1. History of or concurrent asthma or allergic rhinitis (hay fever) in either biologic parent or sibling (at least one shared biological parent) by parental report. The presence of paternal or sibling allergy or asthma will be ascertained by maternal report. 2. Maternal age greater than or equal to 18 years at the time of study enrollment. 1. Maternal HIV infection at time of delivery. 2. Plans for the family to move out of the geographic area during the period of the study. 3. Does not speak English. 4. Current maternal use of progesterone during pregnancy to prevent preterm birth.
• Progesterone use is only an exclusion if currently being taken at time of enrollment for preterm birth. Previous use to prevent preterm birth or use at any time for other indications is allowed. 5. Pregnancy is a result of an embryo donor (egg and sperm donor pregnancies are permitted). 6. Past or current medical problems or findings from physical examination or laboratory testing which, in the opinion of the investigator or designee, may pose additional risks from participation in the study, may interfere with the participant's ability to comply with study requirements or that may impact the quality or interpretation of the data obtained from the study.

• Culture positive pulmonary MAC meeting ATS/IDSA disease criteria
• Age over 18 years
• Ability to provide informed consent
• Fibrocavitary disease
• Planned surgery for MAC disease
• Patients who have cumulatively taken 6 weeks or more of multi-drug antimicrobial treatment for MAC
• Patients who are currently taking or have taken multi-drug antimicrobial treatment for NTM within the prior 30 days
• Diagnosis of Cystic fibrosis
• Diagnosis of HIV
• History of solid organ or hematologic transplant
• Significant drug-drug interaction not clinically manageable in the opinion of the investigator
• Contraindication to any component of the study treatment regimen

Pregnant Women- Pregnant women who meet all of the following criteria are eligible for enrollment as study participants: 1. Age 18 years or older 2. Able to understand the oral and written instructions associated with study visits and procedures and provide informed consent 3. Pregnant at any stage 4. Planning to give birth at a study-site designated center 5. Agrees to enroll offspring into the study at birth 6. In the case of multiple gestation, agrees to enroll only one child who will be selected by randomized birth order Biological Fathers- Biological fathers who meet all of the following criteria are eligible for enrollment as study participants: 1. Age 18 years or older 2. Able to understand the oral and written instructions associated with study visits and procedures and provide informed consent Pregnant Women- Pregnant women who meet any of these criteria are not eligible for enrollment: 1. Inability or unwillingness to comply with study protocol 2. Serious pregnancy complication (in the judgement of the investigator) prior to enrollment 3. Fetus has a major chromosomal anomaly 4. Plans to move and would not be available for in-person visits at a study site 5. Plans to give up her child for adoption at birth 6. Pregnancy is the result of an egg donation Infants- Infants who meet any of these criteria are not eligible for enrollment: 1. Delivered earlier than 34 weeks of gestation 2. Sibling already enrolled 3. Born with a significant birth defect or medical condition, and in the judgment of the investigators, participation is not in the infant's best interest Biological Father- 1. Biological fathers who are unable or unwilling to comply with the study protocol as it pertains to the biological father's participation are not eligible for enrollment ----Note Regarding Legal Guardians who are not the Biological Parents: 1. At screening for enrollment of either the mother or the child, if the biological mother intends to give the infant up for adoption, neither the mother nor the child are eligible for enrollment 2. If the biological mother gives up legal guardianship of the child during the child's follow-up period, the child may remain enrolled as long as the new legal guardian:
• Agrees to meet the child's study requirements, and
• Provides written informed consent for the child's continued participation. 3. Throughout the protocol where it refers to the mother, father, or parent answering questionnaires about the child or collecting samples from the child and the child's primary home, the legal guardian who provides consent for the child's participation may complete those procedures

• Pregnant, intending to continue pregnancy, enrolled in the Cystic Fibrosis Foundation Patient Registry (CFFPR)
• None

• Age18 ≤ 75 years
• Have BKV infection/viremia following kidney transplantation, where BKV viremia is defined as positive BKV qPCR (≥ 250 copies)
• Have evidence of invasive BKV infection (BK Nephropathy)
• Experience one of the following:
• New, persistent and/or worsening BKV-related symptoms, signs and/or markers of end organ compromise despite being on lower immunosuppressive medication
• Adverse effects of lower immunosuppressive medications (e.g., dnDSA, biopsy proven rejection)
• Eligible Donor
• Provide Written informed consent
• Non-kidney organ transplant recipient
• Patient with acute rejection of the kidney allograft at time of T-cell transfer
• Patient receiving steroids (>0.5 mg/kg body weight (BW) prednisone equivalent) at the time of T-cell transfer
• Patient treated with Thymoglobulin (ATG), Alemtuzumab or T-cell immunosuppressive monoclonal antibodies within 28 days prior to T-cell transfer
• Extra renal tissue invasive BK infection
• Concomitant enrollment in another clinical trial interfering with endpoints of this study
• Any medical condition which could compromise participation in the study according to the investigator's assessment
• Known HIV infection
• Female patient who is pregnant or breast-feeding, or adult of reproductive potential not willing to use an effective method of birth control during study treatment Note: Women of childbearing potential must have a negative urine pregnancy test at study entry.
• Patients unwilling or unable to comply with the protocol or unable to give informed consent Donor Eligibility
• ≥ 18 years old
• Available and capable of undergoing a single standard 2 blood volume leukapheresis
• HLA Compatible (see Donor selection priority below):
• Original kidney transplant donor
• Fully HLA matched family member (6/6 HLA match considering HLA-A, HLA-B and HLA-DRB1 genes)
• Partially matched family member (≥ 2/6 HLA match, considering HLA-A, HLA-B and HLA-DRB1 genes)
• BK IgG seropositive
• Meets the criteria for donor eligibility defined in the UW Program for Advanced Cell Therapy Standard Operating Policies and Procedures for Donor Evaluation and Eligibility Determination for the Donation of Viral Specific T Cells, which is in compliance with FACT standards for Immune Effector Cells, and 21 CFR 1271, subpart C.
• Provide written informed consent Donor selection priority: The original kidney donor will be the first choice of donor peripheral mononuclear cells. If the original donor is not available or does not meet all donor eligibility criteria, alternative related donors will be selected, with preference for fully matched related donors (6/6 HLA match, considering HLA-A, -B, and -DRB1 genes) over related donors with partial HLA match (≥ 2/6 HLA match, considering HLA-A, -B, and -DRB1 genes). Note that if the selected donor is related, but not a biological parent or child of the recipient (i.e., at least haploidentical), then high resolution testing of HLA-A and HLA-B will be performed on donor and recipient (if high resolution HLA genotyping not already available in the medical record). If the degree of matching at high resolution reveals a less favorable match than an alternative donor, then prioritization of the alternative donor will occur.

Key
• Participant has one of the following genotypes:
• Homozygous for F508del;
• Heterozygous for F508del and a gating (F/G) mutation;
• Heterozygous for F508del and a residual function (F/RF) mutation;
• At least 1 other TCR CFTR gene mutation identified as responsive to ELX/TEZ/IVA and no F508del mutation
• Forced expiratory volume in 1 second (FEV1) value >=40% and <=90% of predicted mean for age, sex, and height for participants currently receiving CFTR protein modulator therapy; FEV1 >=40% and <=80% for participants not currently receiving CFTR protein modulator therapy Key
• History of solid organ or hematological transplantation
• Hepatic cirrhosis with portal hypertension, moderate hepatic impairment (Child Pugh Score 7 to 9), or severe hepatic impairment (Child Pugh Score 10 to 15)
• Lung infection with organisms associated with a more rapid decline in pulmonary status
• Pregnant or breast-feeding females Other protocol defined Inclusion/Exclusion criteria may apply

Key
• Has a diagnosis of Nontuberculous Mycobacterial pulmonary disease caused by MABc
• Has at least 2 of the following NTM-infection symptoms present at Screening and Baseline: chronic cough, coughing up blood (hemoptysis), wheezing, chest pain, frequent throat clearing, phlegm or sputum production, shortness of breath, fatigue, fever, night sweats, poor appetite, and/or weight loss.
• At least 1 positive pulmonary (sputum) culture for MABc in the 6 months prior to Screening and 1 positive culture at Screening
• Radiographic evidence of MABc infection via computed tomography (CT) scan of the chest within 3 months prior to Screening
• In the opinion of the investigator, guideline-directed antibiotic therapy for treatment of MABc will not be required within the next 3 months, and a delay, in order for the subject to participate in a placebo-controlled clinical trial, is considered reasonable and clinically acceptable
• Additional inclusion criteria as per protocol Key
• Has received antibiotic treatment within 6 months prior to Screening for MABc or MAC
• Has received systemic or inhaled antibiotic therapy (other than chronic macrolide therapy) within 4 weeks prior to Screening
• Has any of the following medical conditions:
• Active pulmonary malignancy, or any type of malignancy requiring chemotherapy or radiation within 1 year prior to Screening
• Active allergic bronchopulmonary mycosis, or any other condition requiring chronic treatment with systemic corticosteroids within 90 days prior to Screening
• Radiologic evidence of cavitary disease
• Known active pulmonary tuberculosis
• Cystic fibrosis
• History of lung transplantation
• Another advanced lung disease with a known percent predicted forced expiratory volume in 1 second < 30%.
• Disseminated or extra-pulmonary NTM disease
• Has been previously treated with omadacycline
• Has a history of hypersensitivity or allergic reaction to tetracyclines
• Additional exclusion criteria as per protocol

• All Parts (A1, A2, B) 1. Subject's parent(s)/legal representative(s) providing consent must be 18 years or older 2. Biological mother and/or biological father and/or full sibling(s), have a history of asthma, atopic dermatitis, food allergy, or allergic rhinitis as determined by the screening questionnaire 3. Subject's parent(s)/legal representative(s) (if appropriate according to local laws) is/are willing and able to give informed consent for participation in the study 4. Subject's parent(s)/legal representative(s) (if appropriate according to local laws) is/are willing and able, in the PI's opinion, to comply with all study requirements Part A1 Only Inclusion criteria 1-4 for all parts plus: 5 (A1). Subject is between 1 year and < 6 years old at the time of enrollment Part A2 Only Inclusion criteria 1-4 for all parts plus: 5 (A2). Subject is between 28 days and < 12 months of life at the time of enrollment 6 (A2). Subject's parent(s)/legal representative(s) do not plan to give probiotics (including infant formula that contain probiotics) to the subject during the trial Part B Only Inclusion criteria 1-4 for all parts plus: 5 (B). Subject is ≤ 14 days of life at the time of enrollment. Sites should make every effort to enroll newborns as soon as possible after birth. 6 (B). Subject has a birthweight ≥ 2.5 kg and ≤ 4.5 kg 7 (B). Subject's parent(s)/legal representative(s) do not plan to give probiotics (including infant formula that contain probiotics) to the subject from the time of birth to the end of the trial.
• All Parts (A1, A2, B) 1. Subject's twin (or higher order multiple) is enrolled in STMC-103H-102 2. Subject has any congenital abnormalities or condition, significant disease, illness, physical exam finding, or disorder that, in the opinion of the PI, may put the subject at safety risk or is likely to hinder feeding or affect metabolism that may influence the results of the study. (Neonatal hyperbilirubinemia (jaundice), including jaundice that requires phototherapy, should not be considered exclusionary). 3. Subject is acutely ill or on systemic antibiotics at the time of enrollment 4. Subject is participating in another interventional clinical study involving investigational medication, formula, probiotic, or prebiotic use within 30 days (or five half-lives, whichever is longer) of this study 5. Subject has evidence of immune deficiency/immune compromise in the judgment of the investigator Part B Only Exclusion Criteria 1-5 for all parts plus: 6 (B). Subject was born at < 35 weeks' gestation 7 (B). Biological maternal medical condition during the pregnancy that, in the opinion of the PI, may put the subject at risk because of participation in the study. (Maternal antibiotics during the time of delivery should not be considered exclusionary.)

Part A Main 1. Capable of giving signed informed consent. 2. Subject who has a signed and dated Informed Consent Form (ICF). 3. Subject must be 18 to 50 years inclusive, at the time of signing the ICF. 4. Male or female. 5. Female subjects who are not of childbearing potential (or females of childbearing potential who agree to comply with the contraceptive requirements of the clinical trial protocol). 6. Good general health, as determined by the Investigator. 7. A positive SPT to histamine. The following additional inclusion criteria are only applicable to the healthy subjects in Group A1: 8. Healthy subjects (non-atopic) with no clinically significant co-morbidity (including broncho-reactive airway disease like asthma, current allergic rhinitis, etc.). 9. Subjects with no history of allergy or intolerance to peanut or any other food and who consume peanuts with no effect. 10. Subjects with lack of sensitivity to peanut allergen confirmed by SPT using whole peanut extract. 11. Peanut specific immunoglobulin E (IgE) <0.1 kU/L. 12. Ara h 2 specific IgE <0.1 kU/L. 13. Subjects with negative basophil activation test (BAT). The following additional inclusion criteria are only applicable to the subjects with PA in Group A2: 14. Clinical history of physician diagnosed PA. 15. Peanut allergen sensitivity confirmed by SPT and IgE. 16. Subjects who currently adhere to a strict peanut-free diet and who agree to continue this for the duration of the clinical trial. 17. Subjects who are able to handle and correctly use an adrenaline auto-injector. Part B Main 1. Capable of giving signed informed consent. 2. Subject who has a signed and dated ICF. 3. Subjects aged 18 to 50 years of age inclusive, at the time of signing the ICF. 4. Male or female. 5. Female subjects who are not of childbearing potential (or females of childbearing potential who agree to comply with the contraceptive requirements of the clinical trial protocol). 6. Clinical history of physician diagnosed PA. 7. Peanut allergen sensitivity confirmed by SPT and IgE. 8. Subjects with positive BAT. 9. Subjects who currently adhere to a strict peanut-free diet and who agree to continue this for the duration of the clinical trial. 10. Good general health, as determined by the Investigator. 11. Subjects who are able to handle and correctly use an adrenaline auto-injector. Main Exclusion Criteria Part A and B: 1. Pregnant or lactating subject. 2. Presence of any medical condition that may reduce the ability to survive a serious allergic reaction. 3. Subjects with atopic dermatitis with >25% skin surface involvement. 4. For subjects with PA, presence of severe, poorly controlled or uncontrolled asthma. 5. History of severe or life-threatening anaphylactic reactions to peanut resulting in neurological compromise or requiring mechanical ventilation. 6. Clinical history of severe systemic or life-threatening anaphylactic reactions to other foods (apart from peanut), insect venom, exercise, drugs, etc. or idiopathic anaphylaxis. 7. Unable to receive epinephrine therapy. 8. Clinical history of drug or alcohol abuse, which, in the Investigator's opinion, could interfere with the subject's ability to participate in the clinical trial. 9. Participation in a clinical research trial with any investigational drug/placebo within 3 months of screening (Visit 1) or concomitantly with this clinical trial. 10. Personal, financial or other dependent relationship (e.g., employee or immediate relative) with the clinical trial site, Sponsor, Sponsor's representative, or another individual who has access to the clinical trial protocol. 11. Vulnerable subjects or those in judicial or governmental detention, detainment or imprisonment in a public institution.

Key
• Completed study drug treatment in a parent study VX20-121-102 (NCT05033080) and VX20-121-103 (NCT05076149); or had study drug interruption(s) in a parent study but did not permanently discontinue study drug, and completed study visits up to the last scheduled visit of the Treatment Period in the parent study Key
• History of drug intolerance in a parent study
• Pregnant or breast-feeding females Other protocol defined Inclusion/Exclusion criteria may apply.

1. Capable of giving signed informed consent as described in Appendix 1 which includes compliance with the requirements and restrictions listed in the ICF (informed consent form) and in this clinical trial protocol and to attend required clinical trial visits. 2. Subject who has a signed and dated ICF. 3. Subject must be 18 to 65 years of age inclusive, at the time of signing the ICF. 4. Male or female. 5. Female subjects who are not of childbearing potential (defined as at least 12 months natural spontaneous amenorrhoea, or at least 6 weeks following surgical menopause/permanent sterilisation [hysterectomy, bilateral oophorectomy and bilateral salpingectomy]) or females of childbearing potential who agree to comply with the contraceptive requirements of the clinical trial protocol. 6. Good general health, as determined by the Investigator, based on a medical evaluation, including medical history, physical examination, mental status assessment and laboratory tests. A subject with a clinical abnormality or laboratory parameters outside the reference range for the population being studied may be included only if the Investigator agrees that the finding is unlikely to introduce additional risk factors and will not interfere with the clinical trial procedures. 7. Positive history of moderate to severe symptoms of SAR/rhinoconjunctivitis ascribed to grass (Pooideae) pollen exposure of at least 2 seasons duration, despite having received allergy pharmacotherapy (e.g., antihistamines, nasal corticosteroids, leukotriene modifiers, etc.) during the last 2 consecutive grass pollen seasons prior to the clinical trial, confirmed by subject records. Please note: Subjects with asthma may be included, but the asthma must be well controlled (according to current Global Initiative for Asthma [GINA] guidelines [GINA 2022]). 8. A positive SPT (skin prick test) to histamine (wheals [longest diameter] ≥3 mm) and a negative SPT to the negative control (wheal diameter = 0 mm) at screening. 9. A positive SPT for grass pollen (wheals [longest diameter] ≥3 mm). 10. Grass specific IgE (immunoglobulin E) class ≥2 as documented by an ImmunoCAP test at screening. 11. Forced expiratory volume in one second (FEV1) ≥70% of predicted, with a FEV1/forced vital capacity (FVC) ratio >75% and PEFR (peak expiratory flow rate) ≥70% of predicted at screening. 1. Pregnant or lactating subject. 2. Presence of any medical history of moderate to severe allergy symptoms (verified by a positive SPT at screening or positive specific IgE [≥2] at screening) to any other seasonal allergen (other than grass) or perennial allergens. Exception: Period 1, Period 2 and Period 3 of the entire clinical trial will be conducted outside of the pollen season(s) of concern or perennial allergies are irrelevant due to avoidance measures (e.g., cats and dog allergy). Subjects with mild allergy symptoms (only) to any other allergen apart from grass may be included at the discretion of the Investigator. 3. Subjects at US clinical trial sites in regions where southern grasses (Bahia grass, Bermuda grass or Johnson grass) are the dominant grasses and the main cause of grass allergy symptoms with a positive SPT to any of the 3 grasses (irrespective of the severity of symptoms). 4. Moderate to severe symptoms during the 3 years prior to Visit 1 to any other seasonal or perennial allergen not tested in the SPT done at screening that cannot be avoided during the Period 1 to Period 3 of the clinical trial and the symptoms of which may interfere with administration of treatment and/or impact the data collected. 5. Presence of any medical condition that may reduce the ability to survive a serious allergic reaction. 6. Presence of active systemic autoimmune disorder, systemic autoimmune disorders in remission or active organ specific autoimmune disorder. 7. Presence of active malignant neoplasia, severe cardiovascular disease (e.g., coronary artery disease, cardiac insufficiency, etc.), pulmonary insufficiency, severe psychiatric disorders or primary and secondary immunodeficiencies. 8. History of any other immunological disorder or other diseases (including, but not limited cardiovascular [including uncontrolled or inadequately controlled hypertension], gastro-intestinal, hepatic, renal, haematological, neurological, endocrine or pulmonary disease) that in the opinion of the Investigator may pose a safety risk or compromise the interpretation of efficacy of the clinical trial treatment. 9. Presence of severe or poorly controlled or uncontrolled asthma as defined by at least 1 of the following criteria: 1. Severe asthma (as per the current GINA guidelines [GINA, 2022]). 2. Uncontrolled or poorly controlled asthma as per the current GINA guidelines (GINA, 2022). 3. Asthma that requires more than a daily dose above 800 μg of inhaled budesonide (or clinically comparable inhaled corticosteroid) as per the current GINA guidelines (GINA, 2022). 4. History of 2 or more systemic corticosteroid courses within 6 months of screening or Visit 2 or 1 course of systemic corticosteroids within 3 months of screening or Visit 2 to treat asthma. 5. Prior intubation/mechanical ventilation for asthma. 6. Emergency room visit or hospitalisation for asthma in the 12 months prior to screening or Visit 2. 7. Any history of a life-threatening asthma attack. 8. FEV1 <70% of predicted or FEV1/FVC ≤75% or PEFR <70% of predicted with or without controller medications at screening or Visit 2. 10. Presence non-atopic rhinitis and/or rhino-sinusitis (with or without polyps). 11. Presence of nasal polyps and/or chronic sinusitis. 12. Presence of any acute or chronic ocular disorder, other than allergic conjunctivitis. 13. Eye surgery within the past 6 months. 14. Presence of any skin conditions (e.g., skin abnormalities, tattoos etc.), which might interfere with the interpretation of the SPT results. 15. Clinical history of Type I diabetes or poorly controlled Type II diabetes. 16. Moderate to severe upper or lower respiratory infections requiring medication within 14 days before screening (Visit 1) or Visit 2. 17. Presence of acute or chronic infection, fever or inflammation at screening or Visit 2. 18. Clinical history of severe systemic reaction or serious systemic reaction in response to AIT (allergen immunotherapy) in the past. 19. Clinical history of severe or life-threatening anaphylactic reactions to foods, insect venom, exercise, drugs or idiopathic anaphylaxis. 20. Clinical history of allergy, hypersensitivity or intolerance to the excipients of the investigational drug/placebo. 21. Clinical history of allergy, hypersensitivity or intolerance to the relief medications (for relief of allergy symptoms during Period 3) provided for use in this clinical trial. 22. Clinical history of hereditary angioedema. 23. Unable to receive epinephrine therapy (i.e., use of epinephrine is contraindicated such as in subjects with hyperthyroidism, uncontrolled hypertension, cardiac arrhythmias, closed angle glaucoma or subjects taking other sympathomimetics). 24. Tyrosine metabolism disorders, especially tyrosinemia and alkaptonuria. 25. Clinical history of drug or alcohol abuse, which, in the Investigator's opinion, could interfere with the subject's ability to participate in the clinical trial. 26. Subjects who have suspicion or symptoms of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (as assessed by the Investigator) or who have had unprotected contact with a confirmed case of COVID-19 (coronavirus disease 2019) in the 2 weeks prior to screening or Visit 2 (based on the Investigator's discretion). 27. Subjects who were hospitalised for COVID-19 within 6 months prior to screening or Visit 2. 28. Any history of AIT for grass pollen allergy in the past or history of AIT for any other type of allergy (excluding food allergy) in the past 5 years. 29. Inability to adhere to the washout periods listed in the protocol, with respect to screening and to refrain from using the medications indicated until after Visit 11. 30. Treatment with a preparation containing MPL (monophosphoryl lipid-A) (e.g., Cervarix, Shingrix, Fendrix) within 2 years prior to Visit 1 and until after completion of Visit 11 (with the exception of the investigational drug). 31. Previous history of epinephrine auto-injector use. 32. β-blocker medication (local or systemic, including eye drops) for any indication. 33. Monoamine oxidase inhibitors and tricyclic antidepressants. Please note: Tricyclic antidepressants should be avoided at least 2 weeks prior to screening. 34. Any previous therapy (within the previous 5 years) or current therapy with anti IgE (e.g., omalizumab [Xolair]) or anti-interleukins (e.g., mepolizumab). 35. Current or past therapy (within the previous 5 years) with any other immunomodulary biologics. 36. Unable to refrain from any vaccination (including influenza vaccine and COVID-19 vaccine) during the clinical trial (unless administered >30 days prior to randomisation). Please note: Emergency vaccinations (e.g., tetanus due to injury) can be administered at any time. Booster vaccinations (only) for COVID-19 can be administered during the clinical trial apart from during the treatment period. There should be at least 14 days interval from the last administration of the investigational drug/placebo prior to administration of a COVID-19 booster injection. 37. Participation in a clinical research trial with any investigational drug within 4 weeks of Visit 1 or concomitantly with this clinical trial. Please note: The period of exclusion begins at the time of the last visit of the prior clinical research trial. Subjects consented and screened, but not dosed in the prior clinical research trial are not excluded. 38. Personal, financial or other dependent relationship (e.g., employee or immediate relative) with the clinical trial site, Sponsor, Sponsor's representative, or another individual who has access to the clinical trial protocol. 39. Vulnerable subjects or those in judicial or governmental detention, detainment or imprisonment in a public institution. 40. Subjects likely to have prolonged periods of absence (e.g., business or personal travel) during the GPS defined as:
• Absence of a total of 22 days or more in similar geographical regions (as determined by the Investigator), with no single trip in a similar geographical region exceeding 14 days.
• Absence of a total of 15 days or more in non-similar geographic regions (as determined by the Investigator), with no single trip in a non-similar geographical region exceeding 7 days. 41. Have changed residence to a different geographical region(s) since the last GPS. Exception: The old and new residences are in the same or similar geographical region as determined by the Investigator.

1. Have read, understood, and signed the informed consent form (ICF). 2. Be a male or female aged ≥18 years at the time of ICF signature. 3. Have stage 2 moderate (PED) or stage 3 severe (corneal ulcer) NK involving only 1 eye (study eye) and of at least 2 weeks duration. Patients with Stage 1 NK in the fellow eye can be enrolled. for the study eye 4. Have no objective clinical evidence of improvement in the PED or corneal ulceration within the 2 weeks before the screening visit despite use of conventional non-surgical treatment (eg, nonpreserved ocular lubricants, nonpreserved topical antibiotics, oral doxycycline, patching, serum tears, and/or therapeutic contact lenses) as determined by the investigator's or referring physician's medical record. 5. Have decreased corneal sensitivity (≤ 4 cm using the Cochet-Bonnet aesthesiometer) within the area of the PED or corneal ulcer and outside of the area of the defect in at least one corneal quadrant. 6. Have a BCDVA score ≤ 75 ETDRS letters in the study eye, due to NK. 1. Have participated in any clinical trial with an investigational drug/device within 2 months before the Screening Visit and throughout the study duration. 2. Have a known hypersensitivity to one of the components of the study drug or procedural medications (eg, fluorescein), including to a compound chemically related to MT8 3. Have a presence or history of any ocular or systemic disorder or condition that might hinder the efficacy of the study treatment or its evaluation, could possibly interfere with the interpretation of study results, or could be judged by the investigator to be incompatible with the study visit schedule or conduct (eg, progressive or degenerative corneal or retinal conditions, lagophthalmos, uveitis, optic neuritis, poorly controlled diabetes, autoimmune disease, systemic infection, neoplastic diseases), or that may compromise the safety of the patient. 4. Have a significant history of alcohol abuse or drug/solvent abuse 5. Be unwilling to comply with any study assessments or procedures. 6. Be a woman who is pregnant, nursing or planning a pregnancy. 7. Be a woman of childbearing potential not using a highly effective method of birth control. 8. Be a male patient who is not permanently sterile and who is not willing to use condoms during the study and for 4 weeks after the end of study treatment. For the study eye: 9. Have any active ocular infection (bacterial, viral, fungal or protozoal) or active inflammation not related to NK in the study eye. 10. Have any other ocular disease requiring topical ocular treatment in the study eye during the course of the study treatment period, except for glaucoma if treated by preservative-free eye drop (single-agent treatment, once daily, stable regimen 4 weeks before screening and during the study), 11. Receive topical ophthalmological treatments other than the study drug provided by the study Sponsor and the treatments allowed by the study protocol (eg, preservative-free artificial tears; preservative-free eye drop (single-agent treatment, once daily, stable regimen 4 weeks before screening and during the study) for glaucoma; topical antibiotics; other than tetracycline). 12. Have severe blepharitis and/or severe meibomian gland disease in the study eye. 13. Have severe vision loss in the study eye with no potential for visual improvement in the opinion of the investigator as a result of the study treatment. 14. Have evidence of corneal ulceration/melting involving the posterior third of the corneal stroma, or perforation in the study eye. 15. Have a history of any ocular surgery (including laser or refractive surgical procedures) within 3 months before the Screening Visit in the study eye. An exception to the preceding statement will be allowed if the ocular surgery is considered to be the cause of the Stage 2 or 3 NK. 16. Have a history of corneal transplantation in the study eye, except if performed to treat NK and at least 6 months prior screening. 17. Have had prior surgical procedures for the treatment of NK (eg, tarsorrhaphy, conjunctival flap, etc.) except AMT, if at least 2 wks after the membrane has disappeared within the area of the PED or corneal ulcer (and at least 6 weeks after the procedure) in the study eye. 18. Use therapeutic contact lenses or wear contact lenses for refractive correction during the study treatment periods in the eye(s) with NK. 19. Have an anticipated need for punctal occlusion during the study treatment period. Patients with punctal occlusion or punctal plugs inserted before the study are eligible for enrolment provided that the punctal occlusion is maintained during the study. 20. Have an uncontrolled glaucoma at the Screening Visit. (Patients suffering from glaucoma requiring ophthalmic drops for topical treatment at the Screening Visit or during the study are not eligible, except if the ophthalmic drops is a preservative-free treatment administered maximum once daily as a single-agent treatment and at a stable regimen 4 weeks before screening and at the same dose during the study. Patients treated with oral intraocular pressure-lowering drugs at the Screening Visit and during the study may be enrolled if their glaucoma status is assessed as stable and controlled. For the fellow eye 21. Have Stage 2 or 3 NK or perforation. For any eye: 22. Have a history of ocular cancer. 23. Have had prior treatment with Oxervate™

• Female participants: Agreement to remain abstinent (refrain from heterosexual intercourse) or use contraception as defined by the protocol
• Diagnosis of macular edema associated with non-infectious uveitis (NIU)
• Diagnosis of active or inactive, acute, or chronic NIU of any etiology and of any anatomical type (anterior, intermediate, posterior, panuveitis)
• BCVA letter score of 73 to 19 letters (inclusive) on Early Treatment Diabetic Retinopathy Study (EDTRS)-like charts
• Evidence of active or latent syphilis infection
• Evidence of active or latent tuberculosis infection and/or positive tuberculosis assay, or previous or current HIV diagnosis
• Serious acute or chronic medical or psychiatric illness
• History of major ocular and non-ocular surgical procedures
• Uncontrolled IOP or glaucoma or chronic hypotony
• Any anatomical changes or media opacity in the study eye preventing evaluation of retina, vitreous, and capture of study images
• Prior use of IVT biologics including anti-VEGFs less than 2-4 months prior to Day 1; received IVT Methotrexate within 4 months prior to Day 1
• Prior macular laser therapy, cataract surgery within 6 months and laser capsulotomy within 3 months of Day 1
• Topical corticosteroids and/or topical NSAID > 3 drops per day in the 14 days prior to Day 1 (D1); intraocular or periocular corticosteroid injections in the 2 months prior to D1; subconjunctival corticosteroid injection within 1 month prior to Day 1; an OZURDEX implant in the 4 months prior to D1; YUTIQ, RETISERT or ILUVIEN implant in the 3 years prior to D1
• Diagnosis of macular edema due to any cause other than NIU
• Any major ocular conditions that may require medical or surgical intervention during the study period to prevent vision loss

• have documented evidence of rCDI (≥1 recurrence after a primary CDI episode)
• be undergoing antibiotic treatment for the qualifying rCDI episode that was diagnosed by a stool test for the presence of toxigenic C. difficile or C. difficile toxin
• be eligible for FMT as judged by the investigator or current treatment guidelines for rCDI in the US
• be a candidate for colonoscopy as judged by the investigator
• Use or planned use of systemic antibiotics for an indication other than the qualifying rCDI episode.
• Current uncontrolled chronic diarrhea not related to CDI.
• Receipt of CDI vaccine or treatment with CDI monoclonal antibodies within the past 12 months before screening.
• Evidence of active, severe, or fulminant colitis, diagnosis of toxic megacolon or have a current colostomy or ileostomy

Key
• Body mass index is less than (<) 30.0 kilograms per meter square (kg/m^2)
• A total body weight greater than (>) 50 kg
• Stable CF disease
• CFTR gene mutations on both alleles that are not responsive to CFTR modulator therapy o Example mutations include but are not limited to, mutations that do not produce CFTR protein (i.e., Class I): nonsense mutations (e.g., G542X, W1282X) and canonical splice mutations (e.g., 621+1G->T)
• Forced expiratory volume in 1 second (FEV1) value, percent of predicted mean for age, sex, and height (equations of the Global Lung Function Initiative [GLI])18 ≥40% Key
• History of uncontrolled asthma within a year prior to screening
• History of solid organ or hematological transplantation
• Hepatic cirrhosis with portal hypertension, moderate hepatic impairment (Child Pugh Score 7 to 9), or severe hepatic impairment (Child Pugh Score 10 to 15)
• Arterial oxygen saturation on room air less than (<) 94% at screening Other protocol defined Inclusion/Exclusion criteria may apply.

1. Participant and/or parent guardian must be able to understand and provide informed consent 2. Children ages 4-12 years of age 3. Cohort 1: Family is self-identified as Plain community member 4. Cohort 2: Madison-area children with parental report of doctor-diagnosed asthma 5. Cohort 3: Madison-area children with no history of asthma by parental report 1. Inability or unwillingness of a participant to give written informed consent or comply with study protocol 2. Chronic sinusitis (frequent sinus infections) 3. Plans to move out of the area before completing the study 4. Past or current medical problems or findings from physical examination or laboratory testing that are not listed above, which, in the opinion of the investigator, may pose additional risks from participation in the study, may interfere with the participant's ability to comply with study requirements or that may impact the quality or interpretation of the data obtained from the study 5. Enrolled family member

Key
• Participants who have completed study drug treatment in the parent study (VX21-121-105; NCT Number: NCT05422222) Key
• Hepatic cirrhosis with portal hypertension, moderate hepatic impairment, or severe hepatic impairment that might pose an additional risk in administering study drug
• History of solid organ, hematological transplantation, or cancer
• History of drug intolerance in the parent study Other protocol defined Inclusion/Exclusion criteria may apply.