A Study of ASP1570 Taken by Itself, or ASP1570 Taken Together With Either Pembrolizumab, Standard Therapies, or Both, in Adults With Solid Tumors

Participant has locally-advanced (unresectable) or metastatic solid tumor malignancy which is confirmed by available pathology records or current biopsy.

Participant has at least 1 measurable lesion per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1. Lesions situated in a previously irradiated area are considered measurable if progression has been demonstrated in such lesions.

Monotherapy Escalation Cohorts and China-specific Safety Lead-in Cohort:

a) Participant has progressed on standard therapies, is no longer eligible for standard therapies or has refused standard approved therapies (no limit to the number of prior treatment regimens). (UNIQUE to China: Certain tumor types with specific criteria may be prioritized at the sponsor's discretion).

Monotherapy Expansion Cohorts:

a) Participant has MSS-CRC or NSCLC and has progressed was intolerant to at least 2 prior anti-cancer therapy regimens administered for metastatic disease.

Monotherapy Dose Optimization Cohorts:

a) Participant has MSS-CRC or NSCLC and has progressed or was intolerant to at least 2 prior anti-cancer therapy regimens administered for metastatic disease.

Combination Therapy Escalation and/or Expansion Cohorts:

a) For NSCLC (2L+) Combination Therapy Cohort only:

Participant has Stage IV NSCLC and has progressed on or after checkpoint inhibitors with or without platinum-based chemotherapy.

Participant is eligible to receive docetaxel. b) For MSS-CRC (3L+) Combination Therapy Cohorts only:

Participant must have progressed or was intolerant to at least 2 prior anti-cancer therapy regimens administered for metastatic disease.

Participant is eligible to receive TAS-102 and bevacizumab.

All Comers Combination with Pembrolizumab Cohorts only:

Participant who has progressed on standard therapies, are no longer eligible for standard therapies or has refused standard approved therapies.

Participant is eligible to receive pembrolizumab

For NSCLC (1L) Combination Therapy Cohorts only:

Participant has PD-L1 low (TPS = 1% to 49%) or negative (TPS \< 1%) and AGA negative Stage IV adenocarcinoma (mixed histology is not allowed).

Participant has not received prior systemic treatment for their advanced/metastatic NSCLC.

Participant who remains disease free for 12 months following the completion of neoadjuvant/adjuvant treatment is eligible.

Participant is eligible to receive pembrolizumab + pemetrexed + carboplatin.

For MSS-CRC (2L) Combination Therapy Cohorts only:

Participant is AGA negative and HER2 negative.

mFOLFOX6 + Bevacizumab:

Participant must have progressed or was intolerant to first line with irinotecan-based therapy, or previous therapy without oxaliplatin.

Participant is eligible to receive mFOLFOX6 and bevacizumab.

FOLFIRI + Bevacizumab:

Participant must have progressed or was intolerant to first line with oxaliplatin-based therapy, or previous therapy without irinotecan.

Participant is eligible to receive FOLFIRI and bevacizumab.

Eligibility of backfill participants should follow cohort specific criteria for which they are being utilized.

Participant has an Eastern Cooperative Oncology Group (ECOG) Status of 0 or 1 within 7 days before the first dose of study drug.

Participant's adverse events (excluding alopecia) from prior anti-cancer therapies have resolved or improved to grade 1 at least 14 days prior to the first dose of study intervention. Note: Participants with type 1 diabetes mellitus and endocrinopathies stably maintained on appropriate replacement therapy are allowed.

Participant has activated partial thromboplastin time and international normalized ratio (INR) \<= 1.5 x ULN and is not receiving anticoagulation.

Female participant is not pregnant confirmed by pregnancy test or confirmed to be of non-childbearing potential and at least one of the following conditions apply:

* Not a woman of childbearing potential (WOCBP)

* WOCBP who agrees to follow the contraceptive guidance from the time of informed consent through at least 45 days after final ASP1570 administration or at least 120 days after administration of pembrolizumab.

Females participating in the study should be advised to use a highly effective contraception method during treatment and for 2 months after the last dose of docetaxel, and for 6 months after the last dose of TAS-102 and bevacizumab.

Females participating in the study should be advised to use a highly effective contraception method during treatment and for 9 months after the last dose of mFOLFOX6.

(UNIQUE to South Korea): Females participating in the study should be advised to use a highly effective contraception method during treatment and for 15 months after the last dose of mFOLFOX6.

Females participating in the study should be advised to use a highly effective contraception method during treatment and for 6 months after the last dose of FOLFIRI.

(UNIQUE to South Korea): Females participating in the study should be advised to use a highly effective contraception method during treatment and for 7 months after the last dose of FOLFIRI.

Females participating in the study should be advised to use a highly effective contraception method during treatment and for 6 months after treatment with carboplatin, pemetrexed and pembrolizumab.

Female participant must agree not to breastfeed starting at screening and throughout the study period and for at least 45 days after final ASP1570 administration or at least 120 days after administration of pembrolizumab.

Females participating in the study should be advised to not breastfeed during and for 45 days after treatment of docetaxel.

Females participating in the study should be advised to not breastfeed during treatment and for 6 months after the last dose of TAS-102 and bevacizumab.

Females participating in the study should be advised to not breastfeed during treatment and for 45 days after the last dose of mFOLFOX6 or FOLFIRI.

Females participating in the study should be advised to not breastfeed during treatment and for 4 months after treatment with a regimen of carboplatin, pemetrexed, and pembrolizumab.

Female participant must not donate ova starting at first dose of study intervention and throughout the study period and for at least 45 days after final ASP1570 administration or at least 120 days after administration of pembrolizumab.

Females participating in the study should be advised to not donate ova during treatment and for 2 months after the last dose of docetaxel.

Females participating in the study should be advised to not donate ova during treatment and for 6 months after the last dose of TAS-102, bevacizumab or FOLFIRI.

(UNIQUE to South Korea): Females participating in the study should be advised to not donate ova during treatment and for 7 months after the last dose of FOLFIRI.

Females participating in the study should be advised to not donate ova during treatment and for 9 months after the last dose of mFOLFOX6.

(UNIQUE to South Korea): Females participating in the study should be advised to not donate ova during treatment and for 15 months after the last dose of mFOLFOX6.

Females participating in the study should be advised to not donate ova for 6 months after treatment with a regimen of carboplatin, pemetrexed and pembrolizumab.

Male participant with female partner(s) of childbearing potential (including breastfeeding partner) must agree to use contraception throughout the treatment period and for at least 45 days after final ASP1570 administration or at least 120 days after administration of pembrolizumab.

Males participating in the study should be advised to use a highly effective contraception method during treatment and for 4 months after the last dose of docetaxel.

Males participating in the study should be advised to use a highly effective contraception method during treatment and for 3 months after the last dose of TAS-102 and bevacizumab.

Males participating in the study should be advised to use a highly effective contraception method during treatment and for 6 months after the last dose of mFOLFOX6.

(UNIQUE to South Korea): Males participating in the study should be advised to use a highly effective contraception method during treatment and for 12 months after the last dose of mFOLFOX6.

Males participating in the study should be advised to use a highly effective contraception method during treatment and for 3 months after the last dose of FOLFIRI.

Males participating in the study should be advised to use a highly effective contraception method during treatment and for 6 months after the last dose of a regimen of carboplatin, pemetrexed and pembrolizumab.

Male participant must not donate sperm during the treatment period and for at least 45 days after final ASP1570 administration or at least 120 days after administration of pembrolizumab.

Males participating in the study must not donate sperm for at least 4 months after the last dose of docetaxel.

Males participating in the study must not donate sperm for at least 3 months after the last dose of TAS-102 and bevacizumab.

Males participating in the study must not donate sperm during treatment and for 6 months after the last dose of mFOLFOX6.

(UNIQUE to South Korea): Males participating in the study should be advised to not donate sperm during treatment and for 12 months after the last dose of mFOLFOX6.

Males participating in the study must not donate sperm during treatment and for 3 months after the last dose of FOLFIRI.

Males participating in the study must not donate sperm during treatment and for 6 months after the last dose of a regimen of carboplatin, pemetrexed and pembrolizumab.

Male participant with pregnant partner(s) must agree to remain abstinent or use a condom for the duration of the pregnancy throughout the study period and for at least 45 days after final ASP1570 administration or at least 120 days after administration of pembrolizumab.

Males participating in the study with pregnant partner(s) should be advised to remain abstinent or use a condom during treatment and for 4 months after the last dose of docetaxel.

Males participating in the study with pregnant partner(s) should be advised to remain abstinent or use a condom during treatment and for 6 months after the last dose of TAS-102 and bevacizumab.

Males participating in the study with pregnant partner(s) should be advised to remain abstinent or use a condom during treatment and for 6 months after the last dose of mFOLFOX6.

(UNIQUE to South Korea): Males participating in the study with pregnant partner(s) should be advised to remain abstinent or use a condom during treatment and for 12 months after the last dose of mFOLFOX6.

Males participating in the study with pregnant partner(s) should be advised to remain abstinent or use a condom during treatment and for 3 months after the last dose of FOLFIRI.

Males participating in the study with pregnant partner(s) should be advised to remain abstinent or use a condom during treatment and for 6 months after the last dose of a regimen of carboplatin, pemetrexed and pembrolizumab.

Participant agrees not to participate in another interventional study while receiving study treatment in the present study.

What this study is about