Major readouts on the horizon for small developers
Important ovarian cancer data are ahead for Immunogen and Mersana, while Disc Medicine eyes a rare metabolic disorder.
Platinum-resistant ovarian cancer is in the sights of Immunogen and Mersana, with both relying on specific biomarkers. The former is due to report confirmatory data with its antibody drug conjugate Elahere, while Mersana will release what it hopes will be registrational results with its ADC upifitamab rilsodotin. Elsewhere, a mid-stage readout is anticipated from Disc Medicine’s big pharma castoff bitopertin in porphyria, a rare metabolic disorder.
Immunogen’s Elahere became the first antibody-drug conjugate to be approved for ovarian cancer last year, when it gained an accelerated green light in second to fourth-line folate receptor alpha (FRα)-high platinum-resistant disease. Confirmatory results from the Mirasol study, to turn that into full approval, are pending.
The trial sets Elahere against chemotherapy, with a primary endpoint of progression-free survival; Mirasol is designed to detect a hazard ratio of 0.7. Assuming 3.5 months of median PFS in the chemotherapy arm, median PFS needs to reach 5 months in the Elahere-treated cohort for the trial to succeed, analysts estimate.
In Soraya, the single-cohort trial used to gain accelerated approval, median PFS hit 5.5 months by independent central review, but only 4.3 months by investigator assessment. Immunogen has pointed out that Soraya was in a more heavily treated population than Mirasol. Looking to another study, the controlled Forward I, the FRα-high subgroup showed Elahere to confer a 1.9 to 2.4-month median PFS benefit.
Followers of Sutro will be keenly awaiting Immunogen’s confirmatory data. Luveltamab tazevibulin, Sutro is also hoping to take its less advanced antibody drug conjugate down the accelerated approval path. Sutro claims this asset can address a broader population than Elahere, as well as being safer. Elahere’s label comes with a black boxed warning about ocular toxicities.
Uplift for Mersana?
Sticking with platinum resistant ovarian cancer (PROC), registrational data are due from Mersana’s upifitamab rilsodotin. The ADC targets NaPi2b, a sodium-dependent phosphate transporter which is highly expressed in ovarian cancer and non-squamous NSCLC.
Results from a pivotal cohort of the phase 2 Uplift study are due, in second to fourth-line PROC. The primary endpoint of the single arm study is confirmed ORR in NaPi2b-high patients. ORR in all patients, regardless of NaPi2b expression, is a secondary measure.
The dose to report will be 36 mg/m2. A higher 43 mg/m2 dose was initially tested but phase 1 data showed two cases of pneumonitis, a toxicity that will remain in focus.
SVB analysts believe that the Uplift data will probably support approval in NaPi2b-high patients, but that a green light in all-comers is unlikely. Phase 1 updates showed shrinking efficacy across the overall study population. In NaPi2b–high patients the latest data cut from phase 1 showed 34% ORR, and median duration of response of ~5 months in 13 high expressors.
Mersana has indicated that 12% ORR is the regulatory benchmark based on standard of care single-agent chemotherapies available in the setting.
Cast off for Disc
Disc Medicine’s bitopertin is an oral inhibitor of glycine transporter 1, which was previously developed by Roche. The big pharma group tried and failed to get the drug to work in schizophrenia and now Disc expects to report interim data in patients with erythropoietic porphyria (EPP) or X-linked protoporphyria (XLP), rare diseases characterised by extreme pain and damage to skin caused by light. Additionally, patients can suffer from liver impairment and gallstones.
The Australian phase 2 Beacon study is due to report, and the primary endpoint of the open-label trial is the percent change from baseline in protoporphyrin IX (PPIX) concentration. A separate US placebo-controlled study called Aurora has the same endpoint and should report later in the year.
Both EPP and XLP are caused by mutations in the genes that produce enzymes of the haem production pathway. These defects lead to abnormally high levels of PPIX in red blood cells. Bitopertin is said to work by reducing the activity of haem synthesis, and thus lowering the toxic build-up of metabolites such as PPIX.
The only approved therapy for EPP is Clinuvel’s Scenesse, which increases skin melanin production to improve light tolerance.
The table below contains a fuller list of upcoming catalysts with consensus forecasts from Evaluate Pharma.
|Small companies' Q2 clinical catalysts
|2028e indication sales ($m)
|Note/ Vantage coverage
|2-4L folate receptor alpha-high platinum-resistant ovarian cancer
|Confirmatory Mirasol study, vs chemo, early May
|See text and JP Morgan 2023 – Sutro makes its pitch to beat Immunogen
|US Ph1/2 2yr low dose data, 1yr high dose
|AAV gene therapy, earlier pause due to safety issues (Uniqure’s Huntington’s hopes take a hit)
|Alzheimer's disease agitation, agitation in schizophrenia/bipolar disorder (at-home setting)
|Ph3 Tranquility II (AD), Serenity III (part one, schizophrenia/ bipolar)
|Approved in acute treatment of agitation in schizophrenia and bipolar disorders I and II
|Upifitamab rilsodotin (XMT-1536)
|Single-arm registrational Uplift portion of Ph1/2, mid year
|Sickle cell disease
|Update from Ph1/2 Ruby
|Crispr/Cas12a gene-edited cell therapy targeting beta-globin to increase foetal haemoglobin
|Pivotal Felix, ORR data at Asco
|Passed pre-specified futility analysis, EFS data likely at Ash, BLA filing by YE (anti-CD19 Car-T)
|Primary: relative change in liver fat content (assessed by MRI-PDFF) from baseline to week 12 (Spotlight – What is next in Nash)
|Chikungunya vaccine for adolescents
|Ph3 aged 12-17 years mid year
|Filed in adults, Bavarian bought Emergent's CHIKV-VLP in Feb 2023 (Bavarian boosts its travel vaccine offering)
|Reproxalap, ADX-2191, ADX-629
|Allergic conjunctivitis, retinitis pigmentosa, chronic cough
|Ph3 Invigorate-2 (reproxalap, conjunctivitis)
Ph2 ('2191, pigmentosa), Ph2 ('629, cough)
|Reproxalap is filed in dry eye disease, and ADX-2191 is filed in primary vitreoretinal lymphoma
|Ph2 Beacon interim, open-label (Australian study)
|Ph2 Alpine 4
|FGF19 analogue, failed Alpine 2/3 in F2/F3 Nash
|Ph3 mid year Artemis-IgAN, 9 month proteinuria data
|Travere's Filspari received accelerated approval in Feb 2023, competitive space (Calliditas sets the bar for its kidney disease rivals)
|*Marketed already, **as agitation indication. PROC: platinum-resistant ovarian cancer. Sources: clinicaltrials.gov, analyst notes, Evaluate Pharma.