Male subjects who are unwilling to use contraception during the treatment and for at least weeks after the last dose of study treatment ( half-lives of study drug plus days duration of sperm turnover). Women of childbearing potential must agree to follow instruction for method(s) of contraception for the duration of treatment with study drug PRS- plus days post-treatment completion. Males who are sexually active with women of childbearing potential must agree to follow instructions for method(s) of contraception for the duration of treatment with study drug PRS plus days post-treatment completion. WOCPB must agree to follow instructions for method(s) of contraception from the time of enrollment for the duration of treatment with study therapy plus months after the last dose of nivolumab Men who are sexually active with WOCBP must agree to follow instructions for method(s) of contraception for the duration of treatment with study drug plus months after the last dose of nivolumab Women of childbearing potential must agree to follow instructions for method(s) of contraception for the duration of treatment with study drug(s) plus half-lives of study drug plus days (duration of ovulatory cycle); the half-life of nivolumab and ipilimumab is up to days and days, respectively; WOCBP should therefore use an adequate method to avoid pregnancy for a total of weeks posttreatment completion Males who are sexually active with WOCBP must agree to follow instructions for method(s) of contraception for the duration of treatment with study drug(s) plus half-lives of the study drug (s) plus days (duration of sperm turnover); the half-lives of nivolumab and ipilimumab are up to days and days, respectively; men should therefore use an adequate method of contraception for a total of weeks posttreatment completion WOCBP must use appropriate method(s) of contraception from the time of enrollment for the duration of treatment with study drug (s) plus half-lives of study drug (s) plus days (duration of ovulatory cycle) for a total of weeks post treatment completion for subjects enrolled to treatment arm A (nivolumab). Subjects enrolled to treatment arm B (nivolumab + bevacizumab) must use appropriate method(s) of contraception for months post treatment completion. Men who are sexually active with WOCBP must use any contraceptive method with a failure rate of less than % per year. Men receiving nivolumab and who are sexually active with WOCBP will be instructed to adhere to contraception for the duration of treatment with study drug (s) plus half-lives of study drug (s) plus days (duration of sperm turnover) for a total of weeks post-treatment completion. Participants who are WOCBP must agree to follow instructions for method(s) of contraception for the duration of treatment with study drug(s) and up to months post last dose of study drug(s) Women of childbearing potential (WOCBP) must agree to follow instructions for method(s) of contraception for the duration of study treatment with nivolumab and months after the last dose of study treatment i.e., days (duration of ovulatory cycle) plus the time required for the investigational drug to undergo approximately five half-lives Males who are sexually active with WOCBP must agree to follow instructions for method(s) of contraception for the duration of study treatment with nivolumab and months after the last dose of study treatment i.e., days (duration of sperm turnover) plus the time required for the investigational drug to undergo approximately five half-lives WOCBP must agree to follow instructions for method(s) of contraception from the time of enrollment for the duration of treatment with study drug (s) plus half-lives of study drug (s) plus days (duration of ovulatory cycle) for a total of months post treatment completion. Men who are sexually active with WOCBP must agree to follow instructions for method(s) of contraception for the duration of treatment with study drug (s) plus half-lives of study drug (s) plus days duration of sperm turnover for a total of months post-treatment completion. WOCBP must agree to follow instructions for method(s) of contraception from the time of enrollment for the duration of treatment with study drug (s) plus half-lives of study drug (s) plus days (duration of ovulatory cycle) for a total of months post treatment completion Men who are sexually active with WOCBP must agree to follow instructions for method(s) of contraception for the duration of treatment with study drug (s) plus half-lives of study drug (s) plus days (duration of sperm turnover) for a total of months post-treatment completion FOCBP and men who are sexually active with FOCBP must agree to follow instructions for method(s) of contraception for the duration of treatment and the designated post-treatment period WOCBP must agree to follow instructions for method(s) of contraception for the duration of treatment with study drug(s) plus half-lives of study drug plus days (duration of ovulatory cycle); the half-life of nivolumab and ipilimumab is up to days and days, respectively; WOCBP should therefore use an adequate method to avoid pregnancy for a total of weeks post-treatment completion Men who are sexually active with WOCBP must agree to follow instructions for method(s) of contraception for the duration of treatment with study drug(s) plus half-lives of the study drug(s) plus days (duration of sperm turnover); the half-life of nivolumab and ipilimumab is up to days and days, respectively; men should therefore use an adequate method of contraception for a total of weeks post-treatment completion FOCBP and men who are sexually active with FOCBP must agree to follow instructions for method(s) of contraception for the duration of treatment and the designated post-treatment period Women of childbearing potential (WOCBP) must agree to follow instructions for method(s) of contraception for the duration of treatment with study drug(s) plus half-lives of study drug ( days) plus days (duration of ovulatory cycle) for a total of days post-treatment completion Males who are sexually active with WOCBP must agree to follow instructions for method(s) of contraception for the duration of treatment with study drug(s) plus half-lives of the study drug plus days (duration of sperm turnover) for a total of days post-treatment completion; in addition, male subjects must be willing to refrain from sperm donation during this time Females of childbearing potential (FOCBP), and non-sterilized males who are sexually active must agree to the use of two methods of contraception, with one method being highly effective and the other method being either highly effective or less effective; they must also refrain from egg and/or sperm cell donation and breastfeeding for days after the final dose of investigational product(s)\r\n* Females of childbearing potential are defined as those who are not surgically sterile (ie, bilateral tubal ligation, bilateral oophorectomy, or complete hysterectomy) or postmenopausal (defined as months with no menses without an alternative medical cause)\r\n* Women of childbearing potential (WOCBP) must agree to follow instructions for method(s) of contraception for the duration of treatment with nivolumab plus half-lives of nivolumab ( weeks) plus days (duration of ovulatory cycle) for a total of weeks post-treatment completion.\r\n* Men who are sexually active with WOCBP must agree to follow instructions for method(s) of contraception for the duration of treatment with nivolumab plus half-lives of the study drug ( weeks) plus days (duration of sperm turnover) for a total of weeks post-treatment\r\ncompletion Women of childbearing potential (WOCBP) must have a negative urine or serum pregnancy test (minimum sensitivity IU/L or equivalent units of human chorionic gonadotropin [HCG]):\r\n* WOCBP must agree to follow instructions for method(s) of contraception from the time of enrollment for the duration of treatment with study drug plus half-lives of study drug plus weeks (duration of ovulatory cycle) for a total of weeks post treatment completion\r\n* Men who are sexually active with WOCBP must agree to follow instructions for method(s) of contraception for the duration of treatment with study drug plus half-lives of study drug plus days (duration of sperm turnover) for a total of weeks post-treatment completion\r\n* At least one barrier method of contraception must be employed by all sexually active patients (male and female), regardless of other methods, to prevent the transfer of body fluids Women of childbearing potential (WOCBP) must have a negative serum pregnancy test (minimum sensitivity IU/L or equivalent units of human chorionic gonadotropin [HCG])\r\n* WOCBP must agree to follow instructions for method(s) of contraception from the time of enrollment for the duration of treatment with study drug(s) plus half-lives of study drug(s) plus weeks (duration of ovulatory cycle) for a total of weeks post treatment completion\r\n* Men who are sexually active with WOCBP must agree to follow instructions for method(s) of contraception for the duration of treatment with study drug(s) plus half-lives of study drug(s) plus days (duration of sperm turnover) for a total of weeks post-treatment completion\r\n* Women who are not of childbearing potential (i.e., who are postmenopausal or surgically sterile) as well as azoospermic men do not require contraception\r\n* Women must not be breastfeeding\r\n* At least one barrier method of contraception must be employed by all sexually active patients (male and female), regardless of other methods, to prevent the transfer of body fluids ADDITIONAL CRITERIA FOR STUDY CONTINUATION: Women of childbearing potential (WOCBP) must have a negative pregnancy test (minimum sensitivity IU/L or equivalent units of human chorionic gonadotropin [HCG])\r\n* WOCBP must agree to follow instructions for method(s) of contraception from the time of enrollment for the duration of treatment with study drug(s) plus half-lives of study drug(s) plus weeks (duration of ovulatory cycle) for a total of weeks post treatment completion\r\n* Men who are sexually active with WOCBP must agree to follow instructions for method(s) of contraception for the duration of treatment with study drug(s) plus half-lives of study drug(s) plus days (duration of sperm turnover) for a total of weeks post-treatment completion\r\n* At least one barrier method of contraception must be employed by all sexually active patients (male and female), regardless of other methods, to prevent the transfer of body fluids WOCBP must agree to follow instructions for method(s) of contraception from the time of enrollment for the duration of treatment with study drug (s) plus half-lives of study drug (s) plus days (duration of ovulatory cycle) for a total of weeks post treatment completion Men who are sexually active with WOCBP must agree to follow instructions for method(s) of contraception for the duration of treatment with study drug (s) plus half-lives of study drug (s) plus days duration of sperm turnover for a total of weeks post-treatment completion Women of childbearing potential (WOCBP) must be willing to use a highly effective method of contraception (hormonal or intrauterine device [IUD] method of birth control with a failure rate of <% when used consistently and correctly; or abstinence) for the duration of treatment with TAR- in combination with nivolumab plus half-lives of study treatment, plus days (duration of ovulatory cycle), for a total of months post treatment completion. Note: WOCBP who are continuously not heterosexually active are exempt from contraceptive requirements, but still must undergo pregnancy testing as described in this protocol. Males must be willing to use an effective method of contraception to avoid seminal transfer (double barrier method) or abstinence for the duration of treatment with TAR in combination with nivolumab plus half-lives of the study treatment, plus days (duration of sperm turnover), for a total of months post-treatment completion. In addition, male participants must be willing to refrain from sperm donation during this time. WOCBP must agree to follow instructions for method(s) of contraception for the duration of treatment with study drug(s) plus half-lives of study drug (half-life up to days) plus days (duration of ovulatory cycle) for a total of months post-treatment completion Males who are sexually active with WOCBP must agree to follow instructions for method(s) of contraception for the duration of treatment with study drug (s) plus half-lives of the study drug (half-life up to days) plus days (duration of sperm turnover) for a total of months post-treatment completion Males who are sexually active with WOCBP must agree to follow instructions for method(s) of contraception for the duration of treatment with study drug(s) study therapy plus half-lives of the study drug study therapy up to days plus days (duration of sperm turnover) for a total of weeks post-treatment completion Both women of childbearing potential (WOCBP) and men who are sexually active with WOCBP must agree to use highly effective methods of contraception as outlined in this protocol for the duration of treatment with study drug plus half-lives of study drug plus days (duration of sperm turnover) for a total of weeks post-treatment completion Males who are sexually active with WOCBP must agree to follow instructions for method(s) of contraception for the duration of study treatment with nivolumab and months after the last dose of study treatment (i.e., days (duration of sperm turnover) plus the time required for the investigational drug to undergo approximately five half-lives) FOCBP and men who are sexually active with FOCBP must agree to follow instructions for method(s) of contraception for the duration of treatment and the designated post-treatment period Women of childbearing potential (WOCBP) must have a negative serum pregnancy test (minimum sensitivity IU/L or equivalent units of human chorionic gonadotropin [HCG])\r\n* WOCBP must agree to follow instructions for method(s) of contraception from the time of enrollment for the duration of treatment with study drug(s) plus half-lives of study drug(s) plus weeks (duration of ovulatory cycle) for a total of weeks post treatment completion\r\n* Men who are sexually active with WOCBP must agree to follow instructions for method(s) of contraception for the duration of treatment with study drug(s) plus half-lives of study drug(s) plus days (duration of sperm turnover) for a total of weeks post-treatment completion\r\n* At least one barrier method of contraception must be employed by all sexually active patients (male and female), regardless of other methods, to prevent the transfer of body fluids Women of childbearing potential must agree to follow instruction for method(s) of contraception from time of enrollment for the duration of treatment with nivolumab plus half-lives plus days for a total of weeks post treatment completion WOCBP must agree to follow instructions for method(s) of contraception for the duration of treatment with study drug FS plus days (duration of ovulatory cycle) for a total of days post-treatment completion. Males who are sexually active with WOCBP must agree to follow instructions for method(s) of contraception for the duration of treatment with study drug FS plus days (duration of sperm turnover) for a total of days post-treatment completion. Women of childbearing potential must agree to follow instructions for method(s) of contraception for the duration of treatment with study drug(s) plus half-lives of study drug plus days (duration of ovulatory cycle). The half-lives of nivolumab and ipilimumab is up to days and days, respectively. Given the blinded nature of this study, WOCBP should therefore use an adequate method to avoid pregnancy for a total of weeks posttreatment completion. Males who are sexually active with WOCBP must agree to follow instructions for method(s) of contraception for the duration of treatment with study drug(s) plus half lives of the study drug(s) plus days (duration of sperm turnover). The half-lives of nivolumab and ipilimumab are up to days and days, respectively. Given the blinded nature of this study, men should therefore use an adequate method of contraception for a total of weeks posttreatment completion. Women of childbearing potential (WOCBP) must have a negative serum or urine pregnancy test (minimum sensitivity IU/L or equivalent units of human chorionic gonadotropin [HCG]) within hours prior to the start of study drug; women who undergo fertility preservation within weeks of beginning chemotherapy are expected to have false-positive pregnancy tests and therefore testing may be waived for these patients\r\n* WOCBP must agree to follow instructions for method(s) of contraception from the time of enrollment for the duration of treatment with study drug plus half-lives of study drug plus days (duration of ovulatory cycle) for a total of weeks post treatment completion\r\n* Women must not be breastfeeding Men who are sexually active with WOCBP must agree to follow instructions for method(s) of contraception for the duration of treatment with study drug plus half-lives of study drug plus days (duration of sperm turnover) for a total of weeks posttreatment completion Any of the following:\r\n* Pregnant women\r\n* Nursing women\r\n* Men or women of childbearing potential who are unwilling to employ adequate contraception\r\n** Note: women of child bearing potential must agree to follow instructions for method(s) of contraception for the duration of treatment with study drug (s) plus days after finishing the last dose\r\n** Males who are sexually active with WOCBP must agree to follow instructions for method(s) of contraception for the duration of treatment with study drug (s) plus days after finishing the last dose\r\n** Azoospermic males and WOCBP who are continuously not heterosexually active are exempt from contraceptive requirements; however they must still undergo pregnancy testing as described in this section Male subjects who are unwilling to use contraception during the treatment and for at least weeks after the last dose of study treatment ( half-lives of study drug plus days duration of sperm turnover) Women must not be breastfeeding, WOCBP must agree to follow instructions for method(s) of contraception for the duration of treatment with study drug(s) apixaban plus half-lives of study drug apixaban (. days) plus days (duration of ovulatory cycle) for a total of . days post-treatment completion WOCBP must agree to follow instructions for method(s) of contraception at the restart of treatment with study drug (dasatinib) and for the duration treatment plus days (duration of ovulatory cycle) for a total of days post-treatment completion Men who are sexually active with WOCBP must agree to follow instructions for method(s) of contraception for days after study entry (withdrawal of dasatinib), at restart of study drug (dasatinib) and for the duration of treatment with study drug (dasatinib) plus days (duration of sperm turnover) for a total of days post-treatment completion