Evidence of non-childbearing status for women of childbearing potential (WOCBP). WOCBP must agree to use a highly effective contraceptive measure up to six weeks after treatment discontinuation. Fertile male patients with WOCBP partners should use condoms during treatment and for four months following the last investigational medicinal product dose. Investigators shall counsel WOCBP and male subjects who are sexually active with WOCBP on the importance of pregnancy prevention and the implications of an unexpected pregnancy Investigators shall advise WOCBP and male subjects who are sexually active with WOCBP on the use of highly effective methods of contraception; highly effective methods of contraception have a failure rate of < 1% per year when used consistently and correctly If female, may participate if not pregnant, not breastfeeding, and at least one of the following conditions apply: 1) not a woman of childbearing potential (WOCBP); or 2) a WOCBP who agrees to follow contraceptive guidance during the treatment period and for at least 180 days after the last dose of study treatment. WOCBP and men with female partners (WOCBP) that are not willing to use contraception Azoospermic males and WOCBP who are continuously not heterosexually active are exempt from contraceptive requirements; however, they must still undergo pregnancy testing Women who are pregnant or lactating, or intending to become pregnant before, during, or within 6 months after the last dose of study drug. Women of childbearing potential (WOCBP) and fertile men with WOCBP partner(s), not using and not willing to use a highly effective method of contraception. A female participant is eligible to participate if she is not pregnant, not breastfeeding, and at least one of the following conditions applies: \r\n* Not a woman of childbearing potential (WOCBP) OR\r\n* A WOCBP who agrees to follow the contraceptive guidance during the treatment period and for at 120 days after the last dose of study treatment. \r\n* Note: Abstinence is acceptable if this is the usual lifestyle and preferred contraception for the participant Women of childbearing potential (WOCBP) or male subjects with a partner who is WOCBP must agree to use contraception during the study, if sexually active Azoospermic males and WOCBP who are continuously not heterosexually active are exempt from contraceptive requirements. However WOCBP subjects must still undergo pregnancy testing as described in these sections. Recovery from the toxic effects of prior therapy, with a minimum time of: \r\n* >= 28 days elapsed from the administration of any investigational agent\r\n* >= 28 days elapsed from the administration of any prior cytotoxic agents, except\r\n* >= 14 days from vincristine, >= 21 days from procarbazine, and >= 42 days from nitrosureas\r\n• >= 14 days elapsed from administration of any non-cytotoxic agent (e.g., interferon, tamoxifen, thalidomide, cis-retinoic acid) \r\nInvestigators shall counsel WOCBP and male subjects who are sexually active with WOCBP on the importance of pregnancy prevention and the implications of an unexpected pregnancy. Investigators shall advise WOCBP and male subjects who are sexually active with WOCBP on the use of highly effective methods of contraception. Highly effective methods of contraception have a failure rate of < 1% per year when used consistently and correctly. WOCBP and male partners of WOCBP must agree to use two methods of contraception until at least 5 months after last dose of each study drug for WOCBP subjects, and 7 months for male partners of WOCBP Participants who are WOCBP who are continuously not heterosexually active are exempted from contraceptive requirements but still must undergo pregnancy testing Investigators shall counsel WOCBP, and male participants who are sexually active with WOCBP, on the importance of pregnancy prevention and the implications of an unexpected pregnancy; investigators shall advise on the use of highly effective methods of contraception, which have a failure rate of < 1% when used consistently and correctly Female participants who are not pregnant or breastfeeding, and who are either not a woman of childbearing potential (WOCBP), or are a WOCBP who agrees to use approved contraception during the treatment period and for at least 120 days after the last dose of study treatment A WOCBP who agrees to follow the contraceptive guidance in protocol during the treatment period and for at least 120 days after the last dose of trial treatment. Women who are pregnant or lactating, or intending to become pregnant before, during, or within 6 months after the last dose of study drug. Women of childbearing potential (WOCBP) and fertile men with WOCBP partner(s), not using and not willing to use a highly effective method of contraception. Azoospermic males and WOCBP who are continuously not heterosexually active are exempt from contraceptive requirements. However WOCBP must still undergo pregnancy testing as described in these sections. Azoospermic males and WOCBP who are continuously not heterosexually active are exempt from contraceptive requirements. However, WOCBP must still undergo pregnancy testing WOCBP and male subjects who are sexually active with WOCBP must agree to use 2 highly effective methods of contraception (including a physical barrier) during the study and for 30 days following the last dose of investigational product Investigators shall counsel WOCBP and male subjects who are sexually active with WOCBP on the importance of pregnancy prevention and the implications of an unexpected pregnancy; investigators shall advise WOCBP and male subjects who are sexually active with WOCBP on the use of highly effective methods of contraception; highly effective methods of contraception have a failure rate of < 1% when used consistently and correctly Age, sex, and reproductive status:\r\n* Women of childbearing potential (WOCBP=premenopausal woman capable of becoming pregnant) must have a negative serum or urine pregnancy test (minimum sensitivity 25 IU/L or equivalent units of HCG) within 24 hours prior to the start of study drug\r\n* Women must not be breastfeeding.\r\n* WOCBP must agree to follow instructions for method(s) of contraception for the duration of treatment with study drug(s) plus 5 half-lives of study drug(s) plus 30 days (duration of ovulatory cycle) for up to 5 months 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 5 half-lives of study drug(s) plus 90 days (duration of sperm turnover) for up to 7 months post treatment completion\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\r\n* Investigators shall counsel WOCBP and male subjects who are sexually active with WOCBP on the importance of pregnancy prevention and the implications of an unexpected pregnancy; investigators shall advise WOCBP and male subjects who are sexually active with WOCBP on the use of highly effective methods of contraception; highly effective methods of contraception have a failure rate of < 1% when used consistently and correctly\r\n* At a minimum subjects must agree to the use of one method of highly effective contraception as listed below. In addition, male subjects are expected to use a condom 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 Azoospermic males are exempt from contraceptive requirements; WOCBP who are continuously not heterosexually active are also exempt from contraceptive requirements, and still must undergo pregnancy testing as described in this section Women of childbearing potential (WOCBP) must use highly effective method(s) of contraception; WOCBP should use a highly effective method to avoid pregnancy for the duration of this study and for at least 5 months after the last dose of nivolumab; WOCBP and men must agree to use a highly effective contraception (hormonal or barrier method of birth control; abstinence) prior to study entry and for the duration of study participation and for at least 5 months from the last dose of nivolumab; should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately; men who are sexually active with WOCBP must also use a highly effective contraceptive method for at least 7 months after the last dose of nivolumab DASATINIB\r\n* Women of childbearing potential (WOCBP) must have a negative serum or urine pregnancy test (minimum sensitivity 25 IU/L or equivalent units of human chorionic gonadotropin [HCG]) within 24 hours prior to the start of study drug\r\n* Women must not be breastfeeding\r\n* WOCBP must agree to follow instructions for method(s) of contraception for the duration of treatment with study drug, plus 30 days (duration of ovulatory cycle) for a total of 30 days 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 90 days (duration of sperm turnover) for a total of 90 days post-treatment completion\r\n* Azoospermic males and WOCBP, who are not heterosexually active, are exempt from contraceptive requirements; however, WOCBP must still undergo pregnancy testing\r\n* Investigators shall counsel WOCBP and male subjects who are sexually active with WOCBP on the importance of pregnancy prevention and the implications of unexpected pregnancy; investigators shall advise WOCBP and male subjects who are sexually active with WOCBP on the use of highly effective contraception; highly effective methods of contraception have a failure rate of < 1% when used consistently and correctly\r\n* At a minimum, subjects 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 Men with female partners (WOCBP) that are not willing to use contraception Azoospermic males and WOCBP who are continuously not heterosexually active are exempt from contraceptive requirements; however WOCBP must still undergo pregnancy testing as described; investigators shall counsel WOCBP and male subjects who are sexually active with WOCBP on the importance of pregnancy prevention and the implications of an unexpected pregnancy; investigators shall advise WOCBP and male subjects who are sexually active with WOCBP on the use of highly effective methods of contraception; highly effective methods of contraception have a failure rate of < 1% per year when used consistently and correctly; at a minimum, subjects 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 as listed below: HIGHLY EFFECTIVE METHODS OF CONTRACEPTION:\r\n* Male condoms with spermicide\r\n* Hormonal methods of contraception including combined oral contraceptive pills, vaginal ring, injectables, implants, and intrauterine devices (IUDs) such as Mirena by WOCBP subject or male subject’s WOCBP partner\r\n* Nonhormonal IUDs, such as ParaGard\r\n* Tubal ligation\r\n* Vasectomy\r\n* Complete abstinence\r\n** Complete abstinence is defined as complete avoidance of heterosexual intercourse and is an acceptable form of contraception for all study drugs; abstinence is only acceptable when this is in line with the preferred and usual lifestyle of the subject; periodic abstinence (e.g., calendar, ovulation, symptothermal, profession of abstinence for entry into a clinical trial, post-ovulation methods) and withdrawal are not acceptable methods of contraception Dasatinib\r\n* Normal QTc interval on screening ECG evaluation, defined as < 450 msec for men and < 470 msec for women; discontinuation of any medications known to contribute significantly to the risk of QT prolongation at least 48 hours prior to start of study drug; Levaquin and Zofran are an exception; of note, certain agents that prolong the corrected QT interval may be allowed but only after discussion with the chemotherapy pharmacist; should the investigator believe that therapy with a potentially QT prolonging medication is vital to an individual subject’s care, then additional ECGs should be done at the investigator’s discretion to ensure the subject’s safety\r\n* Serum Na, K, Mg, and total serum Ca or ionized Ca levels must be greater than or equal to the institutional lower limit of normal; subjects with low K or Mg levels, total serum Ca and/or ionized Ca must be replete for protocol entry\r\n* Women of childbearing potential (WOCBP) must have a negative serum or urine pregnancy test (minimum sensitivity 25 IU/L or equivalent units of HCG) within 24 hours prior to the start of study drug\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 90 days (duration of sperm turnover) for a total of 90 days post-treatment completion\r\n* Azoospermic males and WOCBP, who are not heterosexually active, are exempt from contraceptive requirements; however, WOCBP must still under pregnancy testing as described in this section\r\n* Investigators shall counsel WOCBP and male subjects who are sexually active with WOCBP on the importance of pregnancy prevention and the implications of unexpected pregnancy; investigators shall advise WOCBP and male subjects who are sexually active with WOCBP on the use of highly effective contraception; highly effective methods of contraception have a failure rate of < 1% when used consistently and correctly\r\n* At a minimum, subjects 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 as listed Women who are pregnant or lactating, or intending to become pregnant before, during, or within 6 months after the last dose of study drug. Women of childbearing potential (WOCBP) and fertile men with WOCBP-partner(s) not using and not willing to use a highly effective method of contraception. Male or female subjects will be included. A female subject is eligible to participate if she is not pregnant, not breastfeeding, and at least 1 of the following conditions applies: a) Not a woman of childbearing potential (WOCBP) OR b). A WOCBP who agrees to follow the contraceptive guidance during the treatment period and for at least 120 days after the last dose of study treatment. WOCBP must be using highly effective and medically accepted method of contraception to avoid pregnancy throughout the study and for at least 3 months after the study ; 12. WOCBP must have a negative serum or urine pregnancy test within 72 hours prior to the start of study drug. Female subjects: Contraceptive use by men or women should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies. A female subject is eligible to participate if she is not pregnant or breastfeeding, and not a woman of childbearing potential (WOCBP) or is a WOCBP and using a contraceptive method that is highly effective (with a failure rate of <1% per year), preferably with low user dependency, during the intervention period and for at least 80 days after the last dose of study intervention and agrees not to donate eggs (ova, oocytes) for the purpose of reproduction during this period. The investigator should evaluate the effectiveness of the contraceptive method in relationship to the first dose of study intervention. A WOCBP must have a negative highly sensitive serum pregnancy test (as required by local regulations) within 72 hours before the first dose of study intervention. 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 <1% when used consistently and correctly; or abstinence) for the duration of treatment with TAR-200 in combination with nivolumab plus 5 half-lives of study treatment, plus 30 days (duration of ovulatory cycle), for a total of 5 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. The contraception's used by female subject's be consistent with local regulations, regarding methods of contraception for those participating in clinical studies. A female subject is eligible to participate if she is not pregnant or breastfeeding, and at least one of the following conditions applies: is not a woman of child bearing potential (WOCBP) or Is a WOCBP and using a contraceptive method that is highly effective (with a failure rate of <1% per year), preferably with low user dependency, during the intervention period and for at least 120 days after the last dose of study intervention and agrees not to donate eggs (ova, oocytes) for the purpose of reproduction during this period. WOCBP must have 2 negative highly sensitive serum pregnancy tests, as required by local regulations (first within 14 days of Cycle 1 Day 1 and the second one within 72 hours of dosing on Cycle1 Day1) and agree to use effective contraception during the study and for 120 days after the last dose of study medication; The investigator is responsible for review of medical history, menstrual history, and recent sexual activity to decrease the risk for inclusion of a woman with an early undetected pregnancy. Female participants eligible to participate if not pregnant, not breastfeeding, and not a woman of childbearing potential (WOCBP) or is a WOCBP who agrees to follow contraceptive guidance during the treatment period and for ?150 days after the last dose of study treatment Azoospermic males and WOCBP who are continuously not heterosexually active are exempt from contraceptive requirements; however they must still undergo pregnancy testing\r\n* Investigators shall counsel WOCBP and male participants who are sexually active with WOCBP on the importance of pregnancy prevention and the implications of an unexpected pregnancy; investigators shall advise on the use of highly effective methods of contraception, which have a failure rate of < 1% when used consistently and correctly A patient is eligible to participate if she is not pregnant, not breast-feeding, and at least one of the following conditions applies: a.) Not a woman of childbearing potential (WOCBP) OR b.) A WOCBP who agrees to follow the contraceptive guidance during the treatment period and for at least 30 days after the last dose of study treatment Female participants eligible to participate if not pregnant, not breastfeeding, and is not a woman of childbearing potential (WOCBP) or is a WOCBP who agrees to follow contraceptive guidance during the treatment period and for ?180 days after the last dose of study treatment Women of childbearing potential (WOCBP) and men who are sexually active, even if surgically sterilized, with WOCBP must agree to use effective methods of contraception during active treatment, for the duration of the study, and for 3 months after the completion of the study WOCBP using a prohibited contraceptive method Men and women agreement to use effective contraceptive method. For WOCBP and for men, agreement to use an effective contraceptive method from the time of screening throughout the study until 1 month for WOCBP or 6 months for men after administration of the last dose of any study medication. Women of childbearing potential (WOCBP) and men who are sexually active with WOCBP must agree to use effective methods of contraception during active treatment and for the duration of the study WOCBP or men whose sexual partners are WOCBP who are unwilling or unable to use an acceptable method of contraception for at least 1 month prior to study entry, for the duration of the study, and for at least 3 months after the last dose of study medication. Azoospermic males and women of childbearing potential who are continuously not heterosexually active are exempt from contraceptive requirements; however, they still must have a pregnancy test 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. 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. Note: investigators shall counsel WOCBP and male subjects who are sexually active with WOCBP on the importance of pregnancy prevention and the implications of an unexpected pregnancy Investigators shall advise WOCBP and male subjects who are sexually active with WOCBP on the use of highly effective methods of contraception; highly effective methods of contraception have a failure rate of < 1% when used consistently and correctly 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 33 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 93 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; note: investigators shall counsel WOCBP and male subjects who are sexually active with WOCBP on the importance of pregnancy prevention and the implications of an unexpected pregnancy; investigators shall advise WOCBP and male subjects who are sexually active with WOCBP on the use of highly effective methods of contraception; at a minimum, subjects must agree to the use of one method of highly effective contraception as listed below:\r\n*** Male condoms with spermicide\r\n*** Hormonal methods of contraception including combined oral contraceptive pills, vaginal ring, injectables, implants and intrauterine devices (IUDs) such as Mirena by WOCBP subject or male subject’s WOCBP partner \r\n*** Female partners of male subjects participating in the study may use hormone based contraceptives as one of the acceptable methods of contraception\r\n*** IUDs, such as ParaGard\r\n*** Tubal ligation\r\n*** Vasectomy\r\n*** Complete abstinence\r\n**** Complete abstinence is defined as complete avoidance of heterosexual intercourse and is an acceptable form of contraception for all study drugs; acceptable alternate methods of highly effective contraception must be discussed in the event that the subject chooses to forego complete abstinence WOCBP and male subjects who are sexually active with WOCBP must agree to use 2 highly effective methods of contraception (including a physical barrier) before the first dose of study drugs, during the study, and for 5 months for women and 7 months for men following the last dose of study drug.