt single drugs or combinations that are not yet vetted. We believe that a pragmatic framework can aid in such decisions. While we admit there is no canonical answer forwhat is best, we believe consideration of three factors may frame this topic.These factors are safety, efficacy, and cost, and are TAPI-2 solubility depicted in Figure 1.SAFETYIt should be remembered that novel drugs and their combinations may have unexpected safety signals. For example, vemurafenib, a small molecule inhibitor of BRAF, and ipilimumab, an antibody against an immunologic checkpoint, are individually active in BRAF V600E mutant metastatic melanoma, but the combination demonstrated adverse hepatic toxicity in 66 ?5 of patients when combined in a phase I study, requiring the trial to be halted [3]. Notably, this toxicity could not have been predicted,.C Malignancies, Memorial Sloan Kettering Cancer Center, New York, New York, USA; bDivision of Hematology Oncology, Knight Cancer Institute, cDepartment of Public Health and Preventive Medicine, and dCenter for Health Care Ethics, Oregon Health Science University, Portland, Oregon, USADisclosures of potential conflicts of interest may be found at the end of this article.aDebates surrounding the appropriateness of expanded access programs and right-to-try laws center on the question of under what circumstances should cancer patients be able to receive drugs or combinations that have not fully completed the stages of drug development (not completed testing in phase I, II, or III).The commonality here is that the agent in question has not been approved for any use in the U.S. A path to the drug thus requires special logistics. However, the fundamental question raised by expanded access is a broader one. Given that many cancer drugs are approved for one indication but, once approved, can be used alone or in combination for many others, the core question of expanded access is: Under what circumstances should providers and patients be able to attempt drugs or combinations for indications for which we still lack formal clinical trials? At the outset, let us stipulate that we consider this question only as it pertains to off-protocol use of these drugs (i.e., use outside of clinical trials) and for patients who have exhausted all proventherapies.Whenclinicaltrialsareanoption,weencourage theirenrollment, and the ethics ofsuch trials has been extensively discussed. But, outside of trials, few articles have tackled the offprotocol use ofdrugsfor unapproved uses, although authors have recognized that this is a key challenge in clinical medicine [1] and such use is common. It must also be remembered that off-label use often pertains to cancer drugs with annual costs in excess of 100,000[2];thus financial implications ofthis usearelarge.As an example, one of us recently faced the question of whether, for a patient with relapsed refractory multiple myeloma, it was permissible to treat with daratumumab, a monoclonal antibody approved as single agent, in combination with pomalidomide–a combination that has demonstrated relative safety in phase I trials but lacks phase II or phase III efficacy results (i.e., no proof that the combination is better than either agent alone). Thesekinds ofquestions arefrequentlyencountered in clinical oncology, although reliable statistics are absent. For patients with relatively good performance status who are interested in pursuing more treatment but who have exhausted recommended options, many oncologists attempt single drugs or combinations that are not yet vetted. We believe that a pragmatic framework can aid in such decisions. While we admit there is no canonical answer forwhat is best, we believe consideration of three factors may frame this topic.These factors are safety, efficacy, and cost, and are depicted in Figure 1.SAFETYIt should be remembered that novel drugs and their combinations may have unexpected safety signals. For example, vemurafenib, a small molecule inhibitor of BRAF, and ipilimumab, an antibody against an immunologic checkpoint, are individually active in BRAF V600E mutant metastatic melanoma, but the combination demonstrated adverse hepatic toxicity in 66 ?5 of patients when combined in a phase I study, requiring the trial to be halted [3]. Notably, this toxicity could not have been predicted,.