A Modular Phase 1/2 Study With CT7439 in Participants With Solid Malignancies

Core Inclusion Criteria:

• Histopathologically or cytologically confirmed diagnosis of malignant diseaseevaluable by RECIST v1.1

• Provision of signed written informed consent before any study-related activities,willing and able to comply with all scheduled visits, treatment plans, laboratorytests, and other study procedures and willing to permit access to stored historicaltumor tissue, prior tumor radiological assessments and tumor biomarker data.

• ECOG performance status of ≤ 2 with no deterioration over the previous 2 weeks.

• Ability to take oral medications and be willing to record daily adherence to thestudy drug.

• Women either of non-childbearing potential, either confirmed to be post-menopausalor of childbearing potential willing to practice effective contraception for theduration of the study and for minimum 33 days after the last dose of CT7439.

• Sexually active male patients must be willing to refrain from sperm donation fromthe time of signing informed consent and use condoms with all sexual partners forthe duration of the study and for a minimum 93 days months after the last dose ofCT7439.

• Estimated life expectancy of at least 3 months, in the opinion of the investigator.

Core Exclusion Criteria:

• Prior therapy with a specific CDK12/13 inhibitor, within any timeframe prior to thefirst dose of CT7439.

• Participants with any other malignancy that have been active or treated within thepast 3 years prior to enrolment, with the exception of cervical intraepithelialneoplasia and non-melanoma skin cancer.

• Any unresolved toxicity (except alopecia) from prior therapy of ≥ 2 CommonTerminology Criteria for Adverse Events (CTCAE) Grade.

• Active or documented history of autoimmune disease.

• Any current or prior central nervous system metastases

• Active infection requiring systemic antibiotic, antifungal, or antiviral medicationwithin 14 days prior to first dose of study drug.

• Severe or uncontrolled medical condition or psychiatric condition.

• Human immunodeficiency virus (HIV) infection, unless the study participant onanti-retroviral therapy for at least 4 weeks (28 days),and has not had anopportunistic infection within the past 12 months prior to enrollment.

• Active hepatitis B virus (HBV) or hepatitis C virus (HCV) infection, unlessparticipant with HBV patient is on a suppressive antiviral therapy, or participantwith HCV has a viral load below the limit of quantification (LoQ).

• Participant is breastfeeding or pregnant.

• Receipt of cytotoxic and/or non- cytotoxic treatment for the malignancy within 28days before the first dose of IMP.

• Receipt of corticosteroids within 14 days before the first dose of IMP.

• Receipt of any small molecule IMP within 28 days or 5 half-lives, whichever islonger, before the first dose of IMP.

• Receipt of concomitant medication, herbal supplement, or food that is a moderateand/or strong inhibitor or inducer of CYP3A4,,strong inhibitor or inducer of CYP2D6or P-gp or inhibitor of BCRP within 21 days before the first dose of IMP.

• Inadequate hepatic, renal and bone marrow function, receipt of a blood transfusion (blood or blood products) within 14 days before the first dose of IMP.

• Persistent (> 4 weeks) severe pancytopenia due to previous therapy rather than todisease (ANC < 0.5 × 109/L or platelets < 50 x 109/L).

• History of cardiac dysfunction and/or presence of clinically significantcardiovascular disease

• Has received a live virus vaccination within 28 days or less of planned treatmentstart.

Additional Module 1 inclusion criteria:

1. Clinically confirmed locally advanced or metastatic solid malignancy for which there is no potentially curative treatment option.